JP7598909B2 - Control system and method for cargo handling equipment - Google Patents

Description

The present invention relates to a control system and method for loading and unloading equipment, and more specifically to a control system and method for loading and unloading equipment that controls the travel of the loading and unloading equipment based on map data and the equipment's own coordinate data.

In warehouse facilities such as container terminals, map data is created in advance to indicate the locations where loading and unloading work is performed by loading and unloading equipment such as cranes and transport vehicles, and the storage locations of the cargo. In controlling the travel of loading and unloading equipment, travel control (position feedback control) is performed in which a speed command is output to an inverter based on the stopping coordinate data of the target stopping location shown in the map data and the loading and unloading equipment's own coordinate data. The own coordinate data is calculated based on the position coordinates of a specified location of the loading and unloading equipment obtained by a radio-based positioning device that uses Global Navigation Satellite System (GNSS) positioning.

This type of radio wave positioning device can very easily obtain the position coordinates of a specific location on the loading and unloading equipment. However, if the sensitivity of the radio wave transmission and reception (such as the rate of accuracy degradation, signal strength, and number of satellites used for positioning) is lower than the standard, the accuracy of the position coordinates will decrease or the position coordinates will not be able to be obtained. Examples of situations in which sensitivity decreases include situations in which radio wave propagation is delayed in the ionosphere or troposphere, situations in which the number of satellites in the global positioning satellite system that can transmit and receive radio waves is reduced due to the influence of high-rise structures, and situations in which radio wave multipath occurs. In addition, examples of situations in which radio wave interference such as jamming and spoofing occurs, as reported in cases at airports and ports overseas, are also examples. Therefore, in the case of controlling the travel of loading and unloading equipment using a radio wave positioning device, if the radio wave sensitivity is poor and self-coordinate data based on the position coordinates obtained by the radio wave positioning device cannot be obtained, the travel of the loading and unloading equipment must be stopped.

Therefore, various methods for estimating self-coordinate data have been proposed (see Patent Document 1). The invention described in Patent Document 1 uses SLAM (Simultaneous Localization and Mapping), which simultaneously estimates the self-position and creates an environmental map. SLAM is a method that uses a scan matching algorithm such as an ICP (Iterative Closest Point) algorithm or an NDT (Normal Distribution Transform) algorithm to map map data and then estimates the self-position using point cloud data measured by external sensors such as distance sensors and cameras. This method using SLAM does not require the creation of map data in advance, is highly versatile, and can be used indoors.

However, to estimate self-coordinate data with high accuracy using a method using SLAM, scan matching such as point cloud processing must be repeated at a high cycle, which not only increases the computational load of the estimation, but also increases the proportion of memory area occupied by data required for estimation such as point cloud data. Furthermore, a method using SLAM is a general-purpose method that assumes a case where map data has not been created in advance, and is not suitable for warehouse facilities where highly accurate map data has been created in advance. Therefore, there is room for improvement in the travel control of loading and unloading equipment in warehouse facilities to estimate highly accurate self-coordinate data more easily while reducing computational resources.

JP 2020-038498 A

The object of the present invention is to provide a control system and control method for loading and unloading equipment that can more easily estimate highly accurate self-coordinate data while reducing computational resources.

The object of the present invention is to achieve the above-mentioned by providing a control system for loading and unloading equipment, which controls the travel of the loading and unloading equipment based on map data in which stopping coordinate data for a large number of stopping points, including points where loading and unloading operations are performed by the loading and unloading equipment, and on the basis of the self-coordinate data of the loading and unloading equipment, and the control system comprises an external sensor which detects objects to be measured which are installed at each of the stopping points as the loading and unloading equipment passes through the stopping points while traveling, an odometer which sequentially measures the travel distance of the loading and unloading equipment, a radio wave positioning device which sequentially obtains position coordinates of predetermined points of the loading and unloading equipment by transmitting and receiving radio waves to and from at least one radio wave transmitter and receiver, and a coordinate calculation device , wherein the coordinate calculation device calculates a cumulative travel distance obtained by accumulating the travel distances sequentially measured by the odometer from a measurement start point which is one of the large number of stopping points, and a measurement and executing sequential data processing to estimate the self coordinate data based on the coordinate data of a start point of the measurement, and when the external sensor detects the object to be measured, updating the accumulated mileage to zero, and comparing the self coordinate data output by the estimating data processing executed immediately before the external sensor detected the object to be measured with the map data, identifying stop coordinate data that is closest to the self coordinate data from among the many stop coordinate data accumulated in the map data, and executing data processing to update the coordinate data of the measurement start point to the identified stop coordinate data, and in the updating data processing, when the sensitivity of the radio wave positioning device for transmitting and receiving radio waves is higher than a standard, the position coordinates acquired by the radio wave positioning device are used instead of the self coordinate data .
The control system for loading and unloading equipment of the present invention controls the travel of the loading and unloading equipment based on map data in which stopping coordinate data for a large number of stopping points, including points where loading and unloading work is performed by the loading and unloading equipment, and on the basis of the self-coordinate data of the loading and unloading equipment, and the control system includes an external sensor for detecting measurement objects installed at each of the large number of stopping points as the loading and unloading equipment passes through the stopping points while traveling, an odometer for successively measuring the travel distance of the loading and unloading equipment, a radio wave positioning device for successively acquiring position coordinates of predetermined points of the loading and unloading equipment by transmitting and receiving radio waves to and from at least one radio wave transmitter and receiver, and a coordinate calculation device, and the coordinate calculation device calculates a position from a measurement start point which is one of the large number of stopping points to a measurement start point, The odometer sequentially executes data processing to estimate the self-coordinate data based on a cumulative mileage obtained by accumulating the mileage measured and the coordinate data of the measurement start point, and when the external sensor detects the object to be measured or when the sensitivity of the radio wave positioning device for transmitting and receiving radio waves is higher than a standard, the radio wave positioning device compares positioning coordinate data based on the position coordinates acquired by the radio wave positioning device with the map data, and when the positioning coordinate data matches one of the multiple stop coordinate data accumulated in the map data, the data processing is executed to update the cumulative mileage to zero and update the coordinate data of the measurement start point based on the map data.

The control method of the present invention for achieving the above object is a control method for controlling travel of the loading and unloading equipment based on map data in which stop coordinate data for a large number of stopping points including points where loading and unloading work is performed by the loading and unloading equipment and on the self-coordinate data of the loading and unloading equipment, the control method comprising the steps of: sequentially measuring the travel distance of the loading and unloading equipment by an odometer; sequentially acquiring position coordinates of a predetermined point of the loading and unloading equipment by transmitting and receiving radio waves with at least one radio transmitter and receiver by a radio-controlled positioning device; sequentially performing an estimation step of estimating the self-coordinate data by a coordinate calculation device based on a cumulative travel distance obtained by accumulating the travel distance measured by the odometer from a measurement start point which is one of the large number of stopping points and the coordinate data of the measurement start point; When an external sensor detects a measurement object installed at each of the many stopping points as the vehicle passes through a certain place, the coordinate calculation device updates the accumulated travel distance to zero, and performs an updating process in which the coordinate calculation device compares the self coordinate data output by the estimation process executed immediately before the external sensor detected the measurement object with the map data, identifies stop coordinate data that is closest to the self coordinate data from the many stop coordinate data accumulated in the map data, and updates the coordinate data of the measurement start point to the identified stop coordinate data, and in the updating process, when the sensitivity of the radio wave transmission and reception of the radio wave of the radio wave positioning device is higher than a standard, the position coordinates acquired by the radio wave positioning device are used instead of the self coordinate data .
The control method of the present invention controls the travel of the loading and unloading equipment based on map data in which stopping coordinate data for a large number of stopping points, including points where loading and unloading work is performed by the loading and unloading equipment, and on the self-coordinate data of the loading and unloading equipment, in which an odometer sequentially measures the travel distance of the loading and unloading equipment, a radio-controlled positioning device sequentially acquires position coordinates of predetermined points of the loading and unloading equipment by transmitting and receiving radio waves with at least one radio transmitter and receiver, and a coordinate calculation device estimates the self-coordinate data based on a cumulative travel distance obtained by accumulating the travel distance sequentially measured by the odometer from a measurement start point, which is one of the large number of stopping points, and the coordinate data of the measurement start point. and when an external sensor detects a measurement object installed at each of the many stopping points as the loading/unloading equipment passes through the stopping points while traveling, or when the sensitivity of the radio wave positioning device for transmitting and receiving radio waves is higher than a reference value, positioning coordinate data based on the position coordinates acquired by the radio wave positioning device is compared with the map data, and when the positioning coordinate data matches one of the many stopping coordinate data accumulated in the map data, the coordinate calculation device updates the accumulated traveling distance to zero and performs an updating process of updating the coordinate data of the measurement start point based on the map data.

According to the present invention, the cumulative mileage and the coordinate data of the measurement start point are reset each time the external sensor detects an object to be measured, and the highly accurate stop coordinate data accumulated in the map data created in advance is used as the coordinate data of the measurement start point. Therefore, the first coordinate data estimated by processing this data has a small cumulative error and high measurement accuracy. In other words, the present invention uses a very simple method for estimating self-coordinate data using an odometer, and while it is a configuration that can reduce computational resources, it is possible to estimate self-coordinate data with high accuracy.

FIG. 2 is an explanatory diagram illustrating loading and unloading equipment. FIG. 2 is an explanatory diagram illustrating map data; FIG. 2 is an explanatory diagram illustrating a control system for loading and unloading equipment. FIG. 11 is an explanatory diagram illustrating self coordinate data; FIG. 4 is an explanatory diagram illustrating the range finder and a measurement object shown in FIG. 3 . FIG. 4 is an explanatory diagram illustrating an example of distance data in FIG. 3 . FIG. 1 is a flow diagram illustrating a range finder measurement method. 10 is a block diagram illustrating a method for acquiring position coordinates of a predetermined location of the loading equipment in a method for controlling the loading equipment; FIG. 11 is a flow chart illustrating a method for outputting self coordinate data in a control method for cargo handling equipment. FIG. FIG. 10 is a flow diagram illustrating subroutines (S210) and (S220) of FIG. 9. FIG. 11 is a flow diagram illustrating a continuation of I in FIG. 11 is an explanatory diagram illustrating a change in a first contribution rate and a second contribution rate over time. FIG. 11A and 11B are explanatory diagrams illustrating self coordinate data under conditions that change over time. 10 is an explanatory diagram illustrating an example of a change in travel speed due to travel control of cargo handling equipment. FIG.

