Control system and method for cargo handling equipment

Abstract

To provide a control system and a control method for cargo handling equipment, capable of highly accurately stopping the cargo handling equipment at target stop points while suppressing the increase of costs.SOLUTION: A control system 10 for controlling travel of cargo handling equipment 1 on the basis of map data 20 and self-coordinate data 21, comprises: a coordinate acquisition device 11 for sequentially acquiring a positional coordinate at a predetermined point of the cargo handling equipment 1; an odometer 12 for sequentially measuring a remaining distance from the predetermined point to a stop point; and a calculation device 13. The calculation device 13 executes data processing for outputting the self-coordinate data based on the positional coordinate acquired by the coordinate acquisition device 11 until the odometer 12 can measure a remaining distance to a target stop point, data processing for specifying that the odometer 12 can measure the remaining distance to the target stop point on the basis of the positional coordinate, and data processing for outputting the self-coordinate data based on the remaining distance measured by the odometer 12 after specifying that the odometer 12 can measure the remaining distance to the target stop point.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a control system and method for loading and unloading equipment, and more particularly to a control system and method for controlling the travel of loading and unloading equipment based on map data and self-coordinate data of the loading and unloading equipment. [Background technology]

[0002] In warehouse facilities such as container terminals, map data is created in advance to indicate the locations where loading and unloading operations are performed by loading and unloading equipment such as cranes and transport vehicles, and the storage locations of the loaded objects. In the travel control of the loading and unloading equipment, a 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 specific location of the loading and unloading equipment acquired by a radio-based positioning device that uses Global Navigation Satellite System (GNSS) positioning.

[0003] This kind of radio wave positioning device can very easily obtain the position coordinates of a specific location of the loading and unloading equipment, but the accuracy of the obtained position coordinates is limited. Therefore, in the travel control using the self-coordinate data based on the position coordinates obtained by the radio wave positioning device, the stopping accuracy at the target stopping point is low, and it may not be possible to ensure the accuracy of ±20 mm or less required for positioning in loading and unloading work. In that case, the time required for the positioning work becomes long, and the loading and unloading efficiency decreases.

[0004] Accordingly, various methods have been proposed for improving the stopping accuracy of cargo handling equipment at the target stopping point (see Patent Document 1). In the invention described in Patent Document 1, cargo handling equipment is stopped by measurement using a linear encoder that uses a bay mark detector that detects multiple magnetic bay marks that are spaced apart along the longitudinal direction of the lane. An example of this type of device is a device that uses multiple bay marks as white lines and a bay mark detector that is composed of a camera. The invention described in Patent Document 1 has higher stopping accuracy at the target stopping point than a positioning device, and can ensure an accuracy of ±20 mm or less, which is necessary for positioning in cargo handling operations.

[0005] However, the traveling direction of the cargo handling equipment cannot be controlled by only the multiple bay marks. Therefore, in the invention described in Patent Document 1, it is necessary to provide an auto-steering guideline provided along the longitudinal direction of the lane and a guideline detector for detecting the auto-steering guideline. Thus, in the invention described in Patent Document 1, in addition to the increase in the labor and cost required for laying the auto-steering guideline, the cost required for regular maintenance of the auto-steering guideline also increases. Also, in the invention described in Patent Document 1, the multiple bay marks alone cannot specify the bay mark that is the target stop location. Therefore, at least one of the multiple bay marks or the auto-steering guideline must have absolute position information. This is also a factor in increasing costs. Therefore, there is room for improvement in stopping the cargo handling equipment at the target stop location with high accuracy while suppressing the increase in costs. [Prior art documents] [Patent documents]

[0006] [Patent Document 2] Patent No. 4801456 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a control system and a control method for loading and unloading equipment that can stop the loading and unloading equipment at a target stopping point with high accuracy while suppressing an increase in costs. [Means for solving the problem]

