JP7765993B2 - Unloading device, control method for unloading device, and control program for unloading device - Google Patents

Description

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

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

In Patent Document 1, while the CSU is operating automatically, a camera photographs the shape of the cargo inside the warehouse, and machine learning is used to select the optimal operating pattern for each cargo shape from pre-prepared patterns, thereby preventing cargo from shifting during automatic operation of the CSU.

Japanese Patent Application Laid-Open No. 2020-79145

In Patent Document 1, cargo shifting can be prevented if the cargo shape captured by the camera is similar to that learned by machine learning, but cannot be prevented if the cargo shape captured by the camera is not similar to that learned by machine learning.

The present invention was made in light of these circumstances, and its purpose is to provide an unloading device that can effectively prevent cargo from falling over.

To solve the above problem, one aspect of the present invention provides an unloading device that includes a carry-out device control unit that causes the unloading device to unload cargo from the warehouse out of the warehouse; a cargo shape detection unit that detects the shape of the cargo in the warehouse; a trajectory candidate generation unit that generates multiple trajectory candidates for the unloading device within the warehouse; a cargo shape prediction unit that predicts the cargo shape after the unloading device is operated in accordance with each trajectory candidate generated by the trajectory candidate generation unit for the current cargo shape detected by the cargo shape detection unit; a cargo shape evaluation unit that evaluates the possibility of cargo collapse for each cargo shape predicted by the cargo shape prediction unit; and a trajectory generation unit that generates a trajectory for the unloading device from among the multiple trajectory candidates for which the possibility of cargo collapse evaluated by the cargo shape evaluation unit is below a predetermined tolerance.

In this mode, the cargo shape after the unloading device is operated according to multiple trajectory candidates for the current cargo shape in the warehouse is predicted, and the possibility of cargo collapse is evaluated for each of these cargo shapes. Then, a trajectory for the unloading device is generated that keeps the possibility of cargo collapse below the allowable value, thereby effectively preventing cargo collapse.

Another aspect of the present invention is a method for controlling an unloading device. This method includes a discharge device control step for causing a discharge device to unload cargo from a cargo hold out of the cargo hold; a cargo shape detection step for detecting the cargo shape in the cargo hold; a trajectory candidate generation step for generating multiple trajectory candidates for the discharge device within the cargo hold; a cargo shape prediction step for predicting the cargo shape after the discharge device is operated according to each trajectory candidate generated in the trajectory candidate generation step for the current cargo shape detected in the cargo shape detection step; a cargo shape evaluation step for evaluating the possibility of cargo collapse for each cargo shape predicted in the cargo shape prediction step; and a trajectory generation step for generating a trajectory for the discharge device from among the multiple trajectory candidates for which the possibility of cargo collapse evaluated in the cargo shape evaluation step is below a predetermined tolerance.

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.

This invention effectively prevents cargo from falling over due to the unloading device.

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. 2 is a diagram showing the detailed configuration of the loading section. FIG. 2 is a diagram illustrating the appearance of a distance measuring sensor. FIG. 10 is a top view showing an example of the arrangement of distance measurement sensors. The uneven cargo shape in the hold is exaggerated. FIG. 2 is a functional block diagram of a control system of the CSU. 10 is a flowchart showing a specific example of control by the control system. A specific example of the detection of the cargo shape by the cargo shape detection unit will be described.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the description or drawings, identical or equivalent components, parts, and processes are designated by the same reference numerals, and duplicate explanations will be omitted. The scale and shape of each part shown in the drawings have been set for convenience to facilitate explanation, and should not be interpreted as 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 a lifting device 1 as an unloading device according to an embodiment of the present invention. The lifting device 1 is a continuous unloader or a continuous ship unloader that unloads bulk cargo M loaded on a ship 200 or as cargo onto land. Hereinafter, the lifting device 1 will also be referred to as a CSU 1. The CSU 1 continuously transports bulk cargo M stored in a ship 201 of a ship 200 docked at a quay 101 of a wharf 102 at a port or the like onto land. Examples of bulk cargo M include coal, coke, ore, etc. The CSU 1 is operated by an operator in a main control room 16 provided in its main body. The control room for operating the CSU 1 may be provided elsewhere within the CSU 1, or may be provided at any location on land outside the CSU 1.

The wharf 102 where the ship 200 docks constitutes the land where bulk cargo M is unloaded, and is constructed of high-strength materials such as reinforced concrete. As shown in the perspective view of Figure 2, the wharf 102 is provided with a pair of parallel rails 3 as tracks that run along the longitudinal direction (perpendicular to the plane of Figure 1) of the ship 200 docked and anchored at the quay 101. The rails 3 form a track along which the traveling unit 2, which serves as the mobile unit of the CSU 1, can move or run. These rails 3 enable the CSU 1 to move relative to the anchored ship 200. As shown in Figure 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 portions. When unloading cargo from the ship 200, the CSU 1 moves on the rails 3 to a position close to the opening 21 of the shiphouse 201 from which the cargo is to be unloaded. The traveling section 2, the swivel frame 5 (swivel section), and the lifting section 9 (unloading section or unloading device) are then driven to unload the bulk goods M from the warehouse 201.

At the wharf 102, a belt conveyor 45 is installed between the pair of rails 3 as a conveyor that transports unloaded bulk goods M in a certain direction. As shown in Figure 2, the installation direction of the belt conveyor 45, i.e., the transport direction, preferably coincides with the installation direction of the rails 3, but may be any other direction. The belt conveyor 45 may also include curved or bent portions. The belt conveyor 45 must be installed between the pair of rails 3 at locations where bulk goods M unloaded from the CSU 1 are received, but may be installed outside the pair of rails 3 at other locations.

The CSU 1 comprises a traveling section 2 as a mobile section that can move relative to the ship 200, a swivel frame 5 that constitutes a swivel section that can swivel relative to the traveling section 2, and a lifting section 9 that is provided at the tip of the swivel frame 5 and serves as an unloading section or unloading device for unloading bulk cargo M. The swivel frame 5 is supported on the traveling section 2 so that it can swivel around a vertical (up and down in Figure 1) pivot axis. The swivel frame 5 is provided with a boom 7 that extends laterally and intersects the pivot axis, and a bucket elevator that constitutes the main part of the unloading section 9 is supported at the tip of the boom 7.

The lifting unit 9 maintains a vertical position regardless of the boom 7's hoisting angle (the angle of rotation around the hoisting axis perpendicular to the plane of the page in Figure 1) thanks to a parallel link mechanism formed between the swivel frame 5, boom 7, and parallel link 8. A counterweight 13 is attached to the rear end of the swivel frame 5, 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 places the lifting unit 9 in a substantially unloaded state, achieving stable load balance. The main components of the swivel unit, including the swivel frame 5, boom 7, balancing lever 12, and counterweight 13, may be collectively referred to below as the main body.

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

The main control room 16 for operating the CSU 1 is located in the main body. Specifically, the main control room 16 is located on the lifting unit 9 side of the revolving frame 5. An operator in the main control 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 by operating the main control room 16. The operation of the lifting unit 9 to transport bulk goods M can also be controlled from the main control room 16.

The unloading section 9 is equipped with a scraping section 11 that scrapes off bulk goods M, and a bucket elevator that serves as an elevator section that transports the scraped bulk goods M upward. The scraping section 11 is located below the unloading section 9, and continuously excavates and scrapes off bulk goods M within the warehouse 201 using a number of buckets 27 (see Figure 3) that are movably mounted along its periphery. The scraped 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 plurality 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 that it is suspended between the pair of roller chains 25.