The control system and control method for loading and unloading equipment of the present invention will be described below based on the embodiment shown in the figures. In the figures, the X-axis direction in the coordinate system of the warehouse facility is the extension direction of the storage lane 3, the Y-axis direction is the left-right direction perpendicular to the extension direction, and the Z-direction is the vertical direction. Note that an absolute coordinate system can also be used for the coordinate system.

The loading equipment 1 illustrated in FIG. 1 may be any of various known loading equipment such as a crane or a transport vehicle (container truck) that loads and unloads containers or other cargo objects 2 in various known warehouse facilities such as a container terminal. The loading equipment 1 is exemplified by a crane that travels in the extension direction of the storage lane 3, straddling the Y-axis direction across the storage lane 3 in which a large number of cargo objects 2 are stored, in a container terminal. The running road surface 5 on which the running wheels 4 of the loading equipment 1 contact is disposed adjacent to each of both sides of the storage lane 3, and each running road surface 5 extends in the X-axis direction along the storage lane 3. In the warehouse facility, a large number of stopping points are set as locations where the loading equipment 1 performs loading and unloading work, and one of the large number of stopping points is the target stopping point. For example, when the warehouse facility is a container terminal, a large number of stopping points are set for each bay of the storage lane 3. In such a warehouse facility, map data 20 indicating the storage positions of the cargo objects 2 is created in advance.

The map data 20 illustrated in FIG. 2 is a data set that accumulates stopping coordinate data ("(...,...)" in the figure) that indicates the target values of the stopping posture of the loading and unloading equipment 1 at multiple stopping points, including the points where the loading and unloading equipment 1 performs loading and unloading work, as the storage position of the cargo 2. The map data 20 includes stopping posture data for the stopping points for each designated number listed in the leftmost column of the table. The designated numbers (A1,...,An,...,Dn,...) indicate the lane number (A,...,D,...) and bay number (1 to n) of the storage lane 3. Note that the number of bays for each storage lane 3 may be different.

As the target value for the stopping posture of the loading/unloading equipment 1, at least the stopping position of the loading/unloading equipment 1 (position in the X-axis direction) and the stopping orientation of the loading/unloading equipment 1 as viewed in the Z-axis direction (inclination with respect to the X-axis) are required. If there is stopping coordinate data for at least two points separated in the Y-axis direction for one stopping location, it is possible to calculate the orientation as viewed in the Z-axis direction at that stopping location. Therefore, stopping position data is prepared for each of multiple points at one stopping location. The stopping coordinate data is preferably composed of X and Y coordinates, but may be composed of only the X coordinate.

The X coordinate of the stop coordinate data indicates the center position in the X axis direction of the storage position of the cargo 2 at the stopping point. The stop posture angle obtained from the stop coordinate data of multiple points at one stopping point may be different for each stopping point, but the storage lane 3 uses the inclination with respect to the X axis when viewed in the Z direction, and is set to "zero degrees" at multiple stopping points. In other words, by stopping the cargo handling equipment 1 in accordance with the stop coordinate data of multiple points at the stopping point, there is no deviation in the X axis direction with respect to the storage position of the cargo 2 at the stopping point, and alignment in the X axis direction is completed. There is also no deviation in the orientation when viewed in the Z direction, and alignment when viewed in the Z direction is completed.

In the example of map data 20 in FIG. 2, (...,...) indicate stopping coordinate data (X coordinate, Y coordinate), and stopping posture data for one stopping location is composed of stopping coordinate data for each of points P, Q, and R. The X coordinates of points P, Q, and R indicate the center positions in the X-axis direction of the bay of the storage lane 3. Point P is set on one of the traveling road surfaces 5 on which one loading device 1 travels. Point R is set on the other traveling road surface 5. In other words, points P and R indicate points corresponding to both ends of the loading device 1 in the Y-axis direction at the stopping location. Point Q indicates the midpoint between points P and R.

In the loading and unloading operation of the loading and unloading equipment 1, alignment in the Y-axis direction by the movement of the loading and unloading equipment 1 is not essential. Therefore, the stop coordinate data does not necessarily have to have a Y coordinate. However, if the stop coordinate data has a Y coordinate, it becomes possible to use the P line connecting each P point, the Q line connecting each Q point, and the R line connecting each R point in one storage lane 3 as target lines (a set of planar coordinates surrounded by dotted lines in the figure). Controlling the movement of the loading and unloading equipment 1 along these target lines is advantageous in improving the straightness of the movement of the loading and unloading equipment 1.

Figure 3 shows the loading equipment 1 traveling from designated number A1 to designated number An according to the map data 20. The solid dots in Figure 3 indicate points P, Q, and R of the map data 20. The open dots in Figure 3 indicate points p, q, and r at specific locations on the loading equipment 1, and points p, q, and r correspond to points P, Q, and R of the map data 20, respectively.

The embodiment of the control system 10 illustrated in FIG. 3 includes a coordinate acquisition device 11, a range finder 12, and a calculation device 13. The coordinate acquisition device 11 includes a radio wave positioning device 14 (14p, 14r), an internal sensor 15 (15r, 15p), and a coordinate calculation device 16. The range finder 12 includes an external sensor 17 (17p, 17r, 17y) and a distance calculation device 18.

The control system 10 is not limited to one in which the coordinate acquisition device 11, the distance meter 12, and the calculation device 13 are all installed in the loading equipment 1. The control system 10 may have the coordinate acquisition device 11 and the distance meter 12 installed in the loading equipment 1, and the calculation device 13 installed in a location away from the loading equipment 1. Similarly, the coordinate acquisition device 11 and the distance meter 12 may have the radio positioning device 14, the internal sensor 15, and the external sensor 17 installed in the loading equipment 1, and the coordinate calculation device 16 and the distance calculation device 18 installed in a location away from the loading equipment 1. In addition, the calculation device 13, the coordinate calculation device 16, and the distance calculation device 18 are each separate devices, but may be configured as a single device that integrates the functions of each.

The control system 10 executes a driving control process that adjusts the rotation speed of the running wheels 4 of the loading equipment 1 based on a large number of stop coordinate data shown in the map data 20 and the self coordinate data 21 of a predetermined location of the loading equipment 1. The control system 10 executes data processing that outputs the self coordinate data 21 used in the driving control process.

The self-coordinate data 21 illustrated in FIG. 4 indicates the current attitude of the loading equipment 1. The current attitude of the loading equipment 1 can be expressed by the X-coordinate of a specific location on the loading equipment 1 and the current attitude angle θ (tilt with respect to the X-axis) of the loading equipment 1 when viewed in the Z direction. In the example of FIG. 4, the self-coordinate data 21 is composed of the X-coordinates of points p and r corresponding to points P and R of the map data 20. Note that the X-coordinate of point q can be calculated from the X-coordinates of points p and r, since point q is the midpoint between points p and r. Similarly, the attitude angle θ can be calculated from the X-coordinates of points p and r.

The self coordinate data 21 is composed of one of the following coordinate data: first coordinate attitude data based on the position coordinates acquired by the coordinate acquisition device 11, second coordinate data based on the remaining distance acquired by the rangefinder 12, and third coordinate data based on both the first coordinate data and the second coordinate data. The self coordinate data 21 may include a Y coordinate, although the Y coordinate of each point is not essential.

The coordinate acquisition device 11 illustrated in FIG. 3 is a device that acquires the position coordinates of points p and r as predetermined locations of the loading equipment 1, and includes a radio-based positioning device 14, an internal sensor 15, and a coordinate calculation device 16. The coordinate acquisition device 11 can be a combination of various known radio-based positioning devices and an inertial navigation system (autonomous navigation system) that uses various known internal sensors. The combination of the internal sensor 15 and the coordinate calculation device 16 constitutes an inertial navigation system, and this inertial navigation system may be an odometer that acquires the travel distance of the loading equipment 1 at each predetermined period. In other words, one example of the coordinate acquisition device 11 is composed of a combination of the radio-based positioning device 14 and an odometer (15, 16). Note that the odometer may be composed of a combination of the internal sensor 15 and another calculation device other than the coordinate calculation device 16.

The radio wave positioning device 14 acquires its own position coordinates by transmitting and receiving radio waves with the radio wave transceiver 6 at a predetermined cycle. An example of the radio wave positioning device 14 is an antenna that transmits and receives radio waves from the global navigation satellite system (GNSS). The radio wave positioning device 14 can also be a device that uses an indoor positioning system (IPS) such as beacon positioning, ultra-wideband (UWB) positioning, or wireless LAN positioning according to the IEEE 802.11 standard. However, in such devices that use indoor positioning, the range in which radio waves can be transmitted and received with the radio wave transceiver 6 is narrow, and the number of radio wave transceivers 6 installed is large. Therefore, it is desirable that the radio wave positioning device 14 is configured with an antenna of the global navigation satellite system. At least one radio wave transceiver 6 is sufficient, and examples of the global navigation satellite system include positioning satellites such as GPS, QZSS, GLONASS, BeiDou, Galileo, and IRNSS.

The radio wave positioning device 14p is disposed at one end of the loading equipment 1 in the Y-axis direction, and the radio wave positioning device 14r is disposed at the other end of the loading equipment 1 in the Y-axis direction. The radio wave positioning device 14p acquires its own position coordinates (xgp, ygp). The radio wave positioning device 14r acquires its own position coordinates (xgr, ygr). The radio wave positioning device 14 may be configured to acquire spatial coordinates consisting of longitude, latitude, and altitude, or planar coordinates consisting of longitude and latitude, as its own position coordinates. The location of the radio wave positioning device 14 is not particularly limited as long as it is installed on the loading equipment 1, but it is preferable to install it on the top of the loading equipment 1 because this improves the transmission and reception of radio waves with the radio wave transmitter/receiver 6. When the loading equipment 1 is a crane, the radio wave positioning device 14 is preferable to install it on the top of the structure of the crane (for example, the girder or legs).

