JP7633068B2 - Unloading device, calibration method for unloading device, and calibration program for unloading device - Google Patents

Description

The present invention relates to an unloading device for unloading cargo from a ship.

As unloading equipment for unloading cargo from a ship, lifting equipment that unloads cargo loaded on a ship onto land is known. Among such lifting equipment, those that handle bulk cargo or bulk materials such as coal and iron ore are also called unloaders. They are also sometimes called continuous unloaders or continuous ship unloaders (Continuous Ship Unloaders) because they continuously load and unload bulk materials loaded on a ship. In this specification, the abbreviation CSU may be used.

JP 2016-160034 A

A CSU may be equipped with a detection unit such as a distance sensor or a camera that detects the warehouse or bulk cargo that stores the bulk cargo. If each movable part of the CSU (the moving part, rotating part, carrying out part, etc. described below) can be accurately controlled according to the distance to the warehouse or bulk cargo detected by the detection unit, it is possible to prevent the carrying out part inserted inside the warehouse from colliding with the warehouse and to efficiently unload the bulk cargo. However, if there is an error in the installation position or attitude of the detection unit, or if the relationship (relative position and attitude) between the detection unit and each movable part changes due to changes in the external environment such as the weight or temperature of the carrying out part itself or the bulk cargo during loading and unloading, the effect of the above detection unit is reduced.

The present invention was made in consideration of these circumstances, and its purpose is to provide an unloading device that can effectively detect errors related to the position and orientation of the detection unit.

In order to solve the above problem, an unloading device according to one embodiment of the present invention is an unloading device for unloading cargo from a ship, and includes a moving section movable relative to the ship, a rotating section rotatable relative to the moving section, a discharge section provided on the rotating section for discharging cargo, a first detection section for detecting a detection object, a second detection section provided at a position different from the first detection section for detecting the detection object, a first detection section coordinate acquisition section for detecting a detection object with the first detection section and acquiring the first detection section coordinates in a first detection section coordinate system based on the first detection section, a second detection section coordinate acquisition section for detecting a detection object with the second detection section and acquiring the second detection section coordinates in a second detection section coordinate system based on the second detection section, a coordinate conversion section for converting the first detection section coordinates and the second detection section coordinates into the same coordinate system based on the relationship between the first detection section and the second detection section, and a coordinate error detection section for detecting an error between the first detection section coordinates and the second detection section coordinates in the same coordinate system.

According to this aspect, the first and second detection units detect the same detection object, and obtain the detection unit coordinates in each detection unit coordinate system. These detection unit coordinates are converted into the same coordinate system by the coordinate conversion unit, and the error between the two coordinates is detected. Here, "first/second detection unit coordinate system based on the first/second detection unit" means that the position and orientation of the first/second detection unit that serves as the reference in the first/second detection unit coordinate system can be tracked. For example, in a coordinate system that has the first/second detection unit as the origin, respectively, the first/second detection unit is always at the origin and the orientation is constant, so this corresponds to "first/second detection unit coordinate system based on the first/second detection unit".

Another aspect of the present invention is a method for calibrating an unloading device. This method is a method for calibrating an unloading device that includes a moving section that is movable relative to a ship, a rotating section that is rotatable relative to the moving section, a discharge section that is provided on the rotating section and discharges cargo from the ship, a first detection section that detects a detection object, and a second detection section that is provided at a position different from the first detection section and detects the detection object, and includes a first detection section coordinate acquisition step of detecting a detection object with the first detection section and acquiring the first detection section coordinates in a first detection section coordinate system based on the first detection section, and a second detection section of detecting a detection object with the second detection section and acquiring the first detection section coordinates in a first detection section coordinate system based on the first detection section. The method includes a second detection unit coordinate acquisition step for acquiring second detection unit coordinates in a second detection unit coordinate system based on the second detection unit, a coordinate conversion step for converting the first detection unit coordinates and the second detection unit coordinates into the same coordinate system based on the relationship between the first detection unit and the second detection unit, a coordinate error detection step for detecting an error between the first detection unit coordinates and the second detection unit coordinates in the same coordinate system, and a coordinate system correction step for correcting the relationship between the first detection unit coordinate system and the second detection unit coordinate system so as to reduce the error detected in the coordinate error detection step.

In addition, any combination of the above components, and any transformation of the present invention into a method, device, system, recording medium, computer program, etc., are also valid aspects of the present invention.

The present invention provides an unloading device that can effectively detect errors in the relative positions and orientations of multiple detectors.

FIG. 2 is a front view showing the overall configuration of the lifting device. FIG. 2 is a perspective view showing the overall configuration of the lifting device. FIG. 4 is a diagram showing the detailed configuration of the lifting section. FIG. 2 is a diagram showing the appearance of a distance measuring sensor. FIG. 4 is a top view showing an example of the arrangement of distance measuring sensors. 1 is a functional block diagram of a calibration device according to a first embodiment. FIG. FIG. 2 is a diagram showing a schematic diagram of each coordinate system set with respect to the lifting device. FIG. 13 is a top view showing an example of measurement of a reference object using a lifting device. 5 is a flowchart illustrating an example of a calibration process of a distance measuring sensor by the calibration device according to the first embodiment. FIG. 11 is a functional block diagram of a calibration device according to a second embodiment. 10 is a flowchart illustrating an example of a camera calibration process performed by the calibration device according to the second embodiment. FIG. 11 is a functional block diagram of a calibration device according to a third embodiment. 13 is a flowchart illustrating an example of a calibration process for a plurality of detection units by the calibration device according to the third embodiment. FIG. 13 is a functional block diagram of an anomaly detection device according to a fourth embodiment. 13 is a flowchart illustrating an example of an anomaly detection process performed by the anomaly detection device according to the fourth embodiment.

Below, the embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description and drawings, the same or equivalent components, members, and processes are given the same reference numerals, and duplicated descriptions are omitted as appropriate. The scale and shape of each part shown in the drawings are set for convenience in order to facilitate explanation, and should not be interpreted as being limiting unless otherwise specified. The embodiments are illustrative and do not limit the scope of the present invention in any way. All features and combinations thereof described in the embodiments are not necessarily essential to the invention.

Figure 1 shows the overall configuration of the lifting device 1 as a loading device according to the first embodiment of the present invention. The lifting device 1 is a continuous unloader or a ship continuous unloader that unloads bulk cargo M loaded on a ship 200 to land. Hereinafter, the lifting device 1 is also referred to as a CSU 1. The CSU 1 continuously transports bulk cargo M stored in a ship 201 of a ship 200 that is berthed at a quay 101 of a wharf 102 of a port or the like to land. Examples of bulk cargo M include coal, coke, ore, etc. The CSU 1 is operated by an operator in a main operation room 16 provided in the main body of the CSU 1. The operation room for operating the CSU 1 may be provided in a location other than the CSU 1, or may be provided in any location on land outside the CSU 1.

The wharf 102 where the ship 200 comes ashore constitutes the land where the bulk cargo M is unloaded, and is made of high-strength materials such as reinforced concrete. As shown in the perspective view of FIG. 2, the wharf 102 is provided with a pair of parallel rails 3 as a track along the longitudinal direction (perpendicular to the paper surface of FIG. 1) of the ship 200 that is docked and anchored at the quay 101. The rails 3 constitute a track along which the running part 2 as the moving part of the CSU 1 can move or run. The rails 3 allow the CSU 1 to move relative to the anchored ship 200. As shown in FIG. 2, the installation direction of the rails 3 is preferably aligned with the longitudinal direction of the anchored ship 200 or the quay 101, but may be any other direction. The rails 3 may also include curved or bent parts. When unloading cargo from the ship 200, the CSU 1 moves on the rails 3 and stops at a position close to the opening 21 of the ship shed 201 to be unloaded. Then, the rotating frame 5 (rotating section) and the lifting section 9 (discharge section) described below are driven to lift the bulk cargo M from the warehouse 201.

At the wharf 102, a belt conveyor 45 is provided between the pair of rails 3 as a conveyor for transporting the unloaded bulk goods M in a certain direction. As shown in FIG. 2, it is preferable that the installation direction of the belt conveyor 45, i.e., the transport direction, coincides with the installation direction of the rails 3, but it may be any other direction. The belt conveyor 45 may also include curved or bent portions. The belt conveyor 45 needs to be provided between the pair of rails 3 at the location where the unloaded bulk goods M from the CSU 1 is received, but may be provided outside the pair of rails 3 at other locations.

The CSU 1 comprises a traveling section 2 as a mobile section movable relative to the ship 200, a swivel frame 5 constituting a swivel section that can rotate relative to the traveling section 2, and a lifting section 9 provided at the tip of the swivel frame 5 as a discharge section for discharging bulk cargo M. The swivel frame 5 is supported on the traveling section 2 so as to be rotatable about a vertical (up and down direction in FIG. 1) swivel axis. The swivel frame 5 is provided with a boom 7 extending laterally and intersecting the swivel axis, and a bucket elevator constituting the main part of the lifting section 9 is supported at its tip.

The lifting unit 9 maintains a vertical position regardless of the boom 7's elevation angle (the rotation angle around the elevation axis perpendicular to the plane of the paper in FIG. 1) by a parallel link mechanism formed between the revolving frame 5, boom 7, and parallel link 8. A counterweight 13 is provided at the rear end of the revolving frame 5 on the side opposite the tip of the boom 7. The counterweight 13 is connected to the tip of the boom 7 via a balancing lever 12. The action of this counterweight 13 puts the lifting unit 9 in a substantially unloaded state, achieving a stable load balance. The main components of the revolving unit, such as the revolving frame 5, boom 7, balancing lever 12, and counterweight 13, may be collectively referred to as the main body below.

A cylinder 15 is provided to adjust the hoisting angle of the boom 7. When the cylinder 15 is at its standard length, the hoisting angle is 0°, i.e., the boom 7 is parallel or horizontal to the ground (left and right direction in Figure 1). When the cylinder 15 is extended beyond the standard length, the tip of the boom 7 rises, resulting in a positive hoisting angle. When the cylinder 15 is shortened beyond the standard length, the tip of the boom 7 descends, resulting in a negative hoisting angle. The lifting unit 9 supported at the tip of the boom 7 rises while maintaining a vertical position when the hoisting angle of the boom 7 increases, and descends while maintaining a vertical position when the hoisting angle of the boom 7 decreases.

The main operation room 16 for operating the CSU 1 is provided in the main body. Specifically, the main operation room 16 is provided on the lifting unit 9 side of the revolving frame 5. An operator in the main operation room 16 can safely operate the CSU 1 while visually checking the lifting unit 9. Parameters related to the position and attitude of the CSU 1, such as the position of the traveling unit 2, the rotation angle of the revolving frame 5, and the elevation angle of the boom 7, are controlled according to the operation of the main operation room 16. In addition, the operation of discharging bulk cargo M by the lifting unit 9 can also be controlled from the main operation room 16.

The lifting section 9 is equipped with a scraping section 11 that scrapes off bulk goods M, and a bucket elevator as an elevator section that transports the scraped off bulk goods M upward. The scraping section 11 is provided at the bottom of the lifting section 9, and continuously excavates and scrapes off the bulk goods M in the warehouse 201 using a number of buckets 27 (see Figure 3) that are movably provided along its periphery. The scraped off bulk goods M are transported upward together with the buckets 27 by the bucket elevator.

Figure 3 shows the detailed configuration of the lifting section 9. The bucket elevator comprises a cylindrical elevator body 14 extending vertically, and a chain bucket 29 that moves in circles relative to the elevator body 14. The chain bucket 29 comprises a pair of roller chains 25, each of which is an endless chain, and a number of buckets 27 supported on both sides by the pair of roller chains 25. Specifically, the pair of roller chains 25 are arranged side by side in a direction perpendicular to the plane of the paper in Figure 3 (B), and each bucket 27 is attached so as to be suspended between the pair of roller chains 25.

The bucket elevator is equipped with a drive roller 31a that guides the roller chain 25, driven rollers 31b and 31c, and a deflecting roller 33. The drive roller 31a is provided at the top 9a of the bucket elevator, and is rotated by a motor or the like (not shown) to rotate the chain bucket 29. The driven roller 31b is provided in front of the scraping section 11 (left side of FIG. 3(B)), and the driven roller 31c is provided behind the scraping section 11 (right side of FIG. 3(B)), and each guides the rotating chain bucket 29. The deflecting roller 33 is a driven roller provided below the drive roller 31a, and guides the rotating chain bucket 29 and changes its direction of movement. An expandable cylinder 35 is provided between the driven roller 31b and the driven roller 31c. When the cylinder 35 expands and contracts, the distance between the axes of the driven rollers 31b and 31c changes, and the orbit of the orbital motion of the chain bucket 29 changes. The expansion and contraction control of the cylinder 35 may be performed by the operation of the main operation room 16, or may be performed automatically according to a program by a computer built into the CSU 1. In addition, in response to the provision of two roller chains 25, two each of the drive roller 31a, driven rollers 31b and 31c, and deflection roller 33 are also provided, and are arranged side by side in a direction perpendicular to the paper surface of FIG. 3(B).

The chain bucket 29 rotates relative to the elevator body 14 as the drive roller 31a rotates. For example, the chain bucket 29 rotates counterclockwise along the arrow W shown in FIG. 3(B). At this time, the chain bucket 29 reciprocates between the scraping unit 11 provided at the bottom of the bucket elevator and the drive roller 31a provided at the top 9a of the bucket elevator.

Each bucket 27 of the chain bucket 29 rises inside the elevator body 14 with its opening facing upward. When each bucket 27 passes over the drive roller 31a at the top 9a of the bucket elevator, its direction of motion changes from upward to downward, and the opening of each bucket 27 also rotates from upward to downward. A discharge chute (not shown) is provided below the opening of each bucket 27 that has been turned downward in this way, and the bulk goods M picked up by each bucket 27 are discharged. The discharge chute discharges the bulk goods M onto a rotary feeder 37 (Figure 1) provided on the outer periphery of the upper part of the lifting section 9.

The rotary feeder 37 rotates around a rotation axis in the extension direction of the elevator body 14, i.e., the vertical direction, and transfers the bulk goods M discharged from the discharge chute to the boom conveyor 39 of the boom 7. The boom conveyor 39 transports the bulk goods M within the boom 7 to the vicinity of the rotation axis of the rotating frame 5, and supplies them to a hopper (not shown) provided there. An internal conveyor 43 that receives the bulk goods M is provided within the running section 2 below the discharge opening of the hopper. The internal conveyor 43 transfers the bulk goods M to the aforementioned belt conveyor 45 provided on the wharf 102 as land.

Next, we will explain the basic lifting operation of the CSU1 with the above configuration.

The operator of the CSU 1 operates the CSU 1 in the main operation room 16. First, the traveling part 2 travels on the rail 3 and stops at a position close to the opening 21 of the shipyard 201 to be unloaded. Next, the revolving frame 5 is rotated around a vertical rotation axis provided at a position overlapping with the traveling part 2 in a top view (when viewed from above in FIG. 1), and the lifting part 9 provided at the tip of the boom 7 is moved above the opening 21 of the shipyard 201 to be unloaded. Here, it is preferable to perform the traveling operation and the revolving operation with the lifting part 9 raised by raising the boom 7 in the positive direction (clockwise direction in FIG. 1) so that the lifting part 9 does not collide with the wharf 102 or the ship 200. Next, the boom 7 is raised and lowered in the negative direction (counterclockwise direction in FIG. 1), and the scraping part 11 provided at the tip of the lifting part 9 is inserted into the shipyard 201 through the opening 21. The movement of the travel section 2, the rotation of the rotating frame 5, and the raising and lowering of the boom 7 may be performed simultaneously.

After the scraping unit 11 is inserted into the shipyard 201, the roller chain 25 is rotated along the arrow W. As the multiple buckets 27 attached to the roller chain 25 rotate together with the roller chain 25, they excavate and scrape off the bulk goods M stored in the shipyard 201. The bulk goods M scraped off by each bucket 27 are transported upward in the elevator body 14 as the roller chain 25 rotates.