The bucket elevator is equipped with a drive roller 31a, driven rollers 31b and 31c, and a diverting roller 33 that guide the roller chain 25 that is stretched across it. The drive roller 31a is located at the top 9a of the bucket elevator and is driven to rotate by a motor (not shown) or similar device, causing the chain bucket 29 to move in an orbital motion. The driven roller 31b is located in front of the scraping section 11 (left side of Figure 3(B)), and the driven roller 31c is located behind the scraping section 11 (right side of Figure 3(B)), and each guides the orbiting chain bucket 29. The diverting roller 33 is a driven roller located below the drive roller 31a, and guides the orbiting chain bucket 29 and changes its direction of movement. An extendable cylinder 35 is located between the driven rollers 31b and 31c. When this cylinder 35 extends or retracts, the distance between the axes of the driven rollers 31b and 31c changes, changing the trajectory of the orbital motion of the chain bucket 29. The extension and retraction of the cylinder 35 can be controlled by operating the main operation room 16, or automatically by a computer built into the CSU 1 according to a program. Since two roller chains 25 are provided, two drive rollers 31a, two driven rollers 31b and 31c, and two deflection rollers 33 are also provided, and are arranged side by side in a direction perpendicular to the plane of the paper in Figure 3(B).

The rotational drive of the drive roller 31a causes the chain bucket 29 to move in an orbit relative to the elevator body 14. For example, the chain bucket 29 moves in an orbital motion counterclockwise along the arrow W shown in Figure 3(B). At this time, the chain bucket 29 moves back and forth between the scraping unit 11 located at the bottom of the bucket elevator and the drive roller 31a located at the top 9a of the bucket elevator.

Each bucket 27 of the chain bucket 29 rises within the elevator body 14 with its opening facing upward. As each bucket 27 passes over the drive roller 31a at the top 9a of the bucket elevator, its direction of movement changes from upward to downward, causing the opening of each bucket 27 to rotate from upward to downward. A discharge chute (not shown) is provided below the opening of each bucket 27 that has rotated downward in this way, and the bulk goods M scraped 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) installed there. An internal conveyor 43 that receives the bulk goods M is installed within the running section 2 below the hopper's discharge opening. The internal conveyor 43 transfers the bulk goods M to the aforementioned belt conveyor 45 installed on the pier 102, which serves as land.

Next, the basic lifting operation of the CSU1 having the above configuration will be explained. In this lifting operation, the lifting unit 9 and/or the CSU1 function as a discharge device that discharges bulk cargo M (cargo) from the warehouse 201 out of the warehouse 201.

The operator of the CSU 1 operates the CSU 1 from the main control room 16. First, the running unit 2 travels on the rails 3 until it approaches the opening 21 of the shed 201, the target for unloading. Next, the swivel frame 5 is rotated around a vertical pivot point that overlaps the running unit 2 in a top view (as viewed from above in Figure 1), and the lifting unit 9 at the tip of the boom 7 is moved above the opening 21 of the shed 201, the target for unloading. Here, to prevent the lifting unit 9 from colliding with the wharf 102 or the ship 200, it is preferable to raise and lower the boom 7 in the forward direction (clockwise in Figure 1) and perform the running and swinging operations with the lifting unit 9 raised. Next, the boom 7 is raised and lowered in the reverse direction (counterclockwise in Figure 1), and the scraping unit 11 at the tip of the lifting unit 9 is inserted into the shed 201 through the opening 21. The movement of the travel section 2, the rotation of the swivel frame 5, and the raising and lowering of the boom 7 may be performed simultaneously.

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

The scraping unit 11 changes its three-dimensional position within the shed 201 as needed to efficiently scrape bulk goods M from various locations within the shed 201. For example, if the surface of the bulk goods M becomes lower as the unloading operation progresses, the boom 7 is raised and lowered in the negative direction to lower the scraping unit 11. Furthermore, to scrape bulk goods M near the walls of the shed 201, the running unit 2 and/or the swivel 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 posture 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 as desired. Furthermore, as shown by the dashed line in Figure 3(B), the scraping unit 11 can assume an inclined or horizontally elongated shape, contracting vertically and extending horizontally. This allows the scraping unit 11 to be moved closer to the wall, even in a shipyard 201 where the horizontal distance from the opening 21 to the wall is large, allowing the bulk cargo M to be scraped off efficiently.

Changes in the position, posture, and shape of the scraping unit 11 (unloading unit 9) within the shed 201 related to the unloading operation of the CSU 1 as described above may be performed autonomously by the CSU 1 using a ranging sensor or camera (described below) (i.e., the unloading unit 9 and/or CSU 1 may be operated automatically), or may be performed manually by an operator in the main control room 16 while communicating with workers in the shed 201.

After scraping out the bulk goods M from the warehouse 201, the bucket 27 rises within the elevator body 14 and rotates from an upward to a downward orientation as it passes over 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 transported via the boom conveyor 39 and internal conveyor 43 to a belt conveyor 45 installed on the pier 102, which serves as land. By repeatedly performing the above-described discharge operation using multiple buckets 27, the bulk goods M from 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 unloading.

As shown in FIG. 1, the upper part of the lifting section 9 is provided with multiple distance measuring sensors 19 for measuring the distance to objects located below and to the side. During the illustrated lifting operation, the objects measured by the distance measuring sensors 19 include 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 bottom-drilling bulldozer, the scraping section 11, the ship 200, other parts of the CSU 1 such as the boom 7, rotating frame 5, running section 2, and main control room 16, the quay 101, the wharf 102, the rails 3, the belt conveyor 45, etc. The multiple distance measuring sensors 19 may be positioned, for example, on the upper part of the cylindrical elevator body 14, surrounding the outer periphery of the elevator body 14. Alternatively, the multiple distance measuring sensors 19 may be mounted on a flange 91 that rotatably supports the upper part of the elevator body 14, surrounding the outer periphery of the elevator body 14. It is preferable that the multiple distance measuring sensors 19 be installed below the connection between the lifting unit 9 and the boom 7 so that the boom 7 does not enter the measurement range below or to the sides of the multiple distance measuring sensors 19. On the other hand, if the multiple distance measuring sensors 19 are installed above the connection between the lifting unit 9 and the boom 7, each distance measuring sensor 19 should be installed in a position that does not overlap with the boom 7 when viewed from above (when viewed from above in Figure 1). Examples of the placement 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 installed.

The scraping section 11 below the lifting section 9 is equipped with multiple distance measuring sensors 18 for measuring the distance to measurement targets above, to the side, and below. During lifting as shown, the measurement targets of the distance measuring sensors 18 include the edge of the opening 21, the ceiling/walls/bottom of the shed 201, bulk goods M and other objects, people/structures within the shed 201, the bottom-drilling bulldozer, and other parts of the CSU 1 such as the boom 7. The distance measuring sensors 18 are provided at the front (left side of Figure 1) and rear (right side of Figure 1) of the scraping section 11. To avoid a deterioration in measurement accuracy due to dust from the bulk goods M scraped by the bucket 27 of the scraping section 11, it is preferable to install the multiple distance measuring sensors 18 at a location (above the scraping section 11) away from the location where the bucket 27 excavates the bulk goods M (below the scraping section 11). The number of distance measuring sensors 18 is optional. For example, any number of distance measurement sensors 18 that measure distances centered on the sides of the scraping unit 11 and any number of distance measurement 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, 19. Distance measuring sensors 18, 19 are laser sensors capable of measuring distances, and comprise 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 that allows laser light to pass through is formed in an endless band shape around the entire periphery of the side of the cylindrical housing 17 of distance measuring sensors 18, 19.