It is desirable that the installation positions of the radio positioning devices 14p and 14r on the loading equipment 1 are based on points p and r, respectively. More specifically, it is desirable that the X coordinate of the self-position coordinates acquired by each of the radio positioning devices 14p and 14r approximately coincide when the attitude angle θ of the loading equipment 1 is "zero°". It is desirable that the Y coordinate of the self-position coordinates acquired by the radio positioning device 14p approximately coincides with the Y coordinate of point p of the loading equipment 1 when the attitude angle θ of the loading equipment 1 is "zero°". Similarly, it is desirable that the Y coordinate of the self-position coordinates acquired by the radio positioning device 14r approximately coincides with the Y coordinate of point r of the loading equipment 1 when the attitude angle θ of the loading equipment 1 is "zero°".

The odometer (15, 16) measures the state of the loading equipment 1 by the internal sensor 15 at a predetermined cycle, and calculates the travel distance for each predetermined cycle from the state of the loading equipment 1 measured by the internal sensor 15 by the coordinate calculation device 16. The internal sensor 15 may be any sensor that measures the state of the loading equipment 1, and may be any of various known internal sensors such as a rotary encoder, an inertial measurement unit (IMU: a combination of a gyro sensor and an acceleration sensor), or an attitude and heading reference system (AHRS: a combination of an IMU and a geomagnetic sensor). In addition, the internal sensor 15 may be a sensor that detects the current or voltage of an inverter that adjusts the rotation speed of an electric motor that outputs rotational power to the running wheels 4 of the loading equipment 1. However, when the loading equipment 1 is a crane, a sensor such as an IMU may not be able to detect the state of the loading equipment 1 due to the influence of the vibration of the crane. In addition, the running speed and running direction of the crane are controlled by the rotation speed of the running wheels 4. Therefore, when the loading and unloading equipment 1 is configured as a crane, it is desirable for the internal sensor 15 to be a sensor that detects the rotation speed of either the running wheels, the axle, or the electric motor that is the drive source.

The coordinate calculation device 16 may be any of various known computers. The coordinate calculation device 16 has a central processing unit (CPU), a main memory (memory), an auxiliary memory (e.g., HDD), and an input/output unit. The coordinate calculation device 16 starts a specific program stored in the auxiliary memory, and executes each procedure instructed by the started specific program. Specifically, the coordinate calculation device 16 executes data processing to calculate a travel distance for each specified period from the state of the loading equipment 1 measured by the internal sensor 15, and data processing to calculate first coordinate data using the calculated travel distance, and outputs the calculated first coordinate data to the calculation device 13.

The distance meter 12 may be any of a variety of known distance meters, such as a magnetic induction distance sensor that measures the remaining distance to the stopping point at a predetermined interval, an optical or magnetic linear encoder, or a linear position sensor. The external sensor 17 of the distance meter 12 is a sensor that detects the state of the surrounding environment that changes as the loading and unloading equipment 1 travels. The external sensor 17 measures measurement objects 7 (7p, 7r, 7y), such as linear scales and targets, that are arranged at each stopping point.

The distance calculation device 18 may be any of various known computers. The distance calculation device 18 has a central processing unit (CPU), a main memory unit (memory), an auxiliary memory unit (e.g., HDD), and an input/output unit. The distance calculation device 18 stores distance data 22 in its memory unit. The distance calculation device 18 executes data processing to output the remaining distance calculated based on the detection status of the measurement target 7 of the external sensor 17 to the calculation device 13. The distance calculation device 18 also executes data processing to output a predetermined signal S1 to the coordinate calculation device 16 when the calculated remaining distance becomes zero.

The arithmetic unit 13 may be any of a variety of known computers. The arithmetic unit 13 has a central processing unit (CPU), a main memory unit (memory), an auxiliary memory unit (e.g., HDD), and an input/output unit. The arithmetic unit 13 is electrically connected to the coordinate acquisition device 11 and the rangefinder 12 via the input/output unit. The arithmetic unit 13 is also electrically connected to an inverter via the input/output unit. Map data 20 is stored in the auxiliary memory unit.

The computing device 13 starts a specific program stored in the auxiliary memory unit, and executes each procedure according to the started specific program to control the travel of the loading equipment 1. Specifically, when a designated number is specified by a higher-level system (not shown) that is higher than the control system 10, the control system 10 sets the stopping point indicated by the designated number specified by the higher-level system as the target stopping point, and drives the loading equipment 1 to the target stopping point.

Next, the rangefinder 12 will be described in detail.

Figure 5 shows an example of an enlarged view of multiple measurement objects 7 (7p, 7r, 7y) installed at the stopping points and multiple external sensors 17 (17p, 17r, 17y) of the range finder 12. The range finder 12 detects the measurement objects 7 installed at each stopping point using the external sensors 17, and the distance calculation device 18 performs data processing to calculate the remaining distance to the stopping point based on the detection status of the measurement objects 7 by the external sensors 17.

The multiple measurement objects 7 are arranged at each of the multiple stopping points. There are no particular limitations on the multiple measurement objects 7 as long as they can be detected by the external sensor 17. The range finder 12 of this embodiment uses a linear position sensor as the external sensor 17, and the measurement objects 7 are composed of a magnetic ferromagnetic material. The measurement object 7p indicates the X coordinate of the P point of the stopping point. The measurement object 7r indicates the X coordinate of the R point of the stopping point. The measurement object 7y indicates the Y coordinate of the P point, Q point, or R point, or the Y coordinate of one of the target lines P, Q, or R.

Each of the measurement objects 7p and 7r extends in the Y-axis direction and is arranged so that the stopping points P and Q are located at the center of the Z-axis view. Since the measurement objects 7p and 7r extend in the Y-axis direction, the remaining distance in the X-axis direction can be measured even if the traveling of the loading equipment 1 is deviated in the Y-axis direction. The measurement object 7y extends in the X-axis direction and is arranged on a line parallel to a target line such as a P line. Since the measurement object 7y extends in the X-axis direction, the remaining distance in the Y-axis direction can be measured even if the traveling of the loading equipment 1 is deviated in the X-axis direction. The position of the measurement object 7y is not particularly limited, but it may be arranged on one of the traveling road surfaces 5 on both sides of the storage lane 3. In this embodiment, the measurement objects 7p and 7y are arranged on one traveling road surface 5, and the measurement object 7r is arranged on the other traveling road surface 5.

Each of the external sensors 17 is composed of a plurality of detector elements 19. Each of the external sensors 17p and 17r has a plurality of detector elements 19 arranged at equal intervals in the X-axis direction. In the external sensors 17p and 17r, points p and q of the loading equipment 1 are located at one of the plurality of detector elements 19 when viewed in the Z direction. The plurality of detector elements 19 are assigned element numbers (e.g., No. 1 to No. 20) that increase in number from the detector element 19 arranged at one end (e.g., the left end in the figure) of the external sensors 17p and 17r in the X-axis direction to the detector element 19 arranged at the other end (the right end in the figure). In the external sensor 17y, a plurality of detector elements 19 are arranged at equal intervals in the Y-axis direction. The multiple detector elements 19 are assigned element numbers (e.g., No. 1 to No. 20) that increase in number from the detector element 19 located at one end (e.g., the top end in the figure) of the external sensor 17y in the Y-axis direction to the detector element 19 located at the other end (the bottom end in the figure).

The distance data 22 illustrated in FIG. 6 is stored in the storage unit of the distance calculation device 18. The distance data 22 is created for each external sensor 17. The distance data 22 accumulates the element numbers assigned to the multiple detector elements 19 of each external sensor 17 and the distance from the detector element 19 that is the origin position (point p, point r). In the example of FIG. 6, the external sensor 17 has twenty detector elements 19, the distance between adjacent detector elements 19 is 100 mm, and the origin position is the detector element 19 with element number No. 10. Note that the distance calculation device 18 may store a formula using the element numbers assigned to the multiple detector elements 19 and the distance between adjacent detector elements 19 in the storage unit instead of the distance data 22.

Figure 7 shows an example of the measurement method of the distance meter 12. This measurement method is performed individually for each external sensor 17. In the following, the external sensor 17p is used as an example of the measurement method. In this measurement method, the distance calculation device 18 executes each data processing based on the detection status of the measurement target 7p of the external sensor 17p (S110 to S170). Finally, the distance calculation device 18 calculates the remaining distance ΔXp from point p of the loading equipment 1 to point P where the loading equipment 1 stops, and the process returns to the start. This measurement method is repeated at predetermined intervals, and the remaining distance is calculated at each predetermined interval. Each step (S110) to (S170) is described in detail below.

In the step (S110) of determining whether the sensor has detected, the distance calculation device 18 executes data processing to determine that the sensor has detected the object 7p if any of the multiple detector elements 19 of the external sensor 17p detects the object 7p, and to determine that the sensor has not detected the object 7p if none of the multiple detector elements 19 detect the object 7p. When the external sensor 17p is positioned directly above the object 7p, a predetermined number of detector elements 19 with consecutive element numbers among the multiple detector elements 19 detect the object 7p. Also, when the external sensor 17p moves away from directly above the object 7p, none of the multiple detector elements 19 detects the object 7p. The predetermined number of detector elements 19 that detect the object 7p when the external sensor 17p is positioned directly above the object 7p can be arbitrarily set based on the magnetic field strength of the object 7p and the distance between adjacent detector elements 19. It is preferable that the specified number be a fixed value, and that it be greater than or equal to three and less than or equal to five.