The scraping unit 11 appropriately changes its three-dimensional position in the shipyard 201 in order to efficiently scrape off the bulk cargo M from various places in the shipyard 201. For example, when the surface position of the bulk cargo M becomes lower as the lifting work progresses, the boom 7 is raised and lowered in the negative direction to lower the scraping unit 11. In addition, in order to scrape off the bulk cargo M near the wall of the shipyard 201, the running unit 2 and/or the rotating frame 5 may be operated to change the position of the scraping unit 11 in the horizontal plane. The scraping unit 11 can change not only its three-dimensional position but also its attitude and shape. For example, the scraping unit 11 can rotate around a rotation axis in the extension direction of the elevator body 14, i.e., the vertical direction, and its orientation can be changed arbitrarily. In addition, as shown by the dashed line in FIG. 3B, the scraping unit 11 can take an inclined shape or a horizontally elongated shape that is contracted vertically and extended horizontally. This allows the scraping section 11 to be brought closer to the wall and efficiently scrape off the bulk cargo M, even in a shipyard 201 with a large horizontal distance from the opening 21 to the wall.

The above-mentioned changes in the position, attitude, and shape of the scraping unit 11 inside the shipyard 201 may be performed autonomously by the CSU 1 using a distance sensor and camera described below, or may be performed manually by an operator in the main operation room 16 while communicating with an operator in the shipyard 201.

The bucket 27 that has scraped off the bulk goods M from the warehouse 201 rises inside the elevator body 14 and rotates from upward to downward as it passes through the drive roller 31a at its top 9a. The bulk goods M that fall as the bucket 27 rotates enters the discharge chute and is discharged onto the rotary feeder 37. The bulk goods M are then transferred via the boom conveyor 39 and the internal conveyor 43 to the belt conveyor 45 installed on the wharf 102 as land. The above-mentioned discharge operation is repeated by multiple buckets 27, so that the bulk goods M in the warehouse 201 are continuously unloaded.

Next, we will explain the distance measurement sensor installed in CSU1 to improve the safety and efficiency of cargo lifting.

1, a plurality of distance measuring sensors 19 are provided on the upper part of the lifting section 9 to measure the distance to the measurement objects below and to the sides. During lifting as shown in the figure, the measurement objects of the distance measuring sensors 19 are the edge of the opening 21, the ceiling/wall/bottom of the warehouse 201, the bulk cargo M and other objects, people/structures in the warehouse 201, the scraping section 11, the ship 200, other parts of the CSU 1 such as the boom 7/rotating frame 5/running section 2/main operation room 16, the quay 101, the wharf 102, the rail 3, the belt conveyor 45, etc. The plurality of distance measuring sensors 19 may be arranged, for example, on the upper part of the cylindrical elevator body 14 so as to surround the outer periphery of the elevator body 14. Alternatively, the plurality of distance measuring sensors 19 may be provided on the flange part 91 that rotatably supports the upper part of the elevator body 14 so as to surround the outer periphery of the elevator body 14. In order to prevent the boom 7 from entering the measurement range below and to the sides of the multiple distance measuring sensors 19, the multiple distance measuring sensors 19 are preferably provided below the connection between the lifting unit 9 and the boom 7. On the other hand, if the multiple distance measuring sensors 19 are provided above the connection between the lifting unit 9 and the boom 7, each distance measuring sensor 19 should be provided at a position that does not overlap with the boom 7 when viewed from above (when viewed from above in FIG. 1). The arrangement of the multiple distance measuring sensors 19 when viewed from above will be described later. The number of distance measuring sensors 19 is arbitrary. For example, any number of distance measuring sensors 19 that measure distances mainly below the lifting unit 9 and any number of distance measuring sensors 19 that measure distances mainly to the sides of the lifting unit 9 may be provided.

The scraping section 11 at the bottom of the lifting section 9 is provided with multiple distance measuring sensors 18 for measuring the distance to the measurement object above, to the side, and below. During lifting as shown in the figure, the measurement objects of the distance measuring sensors 18 are the edge of the opening 21, the ceiling/wall/bottom of the warehouse 201, the bulk goods M and other objects, people/structures in the warehouse 201, and other parts of the CSU 1 such as the boom 7. The distance measuring sensors 18 are provided at the front (left part of FIG. 1) and rear (right part of FIG. 1) of the scraping section 11, respectively. In order to avoid deterioration of the measurement accuracy due to dust of the bulk goods M scraped by the bucket 27 of the scraping section 11, it is preferable that the multiple distance measuring sensors 18 are provided at a position (upper part of the scraping section 11) away from the place where the bucket 27 excavates the bulk goods M (lower part of the scraping section 11). The number of distance measuring sensors 18 is arbitrary. For example, any number of distance measuring sensors 18 that measure distances centered on the sides of the scraping unit 11 and any number of distance measuring sensors 18 that measure distances centered on the bottom of the scraping unit 11 may be provided.

Figure 4 shows the external appearance of distance measuring sensors 18 and 19. Distance measuring sensors 18 and 19 are laser sensors capable of measuring distances, and include a laser emitting unit (not shown) as a wave transmitting unit that transmits laser light to the object to be measured, and a laser receiving unit (not shown) as a wave receiving unit that receives the laser light reflected by the object to be measured, constituting a distance measuring unit that measures the distance to the object to be measured. A light transmitting portion 171 through which laser light can pass is formed in an endless band shape around the entire circumference of the side surface of cylindrical housing 17 of distance measuring sensors 18 and 19.

A plurality of laser emission units are provided at positions facing the light-transmitting portion 171 in the housing 17, and linear laser light is emitted outside the housing 17 through the light-transmitting portion 171. The laser emission units are arranged at a predetermined interval along the direction of the axis A of the housing 17 (the vertical direction in FIG. 4), but FIG. 4 shows the laser light emitted from one point for simplicity. As shown in the schematic diagram, the emission angles of the laser emission units are different from each other by about 0.1° to 3°. With this configuration, the distance measurement sensors 18 and 19 can irradiate laser light within a predetermined angle range above and below the reference plane S (within the range of θ- to θ+ in the figure), with the plane perpendicular to the axis A of the housing 17 as the reference plane S. θ- and θ+ can be designed arbitrarily, but in the following, -θ- = θ+ = 15°. At this time, the distance measurement sensors 18 and 19 irradiate laser light within a range of ±15° centered on the reference plane S. In addition, these multiple laser emitters are integrally provided so as to be rotatable 360° around the axis A of the housing 17. With this configuration, the distance measuring sensors 18 and 19 can irradiate laser light to all measurement objects around (to the sides of) the housing 17. Note that it is preferable to use laser light with an invisible wavelength, such as near-infrared light, so as not to disturb people inside or around the CSU 1 or the ship 200.

Distance measuring sensors 18, 19 rotate multiple laser emitters together and emit pulsed laser light at a predetermined rotation angle. The pulsed laser light emitted by each laser emitter is reflected or scattered by the object to be measured and returns to distance measuring sensors 18, 19, where it is received by a laser receiver provided together with each laser emitter inside housing 17. A calculation unit (not shown) of distance measuring sensors 18, 19 calculates the distance to the object to be measured based on the time from when the laser emitter emits a pulse of laser light to when the laser receiver receives the reflected pulse of laser light. This technology is also called LIDAR (Light Detection and Ranging or Laser Imaging Detection and Ranging).

Although laser sensors have been given as examples of distance measuring sensors 18 and 19 above, distance measuring sensors 18 and 19 may be sensors that use other electromagnetic waves. For example, millimeter wave sensors using so-called millimeter waves with wavelengths of about 1 mm to 10 mm may be used as distance measuring sensors 18 and 19. Since millimeter waves have a high frequency of about 30 GHz to 300 GHz, they have high linearity and can be treated like lasers. The millimeter wave sensor can be configured in the same way as the laser sensor in FIG. 4, and a millimeter wave transmitter that transmits millimeter waves to the object to be measured instead of the laser emitter, and a millimeter wave receiver that receives millimeter waves reflected by the object to be measured instead of the laser receiver may be provided. In addition, optical sensors that use light other than laser light, such as a Time of Flight (ToF) type image sensor, may be used as distance measuring sensors 18 and 19. In addition, distance measuring sensors 18 and 19 may not have a transmitter that transmits electromagnetic waves to the object to be measured. For example, a stereo camera capable of measuring distance by simultaneously photographing the object to be measured from different directions may be used as distance measuring sensors 18 and 19.

The distance measuring sensors 18 and 19 in FIG. 4 are attached to the CSU 1 in FIG. 1 in any orientation depending on the purpose of measurement. For example, the distance measuring sensor 18 in the scraping unit 11 is attached so that the axis A in FIG. 4 is vertical and the reference plane S is a horizontal plane. In this case, the distance measuring sensor 18 can measure distances inside the warehouse 201 with the side of the scraping unit 11 as the center. The distance measuring sensor 18 may also be attached so that the axis A in FIG. 4 is horizontal and the reference plane S is a vertical plane. In this case, the distance measuring sensor 18 can measure distances to the opening 21 above the scraping unit 11 and the bulk cargo M below the scraping unit 11. The direction of the axis A of the distance measuring sensor 18 is not limited to the vertical or horizontal direction and may be any direction.

The distance measuring sensor 19 on the top of the lifting section 9 is attached so that the axis A in FIG. 4 is horizontal and the reference plane S is vertical. In this case, the distance measuring sensor 19 can measure the edge of the opening 21 of the warehouse 201 below and the bulk cargo M inside the warehouse 201. The distance measuring sensor 19 can also emit laser light upward, but since there is no measurement target above, the upper side of the distance measuring sensor 19 is covered with a light-shielding cover, etc., to disable the measurement above. The distance measuring sensor 19 may also be attached so that the axis A in FIG. 4 is vertical and the reference plane S is parallel to the horizontal plane. In this case, the distance measuring sensor 19 can efficiently measure the measurement target outside the warehouse 201 to the side. The direction of the axis A of the distance measuring sensor 19 can be any direction, not limited to the horizontal or vertical direction, but the case of the horizontal direction will be described in detail below.

By providing distance measuring sensors 18, 19 as described above in the lifting section 9, the positions of various measurement targets can be accurately grasped, such as the edge of the opening 21, the ceiling/walls/bottom of the warehouse 201, bulk cargo M and other objects, people/structures within the warehouse 201, the scraping section 11, etc. Therefore, the lifting section 9 can be prevented from colliding with other objects during lifting, and the bulk cargo M can be lifted efficiently.

Figure 5 shows an example of the arrangement of the distance measuring sensor 19 from a top view. Three distance measuring sensors 191, 192, and 193 as the distance measuring sensor 19 are arranged to surround the outer periphery of the flange portion 91 or the elevator body 14. The distance measuring sensor 191 is arranged so that the axis A in Figure 4 is in the left-right direction in Figure 5, and the reference plane S1 corresponding to the reference plane S in Figure 4 is in the up-down direction in Figure 5. The distance measuring sensor 191 measures distance by irradiating laser light within a range of ±15° centered on the reference plane S1. The distance measuring sensors 192 and 193 are arranged so that the axis A in Figure 4 is in the up-down direction in Figure 5, and the reference planes S2 and S3 corresponding to the reference plane S in Figure 4 are in the left-right direction in Figure 5. The distance measuring sensors 192 and 193 measure distance by irradiating laser light within a range of ±15° centered on the reference planes S2 and S3. The reference planes S2 and S3 of the distance measuring sensors 192 and 193 are different planes parallel to each other and are perpendicular to the reference plane S1 of the distance measuring sensor 191.

The CSU 1 unloads the bulk cargo M from the shipyard 201 with the posture shown in FIG. 5 as the basic posture for unloading. In this basic posture, the traveling section 2 is in a position shifted from the front position of the shipyard 201, and the rotating frame 5 and the boom 7 are in a rotating position that forms an acute angle with the rail 3 that forms the track of the traveling section 2. At this time, the unloading section 9 is located above the shipyard 201 of the ship 200, and the scraping section 11 at its lower part is inserted into the shipyard 201 through the opening 21.

The opening 21 of the shipyard 201 is often a long rectangle extending in the direction of travel of the ship 200 (left-right direction in FIG. 5). In this case, the upper edge E11 and the lower edge E12 of the opening 21 can be detected by the distance measurement sensor 191 that irradiates laser light parallel to the short side of the opening 21 (the side in the vertical direction in FIG. 5). Note that the points shown at the centers of the edges E11 and E12 represent the positions where the laser light on the reference plane S1 of the distance measurement sensor 191 hits the edge of the opening 21, and the rectangle surrounding it represents the range where the laser light irradiated within a range of ±15° centered on the reference plane S1 hits the edge of the opening 21. Below, the same notation is used for the distance measurement sensors 192 and 193.

Similarly, distance measurement sensors 192, 193 that irradiate laser light parallel to the long sides of opening 21 (the left and right sides in Figure 5) can detect edges E21, E31 on the left side and edges E22, E32 on the right side of opening 21. By using two distance measurement sensors 192, 193, distance measurement can be performed with high accuracy even in the long direction, which is more difficult to measure than the short direction. In this way, the arrangement of distance measurement sensors 191, 192, 193 in Figure 5 is suitable for detecting the edges of opening 21 that has a shape that is long in one direction, such as a rectangle.

Even if the CSU1 is not in the basic position shown in FIG. 5, if the loading section 9 is within the opening 21 when viewed from above, the three distance measuring sensors 191, 192, and 193 can obtain six distance measuring point groups on the edge of the opening 21 corresponding to E11, E12, E21, E22, E31, and E32, and the position of the opening 21 can be accurately determined.

The basic position of the CSU1 during lifting is not limited to that shown in FIG. 5. For example, the basic position may be one in which the travel section 2 is in front of the shipyard 201 and the revolving frame 5 and boom 7 are at right angles to the rail 3. In this case, the extension direction of the boom 7 coincides with the short side direction of the opening 21, so that the reference surface S1 of the distance measuring sensor 191 is parallel to the extension direction of the boom 7, and the reference surfaces S2 and S3 of the distance measuring sensors 192 and 193 are perpendicular to the extension direction of the boom 7. If the distance measuring sensors 191, 192, and 193 are integrally rotatable around the axis of the cylindrical elevator body 14, the distance measuring sensors 191, 192, and 193 can be easily arranged in a manner suitable for the elongated opening 21 described above in accordance with changes in the basic position of the CSU1 during lifting.

The number and arrangement of the distance measuring sensors 19 described above are merely examples, and any number and arrangement can be adopted. The number of distance measuring sensors 19 is preferably at least two in order to efficiently measure the shape of the opening 21 surrounding the lifting section 9 when viewed from above. More preferably, it is three or more. Multiple distance measuring sensors 19 may be arranged at equal intervals along the outer periphery of the flange section 91 or the elevator body 14. In this case, the installation orientation of each distance measuring sensor 19 is arbitrary, but for example, each distance measuring sensor 19 is installed so that the reference surface S of the distance measuring sensor 19 is in contact with the outer periphery of the flange section 91 or the elevator body 14. With such a symmetrical arrangement, the shape of the opening 21 can be stably measured regardless of the orientation of the CSU 1 when lifting.

By controlling each movable part of the CSU 1, i.e., the movable running part 2, the rotatable rotating frame 5, the riseable boom 7, the rotatable and deformable scraping part 11, etc., according to the distance to the measurement object inside and outside the shipyard 201 measured by the distance measuring sensors 18, 19 as described above, it is possible to prevent the lifting part 9 from colliding with other objects inside and outside the shipyard 201 during lifting, and to efficiently lift the bulk goods M. However, if there is an error in the mounting position or posture of the distance measuring sensors 18, 19, or if the relationship (relative position and posture) between the distance measuring sensors 18, 19 and each movable part of the CSU 1 changes due to changes in the external environment such as the weight of the lifting part 9 itself or the temperature of the bulk goods M being loaded, the effect of the distance measuring sensors 18, 19 described above is reduced. Therefore, in this embodiment, in order to obtain the maximum effect from the distance measurement sensors 18, 19, a calibration device 300 is provided that calibrates or corrects errors in the mounting position and attitude of the distance measurement sensors 18, 19 and changes in the relationship between the distance measurement sensors 18, 19 and each movable part of the CSU 1.

Figure 6 is a functional block diagram of the calibration device 300. The calibration device 300 includes a ranging point coordinate acquisition unit 301, a coordinate conversion unit 302, a coordinate error detection unit 303, and a coordinate system correction unit 304. These functional blocks are realized by the cooperation of hardware resources such as the central processing unit, memory, input device, output device, and peripheral devices connected to the computer of computers inside and outside the CSU1, and software executed using these. Regardless of the type of computer or the installation location, each of the above functional blocks may be realized by the hardware resources of a single computer, or may be realized by combining hardware resources distributed among multiple computers.