Multiple laser emitters are provided in positions facing the light-transmitting portion 171 within the housing 17, and emit linear laser light through the light-transmitting portion 171 to the outside of the housing 17. Each laser emitter is spaced apart along the axis A of the housing 17 (the vertical direction in Figure 4), but Figure 4 shows the laser light emitted from a single point for simplicity's sake. As shown in the schematic diagram, the emission angles of each laser emitter differ by approximately 0.1° to 3°. This configuration allows the distance measuring sensors 18 and 19 to emit laser light within a predetermined angular range above and below the reference plane S, which is a plane perpendicular to the axis A of the housing 17. While θ- and θ+ can be set arbitrarily, in the following discussion, we will assume that -θ- = θ+ = 15°. In this case, the distance measuring sensors 18 and 19 emit laser light within a ±15° range centered on the reference plane S. Furthermore, these multiple laser emitters are integrally mounted so as to be rotatable 360 degrees around axis A of housing 17. With this configuration, distance measuring sensors 18 and 19 can irradiate laser light to all measurement targets around (to the sides of) 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 CSU 1 or ship 200.

Range measuring sensors 18, 19 rotate multiple laser emitters together, emitting pulsed laser light at predetermined rotation angles. The pulsed laser light emitted by each laser emitter is reflected or scattered by the object to be measured, returns to distance measuring sensors 18, 19, and is received by a laser receiver located inside housing 17 alongside each laser emitter. A calculation unit (not shown) in distance measuring sensors 18, 19 calculates the distance to the object to be measured based on the time between when the laser emitter emits a pulsed laser light and when the laser receiver receives the reflected pulsed laser light. This technology is also known as LIDAR (Light Detection and Ranging or Laser Imaging Detection and Ranging).

While laser sensors have been used above as examples of distance measuring sensors 18 and 19, distance measuring sensors 18 and 19 may also use other types of electromagnetic waves. For example, millimeter-wave sensors using so-called millimeter waves with wavelengths of approximately 1 mm to 10 mm may be used as distance measuring sensors 18 and 19. Because millimeter waves have a high frequency of approximately 30 GHz to 300 GHz, they have high directionality and can be treated similarly to lasers. A millimeter-wave sensor can be configured similar to the laser sensor shown in Figure 4, except that instead of a laser emitter, it has a millimeter-wave transmitter that transmits millimeter waves to the object being measured, and instead of a laser receiver, it has a millimeter-wave receiver that receives millimeter waves reflected by the object being measured. Furthermore, optical sensors that use light other than laser light, such as Time of Flight (ToF) image sensors, may also be used as distance measuring sensors 18 and 19. Furthermore, distance measuring sensors 18 and 19 may not have a transmitter that transmits electromagnetic waves to the object being measured. For example, a stereo camera or the like that can measure distance by simultaneously photographing an object to be measured from different directions may be used as distance measurement sensors 18 and 19.

The distance measuring sensors 18 and 19 in Figure 4 can be attached to the CSU 1 in Figure 1 in any orientation depending on the purpose of measurement. For example, the distance measuring sensor 18 of the scraping unit 11 is attached so that axis A in Figure 4 is vertical and reference plane S is a horizontal plane. In this case, the distance measuring sensor 18 can measure distances within the warehouse 201, centered on the side of the scraping unit 11. The distance measuring sensor 18 may also be attached so that axis A in Figure 4 is horizontal and 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. Note that the orientation of axis A of the distance measuring sensor 18 is not limited to vertical or horizontal and can be any orientation.

The distance measurement sensor 19 at the top of the loading section 9 is mounted so that axis A in Figure 4 is horizontal and reference plane S is vertical. In this case, the distance measurement sensor 19 can measure the distance to the edge of the opening 21 of the warehouse 201 below, the bulk cargo M inside the warehouse 201, etc. Note that this distance measurement sensor 19 can also emit laser light upward, but since there are no objects to be measured above, upward distance measurement can be disabled by covering the top of the distance measurement sensor 19 with a light-blocking cover, for example. The distance measurement sensor 19 may also be mounted so that axis A in Figure 4 is vertical and reference plane S is parallel to the horizontal plane. In this case, the distance measurement sensor 19 can efficiently measure the distance to objects to be measured outside the warehouse 201 to the side. The direction of axis A of the distance measurement sensor 19 can be any direction, not just horizontal or vertical, but the horizontal direction will be described in detail below.

By installing distance measuring sensors 18, 19 as described above in the lifting section 9, the positions of various measurement targets can be accurately determined, such as the edge of the opening 21, the ceiling/walls/bottom of the shed 201, bulk goods M and other objects, people/structures inside the shed 201, a bulldozer used for bottom raking, and the scraping section 11. This prevents the lifting section 9 from colliding with other objects during lifting, allowing bulk goods M to be lifted efficiently.

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

The CSU 1 unloads bulk cargo M from the shed 201 with the posture shown in Figure 5 as the basic posture for unloading. In this basic posture, the traveling section 2 is positioned away from the front of the shed 201, and the rotating frame 5 and boom 7 are in a rotation 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 shed 201 of the ship 200, and the scraping section 11 at its bottom is inserted into the shed 201 through the opening 21.

The opening 21 of the shipyard 201 is often rectangular and elongated in the direction of travel of the ship 200 (left-right in Figure 5). In this case, the upper edge E11 and lower edge E12 of the opening 21 can be detected by a distance measurement sensor 191 that emits laser light parallel to the short sides of the opening 21 (the sides in the vertical direction in Figure 5). Note that the points shown at the centers of 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 schematically represents the range in which the laser light emitted within a ±15° range centered on the reference plane S1 hits the edge of the opening 21. The same notation will be used for distance measurement sensors 192 and 193 below.

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

Even if the CSU1 is not in the basic position shown in Figure 5, if the loading/unloading unit 9 is within the opening 21 when viewed from above, the three distance measurement sensors 191, 192, and 193 can acquire six distance measurement 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.

Furthermore, the basic position of the CSU 1 during lifting is not limited to that shown in Figure 5. For example, the basic position may be one in which the running unit 2 is located in front of the shipyard 201 and the swivel frame 5 and boom 7 are perpendicular 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 the reference plane S1 of the distance measuring sensor 191 is parallel to the extension direction of the boom 7, and the reference planes S2 and S3 of the distance measuring sensors 192 and 193 are perpendicular to the extension direction of the boom 7. Here, if the distance measuring sensors 191, 192, and 193 are rotatable integrally around the axis of the cylindrical elevator body 14, it is possible to easily arrange the distance measuring sensors 191, 192, and 193 appropriately for the elongated opening 21 described above, depending on whether the basic position of the CSU 1 during lifting is changed.

The above number and arrangement of distance measuring sensors 19 are merely examples, and any number and arrangement can be adopted. It is preferable to have at least two distance measuring sensors 19 in order to efficiently measure the shape of the opening 21 surrounding the lifting section 9 when viewed from above. More preferably, three or more distance measuring sensors 19 are used. Multiple distance measuring sensors 19 may be arranged at equal intervals along the outer periphery of the flange section 91 or 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 its reference surface S is in contact with the outer periphery of the flange section 91 or elevator body 14. Such a symmetrical arrangement allows the shape of the opening 21 to be measured stably regardless of the orientation of the CSU 1 during lifting.

By controlling each movable part of the CSU 1, namely the movable traveling part 2, the swivelable swivel frame 5, the raiseable boom 7, and the rotatable and deformable scraping part 11, etc., according to the distance to the measurement object inside or outside the shed 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 or outside the shed 201 during unloading, and to efficiently unload the bulk goods M. Note that in addition to or instead of the distance measuring sensors 18, 19, objects inside or outside the shed 201 may be detected by an image sensor or camera that photographs the measurement object.