In step S120 of turning on flag A and step S130 of turning off flag A, data processing is executed to set or clear flag A, which is used by the distance calculation device 18 in the control method described later, based on the determination result of step S110. Specifically, if it is determined that the sensor has detected something (S110: YES), flag A is set (flagA: ON), and if it is determined that the sensor has not detected something (S110: NO), flag A is cleared (flagA: OFF).

In the step of determining the positional relationship (S140), the distance calculation device 18 executes data processing to determine the positional relationship between the external sensor 17p and the measurement object 7p based on the detection status of the measurement object 7p of the external sensor 17p. Specifically, the distance calculation device 18 determines the positional relationship between the external sensor 17p and the measurement object 7p based on the predetermined number of detection elements 19 that detected the measurement object 7p and the element numbers assigned to each of the predetermined number of detection elements 198. When the predetermined number of detection elements 19 that detected the measurement object 7p is an odd number, the distance calculation device 18 considers that the measurement object 7p exists directly below the detection element 19 that is assigned the middle element number among the predetermined number of detection elements 19. Also, when the predetermined number is an even number, the distance calculation device 18 considers that the measurement object 7p exists directly below the middle position between the detection element 19 with the maximum element number and the detection element 19 with the minimum element number.

In the remaining distance calculation step (S150), data processing is performed to calculate the remaining distance ΔXp from the detector element 19 indicating point p to the stopping point P, based on the distance data 22 by the distance calculation device 18 and the positional relationship between the external sensor 17p and the measured object 7p identified. If the predetermined number of detector elements 19 that detected the measured object 7p is an odd number, the remaining distance ΔXp is calculated from the element number assigned to the detector element 19 located directly above the measured object 7p. If the predetermined number of detector elements 19 that detected the measured object 7p is an even number, the remaining distance ΔXp is calculated as the median of two distances obtained from the element numbers assigned to the detector elements 19 adjacent to both sides of the position directly above the measured object 7p.

In the step (S160) of determining whether the remaining distance ΔXp is zero and the step (S170) of outputting a signal, data processing is performed to determine whether the remaining distance ΔXp calculated by the distance calculation device 18 is zero, and if it is determined that the remaining distance ΔXp is zero, data processing is performed to transmit a signal S1 to the coordinate acquisition device 11. This transmitted signal S1 is used to acquire first coordinate data in the coordinate acquisition device 11, which will be described later. Step (S160) can also be omitted. In this case, in step (S170), data processing is performed to transmit a signal S1 to the coordinate acquisition device 11 when the external sensor 17p detects the measurement target 7p by the distance calculation device 18 (flag A: ON).

The above steps (S110) to (S170) are always performed when the loading equipment 1 arrives at the target stopping point, but may not be performed at all stopping points between the starting point and the target stopping point. In the travel control process of the loading equipment 1, the loading equipment 1 may be caused to travel in a direction deviated from the target line in the Y-axis direction until it arrives at the target stopping point, within a range that does not contact the storage lane 3 or other loading equipment. In this case, even if the loading equipment 1 passes a stopping point, a situation may arise in which the external sensor 17p is unable to detect the measurement object 7p at the stopping point that it has passed. In addition, even if the traveling speed of the loading equipment 1 is high and the external sensor 17p detects the measurement object 7p, a situation may arise in which it is unable to detect the timing when the remaining distance ΔXp becomes zero.

In the example of FIG. 5, the predetermined number of detector elements 19 that have detected the measurement object 7 is set to a fixed value of "three." In the external sensor 17p, the measurement object 7p is located directly below the detector element 19 with element number No. 3, and the measured remaining distance ΔXp is +700 mm. In the external sensor 17r, the measurement object 7r is located directly below the detector element 19 with element number No. 1, and the measured remaining distance ΔXr is +900 mm. In the external sensor 17y, the measurement object 7y is located directly below the detector element 19 with element number No. 8, and the measured remaining distance ΔY is +200 mm.

Next, the coordinate acquisition device 11 will be described in detail. The coordinate acquisition device 11 acquires first coordinate data, which are the position coordinates of points p and r, using an odometer (15, 16) and an external sensor 17. More specifically, the coordinate acquisition device 11 acquires first coordinate data of point p of the loading equipment 1 using an odometer (15p, 16) and an external sensor 17p, and acquires first coordinate data of point r using an odometer (15r, 16) and an external sensor 17r.

The method of acquiring the first coordinate data is the same for points p and r, so the method of acquiring the first coordinate data for point p will be described below as an example. In this acquisition method, the coordinate calculation device 16 sequentially executes an estimation process to estimate the first coordinate data for point p based on the accumulated travel distance Lp from the measurement start point and the coordinate data of that measurement start point. In addition, when the external sensor 17p detects the measurement target 7p and receives a signal S1, the coordinate calculation device 16 executes an update process to update the accumulated travel distance Lp to zero and update the coordinate data of the measurement start point based on the map data 20.

The cumulative travel distance Lp is the distance obtained by accumulating the travel distance ΔLp measured at each predetermined period from the start of measurement until it is updated to zero. The travel distance ΔLp is calculated by the coordinate calculation device 16 based on the number of rotations of the running wheels 4 of the loading equipment 1 measured by the internal sensor 15p and the outer diameter of the running wheels 4 pre-stored in the memory of the coordinate calculation device 16. In other words, the cumulative travel distance Lp is accumulated and increases at each measurement period of the internal sensor 15p.

The measurement start point is the point where accumulation of the cumulative travel distance Lp begins. The measurement start point indicates point P at one of the many stopping points. In other words, the measurement start point is the point where the external sensor 17p detects the measurement target 7p, and more specifically, the point where the remaining distance ΔXp from point p to point P measured by the distance meter 12 is zero.

The block diagram illustrated in FIG. 8 shows an example of a control method for the loading equipment 1. The control method for the loading equipment 1 includes data processing for calculating first coordinate data (self-coordinate data) used in the travel control processing for the loading equipment 1, and the block diagram in FIG. 8 shows an example of this data processing. The coordinate calculation device 16 has an accumulation unit 23, a selection unit 24, a lookup table 25, a setting unit 26, and an addition unit 27. Each part shown in the block diagram is stored as a program in the memory unit of the coordinate calculation device 16, but each part may also be composed of an electronic circuit.

The accumulation unit 23 receives the mileage ΔLp measured by the odometer (15p, 16) and the signal S1 transmitted from the odometer 12. The accumulation unit 23 sequentially accumulates the mileage ΔLp that is input, and outputs the accumulated accumulated mileage Lp. When the accumulation unit 23 receives the signal S1, it updates the accumulated accumulated mileage Lp to zero. In other words, the accumulation unit 23 outputs the accumulated mileage Lp from the timing when the signal S1 is input to the timing when the next signal S1 is input. The data processing by the accumulation unit 23 corresponds to a part of the data processing of the estimation process of the present invention. The data processing by the accumulation unit 23 corresponds to a part of the data processing of the update process of the present invention.

The selection unit 24 receives as input the X coordinate (xgp) of the self-location coordinate measured by the radio wave positioning device 14p, the radio wave transmission and reception sensitivity of the radio wave positioning device 14p, and the first coordinate data (xcp) of point p output by the series of data processing shown in this block diagram. If the input sensitivity is higher than the standard (if the sensitivity is good), the selection unit 24 outputs the self-location coordinate (xgp), and otherwise outputs the first coordinate data (xcp) of point p.

The selection unit 24 may use positioning coordinate data of point p calculated based on the self-position coordinate measured by the radio positioning device 14p and the self-position coordinate (xgr) measured by the radio positioning device 14r, instead of the self-position coordinate measured by the radio positioning device 14p. The positioning coordinate data of point p can be calculated by the coordinate calculation device 16 based on the self-position coordinate (xgp, ygp) acquired by the positioning device 14p and the self-position coordinate (xgr, ygr) acquired by the positioning device 14r.

Sensitivity is an index of the accuracy of the self-position coordinates, and indicates the degree to which it affects the quality of radio waves transmitted and received between the radio wave positioning device 14p and the radio wave transceiver 6, and the degree to which it affects the strength of receivable radio waves. The accuracy degradation rate, signal strength, number of satellites used for positioning, etc. can be used as the sensitivity, and a value obtained by comprehensively quantifying these may also be used. Self-position coordinates obtained in a high sensitivity state have high accuracy, but self-position coordinates obtained in a low sensitivity state have low accuracy and lack reliability. The standard level of sensitivity can be set arbitrarily, and it is advisable to take into account the constant radio wave conditions in the warehouse facility, the radio wave conditions at specific locations in the warehouse facility, etc. In the figure, a state in which sensitivity is higher than the standard is called good.

The lookup table 25 receives the coordinate data output from the selection unit 24 and the signal S1. The lookup table 25 has map data 20 as data to be matched. At the timing when the signal S1 is input, the lookup table 25 compares the input coordinate data (self-position coordinates or first coordinate data) with the map data 20 to identify the stop coordinate data that is closest to the input coordinate data. The stop coordinate data identified at the timing when the signal S1 is input indicates the stop coordinate data of point P, which is a stop location that exists directly below point p of the loading equipment 1 at that timing.

The setting unit 26 receives the stop coordinate data output from the lookup table 25 and the signal S1. When the signal S1 is input, the setting unit 26 resets the coordinate data of the measurement start point that was set before that timing, and updates the coordinate data to the stop coordinate data output from the lookup table 25. This data processing by the setting unit 26 corresponds to a part of the data processing of the update process of the present invention.

The adder 27 receives the accumulated travel distance Lp output from the accumulator 23 and the coordinate data of the measurement start point output from the setting unit 26. The adder 27 outputs the sum of the accumulated travel distance Lp and the coordinate data of the measurement start point as the first coordinate data (xcp) of point p. This data processing by the adder 27 corresponds to a part of the data processing of the estimation process of the present invention.

Similarly, the first coordinate data (xcr) of point r is also output. The first coordinate data of points p and r obtained by this estimation method are input to the calculation device 13. After undergoing data processing described below, the calculation device 13 uses the first coordinate data as its own coordinate data to execute the travel control processing of the loading equipment 1.