Before describing each functional block of the calibration device 300, the coordinate system that serves as the premise will be described. Figure 7 shows a schematic diagram of each coordinate system set for the CSU 1. Figure 7(A) is a schematic diagram of the CSU 1 in a vertical plane including the travel unit 2, the rotating frame 5, the boom 7, and the lifting unit 9, and Figure 7(B) is a schematic diagram of the CSU 1 as viewed from above. Figure 7(A) is a cross-sectional view of a plane including the boom 7 that extends diagonally downward and to the left in Figure 7(B).

The coordinate system u is a ground coordinate system based on the ground on which the traveling unit 2 travels (or a moving unit coordinate system based on the traveling unit 2), and is defined by the u _x axis as the x axis, the u _y axis as the y axis, and the u _z axis as the z axis in the xyz Cartesian coordinate system. The origin of the coordinate system u is provided on the track of the traveling unit 2 formed by the rails 3, the direction of the u _x axis coincides with the laying direction of the rails 3, which is the moving direction of the traveling unit 2, the direction of the u _y axis is perpendicular to the u _x axis in the horizontal plane, and the direction of the u _z axis is vertical.

Here, "the coordinate system u is a ground coordinate system based on the ground" means that the coordinate system u has an origin at an arbitrary point on the ground or an object whose position on the ground is known. For example, the ground coordinate system u may be a coordinate system whose origin is an arbitrary position on the wharf 102 as the land on which the running unit 2 is installed, or may be a coordinate system whose origin is the running unit 2 whose position on the ground is known. The ground coordinate system u is also a moving unit coordinate system whose reference is the running unit 2. Here, "the coordinate system u is a moving unit coordinate system whose reference is the running unit 2" means that the position and posture of the running unit 2, which is the reference, can be accurately tracked in the coordinate system u. In the illustrated example, the running unit 2 moves only in the u _x axis direction with a constant posture in the coordinate system u, so its u _y coordinate and u _z coordinate do not change (hereinafter, to simplify the explanation, the u _y coordinate and u _z coordinate of the running unit 2 are set to 0). The u _x coordinate of the running unit 2 can be accurately tracked by a position sensor or the like that measures the position x _tl of the running unit 2 on the rail 3. In this way, since the three-dimensional coordinates ( _ux , _uy , _uz ) = ( _xtl , 0, 0) and the posture of the traveling unit 2 in the coordinate system u can be accurately tracked, the coordinate system u is a moving unit coordinate system based on the traveling unit 2. Note that in the illustrated example, for simplicity of explanation, the direction of the _ux axis is made to coincide with the laying direction of the rails 3, but the direction of each axis of the ground coordinate system u can be set arbitrarily.

The coordinate system r is a rotating part coordinate system based on the rotating frame 5, and is determined by the rx axis as the x-axis, the _ry axis as the y _- axis, and the _rz axis as the z-axis in the xyz Cartesian coordinate system. The origin of the coordinate system r coincides with the rotating center _Or of the rotating frame 5 in the top view of Fig. 7(B), and coincides with a point on land directly below the rotating center _Or in the cross-sectional view of Fig. 7(A). The direction of _{the rx} axis rotates by a rotation angle _θ2 with respect to the direction of the _ux axis, the direction of the _ry axis is a direction perpendicular to the _rx axis in the horizontal plane (the extension direction of the boom 7 in Fig. 7(B) in the top view), and the direction of the _rz axis is the vertical direction.

Here, "the coordinate system r is a rotating part coordinate system based on the rotating frame 5" means that the position and attitude of the rotating center O _r of the rotating frame 5, which is the reference, can be accurately tracked in the coordinate system r. In the illustrated example, the rotating center O _r coincides with the origin of the coordinate system r in a top view, so its r _x coordinate and r _y coordinate are 0. In addition, the r _z coordinate of the rotating center O _r is constant at a height h _r from the land. In addition, the turning angle θ ₂ representing the attitude of the rotating frame 5 can be measured by an angle sensor or the like. In this way, the three-dimensional coordinates (r _x , r _y , r _z ) = (0, 0, h _r ) and attitude of the rotating center O _r of the rotating frame 5 in the coordinate system r can be accurately tracked, so the coordinate system r is a rotating part coordinate system based on the rotating frame 5. The rotating part coordinate system r may be a coordinate system having its origin at any position on the rotating frame 5, boom 7, and counterweight 13 constituting the rotating part, or on the main operation room 16 which can rotate integrally with the rotating part. In the illustrated example, the direction of the r and _y axes is made to coincide with the extension direction of the boom 7 in a top view for the sake of simplicity of explanation, but the direction of each axis of the rotating part coordinate system r can be set arbitrarily.

Coordinate system b is a hoisting unit coordinate system based on the boom 7 and the lifting unit 9, and is defined by the b _x axis as the x axis, the b _y axis as the y axis, and the b _z axis as the z axis in an xyz Cartesian coordinate system. The origin of coordinate system b is provided at the connection between the boom 7 and the lifting unit 9. The b _y axis is horizontal and coincides with the extension direction of the boom 7 when viewed from above in Figure 7 (B), the b _x axis is perpendicular to the b _y axis in the horizontal plane, and the b _z axis is vertical.

Here, "the coordinate system b is a hoisting section coordinate system based on the boom 7 and the lifting section 9" means that the position and attitude of the hoisting center O _b , which is the reference, can be accurately tracked in the coordinate system b. In the illustrated example, the boom 7 hoists around the hoisting center O _b on the base end side by a hoisting angle θ _1. If the distance between the origin of the coordinate system b and the hoisting center O _b is L _b1 as shown in FIG. 7(A), the coordinates (b _x , b _y , b _z ) of the hoisting center O _b in the coordinate system b are (0, -L _b1 cos θ ₁ , -L _b1 sin θ ₁ ). In addition, the hoisting angle θ _1, which represents the attitude of the hoisting section, can be measured by an angle sensor or the like. In this way, since the position and attitude of the hoisting center O _b in the coordinate system b can be accurately tracked, the coordinate system b is a hoisting section coordinate system based on the boom 7 and the scraping section 9. The origin of the hoisting portion coordinate system b may be any point on the boom 7 that constitutes the hoisting portion, for example, the hoisting center _Ob may be the origin of the hoisting portion coordinate system b. In this case, the direction of _each axis remains as shown in the figure, and the coordinates ( _bx , _by , _bz ) of the connection part between the boom 7 and the scraping part ₉ are (0, _Lb1cosθ1 , _Lb1sinθ1 ). In the example shown in the figure, the direction of the _by axis is made to coincide with the extension direction of the boom 7 when viewed from above for simplicity of explanation, but the direction of each axis of the hoisting portion coordinate system b can be set arbitrarily.

The coordinate system l is a distance measurement unit coordinate system based on the distance measurement sensor 19, and is determined by the l _x axis as the x axis, the l _y axis as the y axis, and the l _z axis as the z axis in the xyz Cartesian coordinate system. The origin of the coordinate system l is provided at the attachment position of the distance measurement sensor 19. The direction of the l _y axis is horizontal and coincides with the extension direction of the boom 7 when viewed from above in FIG. 7B, the direction of the l _x axis is perpendicular to the l _y axis in the horizontal plane, and the direction of the l _z axis is vertical. When multiple distance measurement sensors are provided, such as the distance measurement sensors 191 to 193 in FIG. 5, the coordinate system l may be common to the multiple distance measurement sensors, or a coordinate system l may be set for each distance measurement sensor.

Here, "the coordinate system l is a distance measuring unit coordinate system based on the distance measuring sensor 19" means that the position and attitude of the distance measuring sensor 19, which is the reference, can be accurately tracked in the coordinate system l. In the above example, the three-dimensional coordinates (l _x , l _y , l _z ) of the distance measuring sensor 19, which coincides with the origin of the coordinate system l, are always (0,0,0) and the attitude is also constant. The distance measuring unit coordinate system l may have an origin at any position on the upper part of the lifting unit 9 where the distance measuring sensor 19 is attached. In this case, if the mounting positions and attitudes of each distance measuring sensor 19 on the upper part of the lifting unit 9 are recorded, the position and attitude of each distance measuring sensor 19 relative to the origin of the distance measuring unit coordinate system l can be calculated. In addition, in the illustrated example, the direction of the l _y axis is made to coincide with the extension direction of the boom 7 when viewed from above for simplicity of explanation, but the direction of each axis of the distance measuring unit coordinate system l can be set arbitrarily.

The coordinate system d is a distance measuring unit coordinate system based on the distance measuring sensor 18, and is determined by the d _x axis as the x axis, the d _y axis as the y axis, and the d _z axis as the z axis in the xyz Cartesian coordinate system. The origin of the coordinate system d is provided at the connecting portion between the elevator body 14 and the scraping unit 11. The direction of the _{d y} axis is horizontal and coincides with the extension direction of the scraping unit 11 (not shown) in the top view of FIG. 7(B), the direction of the d _x axis is perpendicular to the d _y axis in the horizontal plane, and the direction of the d _z axis is vertical. As shown in FIG. 7(B), the direction of the d _y axis is shifted by a rotation angle θ ₄ with respect to the directions of the b _y axis and the r _y axis, i.e., the extension direction of the boom 7 in the top view. This indicates that the scraping unit 11 rotates by θ ₄ around the axis of the elevator body 14.

Here, "the coordinate system d is a distance measurement unit coordinate system based on the distance measurement sensor 18" means that the position and attitude of the distance measurement sensor 18, which is the reference, can be accurately tracked in the coordinate system d. In FIG. 1, the mounting positions and attitudes of the multiple distance measurement sensors 18 on the scraping unit 11 are known, so the three-dimensional coordinates and attitudes of each distance measurement sensor 18 relative to the origin of the distance measurement unit coordinate system d at the connecting portion between the elevator body 14 and the scraping unit 11 can be calculated. The origin of the distance measurement unit coordinate system d may be any position on the scraping unit 11, and for example, the mounting position of the distance measurement sensor 18 may be the origin of the distance measurement unit coordinate system d. Here, when multiple distance measurement sensors 18 are provided as in FIG. 1, the coordinate system d may be common to the multiple distance measurement sensors, or a coordinate system d may be set for each distance measurement sensor. In addition, in the illustrated example, the direction of the _z- axis of d is set to the vertical direction for simplicity of explanation, but the direction of each axis of the distance measurement unit coordinate system d can be set arbitrarily.

In Fig. 7(A), the scraping unit 11 is shown as a rectangle extending in a direction perpendicular to the axial direction of the elevator body 14, but as shown in Fig. 7(C) as a schematic, the scraping unit 11 may be configured with a main part 11A that scrapes off the bulk goods M and a bent part 11B that can be bent with respect to the elevator body 14. In this case as well, the origin of the distance measuring unit coordinate system d can be set at any position on the scraping unit 11, i.e., on the main part 11A and the bent part 11B. In the coordinate transformation described later, the bending angle _θ5 of the bent part 11B is also taken into consideration.

Next, each functional block of the calibration device 300 in FIG. 6 will be described. The ranging point coordinate acquisition unit 301 uses the ranging sensors 18 and 19 to measure a reference object whose coordinates are known in a ground coordinate system u based on the ground on which the traveling unit 2 travels, and acquires the ranging point coordinates in the ranging unit coordinate systems l and d based on the ranging sensors 18 and 19, respectively.

FIG. 8 shows an example of measuring a reference object by the CSU 1 from a top view. In this example, eight measurement positions P1 to P8 are provided, with the rotation angle of the rotating frame 5 differing from each other by 45°. The CSU 1 measures the reference object at each measurement position P1 to P8 using the distance measurement sensor 18 (not shown) and the distance measurement sensor 19 (191 to 193). The reference object is any stationary object whose coordinates in the ground coordinate system u used for calibrating the CSU 1 by the calibration device 300 are known. As described with reference to FIG. 7, the origin of the ground coordinate system u may be any position on the wharf 102. Therefore, any stationary object on the wharf 102 can be used as the reference object. Preferably, a structure having a linear edge and flat surfaces on both sides thereof that can be easily measured by the distance measurement sensors 18 and 19 is used as the reference object. For example, the quay wall 101, the rail 3, and the belt conveyor 45 shown in FIG. 8 are suitable as reference objects because they have long linear edges and wide flat surfaces on both sides thereof. 7 is located on the track of the traveling unit 2, the rail 3 and the belt conveyor 45, which are structures arranged along the track, are particularly suitable as reference objects. As will be described in detail later, in this case, it is sufficient to substantially consider only the u _{and x} coordinates in the direction in which the reference object extends, among the distance measurement information of the reference object by the distance measurement sensors 18 and 19, so that the CSU 1 can be calibrated efficiently. Furthermore, in order to improve the distance measurement accuracy of the distance measurement sensors 18 and 19, reflectors with high reflectivity for the laser light from the distance measurement sensors 18 and 19 may be arranged along the rail 3 and the belt conveyor 45.

The measurement position P1 is shown in FIG. 5. In FIG. 5, which shows the time of unloading, the ship 200 is present below the unloading section 9, but the ship 200 does not have to be present when measuring the distance to the reference object for calibrating the CSU 1. On the other hand, if the ship 200 is present as in FIG. 5, the CSU 1 can be calibrated in real time while unloading the bulk cargo M from the shipyard 201. The dotted lines extending in both directions from each of the distance measuring sensors 191 to 193 represent the respective reference planes S1 to S3 (see FIG. 5), and distance measurement is possible when these dotted lines intersect with the reference object. Therefore, at the measurement position P1, only the distance measuring sensor 191 can measure the distance to the reference object on the wharf 102. The measurement points, which are the intersections of the dotted lines extending from the distance measuring sensor 191 toward the wharf 102 and each reference object, are indicated by black circles. The ranging point coordinate acquisition unit 301 acquires the positions of these ranging points as ranging point coordinates ( _lx , _ly , _lz ) in a ranging point coordinate system l based on the ranging sensor 191. Similarly, the ranging sensor 18 (not shown) also measures the distance to each reference object on the wharf 102 at measurement position P1, and the ranging point coordinate acquisition unit 301 acquires the ranging point coordinates ( _dx , _dy , _dz ) in the ranging point coordinate system d based on the ranging sensor 18.

Similarly, at the other measurement positions P2 to P8, the distance measurement point coordinate acquisition unit 301 acquires the distance measurement point coordinates ( _lx , _ly , _lz ), ( _dx , _dy , _dz ) of the reference object by the distance measurement sensors 18 and 19. With regard to the distance measurement sensors 19, all distance measurement sensors 191 to 193 at measurement position P2, distance measurement sensors 192 and 193 at measurement position P3, all distance measurement sensors 191 to 193 at measurement position P4, distance measurement sensor 191 at measurement position P5, all distance measurement sensors 191 to 193 at measurement position P6, distance measurement sensors 192 and 193 at measurement position P7, and all distance measurement sensors 191 to 193 at measurement position P8 can measure the distance to the reference object on the pier 102. In this way, the distance measuring sensors 191 to 193 capable of measuring the distance to the reference object are different at each of the measurement positions P1 to P8, but all of the distance measuring sensors 191 to 193 can be calibrated by rotating the CSU 1 around the multiple measurement positions P1 to P8. Note that, although FIG. 8 illustrates eight measurement positions P1 to P8 with rotation angles differing from each other by 45°, the rotation angles of the measurement positions are arbitrary.

As mentioned above, of the measurement positions P1 to P8, only measurement position P1 performs unloading in the basic posture in FIG. 5. At the other measurement positions P2 to P8, unloading in the basic posture is not assumed, but in this embodiment, the ranging point coordinate acquisition unit 301 acquires the ranging point coordinates of the reference object even in such postures where unloading is not normally performed. In other words, the ranging point coordinate acquisition unit 301 acquires the ranging point coordinates when the unloading unit 9 is not above the ship 200 due to the rotation of the rotating frame 5 (including when the ship 200 is not at measurement position P1). Also, at measurement positions P2 to P6, the unloading unit 9 is above land (pier 102). Thus, in this embodiment, the ranging point coordinate acquisition unit 301 acquires the ranging point coordinates of the reference object even in postures that the CSU 1 cannot assume when unloading. In particular, at measurement positions P2 and P6, the lifting section 9 on which the distance measuring sensors 18 and 19 are installed is located directly above the reference object as the object to be measured, so that all distance measuring sensors can obtain the coordinates of the measuring points with high accuracy, and the CSU 1 can be calibrated efficiently.