As shown in an exaggerated manner in Figure 6, the cargo shape in the shed 201 is not flat, and the height of the bulk goods M can vary greatly depending on the location. Furthermore, the cargo shape in the shed 201 changes from moment to moment as the scraping section 11 of the unloading section 9 sequentially scrapes off the bulk goods M from each location. Typically, bulk goods M tend to pile up higher near the walls and corners of the shed 201, where it is difficult for the scraping section 11 to scrape off the bulk goods M, than in other locations. Furthermore, in areas where the scraping section 11 is scraping off the bulk goods M, the height of the bulk goods M decreases by the amount scraped off, which may result in an excessive difference in height between the bulk goods M and the surrounding areas. If the bulk goods M piled up around the scraping section 11 collapse (cargo collapse), excessive load will be placed on the scraping section 11 or the entire unloading section 9 where the bulk goods M are collapsing, which may require the CSU 1 to stop operating.

As will be explained in detail below, according to this embodiment, the cargo shape after the unloading unit 9 operates according to multiple trajectory candidates for the current cargo shape in the warehouse 201 (e.g., the height distribution of bulk cargo M) is predicted, and the possibility of cargo collapse is evaluated for each of the cargo shapes. Then, a trajectory for the unloading unit 9 is generated that keeps the possibility of cargo collapse below an acceptable value, thereby effectively preventing cargo collapse.

Figure 7 is a functional block diagram of the control system 300 for the CSU 1 (particularly the unloading unit 9). The control system 300 includes a cargo shape detection unit 301, a discharge device position detection unit 302, a discharge device control unit 303, a trajectory candidate generation unit 304, a cargo shape prediction unit 305, a prediction model storage unit 306, a prediction model adoption unit 307, a cargo shape evaluation unit 308, a trajectory generation unit 309, an approval acceptance unit 310, a cargo shape prediction presentation unit 311, a cargo collapse possibility presentation unit 312, a discharge stop unit 313, and an alarm unit 314. These functional blocks are realized through the cooperation of hardware resources such as the computer's central processing unit, memory, input devices, output devices, and peripheral devices connected to the computer, as well as software executed using these resources. Regardless of the type of computer or its location, each of the above functional blocks may be realized by the hardware resources of a single computer or by combining hardware resources distributed across multiple computers. In particular, in this embodiment, some or all of the functional blocks of the control system 300 may be implemented by a computer in the CSU1, or may be implemented by a computer installed outside the CSU1 and capable of communicating with the CSU1.

The cargo shape detection unit 301 and the discharge device position detection unit 302 are one or more sensors provided in the CSU 1 (including the unloading unit 9) serving as the discharge device. Each sensor may be a distance measurement sensor provided in the CSU 1 to measure the distance to the measurement object, an image sensor provided in the CSU 1 to photograph the measurement object, or any other sensor capable of detecting the measurement object. As will be explained below, the main measurement objects in the illustrated example are the bulk goods M (cargo), the unloading unit 9, or the scraping unit 11 (discharge device).

The cargo shape detection unit 301 detects the shape of the cargo (shape of the bulk goods M) in the warehouse 201. The cargo shape detection unit 301 can be the aforementioned distance measuring sensors 18, 19 or image sensor provided in the unloading unit 9. The discharge device position detection unit 302 detects the position of the unloading unit 9 as a discharge device in the warehouse 201, specifically the position of the front and rear ends of the scraping unit 11 that scrapes off the bulk goods M in the unloading unit 9. The discharge device position detection unit 302 can be the aforementioned distance measuring sensors 18, 19 or image sensor provided in the unloading unit 9 itself. Note that if the discharge device control unit 303 that controls the unloading unit 9 is able to recognize the position of the unloading unit 9 in the warehouse 201, the discharge device position detection unit 302 does not need to be provided.

The trajectory candidate generation unit 304 generates multiple trajectory candidates for the unloading unit 9 within the warehouse 201 based on the cargo shape detected by the cargo shape detection unit 301, the position of the unloading unit 9 detected by the unloading device position detection unit 302, and the operating information of the unloading unit 9 provided by the unloading device control unit 303.

The cargo shape prediction unit 305 predicts the cargo shape after the unloading unit 9 is operated according to each trajectory candidate generated by the trajectory candidate generation unit 304, based on the current cargo shape detected by the cargo shape detection unit 301. Note that since the cargo shape changes not only depending on the trajectory of the unloading unit 9 but also on operating information such as the scraping speed of the scraping unit 11, it is preferable that the cargo shape prediction unit 305 also considers the operating information of the unloading unit 9 provided by the discharge device control unit 303 when predicting the cargo shape.

The cargo shape prediction unit 305 may predict the cargo shape using multiple prediction models stored in the prediction model storage unit 306. Each prediction model differs depending on the characteristics of the cargo. For example, different prediction models are prepared in advance and stored in the prediction model storage unit 306 depending on the cargo properties, such as the material and physical properties of the bulk cargo M, and the state of the cargo, such as the moisture content of the bulk cargo M and the associated viscosity.

The prediction model adoption unit 307 compares the cargo shape detected by the cargo shape detection unit 301 after the unloading unit 9 operates according to the trajectory generated by the trajectory generation unit 309 (the final adopted trajectory from the multiple trajectory candidates generated by the trajectory candidate generation unit 304), described below, with multiple cargo shapes based on multiple prediction models predicted by the cargo shape prediction unit 305, and adopts the prediction model with the smallest deviation. As a result, the prediction model that best matches the characteristics of the current cargo (bulk cargo M) is selected from the prediction model storage unit 306, allowing for highly accurate evaluation by the cargo shape evaluation unit 308 (described below) and trajectory generation by the trajectory generation unit 309. Note that it is possible that the moisture content and other properties of the bulk cargo M may differ between the top and bottom of the bulk cargo M, for example. Therefore, different prediction models may be adopted by the prediction model adoption unit 307 depending on the position of the unloading unit 9 and the progress of the unloading operation.

The cargo shape evaluation unit 308 evaluates the possibility of collapse of the bulk cargo M for each cargo shape predicted by the cargo shape prediction unit 305 (or, if the prediction model storage unit 306 and the prediction model adoption unit 307 are provided, each cargo shape predicted based on the prediction model adopted by the prediction model adoption unit 307). For example, the cargo shape evaluation unit 308 evaluates the flatness of each cargo shape predicted by the cargo shape prediction unit 305 using the standard deviation of the bulk cargo M, etc. A cargo shape with high flatness is less likely to collapse, while a cargo shape with low flatness is more likely to collapse. Specific examples of evaluation by the cargo shape evaluation unit 308 will be described later.

The trajectory generation unit 309 generates a trajectory for the unloading unit 9 from among the multiple trajectory candidates generated by the trajectory candidate generation unit 304, where the likelihood of cargo collapse evaluated by the cargo shape evaluation unit 308 is below a predetermined tolerance. For example, the trajectory generation unit 309 may generate a trajectory for the unloading unit 9 from among the multiple trajectory candidates generated by the trajectory candidate generation unit 304, where the likelihood of cargo collapse evaluated by the cargo shape evaluation unit 308 is lowest. Alternatively, the trajectory generation unit 309 may select a trajectory candidate where the likelihood of cargo collapse evaluated by the cargo shape evaluation unit 308 is below a predetermined tolerance and which also receives high evaluations in other evaluation perspectives described below. When the cargo shape evaluation unit 308 evaluates the flatness of the cargo shape, the trajectory generation unit 309 selects a trajectory candidate where the flatness is above a predetermined tolerance (for example, the standard deviation of the bulk load M is below a predetermined tolerance). Specific examples of trajectory generation by the trajectory generation unit 309 will be described later.