As described above, according to this embodiment, the cumulative mileage and the coordinate data of the measurement start point are reset each time the external sensor 17 detects the measurement target 7, and the stop coordinate data accumulated in the highly accurate map data 20 created in advance is used as the coordinate data of the measurement start point. Therefore, the cumulative mileage has a small cumulative error and high measurement accuracy. In other words, the control system 10 of this embodiment uses a very simple estimation method of the first coordinate data (self-coordinate data) using the odometer (15, 16), and is capable of estimating the first coordinate data (self-coordinate data) with high accuracy while being configured to reduce computational resources.

The accuracy of the cumulative mileage obtained by measurement with the odometer (15, 16) is higher when the outer diameter of the running wheels 4 of the loading equipment 1 is closer to the actual value. However, the weight of the loading equipment 1 changes when the cargo 2 is loaded, and this change in weight causes the outer diameter of the running wheels 4 to change. In addition, the outer diameter of the running wheels 4 changes due to deterioration over time. Such changes in the outer diameter of the running wheels are a factor that cause a large accumulated error in the cumulative mileage.

In this regard, according to the present embodiment, the timing when the remaining distance ΔXp measured by the distance meter 12 becomes zero is regarded as the timing when the stopping point P is located directly below point p of the loading and unloading equipment 1, and the coordinate data of the measurement start point is updated. In other words, each time the stopping point P is located directly below point p, the control system 10 uses the stopping coordinate data of point P as the coordinate data of the measurement start point for the next accumulated travel distance, thereby reducing the effect of accumulated errors in the accumulated travel distance.

The coordinate data of the measurement start point can be determined by using only the first coordinate data estimated based on the cumulative mileage, without using the self-location coordinates acquired by the radio-controlled positioning device 14. However, the cumulative mileage includes an accumulated error, and the accuracy of the self-location coordinates acquired by the radio-controlled positioning device 14 may be higher than the accuracy of the first coordinate data estimated based on the cumulative mileage. Therefore, by using both the first coordinate data estimated based on the cumulative mileage and the self-location coordinates acquired by the radio-controlled positioning device 14 to determine the coordinate data of the measurement start point, the coordinate data of the measurement start point can be determined more accurately. In addition, when the sensitivity of the radio-controlled positioning device 14 for transmitting and receiving radio waves is lower than the standard and the reliability of the accuracy of the acquired self-location coordinates cannot be ensured, the first coordinate data estimated based on the cumulative mileage is used, so that it is possible to determine the coordinate data of the measurement start point even in poor radio wave conditions. The coordinate acquisition device 11 does not require the radio wave positioning device 14, and can be configured with only the odometer (15, 16) without the radio wave positioning device 14 when the radio wave conditions are constantly poor.

In addition, the timing when the remaining distance measured by the range finder 12 becomes zero is used as a trigger for updating the coordinate data of the measurement start point. When the sensitivity of the radio wave transmission and reception of the radio wave positioning device 14 is higher than the standard, the timing when the positioning coordinate data based on the self-position coordinate acquired by the radio wave positioning device 14 matches the stop coordinate data can also be used as this trigger. Depending on the running state of the loading equipment 1, the timing when the remaining distance measured by the range finder 12 becomes zero may not be detected. For example, a case is exemplified in which the loading equipment 1 is running with a deviation in the Y-axis direction, and even if the loading equipment 1 passes a stop point, the external sensor 17 cannot detect the measurement object 7 at the stop point that it has passed. In addition, a case is exemplified in which the running speed of the loading equipment 1 is fast, and even if the external sensor 17 detects the measurement object 7, the timing when the remaining distance becomes zero may not be detected. In such a case, instead of the timing when the remaining distance measured by the range finder 12 becomes zero, the timing when the positioning coordinate data matches the stop coordinate data may be used as a trigger for updating the coordinate data of the measurement start point. This increases the frequency of updates to the coordinate data of the measurement start point and shortens the cumulative distance traveled, further improving the accuracy of the self-coordinate data.

The mileage measured by the odometer (15, 16) is calculated based on the number of rotations of the running wheel 4 measured by the internal sensor 15 and the outer diameter of the running wheel 4. Therefore, the higher the accuracy of the outer diameter of the running wheel 4, the higher the accuracy of the mileage and the higher the estimation accuracy of the first coordinate data. Therefore, even after performing the update process, the coordinate calculation device 16 should store in the memory unit the coordinate data of the measurement start point before the coordinate data of the measurement start point updated by the update process and the cumulative mileage before being updated to zero. Then, it is desirable for the coordinate calculation device 16 to perform data processing to update the outer diameter of the running wheel 4 that was previously stored based on the coordinate data of the updated measurement start point, the coordinate data of the measurement start point before being updated, and the cumulative mileage before being updated. Specifically, it is desirable for the coordinate calculation device 16 to execute data processing to update the outer diameter of the running wheel 4 used in calculating the travel distance to a value obtained by dividing the difference between the coordinate data of the updated measurement start point and the coordinate data of the measurement start point before the update by the cumulative travel distance before the update, and multiplying the result by the stored outer diameter of the running wheel 4.

The difference between the coordinate data of the updated measurement start point and the coordinate data of the measurement start point before the update (the distance between the coordinate data) is the difference between the two stopping coordinate data points in the map data 20. In other words, this difference indicates the distance that the loading/unloading equipment 1 has actually traveled, and the difference between this difference and the accumulated travel distance before the update indicates the accumulated error contained in that accumulated travel distance. The main cause of the accumulated error is the change in the outer diameter of the running wheels 4. Therefore, updating the outer diameter of the running wheels 4 is advantageous in improving the estimation accuracy of the first coordinate data.

If it is possible to identify that the cause of the cumulative error in the cumulative mileage is a change in the outer diameter of the running wheels 4 due to a change in the total weight of the loading equipment 1 caused by loading the cargo 2 onto the loading equipment 1, it is advisable to update the outer diameter of the running wheels 4 before and after the loading operation of the loading equipment 1. For example, when loading the cargo 2 onto the loading equipment 1, it is advisable to update the outer diameter of the running wheels 4 that was previously stored by the above-mentioned data processing, and when the loaded cargo 2 is loaded, it is advisable to return the outer diameter of the running wheels 4 to the previously stored outer diameter. In addition, if the outer diameter of the running wheels 4 is frequently updated due to reasons other than the change in the outer diameter of the running wheels 4 due to the change in the total weight of the loading equipment 1, it can be determined that the running wheels 4 have deteriorated over time. In such a case, it is possible to encourage the inspection or replacement of the running wheels 4.

Figures 9 to 11 show an example of the travel control process of the loading equipment 1. The series of flows shown in Figures 10 and 11 are detailed flows of the subroutines shown in (S210) and (S220) of Figure 9. The travel control process of the loading equipment 1 includes a method of estimating the self-coordinate data 21 used in the travel control process. The predetermined period moves to the next period each time the process returns to the start by return in Figure 9. Note that the measurement method of the rangefinder 12 shown in Figure 6 is performed in parallel with this control method. Also, the method of acquiring the first coordinate data shown in Figure 8 is performed in step (S310) of Figure 10.

First, the calculation device 13 calculates the X coordinates of points p and r, and creates self-coordinate data 21 (S210, S220). Next, the calculation device 13 calculates the X coordinate and attitude angle θ of point q based on the self-coordinate data 21 (S230), and performs a travel control process based on the calculated X coordinate and attitude angle θ of point q and the map data 20 (S240). Finally, the process ends when the loading equipment 1 stops in accordance with the stop coordinate data of the target stop location.

In calculating the X coordinate of point p (the calculation of the X coordinate of point r is similar), first, the coordinate calculation device 16 calculates the first coordinate data (xcp) (S310). Next, the calculation device 13 performs each step (S320 to S350, S410 to S450). Finally, until the range finder 12 is able to measure (S410: NO or S4320: NO), the calculation device 13 outputs the first coordinate data (xcp) as the X coordinate of point p (S460). Also, until a predetermined time Ta has elapsed since the range finder 12 became able to measure (S440: NO), the calculation device 13 outputs the third coordinate data (xcmp) as the X coordinate of point p (S470). Also, after the predetermined time Ta has elapsed (S440: YES), the calculation device 13 outputs the second coordinate data (xmp) as the X coordinate of point p (S480). The details of each step, (S210) to (S240), (S310) to (S350), and (S410) to (S480), are described below.

In the step of calculating the X coordinate of point p (S210) and the step of calculating the X coordinate of point r (S220), the calculation device 13 executes data processing to calculate the X coordinates of points p and r. Through these two steps, self-coordinate data 21 is created and stored in the memory unit of the calculation device 13.

In the step (S230) of calculating the X-coordinate and the attitude angle θ of the q-point, the arithmetic device 13 executes data processing to calculate the X-coordinate of the q-point as the midpoint of the p-point and the q-point of the self-coordinate data 21. The arithmetic device 13 also executes data processing to calculate the attitude angle θ of the cargo handling equipment 1 based on the X-coordinates of the p-point and the r-point and the length Bc of the line segment connecting the p-point and the r-point. The attitude angle θ indicates the inclination of the normal of the line segment connecting the p-point and the r-point with respect to the X-axis. The length Bc of the line segment connecting the p-point and the r-point is a shape parameter of the cargo handling equipment 1 that is known in advance, and is a numerical value that can be known at the design and manufacturing stage of the cargo handling equipment 1. As the length Bc, the length between the radio wave positioning devices 14p and 14r, or the length between the external sensors 17p and 17r, are exemplified. The attitude angle θ is calculated as the cotangent (tan ⁻¹ ) of the difference between the X coordinates of points p and r divided by the length Bc of the line segment connecting points p and r.