7, it is preferable to acquire as many distance measurement point coordinates as possible by the distance measurement point coordinate acquisition unit 301 while changing each parameter of the CSU ₁ , such as the hoisting angle θ ₁ of the boom 7, the rotation angle θ ₄ of the scraping unit 11, and the bending angle θ ₅ of the scraping unit 11. In the above example in which the reference object is placed along the track (rail 3) of the traveling unit 2, it is not necessary to move the traveling unit 2 to calibrate the CSU 1, but if the reference object has a shape that does not follow the track of the traveling unit 2, it is preferable to acquire distance measurement point coordinates while also changing the position _xtl of the traveling unit 2.

The coordinate conversion unit 302 converts the ranging point coordinates in the ranging unit coordinate system l, d and the known coordinates of the reference object in the ground coordinate system u into an identical coordinate system based on the relative position and attitude of the lifting unit 9 with respect to the ranging sensors 18, 19, the relative position and attitude of the lifting unit 9 with respect to the lifting unit 9, and the relative position and attitude of the traveling unit 2 with respect to the revolving frame 5. In the following, the identical coordinate system to which the conversion is made is described as the ground coordinate system u. In this case, the coordinate conversion unit 302 converts the ranging point coordinates ( _lx , _ly , _lz ), ( _dx , _dy , _dz ) of the reference object on the wharf 102 from the ranging unit coordinate system l, d to coordinates ( _ux , _uy , _uz ) in the ground coordinate system u.

The coordinates of the distance measurement point of the reference object measured by the distance measurement sensor 19 in the distance measurement unit coordinate system l are expressed as a three-dimensional vector p _l = (l _x , l _y , l _z ). In order to convert this distance measurement point coordinate p _l from the distance measurement unit coordinate system l to the ground coordinate system u, the coordinate conversion unit 302 performs three-stage coordinate conversion: converting the coordinate p _l in the distance measurement unit coordinate system l to a coordinate p _b = (b _x , b _y , b _z ) in the undulating unit coordinate system _b , converting the coordinate p b in the undulating unit coordinate system b to a coordinate p _r = (r _x , _ry , r _z ) in the rotating unit coordinate system r, and converting the coordinate p _r in the rotating unit coordinate system r to a coordinate p _u = ( _ux , _uy , _uz ) in the ground coordinate system u. Each coordinate conversion is expressed by the following equation.

The first equation is an equation for converting a coordinate _p1 in the distance measurement unit coordinate system l to a coordinate _pb in the undulating unit coordinate system b. _t1b is a three-dimensional translation vector connecting the origin of the distance measurement unit coordinate system l and the origin of the undulating unit coordinate system b, and _R1b is a 3x3 matrix representing the difference in attitude between the distance measurement unit coordinate system l and the undulating unit coordinate system b, i.e., rotation. _t1b and _R1b are determined according to the position and attitude at which the distance measurement sensor 19 is provided on the lifting unit 9. In the example of Fig. 7, since there is no rotation between the distance measurement unit coordinate system l and the undulating unit coordinate system b, whose axes are in the same direction, _R1b is a 3x3 unit matrix.

The second equation is an equation for converting the coordinate p _b in the hoisting unit coordinate system b to the coordinate p _r in the rotating unit coordinate system r. _{R x} (±θ ₁ ) is a 3×3 rotation matrix that rotates the three-dimensional coordinate in the positive or negative direction by the hoisting angle θ ₁ around the b _x axis that passes through the origin of the hoisting unit coordinate system b. First, R _x (−θ ₁ ) is applied to p _b to convert its y coordinate into a value along the extension direction of the boom 7 being hoisted at the hoisting angle θ _1. Then, the distance L _b1 to the hoisting center O _b along this direction is added. Next, R _x (+θ ₁ ) is applied to return it to a coordinate along the original attitude of the hoisting unit coordinate system b (which is also the same attitude as the rotating unit coordinate system r of the conversion target). Then, the distance L _b3 in the y direction between the hoisting center O _b and the origin of the rotating unit coordinate system r is subtracted, and the distance L _p in the z direction is added. In this way, the second equation gives the coordinate transformation from the hoisting unit coordinate system b to the rotating unit coordinate system r via the hoisting center _Ob . The parameters _θ1 , _Lb1 , _Lb3 , and _Lp in this equation are determined according to the relative position and attitude of the rotating frame 5 with respect to the lifting unit 9.

The third equation is an equation for converting the coordinate p _r in the rotating unit coordinate system r to the coordinate p _u in the ground coordinate system u. R _z (θ ₂ ) is a 3×3 rotation matrix that rotates the three-dimensional coordinates by a rotation angle θ ₂ around the r _z axis passing through the origin of the rotating unit coordinate system r, and acts to align the rotating unit coordinate system r with the attitude of the ground coordinate system u. In addition, the x-direction vector having x _tl as the x coordinate is a translation vector connecting the origin of the rotating unit coordinate system r and the origin of the ground coordinate system u. In this way, the third equation gives the coordinate conversion from the rotating unit coordinate system r to the ground coordinate system u by the first term that converts the rotation component and the second term that converts the translation component. In addition, the parameter θ ₂ in this equation is determined based on the relative attitude of the running unit 2 with respect to the rotating frame 5, and x _tl is measured by a position sensor or the like that measures the position of the running unit 2 on the rail 3.

By the above first to third equations, the distance measurement point coordinate p _l = (l _x , l _y , l _z ) of the reference object measured by the distance measurement sensor 19 in the distance measurement unit coordinate system l is converted to the distance measurement point coordinate p _u = (ux, uy, _uz ) in the ground coordinate system u via the undulating part coordinate system b and the rotating part coordinate system r. Similarly, the distance measurement point coordinate p _d = ( _dx , _dy , dz ) of the reference object measured by the distance measurement sensor 18 in the distance measurement unit coordinate system d can also be converted to the distance measurement point coordinate p _u = ( _{ux , uy} , _uz ) in the ground coordinate system u via the undulating part coordinate system b and _the rotating part coordinate system _r . In this case, the above first equation is replaced with an equation that converts the coordinate p _d in the distance measurement unit coordinate system d to the coordinate p _b in the undulating part coordinate system b. The position and attitude of the distance measuring sensor 18 also change depending on the rotation angle θ ₄ and bending angle θ ₅ of the scraping part 11 shown in FIGS. 7B and 7C, so these parameters are included in the conversion formula.

The coordinate error detection unit 303 detects the error between the distance measurement point coordinates p _u = ( _ux , _uy , _uz ) of the reference object in the ground coordinate system u and the known coordinates p _u0 = ( _ux0 , _uy0 , _uz0 ) of the reference object. Here, when the reference object is a mark or an end point set at a specific point on the pier 102, or when a mark is attached to a specific point on the quay wall 101, rail 3, or conveyor belt 45 as the reference object, the coordinate error detection unit 303 detects the errors _ux - _ux0 , uy - _uy0 , _uz - uz0 of each coordinate between the distance measurement point coordinate p _u = ( _ux , _uy , _uz ) obtained by measuring the distance to the mark by the distance measurement sensors ₁₈ , ₁₉ and _{the known coordinate p u0 = (ux0, uy0, uz0 ) of the} mark, or the distance (( _ux - _ux0 )^2+( _uy - _uy0 )^2+( _uz - _uz0 )^2)^0.5, etc. as coordinate errors. If a significant detection error is detected, the detection error is corrected or calibrated in the subsequent coordinate system correction unit 304 .

On the other hand, when a reference object is provided over a certain range, such as the quay wall 101, the rail 3, the belt conveyor 45, or a long reflector, it may be unclear which point on the reference object corresponds to the coordinates p _u = ( _ux , _uy , _uz ) of the distance measurement point of the reference object measured by the distance measurement sensors 18, 19. In such cases, a coordinate error is detected based on a group of multiple distance measurement points obtained from the same distance measurement sensor 18, 19, rather than a single distance measurement point. As described above with reference to Figures 4 and 5, one distance measurement sensor 18, 19 includes multiple laser emission units and can simultaneously measure distances within a specified angle range (θ- to θ+ in Figure 5) centered on the reference plane S. Therefore, when the distance measuring sensors 18 and 19 measure the distance of the quay wall 101, the rail 3, the belt conveyor 45, a long reflector, etc., which have a straight edge, a group of multiple distance measuring points arranged in a straight line corresponding to the edge and a group of multiple distance measuring points arranged in two planes that are perpendicular or intersecting each other corresponding to the planes on both sides of the edge are obtained. The coordinate error detection unit 303 judges whether there is an error between the distance measuring point coordinates p _u = ( _ux , _uy , _uz ) of the reference object and the known coordinates p _u0 = ( _ux0 , _uy0 , _uz0 ) depending on whether the line segment or plane formed by this group of distance measuring points overlaps with the known edge or plane of the reference object. If the measurement range of the distance measuring sensors 18 and 19 includes the end point (corner) of the reference object such as the belt conveyor 45, the distance measuring point coordinates corresponding to the end point of the reference object can be easily specified, and the distance measuring point group can be accurately compared with the known shape characteristics of the reference object based on the specified coordinates. Details will be described later regarding the processing by the coordinate system correction unit 304.

The coordinate system correction unit 304 corrects the relationship between the ground coordinate system u and the distance measurement unit coordinate systems l and d so as to reduce the error detected by the coordinate error detection unit 303. A correction model for correcting the relationship between the distance measurement unit coordinate system l and the ground coordinate system u is expressed by, for example, the following equation.

The first to third equations correspond to the first to third coordinate conversion equations by the coordinate conversion unit 302, but parameters that are likely to cause errors detected by the coordinate error detection unit 303 are corrected by the following correction parameters.

The first correction parameter R _xyz (φ) corrects an error in the attitude of the distance measurement sensor 19. For example, an error in the attitude of the distance measurement sensor 19 caused by an error in mounting the distance measurement sensor 19, or a change in the relationship between the distance measurement sensor 19 and the lifting unit 9 due to deformation of the lifting unit 9 or the like caused by changes in the external environment such as the weight of the lifting unit 9 itself or the bulk load M being loaded, or changes in temperature, is corrected by R _xyz (φ). Specifically, when the 3×3 matrix R _lb representing the rotation between the distance measurement unit coordinate system l and the undulating unit coordinate system b does not match the actual attitude of the distance measurement sensor 19, R _lb is corrected by the 3×3 matrix R _xyz (φ) that gives a three-dimensional rotation that minimizes the mismatch. Here, the direction of the rotation axis and the rotation angle φ according to R _xyz (φ) are calculated to minimize the mismatch in the attitude of the distance measurement sensor 19.

The second correction parameter b is used to correct the error in the position of the distance measuring sensor 19. For example, the error in the position of the distance measuring sensor 19 caused by an error in mounting the distance measuring sensor 19 or a change in the relationship between the distance measuring sensor 19 and the lifting unit 9 due to deformation of the lifting unit 9 or the like caused by changes in the external environment such as the weight and temperature of the load M or the load itself being loaded, is corrected by b. Specifically, when a three-dimensional translation vector t _lb connecting the origin of the distance measuring unit coordinate system l and the origin of the undulating unit coordinate system b does not match the actual position of the distance measuring sensor 19, t _lb is corrected by a three-dimensional translation vector b that minimizes the mismatch. Here, the direction and magnitude of b are calculated to minimize the mismatch in the position of the distance measuring sensor 19.

The third correction parameter _ρ1 corrects an error in the hoisting angle _θ1 . For example, ρ1 corrects an error in the hoisting angle _θ1 caused by deformation of the boom 7 and other components due to changes in the relationship between the lifting unit 9 and the rotating frame 5 caused by changes in the weight of the lifting unit 9 itself or the bulk load M being loaded, changes in the external environment such as temperature, and an error _in the angle sensor measuring the hoisting angle _θ1 . Specifically, if the hoisting angle _θ1 does not match the actual hoisting angle of the boom 7, _θ1 is corrected by a correction angle _ρ1 that minimizes the mismatch. Here, the direction and magnitude of _ρ1 are calculated to minimize the mismatch in the hoisting angle _θ1 .

The fourth correction parameter _ρ2 corrects an error in the slewing angle _θ2 . For example, the error in the slewing angle _θ2 caused by the deformation of the slewing frame 5 and the like due to changes in the external environment such as the weight of the lifting unit 9 itself or the bulk load M being loaded, the temperature, etc., and the relationship between the slewing frame 5 and the traveling unit 2 changes, and the error in the angle sensor measuring the slewing angle _θ2 is corrected by _ρ2 . Specifically, when the slewing angle _θ2 does not match the actual slewing angle of the slewing frame 5, _θ2 is corrected by a correction angle _ρ2 that minimizes the mismatch. Here, the direction and magnitude of _ρ2 are calculated to minimize the mismatch of the slewing angle _θ2 .

The fifth correction parameter d is for correcting an error in the length L _b1 (the distance between the origin of the hoisting coordinate system b and the hoisting center O _b in FIG. 7) along the extension direction of the boom 7. For example, an error in the length L _b1 caused by deformation of the boom 7 due to changes in the external environment, such as the weight of the lifting unit 9 itself or the weight of the bulk load M being loaded, or temperature, is corrected by d. Specifically, when the length L _b1 does not match the actual length of the boom 7, L _b1 is corrected by a correction amount d that minimizes the mismatch. Here, the direction and magnitude of d are calculated to minimize the mismatch of the length L _b1 . It should be noted that no correction parameters are set for the distance L _b3 in the y direction and the distance L _p in the z direction between the hoisting center O _b and the origin of the rotating unit coordinate system r, because the possible errors are considered to be smaller than those for the length L _b1 of the boom 7. However, correction parameters may also be set for L _b3 and the distance L _p in order to perform more precise correction.

Moreover, the correction parameters _cx and _cy in the third equation of the correction model are used to correct positional errors of the traveling part 2 in the _ux and _uy directions, respectively. For example, errors in the position of the traveling part 2 caused by errors during the installation of the rail 3 and deformation of the traveling part 2 and the rail 3 due to changes in the external environment such as temperature are corrected by _cx and _cy . Specifically, when the ranging point coordinates of the reference object calculated by the first and second terms on the right side of the third equation of the correction model do not match the actual positions of the reference object in the _ux and _uy directions, the ranging point coordinates are corrected by correction amounts _cx and _cy that minimize the mismatch. Here, the directions and magnitudes of _cx and _cy are calculated to minimize the mismatch of the ranging point coordinates. In addition, since the position error of the traveling part 2 in the vertical u _z direction is considered to be smaller than the position error of the traveling part 2 in the u _x and u _y directions, the correction parameter c _z in the u _z direction is not set. However, in order to perform a more precise correction, the correction parameter c _z in the u _z direction may be set.

The correction parameters used in the above correction model are collectively represented as x as follows.

Moreover, the above three equations of the correction model can be transformed into the following equations which express the relationship between the distance measurement point coordinate p _l in the distance measurement unit coordinate system l and the distance measurement point coordinate p _u in the ground coordinate system u.

The notation in the second line focuses on the rotation R _lu and translation t _lu between the ranging unit coordinate system l and the ground coordinate system u, and the notation in the third line summarizes the ranging point coordinate p _l in the ranging unit coordinate system l, the vector u = (θ ₁ , θ ₂ , x _tl ) representing the upswing/rotation/movement state of CSU1, and the correction parameter x as a variable, as a function g.

The coordinate system correction unit 304 uses the above correction model to correct the relationship between the ground coordinate system u and the distance measurement unit coordinate system l so as to reduce the error detected by the coordinate error detection unit 303. Here, an example of correction using the belt conveyor 45 as a reference object will be described. As shown in Fig. 8, the belt conveyor 45 has a rectangular shape with long sides in the u _x direction and short sides in the u _y direction when viewed from above. Also, as shown in Fig. 2, the belt conveyor 45 has a rectangular parallelepiped shape with a height in the vertical direction (u _z direction).

Among the group of distance measurement point coordinates p _l in the distance measurement unit coordinate system l obtained when the distance measurement sensor 19 to be calibrated measures the distance to the belt conveyor 45 at time k, the set of distance measurement points corresponding to the side of the belt conveyor 45 (surface with the u _y direction as its normal) and the set of distance measurement points corresponding to the top surface of the belt conveyor 45 (surface with the u _z direction as its normal) are expressed as follows.

Meanwhile, in the ground coordinate system u, the _uy coordinate of the side of the belt conveyor 45 is _dy , the normal vector in the _uy direction is _ny = (0,1,0), the _uz coordinate of the top surface of the belt conveyor 45 is _dz , and the normal vector in the _uz direction is _nz = (0,0,1).