The control system 300 may also include an approval receiving unit 310 that receives approval for the trajectory of the unloading unit 9 generated by the trajectory generating unit 309. For example, an operator in the main operation room 16 of the CSU 1 or an administrator of the control system 300 has the authority to approve the trajectory generated by the trajectory generating unit 309 and can input approval or rejection to the approval receiving unit 310.

The carrying-out device control unit 303 causes the unloading unit 9, which serves as a carrying-out device, to carry out the bulk cargo M from the shipyard 201 to the outside of the shipyard 201. The carrying-out device control unit 303 drives the unloading unit 9 according to the recommended trajectory for the unloading unit 9 generated by the trajectory generation unit 309 (or, if an approval reception unit 310 is provided, the trajectory for the unloading unit 9 approved by the approval reception unit 310). The unloading unit 9 may be automatically operated according to the recommended trajectory, or may be manually operated by an operator in the main operation room 16 or the like who is presented with the recommended trajectory.

The cargo shape prediction presentation unit 311, cargo collapse possibility presentation unit 312, discharge stop unit 313, and notification unit 314 provide auxiliary functions related to the trajectory of the unloading unit 9 generated by the trajectory generation unit 309 and/or the evaluation of the cargo shape by the cargo shape evaluation unit 308.

The cargo shape prediction presentation unit 311 presents to the operator of the CSU 1, etc., the prediction by the cargo shape prediction unit 305 of the cargo shape after the unloading unit 9 is operated according to the trajectory generated by the trajectory generation unit 309. The cargo shape prediction presentation unit 311 may also present to the operator of the CSU 1, etc., the prediction by the cargo shape prediction unit 305 of the cargo shape after the unloading unit 9 is operated according to each trajectory candidate generated by the trajectory candidate generation unit 304. In this case, the operator of the CSU 1, etc., can select the optimal trajectory for the unloading unit 9 themselves while checking the cargo shape prediction for each trajectory candidate.

The cargo shift possibility presentation unit 312 presents to the operator of the CSU 1, etc., the possibility of cargo shift as determined by the cargo shape evaluation unit 308 after the unloading unit 9 is operated according to the trajectory generated by the trajectory generation unit 309. The cargo shift possibility presentation unit 312 may also present to the operator of the CSU 1, etc., the possibility of cargo shift as determined by the cargo shape evaluation unit 308 after the unloading unit 9 is operated according to each trajectory candidate generated by the trajectory candidate generation unit 304. In this case, the operator of the CSU 1, etc., can select the optimal trajectory for the unloading unit 9 himself/herself while checking the possibility of cargo shift for each trajectory candidate.

The discharge stop unit 313 stops control of the unloading unit 9 by the discharge device control unit 303 when the likelihood of cargo collapse evaluated by the cargo shape evaluation unit 308 for the multiple trajectory candidates generated by the trajectory candidate generation unit 304 is higher than the allowable value. The notification unit 314 notifies the operator of the CSU 1, etc., that there is a high likelihood of cargo collapse when the likelihood of cargo collapse evaluated by the cargo shape evaluation unit 308 for the multiple trajectory candidates generated by the trajectory candidate generation unit 304 is higher than the allowable value.

Next, a specific example of control by the control system 300 will be described with reference to the flowchart in Figure 8. In the flowchart, "S" denotes a step or process. In the example in Figure 8, the entire CSU 1 or the unloading unit 9 serving as the unloading device is automatically operated. As mentioned above, the trajectory of the unloading unit 9 is generated by the trajectory generation unit 309, and the unloading device control unit 303 automatically operates the entire CSU 1 or the unloading unit 9.

In S1, the relative position of the unloading unit 9 or scraping unit 11 of the CSU 1 and the warehouse 201 is detected. Specifically, the relative position between the position of the opening 21 of the warehouse 201 detected by the distance sensors 18, 19 and image sensors provided in the unloading unit 9 and the position of the unloading unit 9 or scraping unit 11 recognized and controlled by the carry-out device control unit 303 is detected. Note that the position of the unloading unit 9 or scraping unit 11 may be detected by the carry-out device position detection unit 302. The following description is given in a three-dimensional coordinate system (also referred to as the warehouse coordinate system) with an arbitrary reference point fixed to the warehouse 201 as the origin. The position/posture of the unloading unit 9 at time k in the warehouse coordinate system detected in S1 is represented as x _c ^k . Note that the subscript "c" refers to CSU 1. x _c ^k is a vector representing the position (e.g., three-dimensional coordinates) and posture (e.g., rotation angle around the three-dimensional coordinate axis) of one or more representative points of the lifting section 9 (e.g., the front or rear end of the scraping section 11).

In S2, the cargo shape detection unit 301 detects the cargo shape (shape or height distribution of bulk cargo M) in the warehouse 201. Figure 9 shows a specific example of cargo shape detection by the cargo shape detection unit 301. A two-dimensional coordinate system with X and Y axes is set on a plane that approximates the surface or bottom of the warehouse 201, and the surface of the warehouse 201 is divided into a grid along the X and Y axes.

In the example of Figure 9, the bottom of the warehouse 201 is divided into a total of 450 compartments, with 30 sections along the X-axis and 15 sections along the Y-axis. The cargo shape detection unit 301 detects the height of bulk cargo M in each compartment. The height of bulk cargo M in the i-th compartment (i = 1 to 450 in the example of Figure 9) at time k is represented as h _i ^k . The cargo shape detection unit 301 detects the cargo shape h ^k at time k as the total or set of h ₁ ^k to h ₄₅₀ ^k . Note that if the cargo shape detection unit 301 cannot measure the height of bulk cargo M in some compartments due to objects or people inside the warehouse 201, including the unloading unit 9, the height of bulk cargo M in those sections may be estimated using an interpolation technique such as Semantic Scene Completion.

Figure 9 shows a schematic representation of a portion of the preset basic trajectory R or circular trajectory of the unloading unit 9. In principle, the unloading unit 9 is driven by the discharge device control unit 303 to orbit or circulate within the warehouse 201 along the basic trajectory R. However, in cases where there is a high possibility of cargo shifting, the trajectory generation unit 309 recommends a correction trajectory to take a peripheral trajectory that deviates from the basic trajectory R, thereby preventing a large-scale cargo shift that could result in the shutdown of the CSU 1. Note that as long as the height of the bulk cargo M piled up around the scraping unit 11 of the unloading unit 9 is relatively small, even if a cargo shift occurs, the load on the scraping unit 11 and the unloading unit 9 is small. Therefore, the trajectory generation unit 309 may be caused to generate a correction trajectory that actively causes such small-scale cargo shifting, thereby preventing a large-scale cargo shift from occurring.

In S3, the trajectory candidate generation unit 304 generates a plurality of trajectory candidates for the unloading unit 9 within the warehouse 201, based on the cargo shape h ^k detected in S2, the position x _c ^k of the unloading unit 9 detected in S1, operation information of the unloading unit 9 provided by the carry-out device control unit 303, etc. In S4, the cargo shape evaluation unit 308 evaluates the possibility of collapse of the bulk goods M for each cargo shape predicted by the cargo shape prediction unit 305 with respect to the plurality of trajectory candidates generated in S3. At this time, the load state φ of the unloading unit 9 is also predicted and evaluated, as described below. Details of S3 and S4 will be described later.