In the travel control step (S240), the calculation device 13 executes a travel control process that controls the travel of the loading equipment 1 based on the deviation between the X-coordinate of point q and the X-coordinate of point Q of the target stopping point in the map data 20, and the calculated attitude angle θ. In the travel control process, the travel speed and travel direction of the loading equipment 1 are adjusted. The travel speed is adjusted by adjusting the deceleration of the loading equipment 1 near the target stopping point based on the deviation of the X-coordinate, and switching between constant acceleration, constant speed, and constant deceleration is performed elsewhere. The travel direction is adjusted by adjusting the difference in travel speed between both ends of the loading equipment 1 in the Y-axis direction based on the attitude angle θ.

In the step of calculating the first coordinate data of point p (S310), the coordinate calculation device 16 executes the data processing illustrated in FIG. 8. Specifically, the coordinate calculation device 16 calculates the first coordinate data (xcp) of point p of the loading equipment 1 using the odometer (15p, 16) and the external sensor 17p.

In the step of calculating the deviation Δxp (S320), the calculation device 13 executes data processing to calculate the deviation Δxp in the X-axis direction between the calculated first coordinate data (xcp) and the X-coordinate (xP) of point P of the target stopping location in the map data 20. The deviation Δxp indicates the approximate distance from point p of the loading equipment 1 to point P of the target stopping location.

In the step (S330) of determining whether the deviation Δxp is equal to or smaller than the predetermined distance ΔL, the calculation device 13 performs data processing to compare the calculated deviation Δxp with the preset predetermined distance ΔL to determine whether the distance meter 12 is ready to measure. The deviation Δxp indicates the approximate distance from point p of the loading equipment 1 to point P of the target stopping location, and is therefore an index for determining whether point p of the loading equipment 1 has approached the vicinity of point P of the target stopping location. In other words, the deviation Δxp is an index that indicates that the distance meter 12 is ready to measure the remaining distance.

The predetermined distance ΔL is set as a criterion for indicating that the distance meter 12 is able to measure the remaining distance ΔXp to the target stopping point P point. When the deviation Δxp, which is the index, is longer than the predetermined distance ΔL, which is the criterion, it indicates that the distance meter 12 is not able to measure the remaining distance ΔXp, and when the deviation Δxp is equal to or less than the predetermined distance ΔL, it indicates that the distance meter 12 is able to measure the remaining distance ΔXp. The predetermined distance ΔL can be set appropriately according to the length of the external sensor 17p in the X-axis direction and the strength of the magnetic field of the measurement object 7p. The lower limit of the predetermined distance ΔL may be a distance at which the external sensor 17p can detect the measurement object 7p. In addition, the upper limit of the predetermined distance ΔL is shorter than the shortest distance between adjacent stopping points in the travel direction of the loading equipment 1, and is preferably shorter than half the distance of the shortest distance, and more preferably within the range of 50 mm to 500 mm.

In the step (S340) of turning on flag B and the step (S350) of turning off flag B, the calculation device 13 executes data processing to set or clear flag B based on the result of the determination in step (S330). Specifically, when it is determined that the range finder 12 is capable of measuring the remaining distance ΔXp (S330: YES) based on a comparison between the deviation Δxp and the predetermined distance ΔL, flag B is set (flagB: ON), and when it is determined that the range finder 12 is not capable of measuring (S330: NO), flag B is cleared (flagB: OFF).

In the steps (S410, S420) of determining whether flags A and B are on, the arithmetic unit 13 executes data processing to determine whether each flag is on or off. The loading equipment 1 may pass through multiple stopping points before arriving at the target stopping point. In this case, the external sensor 17p detects the measurement object 7p installed at the stopping point before arriving at the target stopping point. In other words, it is not possible to determine whether the measured remaining distance ΔXp is the remaining distance to the target stopping point only by the remaining distance ΔXp measured by the range finder 12. Therefore, by determining the flag B set by comparing the deviation Δxp with the predetermined distance ΔL, it is possible to determine whether the range finder 12 is in a state where it can measure. On the other hand, in step (S330), the deviation Δxp is used as an index, but even if the flag B is on, the external sensor 17p may not actually be able to detect the measurement object 7p. Therefore, by judging flag A, which is set when external sensor 17p actually detects object 7p to be measured, it is possible to determine whether rangefinder 12 can reliably measure remaining distance ΔXp to the target stopping point. Therefore, when judging the flags, it is desirable to judge flag B first, and then judge flag A. In this way, by judging the two flags in order, it is possible to more reliably judge whether rangefinder 12 can measure remaining distance ΔXp to the target stopping point.

Each of steps (S120), (S130), (S330) to (S350), (S410), and (S420) is data processing that determines when the distance meter 12 is able to measure the remaining distance to the target stopping point. If the accuracy of the deviation Δxp is high, this data processing may consist of only steps (S330) to (S350) and (S410).

In the step of calculating the second coordinate data (S430), the calculation device 13 executes data processing to calculate the second coordinate data (xmp) of point p based on the remaining distance ΔXp measured by the range finder 12. Specifically, the calculation device 13 calculates the second coordinate data (xmp) using the stopping posture coordinate data of the target stopping location, with the remaining distance ΔXp set as the relative distance from point p to point P of the target stopping location. The second coordinate data is calculated by subtracting the remaining distance ΔXp from the X coordinate (xP) of point P of the target stopping location.

In the step (S440) of determining whether the elapsed time T has exceeded the predetermined time Ta, the calculation device 13 executes data processing to compare the elapsed time T since flag A was turned on with a preset predetermined time Ta and determine whether the elapsed time T has exceeded the predetermined time Ta. The elapsed time T may be measured by a timer possessed by the calculation device 13, or may be estimated from the number of periods measured by a counter possessed by the calculation device 13. It is desirable that the predetermined time Ta is set to a time that is shorter than the time from when flag A is turned on until the loading equipment 1 stops traveling, and that allows the predetermined period to be repeated multiple times. The predetermined time Ta can be set arbitrarily. The elapsed time T in this step may be the time that has passed since flag B was turned on.

In the step (S450) of calculating the third coordinate data (xcmp), the calculation device 13 executes data processing to calculate the third coordinate data (xcmp) based on both the coordinates of the first coordinate data (xcp) and the second coordinate data (xmp) until the elapsed time Ta reaches a predetermined time Ta. If the self-coordinate data 21 immediately switches from the first coordinate data to the second coordinate data immediately after the flags A and B are turned on, there is a risk of a sudden change in the running speed in the running control process if the difference between the first coordinate data and the second coordinate data is large. A sudden change in the running speed causes pitching vibration of the loading equipment 1 and swinging of the hoisting equipment due to the pitching vibration. Even if the loading equipment 1 stops at the target stopping point without deviation, if vibration or swing occurs, accurate alignment with the loading object 2 cannot be performed until the vibration or swing subsides, and the loading operation stagnates. Therefore, immediately after flags A and B are turned on, the transition of the coordinate data can be made smooth by using third coordinate data based on the coordinates of both the first coordinate data and the second coordinate data. In this way, the transition of the coordinate data becomes smooth, which is advantageous in suppressing sudden fluctuations in the driving speed.

The third coordinate data can also be the median (average value) of the first coordinate data and the second coordinate data. It is desirable to decrease the contribution of the first coordinate data to the third coordinate data as the elapsed time Ta progresses, and conversely increase the contribution of the second coordinate data. This allows the third coordinate data to smoothly transition from a value close to the first coordinate data to a value close to the second coordinate data as the elapsed time Ta progresses. The contribution indicates the degree of contribution to the transition of the third coordinate data as the elapsed time Ta progresses. In other words, the third coordinate data will have a value closer to the coordinate data with a higher contribution and farther from the coordinate data with a lower contribution.

The solid line in FIG. 12 shows an example of the first contribution rate, and the dashed line shows an example of the second contribution rate. The first contribution rate indicates the ratio of the contribution rate of the first coordinate data, and the second contribution rate indicates the ratio of the contribution rate of the second coordinate data. The sum of the first contribution rate and the second contribution rate is "1.0" regardless of the elapsed time T. The first contribution rate gradually changes from "1.0" to "0.0" as the time lapse Ta progresses, and the second contribution rate changes from "0.0" to "1.0" as the time lapse Ta progresses. The third coordinate data is calculated as the average value of the value obtained by multiplying the first coordinate data by the first contribution rate and the value obtained by multiplying the second coordinate data by the second contribution rate. In this way, by changing the contribution rate of the first coordinate data and the contribution rate of the second coordinate data as the elapsed time Ta progresses, the transition of the third coordinate data becomes smoother.

In the step of outputting the first coordinate data (S460), the step of outputting the third coordinate data (S470), and the step of outputting the second coordinate data (S480), the calculation device 13 executes data processing to output each data. More specifically, when flags A and B are not both on, the calculation device 13 assumes that the distance meter 12 is not capable of measuring the remaining distance ΔXp to the target stopping point, and outputs the first coordinate data (xcp). Furthermore, when the elapsed time T since both flags A and B turned on has not passed a predetermined time Ta, the calculation device 13 outputs the third coordinate data (xcmp). Furthermore, when the elapsed time T since both flags A and B turned on has passed a predetermined time Ta, the calculation device 13 outputs the second coordinate data (xmp).

Figure 13 shows the X coordinate of point q under conditions that change over time. The top row in the figure shows the passage of time. Point p indicates one end side of the loading equipment 1 in the Y-axis direction, and indicates the side where the radio wave positioning device 14p, internal sensor 15p, and external sensor 17p are installed. Point r indicates the other end side of the loading equipment 1 in the Y-axis direction, and indicates the side where the radio wave positioning device 14r, internal sensor 15r, and external sensor 17r are installed.

At time t1, flags A and B on both the p and r sides are off. The X coordinate of point q at time t1 is calculated as the intermediate coordinate between the first coordinate data of point p (xcp) and the first coordinate data of point r (xcr).

At time t2, flags A and B on the side of point p are both on, and flags A and B on the side of point r are both off. Also, at time t2, the elapsed time Tp since flag B on the side of point p was turned on is less than the predetermined time Ta. The X coordinate of point q at time t2 is calculated as the intermediate coordinate between the third coordinate data (xcmp) of point p and the first coordinate data (xcr) of point r.