In this case, in the following error evaluation formula, n _y g-d _y = n _y p _u -d _y represents the error between the u _y coordinate (n _y p _u ) of the distance measurement point coordinate p _u on the side of the belt conveyor 45 transformed into the ground coordinate system u and the known u _y coordinate (d _y ) on the side of the belt conveyor 45, and n _z g-d _z = n _z p _u -d _z represents the error between the u _z coordinate (n _z p _u ) of the distance measurement point coordinate p _u on the top surface of the belt conveyor 45 transformed into the ground coordinate system u and the known u _z coordinate (d _z ) on the top surface of the belt conveyor 45. Therefore, the objective function E(x) in the following error evaluation formula is the sum of the total squared error of the distance measurement point coordinate on the side of the belt conveyor 45 and the average of the total squared error of the distance measurement point coordinate on the top surface of the belt conveyor 45 over time 1 to K.

If there is no error in the ranging point coordinates, the objective function E(x) will be 0, and calibration of the ranging sensor 19 is not necessary. On the other hand, if there is an error in the ranging point coordinates, the objective function E(x) will have a positive value. In this case, the coordinate system correction unit 304 calibrates the ranging sensor 19 by searching for a correction parameter x that minimizes the objective function E(x).

Note that the correction parameter x is a high-dimensional quantity including many correction parameters (φ, ρ ₁ , ρ ₂ , _b , c _x , cy , d), and it may be difficult to uniquely find a solution x that minimizes the objective function E(x). Therefore, instead of minimizing E(x), the following equation, which is L2 regularized, is minimized. η is a regularization coefficient, and N is the total number of points.

In addition to/instead of the error evaluation formula using the above objective function E(x), the root mean square error RMSE _y for the side surface of the belt conveyor 45 and the root mean square error RMSE _z for the upper surface of the belt conveyor 45 may be evaluated individually, and the correction parameter x may be adjusted so that they are minimized.

The above describes the method of calibrating the distance measurement sensor 19 provided in the distance measurement unit coordinate system l by the coordinate system correction unit 304. The distance measurement sensor 18 provided in the distance measurement unit coordinate system d can be calibrated in the same manner. If the "distance measurement sensor 19" is replaced with the "distance measurement sensor 18" and "l" in the distance measurement unit coordinate system is replaced with "d", the above formulas and explanations are almost directly applicable to the calibration of the distance measurement sensor 18. Note that in the distance measurement sensor 18 provided in the scraping unit 11, the rotation angle _θ4 and bending angle _θ5 of the scraping unit 11 are added as parameters representing the state of the CSU1, so that the vector u representing the _{state of the CSU1 is rewritten as (θ1, θ2, θ4, θ5, xtl). In addition, the correction parameters ρ4, ρ5 for θ4 , θ5 may be set in} the same way as the correction parameters _ρ1 , _ρ2 for _θ1 , _θ2 .

In the above description of the calibration device 300, the distance measurement point coordinates p l , p d in the distance measurement unit coordinate system _l , _d are converted to the distance measurement point coordinate p _u in the ground coordinate system u, and then the error with the known coordinates of the reference object is detected, but the error detection may be performed in any coordinate system other than the ground coordinate system u. For example, the known coordinates of the reference object in the ground coordinate system u may be converted to the distance measurement unit coordinate system l, d, and then the error with the distance measurement point coordinates p _l , p d in the distance measurement unit coordinate system l, _d may be detected. Furthermore, the distance measurement point coordinates and the known coordinates of the reference object may be converted to a coordinate system intermediate between the distance measurement unit coordinate system l, d and the ground coordinate system u, such as the undulating unit coordinate system b or the rotating unit coordinate system r, and then the error may be detected. Furthermore, the distance measurement point coordinates and the known coordinates of the reference object may be converted to any identical coordinate system other than the above-mentioned coordinate systems, and then the error may be detected.

Next, a second example of a correction model for correcting the relationship between the distance measurement unit coordinate system l and the ground coordinate system u by the coordinate system correction unit 304 will be shown. This correction model is expressed by the following equation.

Moreover, the correction parameters set in the second correction model are as follows:

The second correction model is intended to accurately correct in real time various errors that occur during the lifting of the CSU 1. Examples of such real-time errors include the position and attitude of each part of the CSU 1 during lifting, the weight of each part of the CSU 1 itself and the bulk load M being loaded, external forces applied to each part of the CSU 1 during lifting, and the inclination of the lifting unit 9 and the twist of the boom 7 that occur due to changes in the external environment such as temperature. In addition, the hoisting angle θ ₁ and the rotation angle θ ₂ may not be accurately measured by the sensors due to gear backlash in the hoisting unit and the rotating unit.

In order to correct such real-time errors, the second correction model includes, in addition to the first correction model, a 3×3 matrix R _bs that corrects the inclination of the lifting unit 9, a 3×3 matrix R _y (ζ) that corrects the torsion of the boom 7, and correction angles ξ ₁ and ξ ₂ that correct the hoisting angle θ ₁ and the swing angle θ ₂ as correction parameters. Here, parameters κ ₁ and κ ₂ included in R _bs represent the inclination angles of the lifting unit 9 in the x and y directions, respectively, and parameter ζ included in R _y (ζ) represents the torsion angle of the boom 7. Note that superscript k represents a discrete time, and superscript m (=1 to M) represents the number of each distance measurement sensor 19.

The above three equations of the second correction model can be transformed into the following equations which express the relationship between the distance measurement point coordinate p _l in the distance measurement unit coordinate system l and the distance measurement point coordinate p _u in the ground coordinate system u.

In this formula, x (y and z) below corresponds to the correction parameter x in the first correction model, and the optimal one that minimizes the coordinate error can be found by the method described for the first correction model.

Meanwhile, v below is a correction parameter for correcting the real-time error additionally provided in the second correction model. Hereinafter, a method for finding an optimal correction parameter v that minimizes the real-time error will be described.

An error evaluation formula for finding the optimal correction parameter v is given, for example, as follows:

This error evaluation formula corresponds to the error evaluation formula of the first correction model with E(x) as the objective function. Here, i in the first term in parentheses represents the number (1 to N _{y )} of the distance measurement point belonging to the set representing the side (surface with the u _y direction as the normal line) of the belt conveyor 45 as the reference object, and i in the second term in parentheses represents the number (1 to N z ₎ of the distance measurement point belonging to the set representing the upper surface (surface with the u _z direction as the normal line) of the belt conveyor 45 as the reference object. In addition, the u _y coordinate of the side surface and the u _z coordinate of the upper surface of the belt conveyor 45, which are denoted as d _y and d _z in the error evaluation formula of the first correction model, are denoted as β _y and β _z here.

If there is no error in the ranging point coordinates, the objective function E(v) will be 0, and calibration of the ranging sensor 19 is not necessary. On the other hand, if there is an error in the ranging point coordinates, the objective function E(v) will have a positive value. In this case, the coordinate system correction unit 304 calibrates the ranging sensor 19 in real time by searching for the correction parameter v that minimizes the objective function E(v).

In order to find the optimal correction parameter v, the following formula may be used:

The second term in the parentheses is a regularization term, which has the effect of stabilizing the estimation of the correction parameter v. χ is a group of parameters that are set according to the required correction amount for each correction parameter, and values corresponding to correction parameters that require a large amount of correction are set small, and values corresponding to correction parameters that require a small amount of correction, such as when a good sensor is installed, are set large.

The third term in the parentheses has the effect of stabilizing the estimation of the correction parameter v ^k at the current time point k by considering the difference with the estimated value v ^{k-1 at the previous time point k-1} . γ is a parameter group set according to the amount of fluctuation of each correction parameter, and a value corresponding to a correction parameter with a large amount of fluctuation is set small, and a value corresponding to a correction parameter with a small amount of fluctuation is set large.

Figure 9 is a flowchart showing an example of the calibration process of the distance measuring sensors 18 and 19 by the calibration device 300. "S" in the flowchart means a step.

In S1, the calibration device 300 moves each movable part of the CSU 1 to one of the measurement positions P1 to P8 as shown in Fig. 8. In S2, the calibration device 300 causes the distance measuring sensors 18, 19 to measure the distance to a reference object on the wharf 102 from the measurement position to which the CSU 1 moved in S1. At this time, it is preferable to change each state parameter of the CSU 1, such as the hoisting angle θ ₁ of the boom 7, the swivel angle θ ₂ of the swivel frame 5, the rotation angle θ ₄ of the scraping unit 11, the bending angle θ ₅ of the scraping unit 11, and the position _xtl of the traveling unit 2, while taking the measurement position to which the CSU 1 moved in S1 as a reference, and to measure the distance to the reference object while gradually changing the measurement attitude of the distance measuring sensors 18, 19.

In S3, the ranging point coordinate acquisition unit 301 acquires ranging point coordinates which are the results of the ranging by the ranging sensors 18 and 19 in S2. The ranging point coordinate _{p_l} of the ranging sensor 18 belongs to the ranging unit coordinate system l, and the ranging point coordinate _{p_d} of the ranging sensor 19 belongs to the ranging unit coordinate system d. In S4, the ranging point coordinate acquisition unit 301 extracts, from the group of ranging point coordinates acquired in S3, a planar set of ranging points corresponding to the side surface (surface having the _{u_y} direction as a normal line) of a reference object such as the belt conveyor 45, a planar set of ranging points corresponding to the top surface (surface having the _{u_z} direction as a normal line) of a reference object such as the belt conveyor 45, and a line segment set of ranging points corresponding to a linear edge of a reference object such as the belt conveyor 45.

In S5, the calibration device 300 acquires the state vector u=(θ ₁ , θ ₂ , θ ₄ , θ ₅ , x _tl ) of the CSU 1 at each ranging time in S2. In S6, the calibration device 300 judges whether or not ranging has been completed at all measurement positions. If there are measurement positions for which ranging has not been performed, the process returns to S1, and each movable part of the CSU 1 moves to the next measurement position. As described above, the CSU 1 during unloading from the ship 200 basically needs to be at the measurement position P1 in FIG. 8, so when calibration is performed in real time during unloading, the processes of S1 to S5 are executed for the measurement position P1, and the process proceeds to the subsequent S7. On the other hand, while the CSU 1 is not unloading, such as before the ship 200 calls at a port, the calibration accuracy can be improved by measuring the distance of the reference object at measurement positions P2 to P8 other than the measurement position P1.

If it is determined in S6 that distance measurement has been completed at all measurement positions, in S7 the coordinate conversion unit 302 converts the distance measurement point coordinates in the distance measurement unit coordinate system l, d acquired in S3 and the known coordinates of the reference object in the ground coordinate system u into the same coordinate system based on the CSU state acquired in S5. In S8, the coordinate error detection unit 303 detects an error in the distance measurement point coordinates and the known coordinates of the reference object in the same coordinate system converted in S7.

In S9, the coordinate system correction unit 304 determines correction parameters for correcting the relationship between the ground coordinate system u and the ranging unit coordinate systems l and d so as to reduce the error detected in S8. Here, if calibration is performed while the CSU1 is not unloading, it is preferable to determine the correction parameter x using the first correction model. On the other hand, if calibration is performed in real time while the CSU1 is unloading, it is preferable to determine the dynamic correction parameter v in real time in addition to the static correction parameter x using the second correction model. In this case, the correction parameters x and v determined in S9 are immediately applied to the CSU1, and after a certain period of time has elapsed, the process returns to S2 and the subsequent processes S2 to S9 (S6 is skipped) are repeated.

Next, a second embodiment of the present invention will be described. In the CSU 1 according to the second embodiment, instead of/in addition to the distance measuring sensors 18 and 19 in the first embodiment, one or more cameras as a photographing unit for photographing a photographing object are provided at any position of the lifting unit 9 in any posture. The camera may be provided in the scraping unit 11 at the bottom of the lifting unit 9 like the distance measuring sensor 18, or in the upper part of the lifting unit 9 like the distance measuring sensor 19. The object photographed by the camera is not particularly limited, but when the CSU 1 is lifted, the edge of the opening 21, the ceiling/wall/bottom of the warehouse 201, the bulk cargo M and other objects, people/structures in the warehouse 201, the scraping unit 11, the ship 200, other parts of the CSU 1 such as the boom 7/swivel frame 5/traveling unit 2/main operation room 16, the quay wall 101, the wharf 102, the rail 3, the belt conveyor 45, etc. are photographed as with the distance measuring sensors 18 and 19. By installing a camera in the lifting section 9, the positions of the edge of the opening 21, the ceiling/walls/bottom of the warehouse 201, the bulk cargo M and other objects, people/structures in the warehouse 201, the scraping section 11, etc. can be accurately grasped. Therefore, the lifting section 9 can be prevented from colliding with other objects during lifting, and the bulk cargo M can be lifted efficiently.

Figure 10 is a functional block diagram of the calibration device 300 according to the second embodiment. It has the same configuration as the calibration device 300 according to the first embodiment, except that the ranging point coordinate acquisition unit 301 in Figure 6 is replaced with a pixel coordinate acquisition unit 305.

The pixel coordinate acquisition unit 305 photographs a reference object whose coordinates in a ground coordinate system u based on the ground on which the traveling unit 2 travels are known, using a camera, and acquires pixel coordinates of the reference object in the pixel coordinate system in the obtained image. Here, the pixel coordinate system is a coordinate system that determines the positions of pixels that constitute an image, and in the case of a planar image, it is a two-dimensional orthogonal coordinate system, and in the case of a stereoscopic image obtained by a camera equipped with a ToF image sensor, it is a three-dimensional orthogonal coordinate system. Since a camera capable of photographing a stereoscopic image can be treated as the distance measurement sensors 18 and 19 of the first embodiment, the following second embodiment will explain the case where the image photographed by the camera is a planar image and the pixel coordinate system is a two-dimensional orthogonal coordinate system. The two orthogonal axes that constitute the pixel coordinate system are the u axis and the v axis, and the pixel coordinate is expressed as q = (q _u , q _v ), etc.

The reference object photographed by the pixel coordinate acquisition unit 305 for calibrating the mounting position and attitude of the camera may be any stationary object on the wharf 102, as in the first embodiment. The reference object in the image can be recognized by image recognition technology, and the pixel coordinates q of each point of the reference object can be obtained. In particular, since the current image recognition technology has high detection accuracy for lines (boundaries, etc.) in an image, it is preferable to use a structure with a linear edge that is easy to detect as the reference object. Therefore, as in the first embodiment, a structure with a long linear edge such as the quay wall 101, the rail 3, the belt conveyor 45, etc. is suitable as the reference object. In addition, a marker (mark) with a linear edge arranged along the rail 3, etc. may be used as the reference object. In this case, the pixel coordinate acquisition unit 305 acquires pixel coordinates of at least two points on the edge of the reference object. Note that the shape feature for which the pixel coordinate acquisition unit 305 acquires pixel coordinates is not limited to a straight line, and may be a curve, a dotted line, a chain line, a corner, a circle, an ellipse, a polygon, etc.

The pixel coordinate acquisition unit 305 can sequentially capture images of reference objects on the wharf 102 with the camera while changing the position and posture of each movable part of the CSU 1, as in FIG. 8 of the first embodiment. While the CSU 1 is unloading in the basic posture, it is at the shooting position P1 in FIG. 8, but while the CSU 1 is not unloading in the basic posture, it can also patrol other shooting positions P2 to P8 and capture multiple pixel coordinates at different positions and postures, and the camera can be calibrated with high accuracy by the coordinate system correction unit 304 in the subsequent stage.

The coordinate conversion unit 302 converts pixel coordinates in the pixel coordinate system and known coordinates of the reference object in the ground coordinate system u into an identical coordinate system based on the relative position and attitude of the lifting unit 9 with respect to the camera, the relative position and attitude of the swivel frame 5 with respect to the lifting unit 9, and the relative position and attitude of the traveling unit 2 with respect to the swivel frame 5. In the following, the identical coordinate system to which the conversion is made is described as a pixel coordinate system, but it may be any other coordinate system including the ground coordinate system u, the swivel unit coordinate system r, the undulating unit coordinate system b, the ranging unit coordinate systems l and d, and the imaging unit coordinate system c described below. The coordinate conversion unit 302 converts the known coordinates of the reference object from the ground coordinate system u into coordinates (r _u , r _v ) in the pixel coordinate system. Specifically, a coordinate transformation is performed to project the known coordinates p _u1 = (p _u1x , p _u1y , p _u1z ) and p _u2 = (p _u2x , p _u2y , p _u2z ) of the two endpoints of the linear edge of the reference object in the ground coordinate system u onto the endpoints r ₁ = (r _1u , r _1v ) and r ₂ = (r _2u , r _2v ) of the line segment in the pixel coordinate system.