In S5, the trajectory generation unit 309 selects a trajectory for the unloading unit 9 from the multiple trajectory candidates generated in S3, for which the possibility of cargo collapse evaluated in S4 is below a predetermined tolerance. For example, a trajectory candidate for which the possibility of cargo collapse evaluated in S4 is below a predetermined tolerance and which has also been highly evaluated in other evaluation perspectives described below is selected in S5. The trajectory (position/attitude) of the unloading unit 9 from future time k+1 to H selected in S5 is represented as x _c ^k+1:H (a set of x _c ^k+1 to x _c ^H ). Hereinafter, the future time H that defines the range for predicting or generating the trajectory x _c ^k+1:H of the unloading unit 9 is also referred to as the prediction horizon H. Details of S5 will be described later.

In S6, it is determined whether a trajectory x _c ^k+1:H of the unloading unit 9 for which the possibility of cargo collapse is within a predetermined tolerance level has been found in S5. If the determination in S6 is Yes, that is, if a recommended trajectory x _c k+ ^1:H of the unloading unit 9 for which the possibility of cargo collapse is within a predetermined tolerance level has been selected in S5, the process proceeds to S7, in which the unloading device control unit 303 automatically operates (trajectory tracking control) the unloading unit 9 from time k+1 to H in accordance with the recommended trajectory _x c k+1 ^:H . After S7, the process returns to S1, and the series of processes from S1 to S7 are repeated intermittently or continuously. If the answer is No in S6, that is, if the trajectory x _c ^k+1:H of the unloading unit 9 where the possibility of cargo collapse is below a predetermined tolerance value is not selected in S5, the process proceeds to S8, in which the unloading stop unit 313 stops the control of the unloading unit 9 by the unloading device control unit 303, and the alarm unit 314 notifies the operator of the CSU 1, etc., that there is a high possibility of cargo collapse.

Next, steps S3 to S5 will be described in detail. In steps S3 to S5, a trajectory x _c ^k+1:H of the unloading unit 9 from future times k+1 to H is generated, but here, the control state y _c ^k of the unloading unit 9 or CSU 1, such as the scraping speed of the scraping unit 11, is also taken into consideration. The combination of the trajectory x _c ^k and control state y _c ^k of the unloading unit 9 at time k is defined as the state z _c ^k = (x _c ^k , y _c ^k ) of the unloading unit 9 at time k.

Based on the above, consider a function g that ^generates the state _zc1 ^: H of the unloading unit 9 at future times ¹ to H from the set ( _zc0 , ^h0 ) of the state zc0 of the unloading unit 9 at the current time k=0 and the cargo shape h0 at the current time k _{=0. That is, zc1 :} ^{H =} g( _zc0 , ^h0 ). Note that, in order to take into account the ^speed and acceleration of the unloading unit 9, it is preferable to input the state _zc ^-L:0 of the unloading unit 9 from time -L, which is slightly before the current time 0, to the current time 0 into function g. L is, for example, 1. In this case, function g is expressed as _zc1 ^:H = g( _zc ^-L:0 , ^h0 ). The purpose of the trajectory generation process of S3 to S5 is to find the optimal function g that gives the trajectory z _c ^1:H of the unloading unit 9 at future times 1 to H, which will not cause large-scale cargo collapse and will maximize the efficiency of the scraping unit 11 in removing the bulk cargo M.

In z _c ^1:H = g (z _c ^{- L: 0} , h ⁰ ), z _c ^{- L: 0} and h ⁰ which are inputs to the function g on the right-hand side are detected by the unloading device position detection unit 302 (and/or the unloading device control unit 303) and the cargo shape detection unit 301, respectively. The trajectory candidate generation unit 304 acquires these parameters (z _c ^{- L: 0} , h ⁰ ) and generates multiple trajectory candidates z _c ^1:H for the unloading unit 9.

The cargo shape prediction unit 305 predicts cargo shapes h ¹ to h ^H and load states φ 1 to φ H of the unloading unit 9 at future times 1 to H after the unloading unit 9 has been operated according to each generated trajectory candidate z _c ¹ : ^H . Here, the cargo shape h ^k and load state φ ^k at time k are expressed as (h ^k , φ ^k ) = f (h ^k-1 , φ ^k-1 , z _c ^k ) based on the cargo shape h ^k -1 and load state φ ^{k-1 at the previous time k -} 1 and the state z _c ^{k of the unloading unit 9 at time k} . Here, the function f is prepared in advance by machine learning using a neural network or the like. The data used for machine learning may be real-world data collected during manual operation by an operator or data collected by simulation. It is generally known that such input/output machine learning works well even with little data prepared for learning. The cargo shape prediction unit 305 sequentially inputs each trajectory candidate z _c ^1:H , the cargo shape h ⁰ at the current time detected by the cargo shape detection unit 301, and the load state φ 0 at the current time obtained from a load sensor such as a load sensor installed in the scraping unit ¹¹ or the unloading unit ⁹ into a function f, and predicts the cargo shapes h ¹ to ^hH and the load states φ ¹ to φH of the unloading unit 9 at each future time 1 to H for each trajectory candidate z _c ¹ :H using ( ^{h 1} , φ ¹ ) = f(h ⁰ , φ ⁰ , z _c ¹ ), (h ² , φ 2 ) = f(h ¹ , φ ¹ , z c 2 ⁾ , ..., (h H , _φ ^{H )} = f(h ^{H- 1} , φ H-1 , z _c ^H ).

As described above, for multiple trajectory candidates z _c ^1:H , a transition (h 1:H , φ 1:H , z _c 1 ^: H ^| z _c ^-L:0 , h ^{0 , φ 0 ) is given from the initial state (z c -L:0 , h 0 , φ 0} ₎ of the unloading unit 9 and bulk load M at current time 0 to the state (h ^{1 :H} , φ ^1:H , z _c ^{1:H )} of the unloading ^{unit 9 and} bulk load M at future times 1 to H. The cargo shape evaluation unit 308 evaluates each trajectory candidate zc1:H using an evaluation function J (h1 ^:H , φ1 ^:H , _zc1 ^:H | _zc ^{-L:0, h0, φ0) that evaluates the possibility of the bulk goods M collapsing and the ease of removal during these transitions, and a constraint b (h1:H, φ1:H, zc1:H |zc-L:0 , h0 , φ0} ₎ ^that _allows ^{the unloading unit} 9 to move at a realistic speed and acceleration during these transitions while avoiding collision with the walls of the warehouse ₂₀₁ , etc. The evaluation function J and the constraint ^b will be described later. Note that Patent Document 1 does not take such mechanical and/or non-mechanical constraints into consideration, and therefore there is a risk that a physically unrealistic trajectory or a trajectory in which the unloading unit 9 collides with the walls of the warehouse 201 will be output.

The evaluation of multiple trajectory candidates _zc1 ^:H by the cargo shape evaluation unit 308 using the evaluation function J and constraint condition b can be treated as a constrained nonlinear optimization problem expressed by the following formula. The evaluation may utilize the primal-dual interior point method, SQP (Sequential Quadratic Programming), random shooting, etc. As a result, the trajectory candidate _zc1 ^:H that has the highest overall evaluation is adopted by the trajectory generation unit 309 and used for automatic operation of the unloading unit 9.