At time t3, flags A and B on both the p and r sides are on. Also, at time t3, the elapsed times Tp and Tr from when flags B on the p and r sides were turned on are less than the predetermined time Ta. The X coordinate of point q at time t3 is calculated as the intermediate coordinate between the third coordinate data (xcmp) of point p and the third coordinate data (xcmr) of point r.

At time t4, the elapsed time Tp on the side of point p has passed the predetermined time Ta, and the elapsed time Tr on the side of point r is less than the predetermined time Ta. The X coordinate of point q at time t4 is calculated as the intermediate coordinate between the second coordinate data (xmp) of point p and the third coordinate data (xcmr) of point r.

At time t5, the elapsed times Tp and Tr on the point p and point r sides have passed the predetermined time Ta. The X coordinate of point q at time t5 is calculated as the intermediate coordinate between the second coordinate data (xmp) of point p and the second coordinate data (xmr) of point r.

Figure 14 shows an example of the relationship between the passage of time in the travel control process and the travel speed of the loading equipment 1. When the self-coordinate data 21 is output, the calculation device 13 executes the travel control process of the loading equipment 1 (S240 in Figure 9). The travel control process adjusts two things: the travel speed of the loading equipment 1, and the travel direction of the loading equipment 1 (including the orientation of the loading equipment 1 when travel stops).

In adjusting the traveling speed, the traveling speed of the loading equipment 1 is adjusted based on the deviation between the stop coordinate data of the target stopping point in the map data 20 and the self coordinate data of the self coordinate data 21 (specifically, the deviation between the X coordinate of the target stopping point point Q and the X coordinate of the target stopping point point q). In adjusting the traveling speed, the relationship between the elapsed time from when the loading equipment 1 starts traveling to when it stops and the traveling speed is approximately trapezoidal, and a preset constant acceleration, constant speed, and constant deceleration are switched based on the deviation. Each of the constant acceleration, constant speed, and constant deceleration can be set arbitrarily. In adjusting the traveling speed, the deceleration is adjusted so that the stop coordinate data of the target stopping point and the self coordinate data match (specifically, the X coordinate of the target stopping point point Q and the X coordinate of the target stopping point point q match) after the traveling speed of the loading equipment 1 is switched to the constant deceleration. In other words, constant acceleration, constant speed, and constant deceleration are switched using self coordinate data 21 based on the first coordinate data, and deceleration is adjusted using self coordinate data 21 based on the second coordinate data.

In adjusting the travel direction, the difference in travel speed between both ends of the loading equipment 1 in the Y-axis direction is adjusted based on the attitude angle θ. In adjusting the travel direction, the travel speed adjusted by the travel speed control is corrected, and the travel direction of the loading equipment 1 is adjusted based on the speed difference between both ends in the Y direction. Note that when the travel wheels of the loading equipment 1 are steerable, the steering angle of the loading equipment 1 may be adjusted in adjusting the travel direction.

In the travel control process, in order to further improve the straightness of the travel of the loading equipment 1, it is preferable to adjust the travel speed difference between both ends of the loading equipment 1 in the Y-axis direction based on the deviation from the target line of the map data 20 in the Y-axis direction. Specifically, in the embodiment, instead of the target line, a measurement object 7y installed at each of many stopping points is used to adjust the travel speed difference based on the deviation in the Y-axis direction. At each of the multiple stopping points that the loading equipment 1 passes through before arriving at the target stopping point, the remaining distance ΔY obtained by the external sensor 17y detecting the measurement object 7y is used to adjust the travel speed difference. Note that the measurement object 7y may be installed not only at the multiple stopping points, but also between the stopping points, and may extend over the entire length of the storage lane 3.

As described above, according to the travel control process of the loading equipment 1, the second coordinate data obtained by measurement with the range finder 12 is used in the vicinity of the target stopping point. This second coordinate data is obtained by measuring the measurement target 7 installed at the target stopping point, and is highly accurate. Therefore, the loading equipment 1 can be stopped at the target stopping point with high accuracy by the travel control process using the second coordinate data.

In addition, according to this driving control process, the first coordinate data acquired by the coordinate acquisition device 11 is used until the vehicle reaches the vicinity of the target stopping point. The coordinate acquisition device 11 eliminates the need to install positioning devices and components in sections between multiple stopping points on the driving road surface 5, making it possible to reduce the installation costs and maintenance of these devices and components.

In other words, this travel control process uses the first coordinate data for travel control in travel sections where a certain degree of low accuracy is acceptable, and uses the highly accurate second coordinate data based on the remaining distance for travel control in travel sections where high accuracy is required. In this way, by using the coordinate acquisition device 11 and the distance meter 12 appropriately, the distance meter 12 can compensate for the drawback of the low accuracy of the coordinate acquisition device 11, and the coordinate acquisition device 11 can compensate for the drawback of the high cost required to measure the entire travel range of the loading equipment 1 using the distance meter 12. Therefore, this embodiment is configured to suppress an increase in cost, while being able to stop the loading equipment 1 at the target stopping point with high accuracy. This makes it possible to ensure an accuracy of ±20 mm or less, which is necessary for alignment in the loading and unloading work of the loading and unloading equipment 1. As a result, the time required for alignment can be significantly reduced, and loading and unloading efficiency can be improved.

In addition, the first coordinate data obtained by the coordinate acquisition device 11 is used to determine that the range finder 12 is capable of measuring the remaining distance to the target stopping point, which is one of the many stopping points. This eliminates the need for the range finder 12 to acquire absolute position information, and the range finder 12 can be configured to measure only the remaining distance to the target stopping point, thereby reducing the cost required for the range finder 12. Similarly, the cost required for the measurement object 7 installed at each of the many stopping points can be minimized.

When switching from the first coordinate data to the second coordinate data, third coordinate data based on both the first coordinate data and the second coordinate data is used. This allows for a smooth transition when switching from the first coordinate data to the second coordinate data. Therefore, it is possible to suppress sudden fluctuations in the driving speed during the driving control process due to the difference between the first coordinate data and the second coordinate data. Note that if the difference between the first coordinate data and the second coordinate data is small and switching from the first coordinate data to the second coordinate data does not cause sudden fluctuations in the driving speed during the driving control process, there is no need to use the third coordinate data. In this case, steps (S440), (S450), and (S470) of the above control flow can be omitted.

In a loading device 1 in which the travel direction is controlled by the speed difference between both ends in the Y-axis direction, such as a crane, the time when flag B turns on and the time required for flag A to turn on may differ between the p-point side and the r-point side depending on the attitude angle θ of the loading device 1. Therefore, it is desirable to estimate the self-coordinate data 21 for each of both ends (p-point side, q-point side) in the Y-axis direction of the loading device 1. In this way, it is advantageous to improve the estimation accuracy of the self-coordinate data by estimating the self-coordinate data of both ends of the loading device 1 in the Y-axis direction. Note that even if the loading device 1 is a crane, the self-coordinate data 21 may not be estimated for each end. For example, a case is exemplified in which the self-coordinate data 21 is composed of the X-coordinate of the q-point. In this case, the X-coordinate of the q-point and the attitude angle θ are output only by the flow shown in FIG. 10 and FIG. 11. That is, in steps (S310), (S430), and (S450), the X coordinate of point q, which is calculated from the X coordinate of point p and the X coordinate of point r, and the attitude angle θ are calculated as the respective coordinate data.

Although an embodiment of the present invention has been described above, the control system and control method for loading and unloading equipment of the present invention are not limited to a specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention.

The loading and unloading equipment 1 is not limited to a crane that travels across the storage lane 3. The loading and unloading equipment 1 may be a crane that handles loading and unloading of a ship docked at a quay of a container terminal or an overhead crane that handles loading and unloading in a warehouse facility. The loading and unloading equipment 1 may be a transport vehicle that travels within a warehouse facility such as a container terminal. Furthermore, the cargo 2 that the loading and unloading equipment 1 handles is not limited to a container. The traveling road surface 5 is not limited to one that extends along the storage lane 3. The traveling road surface 5 may include a connecting road that connects the storage lanes 3. Furthermore, the traveling road surface 5 may be a traveling road surface for transport vehicles that runs from the entrance/exit of the container terminal to the storage lane 3.

The multiple stopping locations may include locations other than the locations where the loading and unloading work is performed by the loading and unloading equipment 1. Examples of such locations include locations where the loading and unloading equipment 1 stops on the way to the location where the loading and unloading work is performed, or locations where the traveling direction is changed. Specifically, when the loading and unloading equipment 1 is a crane, an example of such a location is a specified location on a connecting road used for lane changes. When the loading and unloading equipment 1 is a transport vehicle, an example of such a location is a location where the transport vehicle stops temporarily or turns right or left at a container terminal. Furthermore, examples of such a location include locations where maintenance and inspection of the loading and unloading equipment 1 are performed, and locations where the energy of the driving source of the loading and unloading equipment 1 is replenished.

The control system 10 may be configured differently depending on the type of loading equipment 1 to be controlled. When the loading equipment 1 is a transport vehicle, the coordinate control device 11 may have one radio-controlled positioning device and one odometer, and the odometer 12 may have one external sensor.

The coordinate acquisition device 11 is not essential because when the radio wave positioning device 14 has low sensitivity for transmitting and receiving radio waves, the accuracy of the acquired self-location coordinates is low or the self-location coordinates cannot be acquired. However, when the radio wave positioning device 14 has high sensitivity for transmitting and receiving radio waves, it is advantageous to improve the estimation accuracy of the first coordinate data by using the acquired self-location coordinates to estimate the first coordinate data.

When the loading and unloading equipment 1 is used for loading and unloading in a warehouse, the radio wave positioning device 14 may use an indoor messaging system (IMES) as an indoor positioning system. The radio wave positioning device 14 does not need to acquire highly accurate self-position coordinates. Therefore, the radio wave positioning device 14 may be installed in the loading and unloading equipment 1, or may be a portable device carried by the driver of the loading and unloading equipment 1. Examples of portable devices include tablet personal computers, personal digital assistants, smartphones (mobile phones, cell phones), and wearable devices. When a portable device is used as the radio wave positioning device 14, it is desirable that the coordinate calculation device 16 and the calculation device 13 are configured as a computer connected to the portable device so that they can communicate with each other.