First, the coordinate conversion unit 302 substitutes p _u1 and p _u2 for p _u in the following formula, respectively, and converts it into a three-dimensional coordinate p _c of the image capture unit coordinate system c based on the camera (represented as p _c1 and p _c2 , respectively). Here, the image capture unit coordinate system c corresponds to the distance measurement unit coordinate systems l and d in the first embodiment, and the coordinate conversion formula is the same as that described in the first embodiment, except that the subscript representing the coordinate system has been changed to c. That is, t _cb and R _cb in the first formula are determined according to the position and attitude of the camera installed on the lifting unit 9. Specifically, t _cb is a three-dimensional translation vector connecting the origin of the image capture unit coordinate system c and the origin of the undulating unit coordinate system b, and R _cb is a 3×3 matrix representing the difference in attitude between the image capture unit coordinate system c and the undulating unit coordinate system b, i.e., rotation. Note that the superscript k represents the time of image capture by the camera.

The two three-dimensional coordinates p _c1 and p _c2 in the image capture unit coordinate system c obtained by the above coordinate transformation are projected onto pixel coordinates on a planar image according to the camera model. For example, when the camera follows the pinhole camera model, its focal lengths f _u and f _v and image centers c _u and c _v are known, and p _c1 = (p _c1x , p _c1y , p _c1z ) is projected onto r ₁ = (r _1u , r _1v ), and p _c2 = (p _c2x , p _c2y , p _c2z ) is projected onto r ₂ = (r _2u , r _2v ) according to the following equations.

r _1u =f _u (p _c1x /p _c1z )+c _u
r _1v = f _v (p _c1y / p _c1z ) + c _v
r _2u = f _u (p _c2x /p _c2z )+c _u
r _2v = f _v (p _c2y /p _c2z ) + c _v

As described above, the coordinate conversion unit 302 converted the known coordinates p _u1 = (p _u1x , p _u1y , p u1z ), p _u2 = (p u2x , p _u2y , p _u2z ) of the end points of the edge of the reference object in the ground coordinate system u into coordinates _{r 1} = (r _1u , r _1v ), r ₂ = (r _{2u , r 2v ) in the pixel coordinate system via coordinates p c1 = (p c1x , p c1y , p c1z} ), p _c2 = ( _p c2x , p _c2y , p _c2z ) in the imaging unit coordinate system c.

The coordinate error detection unit 303 detects an error between pixel coordinates q = ( _qu , _qv ) obtained by photographing a reference object with a camera and known coordinates r = ( _ru , _rv ) of the reference object in a pixel coordinate system. More specifically, the coordinate error detection unit 303 detects, as a coordinate error, a deviation between a line segment on an image connecting at least two pixel coordinates _q1 = ( _q1u , _q1v ) and _q2 = ( _q2u , _q2v ) on an edge obtained by photographing a linear edge of the reference object with a camera and a line segment on an image connecting at least two known coordinates _r1 = ( _r1u , _r1v ) and _r2 = ( _r2u , _r2v ) on the edge of the reference object. For example, if the distance of point _q1 to a known line segment connecting _r1 and _{r2 is d1} and the distance of point _q2 is _d2 , then coordinate errors are detected based on amounts representing the deviation between the lines, such as _d1 + _d2 , _d1 ^2 + _d2 ^2, ( _d1 ^2 + _d2 ^2)^0.5, etc.

The coordinate system correction unit 304 corrects the relationship between the ground coordinate system u and the pixel coordinate system so as to reduce the coordinate error detected by the coordinate error detection unit 303. As described above, the ground coordinate system u is related to the pixel coordinate system via the image capture unit coordinate system c. Here, since the image capture unit coordinate system c and the pixel coordinate system are related in an almost fixed manner by a pinhole camera model or the like, the main subject of correction is the relationship between the ground coordinate system u and the image capture unit coordinate system c. A correction model for correcting the relationship between the ground coordinate system u and the image capture unit coordinate system c is expressed by, for example, the following equation.

The first to third equations correspond to the first to third coordinate conversion equations by the coordinate conversion unit 302, but parameters that are likely to cause errors detected by the coordinate error detection unit 303 are corrected by the following correction parameters.

The purpose of these correction parameters is the same as in the first embodiment, and therefore the description will be omitted. As in the first embodiment, the correction parameters are collectively represented as x as follows.

２行目の表記は、撮影部座標系ｃと地上座標系ｕの間の回転Ｒ_ｃｕおよび並進ｔ_ｃｕに着目したものである。 Moreover, the three equations of the correction model above can be transformed into the following equations which express the relationship between the three-dimensional coordinate p _c in the image capture unit coordinate system c and the three-dimensional coordinate p _u in the ground coordinate system u.

The notation in the second line focuses on the rotation R _cu and translation t _cu between the camera coordinate system c and the ground coordinate system u.

The coordinate system correction unit 304 uses the above correction model to correct the relationship between the ground coordinate system u and the pixel coordinate system so as to reduce the coordinate error detected by the coordinate error detection unit 303. For example, the coordinate system correction unit 304 finds an optimal correction parameter x that minimizes an objective function E(x) of the following error evaluation formula:

In this error evaluation formula, the subscript k represents the time of photographing by the camera, and the subscript i represents the number of the edges of the reference object. The first term on the right side is the sum of the squares of the distance _d1 of the pixel coordinate _q1 to the i-th known edge (line segment) photographed at time k, over time k and edge number i, and divided by 2. The second term on the right side is the sum of the squares of the distance _d2 of the pixel coordinate _q2 to the i-th known edge (line segment) photographed at time k, over time k and edge number i, and divided by 2. In this way, the above objective function E(x) reflects the magnitude of the error (distance) of the pixel coordinates with respect to the known edge of the reference object.

If there is no error in the pixel coordinates, the objective function E(x) will be 0, and no camera calibration is required. On the other hand, if there is an error in the pixel coordinates, the objective function E(x) will have a positive value. In this case, the coordinate system correction unit 304 calibrates the camera by searching for the correction parameter x that minimizes the objective function E(x).

Instead of minimizing E(x), the following formula, which has been regularized by a second order, may be minimized. This allows the optimum solution x to be stably obtained even when the number of captured images or the number of edges in the reference object is small. In this formula, Λ is a diagonal matrix, and N is the total number of distances obtained. In the diagonal matrix Λ, the components of x corresponding to correction parameters with a large required correction amount are set small, and the components corresponding to correction parameters with a small required correction amount are set large. Specifically, since the design values of the CSU1 are often stable, it is preferable to set the components corresponding to φ and b related to the mounting position and orientation of the camera small, and the components corresponding to ρ ₁ , ρ ₂ , c _x , _cy , and d related to the design values of the CSU1 large.

The above correction model corresponds to the first correction model in the first embodiment. In the first embodiment, a second correction model for correcting various errors that occur during unloading of CSU1 in real time with high accuracy was also exemplified, but a second correction model can be configured in a similar manner in the second embodiment. The specific contents can be understood from the explanation of the first embodiment, so a redundant explanation will not be given here.

Figure 11 is a flowchart showing an example of a camera calibration process performed by the calibration device 300 according to the second embodiment.

In S11, the calibration device 300 moves each movable part of the CSU 1 to one of the photographing positions P1 to P8 as shown in Fig. 8. In S12, the calibration device 300 causes the camera to photograph a reference object on the wharf 102 from the photographing position to which the CSU 1 was moved in S11. At this time, it is preferable to photograph the reference object while gradually changing the photographing attitude of the camera by changing each state parameter of the CSU 1, such as the hoisting angle θ ₁ of the boom 7, the swivel angle θ ₂ of the swivel frame 5, the rotation angle θ ₄ of the scraping unit 11, the bending angle θ ₅ of the scraping unit 11, and the position _xtl of the traveling unit 2, while taking the photographing position to which the CSU 1 was moved in S11 as a reference.

In S13, the pixel coordinate acquisition unit 305 extracts the geometric features of the reference object shown in the image captured in S12. Examples of geometric features include straight lines, curves, dotted lines, chain lines, corners, end points, circles, ellipses, polygons, etc. In S14, the pixel coordinate acquisition unit 305 acquires pixel coordinates on the geometric features extracted in S13.

In S15, the calibration device 300 acquires the state vector u=(θ ₁ , θ ₂ , θ ₄ , θ ₅ , x _tl ) of the CSU 1 at each photographing time in S12. In S16, the calibration device 300 judges whether or not photographing at all photographing positions has been completed. If there is a photographing position that has not been photographed, the process returns to S11, and each movable part of the CSU 1 moves to the next photographing position. As described above, since the CSU 1 during unloading from the ship 200 basically needs to be at the photographing position P1 in FIG. 8, when performing calibration in real time during unloading, the processes of S11 to S15 are executed for the photographing position P1, and the process proceeds to the subsequent S17. On the other hand, while the CSU 1 is not unloading, such as before the ship 200 calls at a port, the calibration accuracy can be improved by photographing the reference object at the photographing positions P2 to P8 other than the photographing position P1.

If it is determined in S16 that photographing at all photographing positions has been completed, in S17, the coordinate conversion unit 302 converts the pixel coordinates in the pixel coordinate system acquired in S14 and the known coordinates of the reference object in the ground coordinate system u into the same coordinate system based on the CSU state acquired in S15. In S18, the coordinate error detection unit 303 detects an error in the pixel coordinates and the known coordinates of the reference object in the same coordinate system converted in S17.

In S19, the coordinate system correction unit 304 determines a correction parameter for correcting the relationship between the ground coordinate system u and the pixel coordinate system so as to reduce the error detected in S18. If calibration is performed while the CSU1 is not unloading, it is preferable to determine the correction parameter x using the first correction model. On the other hand, if calibration is performed in real time while the CSU1 is unloading, it is preferable to determine the dynamic correction parameter v in real time in addition to the static correction parameter x using the second correction model. In this case, the correction parameters x and v determined in S19 are immediately applied to the CSU1, and after a certain period of time has elapsed, the process returns to S12 and the subsequent processes S12 to S19 (S16 is skipped) are repeated.

Next, a third embodiment of the present invention will be described. In the CSU 1 according to the third embodiment, the distance measuring sensor described in the first embodiment and the camera described in the second embodiment are provided in multiple locations on the CSU 1 as detectors for detecting objects to be detected, and calibration is performed between each detector. In the first and second embodiments, the detector (distance measuring sensor or camera) is provided on the lifting unit 9, but in the third embodiment, the detector is provided at any location on the CSU 1, not limited to the lifting unit 9. For example, the detector may be provided on the boom 7, the rotating frame 5, the traveling unit 2, the counterweight 13, the main operation room 16, etc.

Hereinafter, one of any pair of detection units to be calibrated will be referred to as the first detection unit and the other as the second detection unit. The first detection unit and the second detection unit are each composed of a distance measurement sensor or a camera. Therefore, there may be cases where both the first detection unit and the second detection unit are distance measurement sensors, where both the first detection unit and the second detection unit are cameras, or where one of the first detection unit and the second detection unit is a distance measurement sensor and the other is a camera. The difference between a distance measurement sensor and a camera is manifested as a difference in the coordinate system to which the coordinates of the object detected by each belong.

The coordinate system of the object detected by the distance measuring sensor installed in the lifting section 9 is the distance measuring section coordinate system l, d described in the first embodiment. If the distance measuring sensor is installed on the boom 7, etc., it is the elevation section coordinate system b, if the distance measuring sensor is installed on the rotating frame 5, etc., it is the rotation section coordinate system r, and if the distance measuring sensor is installed on the traveling section 2, etc., it is the traveling section coordinate system u. The coordinate system of the object detected by the camera is the pixel coordinate system described in the second embodiment. As described in the second embodiment, the pixel coordinate system is related to the shooting section coordinate system c by a pinhole camera model, etc. Furthermore, the shooting section coordinate system c is related to the elevation section coordinate system b, the rotation section coordinate system r, and the ground coordinate system u depending on the installation position of the camera. Hereinafter, the coordinate system based on the first detection section is referred to as the first detection section coordinate system, and the coordinate system based on the second detection section is referred to as the first detection section coordinate system. As described above, the first detection unit coordinate system and the second detection unit coordinate system can be the ranging unit coordinate system, the undulating unit coordinate system, the rotating unit coordinate system, the ground coordinate system, and the pixel coordinate system (or the image capture unit coordinate system), respectively, but as described in detail in the first and second embodiments, equations are given for converting these coordinate systems into each other. Therefore, the first detection unit coordinate system and the second detection unit coordinate system can be converted into each other.

Figure 12 is a functional block diagram of the calibration device 300 according to the third embodiment. The first detection unit coordinate acquisition unit 306 detects the detection object with the first detection unit and acquires the first detection unit coordinates in the first detection unit coordinate system. When the first detection unit is a distance measurement sensor, the first detection unit coordinate acquisition unit 306 functions as the distance measurement point coordinate acquisition unit 301 of the first embodiment (Figure 6), and when the first detection unit is a camera, the first detection unit coordinate acquisition unit 306 functions as the pixel coordinate acquisition unit 305 of the second embodiment (Figure 10). The second detection unit coordinate acquisition unit 307 detects the detection object with the second detection unit and acquires the second detection unit coordinates in the second detection unit coordinate system. If the second detection unit is a distance sensor, the second detection unit coordinate acquisition unit 307 functions as the distance measurement point coordinate acquisition unit 301 of the first embodiment (FIG. 6), and if the second detection unit is a camera, the second detection unit coordinate acquisition unit 307 functions as the pixel coordinate acquisition unit 305 of the second embodiment (FIG. 10).

The calibration device 300 according to the third embodiment acquires the detection unit coordinates of the same detection object by the first detection unit coordinate acquisition unit 306 and the second detection unit coordinate acquisition unit 307, converts them into the same coordinate system by the coordinate conversion unit 302, and then detects coordinate errors by the coordinate error detection unit 303 and corrects the coordinate system by the coordinate system correction unit 304.

In the first and second embodiments, the reference object on the wharf 102 is used as the detection object for calibrating the detection unit, but in the third embodiment, the detection object commonly detected by the first and second detection units is not limited to the reference object on the wharf 102, and may be any object that each detection unit can detect at the same time or different times. For example, in FIG. 2, the edge of the opening 21, the ceiling/wall/bottom of the shipyard 201, bulk cargo M and other objects, people/structures in the shipyard 201, the ship 200, each part of the CSU 1 such as the lifting unit 9/boom 7/rotating frame 5/traveling unit 2/main operation room 16, the wharf 101, the wharf 102, the rail 3, the belt conveyor 45, etc. can be used as common detection objects for the first and second detection units to calibrate each detection unit. In addition, when the first detection unit and the second detection unit perform detection at the same time, objects that change significantly over time, such as bulk cargo M or people in the warehouse 201, can be detected as objects to be detected. However, when the first detection unit and the second detection unit perform detection at different times, it is preferable to detect other objects that change less over time as objects to be detected.

The coordinate conversion unit 302 converts the first detection unit coordinates in the first detection unit coordinate system and the second detection unit coordinates in the second detection unit coordinate system into the same coordinate system based on the relative positions and attitudes of the first detection unit and the second detection unit. Regarding the conversion of the coordinate system, the conversion formula between the distance measurement unit coordinate system l, d and the undulating unit coordinate system b, the rotation unit coordinate system r, and the ground coordinate system u was shown in the first embodiment, and the conversion formula between the pixel coordinate system and the measurement unit coordinate system c and the undulating unit coordinate system b, the rotation unit coordinate system r, and the ground coordinate system u was shown in the second embodiment. By combining these conversion formulas, the coordinates of both detection units can be converted into the same coordinate system regardless of whether the first detection unit coordinate system and the second detection unit coordinate system are the distance measurement unit coordinate system, the undulating unit coordinate system, the rotation unit coordinate system, the ground coordinate system, or the pixel coordinate system. The same coordinate system converted by the coordinate conversion unit 302 may be the first detection unit coordinate system, the second detection unit coordinate system, or any coordinate system other than the first detection unit coordinate system and the second detection unit coordinate system.

The coordinate error detection unit 303 detects an error between the first detection unit coordinates and the second detection unit coordinates in the same coordinate system converted by the coordinate conversion unit 302. When a distance measurement sensor is used as the first detection unit and/or the second detection unit, the coordinate error can be detected based on the shape features such as edges and planes of the detection object constituted by the distance measurement point cloud as described in the first embodiment. When a camera is used as the first detection unit and/or the second detection unit, the coordinate error can be detected based on the shape features (straight lines, curves, dotted lines, chain lines, corners, end points, circles, ellipses, polygons, etc.) of the detection object shown in the image as described in the second embodiment.