The evaluation function J can be constructed by adding together a plurality of functions r _l (h ^1:H , φ ¹ :H , z _c ^1:H |z _c ^-L:0 , h ⁰ , φ ⁰ ) designed to correspond to a plurality of different evaluation viewpoints, appropriately weighted by a weight α _l . That is, J = Σ _l α _l r _l (h ^1:H , φ ^1:H , z _c ^1:H |z _c ^-L:0 , h ⁰ , φ ⁰ ). Specific examples of the function r _l are given below. A particularly important evaluation viewpoint in this embodiment is that cargo collapse is unlikely to occur and/or that the scraping unit 11 or the landing unit 9 is not overloaded by cargo collapse. The function r _l designed based on this evaluation viewpoint gives a high evaluation to a candidate trajectory for the landing unit 9 that does not form a steep and high slope of the bulk cargo M that could cause a large-scale cargo collapse. Then, each function r _l is designed and an appropriate weight α _l is assigned so that the trajectory generating unit 309 generates a trajectory that maximizes the efficiency of the scraping unit 11 in carrying out the bulk goods M.

The first function _r1 relates to preventing the bulk load M from shifting. For example, in order to prevent the bulk load M from forming a steep slope, _r1 ( ^hH ) = _maxi ( _wiH ^RiH ) is defined. Here, _Rik is defined as _Rik ^{= √} (( _{∂hik /} ∂X) ² + ( ^{∂hik /} ∂Y ^{) 2} ), and represents the magnitude (absolute value) of the gradient of the bulk load M at time k in the i-th section of the warehouse 201 in Figure 9. When obtaining this gradient, image processing filters _such as a Laplacian filter or a Sobel filter may be used, treating Figure 9 as an image of the heights _hik of ^the bulk load M. Furthermore, w _i ^k is a weight for limiting the evaluation targets to sections near the trajectory candidate z _c ^1:H , and is set to a larger value the closer the section is to the unloading unit 9 on the trajectory candidate z _c ^1:H . For example, w _i ^k = 1 is set for sections near the trajectory candidate z _c ^1:H , and w _i ^k = 0 is set for other sections.

In this way, the first function _r1 ( ^hH ) = _maxi ( _wiHRiH ) _gives the maximum value of the gradient ^RiH in the vicinity of the unloading unit 9 (i.e., in the vicinity of the trajectory candidate ^zcH ) for the cargo ^{shape hH} in the _warehouse 201 at the prediction horizon ^H. The smaller the value of _r1 (the maximum value of the _{gradient RiH} ⁾ , the lower the possibility that a steep slope of the bulk goods M will be formed in the vicinity of the unloading unit 9. Therefore, by setting the weight α1, _etc. so that the evaluation by the first function _r1 becomes higher as the value of _r1 becomes smaller, a high evaluation is given to the trajectory candidate _zc1 ^{:H that can effectively prevent the formation of a steep slope of the bulk goods M in the vicinity of the unloading unit 9} and the occurrence of large-scale cargo collapse, and the trajectory generation unit 309 selects it.

The second function _r2 relates to the load state ^φk of the unloading unit 9. When a large-scale collapse of cargo occurs near the unloading unit 9, an excessive load is placed on the scraping unit 11 where the bulk goods M are about to collapse, or on the entire unloading unit 9. On the other hand, in order to increase the efficiency of the scraping unit 11 in carrying out the bulk goods M, it is preferable for the scraping unit 11 to continue scraping as constant an amount of bulk goods M as possible (so that the carrying speed of the bulk goods M is as constant as possible), and in this case the load on the scraping unit 11 becomes approximately constant.

Taking these two viewpoints into consideration, the second function _r2 is defined as, for example, _r2 ( ^φ0:H ) = _Σk | ^φk - c| ² . Here, "c" is a constant target value for the load state ^φk of the unloading unit 9. This _r2 is the sum of the squares of the absolute values of the deviations between the load state ^φk of the unloading unit 9 at each time k (= 0 to H) and the target value c, and the smaller the value, the closer the load state ^φk is to the target value c over the time period from 0 to H. Therefore, by setting a weight _{α2 or} the like so that the smaller the value of r2, the higher the evaluation by the second function _r2 , a high evaluation is given to a trajectory candidate _zc1 ^:H whose load state ^φk is closer to the target value c, and the trajectory generating unit 309 selects it.

The third function _r3 relates to the deviation of the unloading unit 9 from the basic trajectory R ( FIG. 9 ). As mentioned above, since the unloading unit 9 is driven to orbit within the warehouse 201 along the basic trajectory R in principle, it is preferable that the deviation of the trajectory candidate z _c ^1:H from the basic trajectory R be as small as possible. For this purpose, the third function _r3 is defined, for example, as _r3 (x _c ^-L:H ) = Σ _k |l ^k -c| ^2. Here, "l ^k " is the distance between the trajectory candidate x _c ^k and the basic trajectory R at time k, and "c" is its constant target value (for example, c = 0). This _r3 is the sum of the squares of the absolute values of the deviation l ^k from the basic trajectory R at each time k (= 0 to H) and the deviation of the target value c. The smaller the value, the closer the distance l ^k is to the target value c from time 0 to H. Therefore, by setting the weight α3 _etc. so that the smaller the value of _r3 , the higher the evaluation by the third function _r3 , a high evaluation is given to the trajectory candidate _zc1 ^:H whose distance ^lk from the basic trajectory R is close to the target value c, and the trajectory generating unit 309 selects it.

The fourth function _r4 relates to the acceleration/deceleration of the unloading unit 9. Smaller acceleration/deceleration of the unloading unit 9 is preferable, and the absolute value of the acceleration of the unloading unit 9 is evaluated by _r4 . Specifically, the absolute value (a c 0:H-1 ) T (a _c ^{0:H-1 ) of the acceleration a c 0:H-1 of the unloading unit 9 from the current time 0 onward is defined as r4, among the accelerations a c -L+1:H-1 of} _{the unloading unit} ⁹ at times -L+1 to ^H- 1 obtained by ^twice differentiating the trajectory x _{c -L} ^: H of the unloading unit 9 at times -L to H. The higher the evaluation of _r4 (the smaller the value of _r4 ), the smaller the acceleration/deceleration of the unloading unit 9. An evaluation function may also be provided that limits the curvature of the trajectory of the unloading unit 9 so that it does not become excessive (the smaller the curvature, the higher the evaluation). Similarly, an evaluation function may be provided that limits the fluctuation in the moving speed of the unloading unit 9 over future times 1 to H so that it does not become excessive (the smaller the fluctuation in the moving speed, the higher the evaluation).

Next, a specific example of the constraint b (h ^{1:H 1} , φ ^{1:H 1} , z _c ^1:H |z _c ^−L:0 , h ⁰ , φ ⁰ ) will be given.

The first constraint relates to the upper limit of the load on the unloading unit 9. As described above, the load state φ ^k at time k is predicted by the function f based on the load shape h ^0:k-1 and the load state φ ^0:k-1 before the previous time k-1, and the state z _c ^k of the unloading unit 9 at time k. In order to limit the load state φ ^k at each time k (=1 to H) to an upper limit c or less, a constraint expressed by the inequality 0≦c−φ ^k is set. This allows the trajectory generation unit 309 to select a trajectory for the unloading unit 9 that ensures that the load state φ ^k at each time k is equal to or less than the upper limit c. For example, when the scraping unit 11 of the unloading unit 9 scrapes bulk material M from an adjacent high slope, if the scraping unit 11 is inserted sideways or downwards relative to the slope, it is possible that the load state φ ^k will exceed the upper limit c due to the bulk material M collapsing from above. In such a case, by imposing the first constraint, for example by inserting the scraping unit 11 diagonally upward relative to the slope, the trajectory generation unit 309 selects a trajectory that can reduce the amount of bulk material M that falls onto the scraping unit 11.