The coordinate acquisition device 11 updates the accumulated travel distance to zero and updates the coordinate data of the measurement start point based on a signal S1 indicating that the remaining distance measured by the distance meter 12 has reached zero, and executes an update process. The signal S1 only needs to be capable of timing when the stopping point is located directly below a specified point on the loading and unloading equipment 1. For example, in addition to the distance meter 12, an external sensor that detects a measurement object installed at each stopping point may be provided. This external sensor does not need to measure the distance to the measurement object, and only needs to be able to detect the measurement object when it is located directly above it. However, by timing the update process using the measurement results of the distance meter 12, it is possible to obtain a highly accurate accumulated travel distance.

The distance meter 12 does not necessarily need to measure the remaining distance ΔY in the Y-axis direction to the target stopping point. If the self-coordinate data 21 has an attitude angle θ or if the attitude angle θ can be calculated from the self-coordinate data 21, it is possible to ensure the straightness of the traveling of the loading equipment 1. However, if the distance meter 12 can measure the remaining distance ΔY, it is possible to stop at the target stopping point without deviation in both the X-axis and Y-axis directions. Deviation in the Y-axis direction at the target stopping point can be corrected by the loading and unloading operation of the cargo 2. Therefore, it is sufficient for the distance meter 12 to be able to measure at least the remaining distance in the X-axis direction to the target stopping point.

The measurement object 7 is not particularly limited as long as it can be detected by the external sensor 17. For example, in the case of a linear scale, the width of the linear scale needs to be widened in consideration of the deviation of the traveling of the loading and unloading equipment 1, which is not practical. In addition, the measurement object 7 does not need to have absolute position information. The measurement object 7 does not have absolute position information, which is advantageous in reducing the introduction cost compared to those having absolute position information such as absolute type linear scales. Therefore, the combination of the measurement object 7 and the external sensor 17 is appropriately a combination of a magnetic ferromagnetic material and a linear position sensor. Note that a magnetic ferromagnetic material can be used semi-permanently once installed, and the cost required for maintenance can be significantly reduced. Note that, although it requires more maintenance cost than that combination, the combination of the measurement object 7 and the external sensor 17 can also use a combination of a mark installed on the traveling road surface 5 such as a white line and a camera. It is possible to measure the distance to the mark by image processing an image of the surroundings of the mark including the mark by the camera.

Even if the measurement object 7 is located directly below or away from both ends of the external sensor 17 (e.g., detector elements 19 with element numbers: No. 1 and No. 20) and fewer than a predetermined number of detector elements 19 detect the measurement object 7, the remaining distance may be calculated if the predetermined number is a fixed value. For example, a number other than the element number assigned to the detector elements 19 (e.g., No. -1, No. 0, No. 21, No. 22, etc.) and the distance may be added to the distance data 22. When the predetermined number is "three" and only the detector element 19 with element number No. 1 detects the measurement object 7, the measurement object 7 can be considered to be located directly below the position of No. 0.

REFERENCE SIGNS LIST 1 Cargo handling equipment 6 Radio wave transmitter/receiver 7 Measurement target 10 Control system 11 Coordinate acquisition device 12 Rangefinder 13 Attitude calculation device 14 Radio wave positioning device 15 Internal sensor 16 Coordinate calculation device 17 External sensor 18 Distance calculation device 19 Detector element 20 Map data 21 Self coordinate data 22 Distance data

Claims (6)

1. A control system for controlling travel of a loading/unloading device based on map data in which stopping coordinate data for a large number of stopping points, including points where loading/unloading work is performed by the loading/unloading device, and on self-coordinate data of the loading/unloading device,
an external sensor that detects a measurement object installed at each of the stopping points as the loading and unloading equipment passes through the stopping points while traveling; an odometer that sequentially measures the travel distance of the loading and unloading equipment; a radio wave positioning device that sequentially acquires position coordinates of a predetermined point of the loading and unloading equipment by transmitting and receiving radio waves to and from at least one radio wave transmitter and receiver; and a coordinate calculation device ;
The coordinate calculation device is
sequentially executing data processing to estimate the self-coordinate data based on a cumulative mileage obtained by accumulating the mileage measured by the odometer from a measurement start point which is one of the multiple stopping points and the coordinate data of the measurement start point;
When the external sensor detects the object to be measured, the accumulated travel distance is updated to zero , and a data process is executed to compare the self coordinate data output by the estimation data process executed immediately before the external sensor detects the object to be measured with the map data, identify stop coordinate data that is closest to the self coordinate data from among a large number of stop coordinate data accumulated in the map data, and update the coordinate data of the measurement start point to the identified stop coordinate data.
A loading and unloading equipment control system characterized in that, in the updating data processing, when the sensitivity of the radio wave positioning device for transmitting and receiving radio waves is higher than a standard, the position coordinates acquired by the radio wave positioning device are used instead of the self-coordinate data . 2. The loading equipment control system according to claim 1, wherein the coordinate calculation device executes data processing to compare positioning coordinate data based on the position coordinates acquired by the radio-controlled positioning device with the map data when a sensitivity of radio wave transmission and reception of the radio-controlled positioning device is higher than a reference value, and to update the accumulated traveling distance to zero and update the coordinate data of the measurement start point based on the map data when the positioning coordinate data matches one of a large number of stop coordinate data accumulated in the map data. 1. A control system for controlling travel of a loading/unloading device based on map data in which stopping coordinate data for a large number of stopping points, including points where loading/unloading work is performed by the loading/unloading device, and on self-coordinate data of the loading/unloading device,
an external sensor that detects a measurement object installed at each of the stopping points as the loading and unloading equipment passes through the stopping points while traveling; an odometer that sequentially measures the travel distance of the loading and unloading equipment; a radio wave positioning device that sequentially acquires position coordinates of a predetermined point of the loading and unloading equipment by transmitting and receiving radio waves to and from at least one radio wave transmitter and receiver; and a coordinate calculation device ;
The coordinate calculation device is
sequentially executing data processing to estimate the self-coordinate data based on a cumulative mileage obtained by accumulating the mileage measured by the odometer from a measurement start point which is one of the multiple stopping points and the coordinate data of the measurement start point;
a control system for loading and unloading equipment, characterized in that when the external sensor detects the object to be measured, or when the sensitivity of the radio wave positioning device for transmitting and receiving radio waves is higher than a standard, the control system executes data processing to compare positioning coordinate data based on the position coordinates acquired by the radio wave positioning device with the map data, and when the positioning coordinate data matches one of a number of stop coordinate data accumulated in the map data, the control system updates the accumulated travel distance to zero and updates the coordinate data of the measurement start point based on the map data. the odometer has an internal sensor that detects the number of rotations of a running wheel of the loading equipment for each predetermined period, and measures the mileage based on the number of rotations detected by the internal sensor and an outer diameter of the running wheel,
The control system for loading and unloading equipment according to any one of claims 1 to 3, wherein the coordinate calculation device executes data processing to update the outer diameter of the running wheels based on the coordinate data of the measurement start point updated by execution of the updating data processing, the coordinate data of the measurement start point before the update, and the cumulative traveling distance before the update . A control method for controlling travel of a loading/unloading device based on map data in which stopping coordinate data for a large number of stopping points including points where loading/unloading work is performed by the loading/unloading device is accumulated and on self coordinate data of the loading/unloading device, comprising:
A mileage meter is used to successively measure the mileage of the loading and unloading equipment;
A radio wave positioning device sequentially acquires position coordinates of a predetermined location of the loading and unloading equipment by transmitting and receiving radio waves to at least one radio wave transceiver;
a coordinate calculation device sequentially performs an estimation step of estimating the self coordinate data based on a cumulative mileage obtained by accumulating the mileage measured by the odometer from a measurement start point which is one of the many stopping points and the coordinate data of the measurement start point;
When an external sensor detects a measurement object installed at each of the multiple stop locations as the loading and unloading equipment passes through the stop locations while traveling, the coordinate calculation device updates the accumulated travel distance to zero, and performs an update process of comparing the self coordinate data output by the estimation process executed immediately before the external sensor detected the measurement object with the map data, identifying stop coordinate data that is closest to the self coordinate data from among the multiple stop coordinate data accumulated in the map data, and updating the coordinate data of the measurement start location to the identified stop coordinate data ,
A method for controlling loading and unloading equipment, characterized in that , in the update process, when the sensitivity of the radio wave positioning device for transmitting and receiving radio waves is higher than a standard, the position coordinates acquired by the radio wave positioning device are used instead of the self-coordinate data . A control method for controlling travel of a loading/unloading device based on map data in which stopping coordinate data for a large number of stopping points including points where loading/unloading work is performed by the loading/unloading device is accumulated and on self coordinate data of the loading/unloading device, comprising:
A mileage meter is used to successively measure the mileage of the loading and unloading equipment;
A radio wave positioning device sequentially acquires position coordinates of a predetermined location of the loading and unloading equipment by transmitting and receiving radio waves to at least one radio wave transceiver;
a coordinate calculation device sequentially performs an estimation step of estimating the self coordinate data based on a cumulative mileage obtained by accumulating the mileage measured by the odometer from a measurement start point which is one of the many stopping points and the coordinate data of the measurement start point;
a control method for loading and unloading equipment, characterized in that when an external sensor detects a measurement object installed at each of the multiple stopping points as the loading and unloading equipment passes through the stopping points , or when the sensitivity of the radio wave positioning device for transmitting and receiving radio waves is higher than a standard, positioning coordinate data based on the position coordinates acquired by the radio wave positioning device is compared with the map data, and when the positioning coordinate data matches one of the multiple stopping coordinate data accumulated in the map data, the coordinate calculation device updates the accumulated traveling distance to zero and updates the coordinate data of the measurement start point based on the map data.

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