The coordinate system correction unit 304 corrects the relationship between the first detection unit coordinate system and the second detection unit coordinate system so that the error detected by the coordinate error detection unit 303 is reduced. In the first embodiment, an error evaluation formula and an objective function E(x) that minimize the error based on the shape characteristics of the detected object (error related to the side and top surface of the belt conveyor 45) in the ground coordinate system u, which is a three-dimensional coordinate system, are shown. In the second embodiment, an error evaluation formula and an objective function E(x) that minimize the error based on the shape characteristics of the detected object (error related to the line segment corresponding to the edge of the reference object) in the pixel coordinate system, which is a two-dimensional coordinate system, are shown. With these error evaluation formulas and E(x), it is possible to find the optimal correction parameter x that minimizes the coordinate error, whether the coordinate error detection by the coordinate error detection unit 303 and the coordinate system correction by the coordinate system correction unit 304 are performed in a three-dimensional coordinate system (e.g., a ranging unit coordinate system, an undulating unit coordinate system, a rotating unit coordinate system, a ground coordinate system, or a photographing unit coordinate system) or a two-dimensional coordinate system (e.g., a pixel coordinate system).

また、第１実施形態および第２実施形態と同様に、静的な補正パラメータｘに加えて動的な補正パラメータｖを設定し、荷揚げ部９の傾きやブーム７のねじれ等のＣＳＵ１の荷揚げ中に生じる誤差をリアルタイムに補正してもよい。 In the objective function E(x) of the first and second embodiments, there is one detection unit to be calibrated, but in the objective function E(x) of this embodiment, there are two detection units (pairs) to be calibrated, so the correction parameter x includes two φ related to the mounting attitude of each detection unit and two b related to the mounting position of each detection unit, as follows: In the following example, the correction parameter x includes φ _l related to the attitude and b l related to the position of the first detection unit in the ranging unit coordinate system _l , and φ _c related to the attitude and b _c related to the position of the second detection unit in the imaging unit coordinate system c.

Furthermore, similarly to the first and second embodiments, a dynamic correction parameter v may be set in addition to the static correction parameter x, and errors that occur during lifting of the CSU 1, such as the inclination of the lifting section 9 and the twisting of the boom 7, may be corrected in real time.

Figure 13 is a flowchart showing an example of the calibration process of the first detection unit and the second detection unit by the calibration device 300 according to the third embodiment. Figure 13 (A) is a flowchart showing mutual calibration of multiple detection units while the CSU 1 is not unloading cargo, such as before the ship 200 calls at port, and Figure 13 (B) is a flowchart showing mutual calibration of multiple detection units in real time while unloading cargo from the ship 200.

In S21, the calibration device 300 moves each movable part of the CSU 1 to one of the arbitrary detection positions. In the first and second embodiments, as shown in FIG. 8, each movable part of the CSU 1 is moved to a predetermined detection position P1 to P8 so that each detection unit can detect a reference object on the wharf 102, such as a rail 3, at a different position and attitude. On the other hand, in this embodiment, the detection object detected by the first detection unit and the second detection unit can be any object, not limited to a reference object on the wharf 102, so it is not necessary to detect the detection object at the predetermined detection position P1 to P8, and the detection object can be detected at any detection position.

In S22, the calibration device 300 causes the first and second detection units to detect the detection object from the detection position to which the CSU1 moved in S21. Here, if the detection object is within the detection ranges of both the first and second detection units at the detection position of S21, both detection units detect the detection object at the same time. Also, if the detection object is within the detection range of only one detection unit, only that one detection unit detects the detection object (first time). The other detection unit detects the detection object when the CSU1 moves to another detection position in S21, which is executed again at a later time (second time). In this way, according to the calibration device 300 of this embodiment, multiple detection units can be mutually calibrated based on the detection unit coordinates (S24) acquired at different first and second times.

In S23, the first detection unit coordinate acquisition unit 306 and the second detection unit coordinate acquisition unit 307 extract shape features of the detected object from the detection data obtained in S22. In S24, the first detection unit coordinate acquisition unit 306 and the second detection unit coordinate acquisition unit 307 acquire the first detection unit coordinates and the second detection unit coordinates that correspond to the shape features extracted in S23.

In S25, the calibration device 300 acquires the state vector u = ( _θ1 , _θ2 , _θ4 , _θ5 , _xtl ) of the CSU 1 at each detection time in S22. In S26, the calibration device 300 determines whether detection at all detection positions is complete. If there are any undetected detection positions, the process returns to S21, and each movable part of the CSU 1 moves to the next detection position.

If it is determined in S26 that detection at all detection positions has been completed, in S27, the coordinate conversion unit 302 converts the first detection unit coordinates and the second detection unit coordinates acquired in S24 into the same coordinate system based on the relative positions and orientations of the first detection unit and the second detection unit that can be recognized from the CSU state acquired in S25. In S28, the coordinate error detection unit 303 detects an error between the first detection unit coordinates and the second detection unit coordinates in the same coordinate system converted in S27.

In S29, the coordinate system correction unit 304 determines correction parameters for correcting the relationship between the first detection unit coordinate system and the second detection unit coordinate system so as to reduce the error detected in S28. Here, in FIG. 13(A) where calibration is performed while the CSU1 is not lifting, it is not necessary to use the second correction model that takes into account the real-time error that occurs during lifting, and it is preferable to use the simpler first correction model.

In FIG. 13(B), where calibration is performed in real time while the CSU 1 is unloading, in the first step S30, each movable part of the CSU 1 moves to the unloading position (e.g., P1 in FIG. 8). Then, steps S22 to 25 and 27 to 29 are executed similar to those in FIG. 13(A). In correcting the coordinate system in S29, it is preferable to use a second correction model that takes into account real-time errors that occur during unloading. The static correction parameter x and dynamic correction parameter v determined in S29 are applied immediately, and the detection unit is calibrated in real time while unloading. In S30, the calibration device 300 determines whether unloading has been completed. Thereafter, steps S22 to 25 and 27 to 29 are repeated until unloading is completed.

In the above repeated process, CSU1 is stopped at a specified unloading position (e.g., P1 in FIG. 8). In such a case, in the first and second embodiments in which a reference object on the wharf 102 is used to calibrate the detection unit, there are limitations on the acquisition of detection data (distance measurement point coordinates, pixel coordinates) for calibration depending on the mounting position and attitude of the detection unit. For example, at unloading position P1 in FIG. 8, distance measurement sensors 192 and 193 cannot measure the distance to the reference object, and therefore cannot be calibrated in real time during unloading.

However, in this embodiment, the detection object used to calibrate the detection unit can be any object, so the distance measuring sensors 192, 193 can also perform distance measurements for calibration in real time during unloading. For example, as shown in FIG. 5, the distance measuring sensors 192, 193 can detect the ship 200, opening 21, shiphouse 201, etc. during unloading. If a camera serving as a detection unit capable of photographing these detection objects is provided on the boom 7, etc., mutual calibration can be performed between the camera and the distance measuring sensors 192, 193. In this way, the calibration device 300 of the third embodiment is suitable for use in calibrating the detection unit in real time during unloading of the CSU 1.

On the other hand, in the case of calibrating the detector while the CSU 1 is not unloading, such as before the ship 200 calls at port, the calibration device 300 of the first and second embodiments, which individually calibrates each detector based on an absolute reference on the wharf 102, is suitable. Therefore, it is preferable to perform absolute calibration based on the reference of the first and second embodiments when the CSU 1 is not unloading, and to perform relative calibration based on the multiple detectors of the third embodiment when the CSU 1 is unloading. Similarly, it is preferable to perform absolute calibration based on the reference of the first and second embodiments when the unloading unit 9 is not above the ship 200 due to the rotation of the rotating frame 5, and to perform relative calibration based on the multiple detectors of the third embodiment when the unloading unit 9 is above the ship 200 due to the rotation of the rotating frame 5. It is also preferable to perform absolute calibration based on the reference object of the first and second embodiments when the lifting unit 9 is above land due to the rotation of the rotating frame 5, and to perform relative calibration based on the multiple detectors of the third embodiment when the lifting unit 9 is not above land due to the rotation of the rotating frame 5.

Next, a fourth embodiment of the present invention will be described. In the CSU 1 according to the fourth embodiment, an abnormality detection device 400 is provided to detect an abnormality of the CSU 1 based on the position of a detection target detected by a detection unit (distance measurement sensor or camera) provided at an arbitrary position of the CSU 1, as in the third embodiment. Examples of types of abnormalities of the CSU 1 detected by the abnormality detection device 400 include changes in the mounting position and posture of the detection unit, deformations and relative positions and postures of each part of the CSU 1, such as the lifting unit 9, the boom 7, the rotating frame 5, and the traveling unit 2, deformations of the rail 3 on which the traveling unit 2 moves, and discrepancies between the operation amount and the measurement amount of the state parameters of the CSU 1, such as the elevation angle θ ₁ /the turning angle θ ₂ /the rotation angle θ ₄ /the bending angle θ ₅ /the traveling position _xtl , etc.

Figure 14 is a functional block diagram of the anomaly detection device 400. The anomaly detection device 400 includes a detection unit coordinate acquisition unit 401, a coordinate conversion unit 402, a position storage unit 403, a position comparison unit 404, an anomaly detection unit 405, and an anomaly estimation unit 406.

The detection unit coordinate acquisition unit 401 detects a detection object with a detection unit and acquires the detection unit coordinates in a detection unit coordinate system based on the detection unit. Here, the detection unit is composed of a distance measurement sensor or a camera. As in the third embodiment, the number of detection units provided in the CSU 1 is arbitrary, and the mounting positions and postures of the detection units are also arbitrary. For example, each detection unit is mounted on the lifting unit 9, boom 7, rotating frame 5, running unit 2, counterweight 13, main operation room 16, etc. Also, as in the third embodiment, the detection object detected by the detection unit may be any object, not limited to a reference object on the wharf 102. For example, in FIG. 2, the detection objects can be the edge of the opening 21, the ceiling/walls/bottom of the shipyard 201, bulk cargo M and other objects, people/structures in the shipyard 201, the ship 200, various parts of the CSU 1 such as the lifting section 9/boom 7/rotating frame 5/traveling section 2/main operation room 16, the wharf 101, the pier 102, the rail 3, the belt conveyor 45, etc. Also, the number of detection objects is arbitrary.

The detection unit coordinate system based on the detection unit differs depending on the installation location of the detection unit and whether it is a distance sensor or a camera. When the detection unit is a distance sensor installed in the lifting unit 9, the distance sensor coordinate system l, d described in the first embodiment becomes the detection unit coordinate system. Similarly, when the detection unit is a distance sensor installed in the boom 7, the elevation unit coordinate system b becomes the detection unit coordinate system, when the distance sensor is installed in the rotating frame 5, the rotating unit coordinate system r becomes the detection unit coordinate system, and when the distance sensor is installed in the traveling unit 2, the ground coordinate system (or moving unit coordinate system) u becomes the detection unit coordinate system. Also, when the detection unit is a camera, the pixel coordinate system described in the second embodiment becomes the detection unit coordinate system. As described above, the detection unit coordinate systems from which each detection unit acquires the detection unit coordinates may differ from each other, but as described in the first to third embodiments, an equation is given to convert these respective coordinate systems into each other. The coordinate conversion unit 402 described next performs coordinate conversion to compare the detection unit coordinates acquired from different detection units in the same coordinate system. The same coordinate system to which this conversion is made is arbitrary, and may be any of the distance measurement unit coordinate system, undulating unit coordinate system, rotating unit coordinate system, ground coordinate system, pixel coordinate system, and image capture unit coordinate system described in the first to third embodiments, or any other coordinate system. Below, an example is described in which the coordinate conversion unit 402 converts each detection unit coordinate from each detection unit coordinate system to the ground coordinate system u.

The coordinate conversion unit 402 converts the detection unit coordinates acquired by the detection unit coordinate acquisition unit 401 from the detection unit coordinate system to the ground coordinate system u based on the relative positions and attitudes of the detection unit and the traveling unit 2. If the detection unit is installed in the ground coordinate system (or the moving unit coordinate system) u, coordinate conversion is not necessary. In addition, in the position comparison process at the subsequent stage, when comparing detection unit coordinates (positions) acquired by the same detection unit at different times, or when comparing detection unit coordinates (positions) acquired by multiple detection units installed at the same location of the CSU1 (for example, the lifting unit 9), position comparison is possible as is in the detection unit coordinate system, so conversion to the ground coordinate system u is not necessarily required. However, as will be described later, it is preferable to perform coordinate conversion by the coordinate conversion unit 402 even when comparing detection unit coordinates derived from the same detection unit coordinate system, because tracing the calculation process of the coordinate conversion makes it possible to estimate abnormal locations.

The position memory unit 403 stores the detection unit coordinates converted into the ground coordinate system u by the coordinate conversion unit 402 as position data of the detected object. Hereinafter, the position data of the detected object stored in the position memory unit 403 will be represented as P(k, m, n). Here, k represents a discrete detection time, m (= 1 to M) represents the number of the detection unit, and n (= 1 to N) represents the number of the detected object (or each detection point on the detected object). Therefore, the position data P(k, m, n) represents the position where the mth detection unit detected the nth detected object at time k.

The position comparison unit 404 compares a plurality of position data of the same detection object stored in the position storage unit 403, or compares the position data stored in the position storage unit 403 with the position data of the same detection object newly detected by the detection unit. In the latter case, the newly detected position data does not need to be stored in the position storage unit 403, but for convenience, the above notation P(k, m, n) is also used for the position data. Here, assuming that the nth detection object is the position comparison object, the first position data of the comparison object is expressed as P(k ₁ , m ₁ , n), and the second position data of the comparison object is expressed as P(k ₂ , m ₂ , n). That is, the first position data represents the position where the m _1st detection unit detected the nth detection object at time k ₁ (first time), and the second position data represents the position where the m _2nd detection unit detected the _nth detection object at time k 2 (second time).

Here, the first time _k1 and the second time _k2 may be the same time. In this case, position data P( _k0 , _m1 , _n ) and P( _k0 , _m2 , _n ) in which different detection units (m1 ≠ m2) detect the same detection object (n) at the same time ( _k0 = _{k1 =} k2) are compared. Also, the first time _k1 and the second time _k2 may be different times. In this case, position data _P ( _{k1 ,m0} ,n) and P( _k2 , _m0 ,n) obtained when the same detection unit (m0 = _m1 = _m2 ) detects the same detection object (n) at different times ( _k1 ≠ k2) may be compared, or position data P( _k1 , _m1 , _n ) and P( _k2 , _m2 ,n) obtained when different detection units ( _m1 ≠ _m2 ) detect the same detection object (n) at different times (k1 ≠ _k2 ) may be compared. In this way, position comparison unit 404 can compare position data P( _k ,m,n) at different detection times or between different detection units.

In the position comparison process of the position comparison unit 404, as explained with respect to the coordinate error detection unit 303 in the first to third embodiments, the error between both position data P(k ₁ , m ₁ , n) and P(k 2 , m ₂ , n) may be detected based on the shape characteristics of the detected object constituted by the detection point cloud (the ranging point cloud by the _{ranging sensor} or the pixel group by the camera).

The abnormality detection unit 405 detects an abnormality in the CSU 1 when the difference between the first position data P( _k1 , _m1 , n) and the second position data P( _k2 , _m2 , n) compared by the position comparison unit 404 is equal to or greater than a certain value. The first position data P( _k1 , _m1 , n) and the second position data P( _k2 , _m2 , n) are the detection unit coordinates of the same detection object (n) transformed into the same coordinate system (ground coordinate system u), and therefore normally match. Conversely, when the difference between these is equal to or greater than a certain value, there is a high possibility that an abnormality has occurred in the CSU 1, and the abnormality detection unit 405 notifies the operator in the main operation room 16 of this fact.

When detecting an abnormality in the CSU1, the abnormality detection unit 405 refers to the comparison results of a plurality of pairs of position data. As described above, there are a plurality of pairs of position data P( _k1 , _m1 , n) and P( _k2 , _m2 , n) for evaluating the difference in the detection position of the nth detection object, depending on the combination of the detection times _k1 , _k2 and the detection unit numbers _m1 , _m2 . In addition, since there are a total of N detection objects (n=1 to N), the number of pairs of position data that can be referred to when detecting an abnormality in the CSU1 increases accordingly. In this way, the total number of pairs of position data that the abnormality detection unit 405 can refer to when detecting an abnormality in the CSU1 is set to _Np .