The second constraint relates to the motion of the unloading unit 9. The trajectory or state z _c ^1:H of the unloading unit 9 must not involve motion parameters (speed, acceleration, angular velocity, angular acceleration, curvature, etc.) that are physically impossible for the unloading unit 9 to achieve. Therefore, upper and lower limits for each of these motion parameters are set as constraints. For example, when limiting the absolute value of the velocity (speed) of the unloading unit 9 to an upper limit c, the absolute value of the velocity v _c ^1:H-1 of the unloading unit 9 from time 1 onward is limited to an upper limit c among the velocity v _c ^-L+1:H-1 of the unloading unit 9 at times −L+1 to H-1 obtained by time-differentiating the trajectory x _c ^{-L:H of the unloading unit 9} at times −L to H. Specifically, the constraint expressed by the inequality 0≦c−|v _c ^1:H-1 | is set. In addition, the upper limit c may be lowered to avoid collision when the landing unit 9 is within a predetermined distance from a structure such as the wall of the shipyard 201. Similarly, upper and lower limits may be set for the other motion parameters of the landing unit 9.

The third constraint condition relates to avoidance of contact between the unloading unit 9 and the wall of the warehouse 201. For example, by setting the distance between the trajectory candidate x _c ^k of the unloading unit 9 at time k (=1 to H) and the wall of the warehouse 201 as d ^k , and setting a constraint condition expressed by the inequality 0≦d ^k −c, it is possible to ensure that the unloading unit 9 and the wall of the warehouse 201 do not come closer than the minimum approach distance c.

The present invention has been described above based on an embodiment. The embodiment is merely an example, and those skilled in the art will understand that various modifications are possible in the combination of each component and each treatment 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 using hardware resources, software resources, or a combination of hardware and software resources. Processors, ROM, RAM, and other LSIs can be used as hardware resources. Operating systems, applications, and other programs can be used as software resources.

1. Cargo unloading unit (CSU), 9. Unloading unit, 11. Scraping unit, 18. Distance measurement sensor, 19. Distance measurement sensor, 201. Warehouse, 300. Control system, 301. Cargo shape detection unit, 302. Carry-out device position detection unit, 303. Carry-out device control unit, 304. Trajectory candidate generation unit, 305. Cargo shape prediction unit, 306. Prediction model storage unit, 307. Prediction model adoption unit, 308. Cargo shape evaluation unit, 309. Trajectory generation unit, 310. Approval reception unit, 311. Cargo shape prediction presentation unit, 312. Cargo collapse possibility presentation unit, 313. Carry-out stop unit, 314. Notification unit.

Claims (15)

a carrying-out device control unit that causes the carrying-out device to carry out the cargo in the shed to the outside of the shed;
a cargo shape detection unit that detects the shape of cargo in the warehouse;
a trajectory candidate generation unit that generates a plurality of trajectory candidates within the warehouse of the carrying-out device;
a cargo shape prediction unit that predicts a cargo shape after the carrying-out device is operated in accordance with each of the trajectory candidates generated by the trajectory candidate generation unit, for the current cargo shape detected by the cargo shape detection unit;
a cargo shape evaluation unit that evaluates the possibility of cargo collapse for each cargo shape predicted by the cargo shape prediction unit;
a trajectory generating unit that generates a trajectory of the carrying-out device from the plurality of trajectory candidates, the trajectory of which the possibility of cargo collapse evaluated by the cargo shape evaluating unit is within a predetermined allowable value;
An unloading device comprising: The unloading device described in claim 1, wherein the trajectory generation unit generates a trajectory for the unloading device that has the lowest possibility of cargo collapse evaluated by the cargo shape evaluation unit from among the multiple trajectory candidates. the cargo shape evaluation unit evaluates the flatness of each cargo shape predicted by the cargo shape prediction unit,
the trajectory generation unit generates a trajectory of the carry-out device from the plurality of trajectory candidates, the trajectory of which flatness evaluated by the cargo shape evaluation unit is equal to or greater than a predetermined tolerance.
An unloading device according to claim 1 or 2. the cargo shape prediction unit predicts the cargo shape using a plurality of prediction models that differ depending on the properties of the cargo;
a prediction model adoption unit that compares the cargo shape detected by the cargo shape detection unit after the discharge device is operated according to the trajectory generated by the trajectory generation unit with a plurality of cargo shapes predicted by the cargo shape prediction unit based on the plurality of prediction models, and adopts the prediction model with the smallest deviation;
An unloading device according to any one of claims 1 to 3. An unloading device according to any one of claims 1 to 4, wherein the carrying-out device is automatically operated according to the trajectory generated by the trajectory generating unit. further comprising an approval receiving unit that receives approval for the trajectory generated by the trajectory generating unit,
The carry-out device is automatically operated according to a trajectory related to the approval received by the approval receiving unit.
6. An unloading device according to claim 5. The unloading device described in any one of claims 1 to 6, further comprising a cargo shape prediction presentation unit that presents a prediction by the cargo shape prediction unit of the cargo shape after the unloading device is operated according to the trajectory generated by the trajectory generation unit. The unloading device described in any one of claims 1 to 7, further comprising a cargo collapse possibility indicator that indicates the possibility of cargo collapse according to the cargo shape evaluation unit after the unloading device is operated according to the trajectory generated by the trajectory generation unit. An unloading device according to any one of claims 1 to 8, further comprising an unloading stop unit that stops control of the unloading device by the unloading device control unit if the likelihood of cargo collapse evaluated by the cargo shape evaluation unit for each of the multiple trajectory candidates is higher than the allowable value. An unloading device as described in any one of claims 1 to 9, further comprising a notification unit that notifies the user that there is a high possibility of cargo collapse if the likelihood of cargo collapse evaluated by the cargo shape evaluation unit for the multiple trajectory candidates is higher than the allowable value. An unloading device according to any one of claims 1 to 10, wherein the cargo shape detection unit is a sensor provided in the unloading device. The unloading device described in claim 11, wherein the sensor is a distance sensor that measures the distance to the object being measured. The unloading device described in claim 11, wherein the sensor is an image sensor that captures an image of the object to be measured. a carrying-out device control step of carrying out the cargo in the warehouse to the outside of the warehouse by the carrying-out device;
a cargo shape detection step of detecting a cargo shape in a cargo hold;
a trajectory candidate generation step of generating a plurality of trajectory candidates within the warehouse of the unloading device;
a cargo shape prediction step of predicting a cargo shape after the unloading device is operated according to each of the trajectory candidates generated by the trajectory candidate generation step, for the current cargo shape detected by the cargo shape detection step;
a cargo shape evaluation step of evaluating a possibility of cargo collapse for each cargo shape predicted by the cargo shape prediction step;
a trajectory generation step of generating a trajectory of the carrying-out device from the plurality of trajectory candidates, the trajectory of which the possibility of cargo collapse evaluated in the cargo shape evaluation step is equal to or less than a predetermined allowable value;
A method for controlling an unloading device comprising: a carrying-out device control step of carrying out the cargo in the warehouse to the outside of the warehouse by the carrying-out device;
a cargo shape detection step of detecting a cargo shape in a cargo hold;
a trajectory candidate generation step of generating a plurality of trajectory candidates within the warehouse of the unloading device;
a cargo shape prediction step of predicting a cargo shape after the unloading device is operated according to each of the trajectory candidates generated by the trajectory candidate generation step, for the current cargo shape detected by the cargo shape detection step;
a cargo shape evaluation step of evaluating a possibility of cargo collapse for each cargo shape predicted by the cargo shape prediction step;
a trajectory generation step of generating a trajectory of the carrying-out device from the plurality of trajectory candidates, the trajectory of which the possibility of cargo collapse evaluated in the cargo shape evaluation step is equal to or less than a predetermined allowable value;
A control program for the unloading device that causes a computer to execute the above.