The criteria for the anomaly detection unit 405 to detect an anomaly in the CSU1 based on the comparison results of a plurality of pairs of position data can be set arbitrarily. For example, when the difference between a certain number or more (e.g., half (N _p /2) or more) of _Np pairs of position data is a certain number or more, it is determined that an anomaly has occurred in the CSU1. Also, focusing on the detection object, when the difference between the position data pairs in a certain number or more (e.g., half (N/2) or more) of N detection objects is a certain number or more, it is determined that an anomaly has occurred in the CSU1. Also, focusing on the detection unit, when the difference between the position data pairs detected by a certain number or more (e.g., half (M/2) or more) of M detection units is a certain number or more, it is determined that an anomaly has occurred in the CSU1. In this way, by the anomaly detection unit 405 referring to the comparison results of a plurality of pairs of position data when detecting an anomaly in the CSU1, it is possible to prevent erroneous detection due to accidental events such as disturbances temporarily occurring at a specific time k, a detection unit with a specific number m, or a detection object with a specific number n, or detection of a foreign object.

When the anomaly detection unit 405 detects an anomaly, the anomaly estimation unit 406 traces the calculation process in the coordinate conversion unit 402 and estimates the type of anomaly that has occurred in the CSU 1. Specifically, it estimates the type of anomaly, such as a change in the mounting position or posture of the detection unit, deformation of each part of the CSU 1 or a change in the relative position or posture, deformation of the rail 3 on which the traveling unit 2 moves, or a discrepancy between the manipulated variable and the measured variable of the state parameters of the CSU 1.

The abnormality estimation unit 406 performs correction processing based on the first correction model or the second correction model executed by the coordinate system correction unit 304 of the third embodiment on the error of the position data (detection unit coordinates) detected by the position comparison unit 404. As a result of the correction processing based on the first correction model, an optimal correction parameter x that minimizes the objective function E(x) is obtained. As shown in the third embodiment, the correction parameter x includes φ related to the attitude and b related to the position of each detection unit that generated the position data compared by the position comparison unit 404, ρ ₁ related to the hoisting angle θ ₁ , ρ ₂ related to the rotation angle θ ₂ , c _x and _cy related to the position of the traveling unit 2, d related to the length L _b1 of the boom 7, and the like.

The abnormality estimation unit 406 can estimate the location and cause of the abnormality by observing the changes in each of these correction parameters before and after the occurrence of the abnormality. That is, if φ changes significantly before and after the occurrence of the abnormality, it is understood that an abnormality has occurred in the attitude of the detection unit, if b changes significantly before and after the occurrence of the abnormality, it is understood that an abnormality has occurred in the position of the detection unit, if ρ ₁ changes significantly before and after the occurrence of the abnormality, it is understood that an abnormality has occurred in the operation system or sensor for the hoisting angle θ ₁ , if ρ ₂ changes significantly before and after the occurrence of the abnormality, it is understood that an abnormality has occurred in the operation system or sensor for the swing angle θ ₂ , if c _x and c _y change significantly before and after the occurrence of the abnormality, it is understood that an abnormality has occurred in the traveling unit 2 or the rail 3, and if d changes significantly before and after the occurrence of the abnormality, it is understood that deformation of the boom 7, etc. has occurred.

Furthermore, when the abnormality estimation unit 406 performs a correction process based on the second correction model, in addition to the above correction parameter x, an optimal correction parameter v that minimizes the objective function E(v) is obtained. As shown in the first embodiment, the correction parameter v includes ξ ₁ related to the real-time error of the hoisting angle θ ₁ , ξ ₂ related to the real-time error of the slewing angle θ ₂ , κ ₁ and κ ₂ related to the inclination of the lifting unit 9, and ζ related to the twist of the boom 7. As in the above, if ξ ₁ changes significantly before and after the occurrence of an abnormality, it is understood that a real-time error has occurred in the operation system or sensor of the hoisting angle θ ₁ , if ξ ₂ changes significantly before and after the occurrence of an abnormality, it is understood that a real-time error has occurred in the operation system or sensor of the slewing angle θ ₂ , if κ ₁ and κ ₂ change significantly before and after the occurrence of an abnormality, it is understood that a tilt has occurred in the lifting unit 9, and if ζ changes significantly before and after the occurrence of an abnormality, it is understood that a twist has occurred in the boom 7.

The anomaly detection unit 405 notifies the operator in the main operation room 16 of the location and cause of the anomaly estimated by the anomaly estimation unit 406, along with the fact that an anomaly has occurred. This allows the operator to quickly take action to investigate and resolve the anomaly. Furthermore, if the optimal correction parameters x and v change due to the occurrence of an anomaly, the anomaly estimation unit 406 may immediately apply the changed optimal correction parameters x and v to the CSU 1, as in the coordinate system correction unit 304 in the first to third embodiments, in an attempt to resolve the anomaly.

Figure 15 is a flowchart showing an example of an anomaly detection process by the anomaly detection device 400 according to the fourth embodiment. Figure 15 (A) is a flowchart for storing normal position data while the CSU 1 is not unloading cargo, such as before the ship 200 calls at port, and Figure 15 (B) is a flowchart for detecting an anomaly that occurs in the CSU 1 while unloading cargo from the ship 200.

The process of FIG. 15(A) is as follows. In S41, the anomaly detection device 400 moves each movable part of the CSU 1 to one of the arbitrary detection positions. As in the third embodiment, the detection object detected by the detection part may be any object, not limited to the reference object on the wharf 102, so the detection positions are not limited to P1 to P8 shown in FIG. 8.

In S42, the anomaly detection device 400 causes the detection unit to detect the detection object from the detection position to which the CSU1 was moved in S41. In S43, the detection unit coordinate acquisition unit 401 extracts the shape characteristics of the detection object from the detection data obtained in S42. In S44, the detection unit coordinate acquisition unit 401 acquires the detection unit coordinates corresponding to the shape characteristics extracted in S43.

In S45, the anomaly detection device 400 acquires the state vector u=( _θ1 , _θ2 , _θ4 , _θ5 , _xtl ) of the CSU 1 at each detection time in S42. In S46, the anomaly detection device 400 determines whether detection has been completed at all detection positions. If there are any undetected detection positions, the process returns to S41, and each movable part of the CSU 1 moves to the next detection position.

If it is determined in S46 that detection at all detection positions has been completed, in S47 the coordinate conversion unit 402 converts the detection unit coordinates acquired in S44 from the detection unit coordinate system to the ground coordinate system u based on the CSU state acquired in S45. In S48, the position storage unit 403 stores the detection unit coordinates converted to the ground coordinate system u in S47 as position data P(k,m,n) of the detected object.

The process in Fig. 15(B) is as follows. In S49, each movable part of the CSU 1 moves to the unloading position (for example, P1 in Fig. 8). Then, the same processes S42 to S45 and S47 as in Fig. 15(A) are executed. In S50, the position comparison unit 404 compares the first position data P( _k1 , _m1 , n) of the detection object in normal operation stored in S48 with the second position data P( _k2 , _m2 , n) of the same detection object (n) newly acquired in S44 in Fig. 15(B).

In S51, the abnormality detection unit 405 determines that an abnormality has occurred in the CSU 1 if the difference between the first position data P( _k1 , _m1 , n) and the second position data P( _k2 , _m2 , n) compared in S50 is equal to or greater than a certain value. If it is determined that an abnormality has occurred in S51, the process proceeds to S52, where the abnormality estimation unit 406 traces the calculation process of the coordinate transformation in S47 by applying a predetermined correction model to the error in the position data detected in S50, and estimates the type of abnormality that has occurred in the CSU 1. In S53, the abnormality detection unit 405 notifies the operator in the main operation room 16 of the occurrence of the abnormality together with the type of abnormality estimated in S52.

As described above, the anomaly detection device 400 according to this embodiment can effectively detect and report an anomaly that occurs while the CSU 1 is unloading cargo in FIG. 15(B) by using as a reference the position data of the object to be detected during normal times that is recorded while the CSU 1 is not unloading cargo in FIG. 15(A). In addition, by using the correction model described in the first to third embodiments, the type of anomaly that has occurred in the CSU 1 can be specifically identified.

The present invention has been described above based on the embodiments. The embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each processing process, and that such modifications are also within the scope of the present invention.

The present invention is not limited to the bucket elevator type continuous unloader described in the embodiment, but can also be applied to spiral type continuous unloaders and continuous unloaders equipped with an air conveying mechanism.

The functional configuration of each device described in the embodiments can be realized by hardware resources or software resources, or by the cooperation of hardware and software resources. Processors, ROM, RAM, and other LSIs can be used as hardware resources. Programs such as operating systems and applications can be used as software resources.

1 Lifting unit (CSU), 2 Traveling unit, 3 Rail, 5 Swivel frame, 7 Boom, 9 Lifting unit, 11 Scraping unit, 14 Elevator body, 16 Main operation room, 18 Distance measurement sensor, 19 Distance measurement sensor, 21 Opening, 45 Belt conveyor, 101 Quay, 102 Pier, 191-193 Distance measurement sensor, 200 Ship, 201 Warehouse, 300 Calibration device, 301 Distance measurement point coordinate acquisition unit, 302 Coordinate conversion unit, 303 Coordinate error detection unit, 304 Coordinate system correction unit, 305 Pixel coordinate acquisition unit, 306 First detection unit coordinate acquisition unit, 307 Second detection unit coordinate acquisition unit, 400 Abnormality detection device, 401 Detection unit coordinate acquisition unit, 402 Coordinate conversion unit, 403 Position memory unit, 404 Position comparison unit, 405 anomaly detection unit, 406 anomaly estimation unit.

Claims (18)

A discharge device for discharge of cargo from a ship, comprising:
A moving part movable relative to the ship;
A rotating unit that is rotatable relative to the moving unit;
A discharge section provided on the rotating section and configured to discharge the cargo;
A first detection unit that detects a detection object;
A second detection unit that is provided at a position different from that of the first detection unit and detects a detection target;
a first detection unit coordinate acquisition unit that detects a certain detection object with the first detection unit and acquires first detection unit coordinates in a first detection unit coordinate system based on the first detection unit;
a second detection unit coordinate acquisition unit that detects the detection object with the second detection unit and acquires second detection unit coordinates in a second detection unit coordinate system based on the second detection unit;
a coordinate conversion unit that converts the first detection unit coordinates and the second detection unit coordinates into a single coordinate system based on a relationship between the first detection unit and the second detection unit;
a coordinate error detection unit that detects an error between the first detection unit coordinates and the second detection unit coordinates in the same coordinate system. One of the first detection unit and the second detection unit is a distance measurement unit that measures a distance to a measurement object,
The unloading device according to claim 1 , wherein the other of the first detection unit and the second detection unit is an imaging unit that captures an image of an object to be photographed. The first detection unit is a first distance measurement unit that measures a distance to a measurement object,
The unloading device according to claim 1 , wherein the second detection unit is a second distance measuring unit that measures a distance to a measurement object. The first detection unit is a first imaging unit that captures an image of a target object,
The unloading device according to claim 1 , wherein the second detection unit is a second photographing unit that photographs an object to be photographed. The unloading device according to any one of claims 1 to 4, further comprising a coordinate system correction unit that corrects the relationship between the first detection unit coordinate system and the second detection unit coordinate system so as to reduce the error detected by the coordinate error detection unit. The unloading device according to claim 5, wherein the coordinate system correction unit calculates a correction parameter that corrects an error in the position or attitude of at least one of the moving unit, the rotating unit, and the unloading unit. The unloading device according to claim 5 or 6, wherein the coordinate system correction unit corrects in real time errors that occur when the unloading unit is unloading the cargo. The first detection unit is provided at the discharge unit,
the first detection unit coordinate acquisition unit detects, by the first detection unit, a reference object whose coordinates in a ground coordinate system based on the ground on which the moving unit moves are known;
the coordinate conversion unit converts the first detection unit coordinates in a first detection unit coordinate system and the known coordinates of the reference object in a ground coordinate system into an identical coordinate system based on a relationship of the discharge unit to the first detection unit, a relationship of the rotation unit to the discharge unit, and a relationship of the moving unit to the rotation unit;
The unloading device according to claim 1 , wherein the coordinate error detection unit detects an error between the coordinates of the first detection unit and known coordinates of the reference object in the same coordinate system. The coordinate error detection unit
Detecting an error between the first detection unit coordinates and the known coordinates of the reference object when the discharge unit is not discharging the cargo;
The unloading device according to claim 8, further comprising: a detection unit configured to detect an error between the coordinates of the first detection unit and the coordinates of the second detection unit when the unloading unit is unloading the cargo. The coordinate error detection unit
Detecting an error between the first detection unit coordinates and the known coordinates of the reference object when the delivery unit is not above the ship due to the rotation of the rotation unit;
The unloading device according to claim 8 or 9, further comprising: a detecting unit configured to detect an error between the coordinates of the first detection unit and the coordinates of the second detection unit when the unloading unit is located above the ship due to the rotation of the rotating unit. The coordinate error detection unit
detecting an error between the first detection unit coordinates and the known coordinates of the reference object when the delivery unit is above land due to the rotation of the rotation unit;
The unloading device according to claim 8 , further comprising: a detecting unit configured to detect an error between the first detection unit coordinates and the second detection unit coordinates when the unloading unit is not above land due to the rotation of the swivel unit. The moving part is movable along a predetermined trajectory,
The unloading device according to any one of claims 8 to 11, wherein the reference object is a structure arranged along the track. The unloading device according to claim 12, wherein the reference object is a railroad track that constitutes the track. The unloading device according to any one of claims 8 to 13, wherein the reference object is a conveyor that transports the unloaded cargo in a fixed direction in the ground coordinate system. a first time when the first detection unit coordinate acquisition unit acquires the first detection unit coordinates and a second time when the second detection unit coordinate acquisition unit acquires the second detection unit coordinates are different from each other;
The unloading device according to any one of claims 1 to 14, wherein the coordinate conversion unit converts the first detection unit coordinates and the second detection unit coordinates into the same coordinate system based on the relationship between the first detection unit at the first time and the second detection unit at the second time. An unloading device as described in any one of claims 1 to 15, further comprising an abnormality detection unit that detects an abnormality when the error between the first detection unit coordinates and the second detection unit coordinates detected by the coordinate error detection unit is equal to or greater than a certain value. A moving part that is movable relative to the ship;
A rotating unit that is rotatable with respect to the moving unit;
A discharge section provided on the rotating section for discharging cargo from the ship;
A first detection unit that detects a detection object;
A method for calibrating an unloading device comprising: a second detection unit provided at a position different from the first detection unit and configured to detect a detection object, the method comprising:
a first detection unit coordinate acquisition step of detecting a certain detection object with the first detection unit and acquiring first detection unit coordinates in a first detection unit coordinate system based on the first detection unit;
a second detection unit coordinate acquisition step of detecting the detection object with the second detection unit and acquiring second detection unit coordinates in a second detection unit coordinate system based on the second detection unit;
a coordinate conversion step of converting the first detection unit coordinates and the second detection unit coordinates into a single coordinate system based on a relationship between the first detection unit and the second detection unit;
a coordinate error detection step of detecting an error between the first detection unit coordinates and the second detection unit coordinates in the same coordinate system;
a coordinate system correction step of correcting the relationship between the first detection unit coordinate system and the second detection unit coordinate system so as to reduce the error detected in the coordinate error detection step. A moving part that is movable relative to the ship;
A rotating unit that is rotatable with respect to the moving unit;
A discharge section provided on the rotating section for discharging cargo from the ship;
A first detection unit that detects a detection object;
A calibration program for an unloading device comprising: a second detection unit provided at a position different from the first detection unit and configured to detect a detection target,
a first detection unit coordinate acquisition step of detecting a certain detection object with the first detection unit and acquiring first detection unit coordinates in a first detection unit coordinate system based on the first detection unit;
a second detection unit coordinate acquisition step of detecting the detection object with the second detection unit and acquiring second detection unit coordinates in a second detection unit coordinate system based on the second detection unit;
a coordinate conversion step of converting the first detection unit coordinates and the second detection unit coordinates into a single coordinate system based on a relationship between the first detection unit and the second detection unit;
a coordinate error detection step of detecting an error between the first detection unit coordinates and the second detection unit coordinates in the same coordinate system;
A coordinate system correction step of correcting the relationship between the first detection unit coordinate system and the second detection unit coordinate system so as to reduce the error detected in the coordinate error detection step.

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