[0008] The control system for loading and unloading equipment of the present invention, which achieves the above object, controls the 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 basis of the self-coordinate data of the loading and unloading equipment, and includes a coordinate acquisition device which sequentially acquires position coordinates of predetermined points of the loading and unloading equipment, a distance meter which sequentially measures the remaining distance from one of the stopping points to the predetermined point when the loading and unloading equipment approaches the stopping point, and a calculation device. The distance meter has an external sensor that detects a measurement object installed at each of the many stopping points, The calculation device performs data processing to output self-coordinate data based on the position coordinates acquired by the coordinate acquisition device until the distance meter can measure the remaining distance to a target stop point among the multiple stop points; and whether or not the object to be measured is detected by the external sensor. The present invention is characterized in that it executes a data process for determining that the rangefinder is capable of measuring the remaining distance to the target stopping point based on the data, and a data process for outputting self-coordinate data based on the remaining distance measured by the rangefinder after it has determined that the rangefinder is capable of measuring the remaining distance to the target stopping point. 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. The control system includes a coordinate acquisition device which sequentially acquires position coordinates of predetermined points of the loading and unloading equipment, a distance meter which sequentially measures a remaining distance from one of the predetermined points to a stopping point when the loading and unloading equipment approaches the stopping point, and a calculation device, and the calculation device continues to operate the coordinate acquisition device until the distance meter is able to measure the remaining distance to a target stopping point among the large number of stopping points. The data processing system according to the present invention is characterized in that it executes the following data processing: data processing for outputting self-coordinate data based on the position coordinates acquired by the device; data processing for determining that the rangefinder is able to measure the remaining distance to the target stopping point based on the position coordinates; data processing for outputting self-coordinate data based on both the self-coordinate data based on the position coordinates and the self-coordinate data based on the remaining distance measured by the rangefinder until a predetermined time has elapsed since the rangefinder determined that it is able to measure the remaining distance to the target stopping point; and data processing for outputting self-coordinate data based on the remaining distance after the predetermined time has elapsed.

[0009] The control method of the present invention for achieving the above object is a method for controlling travel of 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 basis of the self-coordinate data of the loading and unloading equipment, the method comprising the steps of: sequentially acquiring position coordinates of predetermined points of the loading and unloading equipment by a coordinate acquisition device; An external sensor for detecting a measurement object installed at each of the many stopping points is provided.When the vehicle approaches one of the multiple stopping points, the distance from the predetermined point to the stopping point is measured by a distance meter, and the position coordinates acquired by the coordinate acquisition device are processed by a calculation device to output self-coordinate data based on the position coordinates. and whether or not the object to be measured is detected by the external sensor. The method is characterized in that it determines that the rangefinder is able to measure the remaining distance to a target stopping point among the multiple stopping points based on the above, and after it determines that the rangefinder is able to measure the remaining distance, the remaining distance measured by the rangefinder is processed by the arithmetic device, thereby outputting self-coordinate data based on the remaining distance. The control method of the present invention is a method for controlling travel of 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 self-coordinate data of the loading and unloading equipment, in which position coordinates of predetermined points of the loading and unloading equipment are sequentially acquired by a coordinate acquisition device, and when the loading and unloading equipment approaches one of the large number of stopping points, a remaining distance from the predetermined point to the stopping point is sequentially measured by a distance meter, and the position coordinates acquired by the coordinate acquisition device are data-processed by a calculation device to output self-coordinate data based on the position coordinates, and the travel of the loading and unloading equipment is controlled based on the position coordinates. The method is characterized in that the rangefinder determines that it is able to measure the remaining distance to a target stopping point among the multiple stopping points, and from when the rangefinder determines that it is able to measure the remaining distance to the target stopping point until a predetermined time has elapsed, the position coordinates and the remaining distance measured by the rangefinder are data-processed by the arithmetic device, thereby outputting self-coordinate data based on both the self-coordinate data based on the position coordinates and the self-coordinate data based on the remaining distance, and after the predetermined time has elapsed, the remaining distance measured by the rangefinder is data-processed by the arithmetic device, thereby outputting self-coordinate data based on the remaining distance. Effect of the Invention

[0010] According to the present invention, in a travel section where a certain degree of low accuracy is acceptable, self-coordinate data based on position coordinates is used, and in a travel section where high accuracy is required, self-coordinate data based on the remaining distance is used. In this way, by using a coordinate acquisition device and a rangefinder separately, the disadvantage of the low accuracy of the coordinate acquisition device can be compensated for by the rangefinder, and the disadvantage of the high cost required to measure the entire travel range of the loading and unloading equipment using the rangefinder can be compensated for by the coordinate acquisition device. The present invention is configured to suppress an increase in cost, while being able to stop the loading and unloading equipment at the target stopping point with high accuracy. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is an explanatory diagram illustrating loading and unloading equipment. [Diagram 2] FIG. 2 is an explanatory diagram illustrating map data; [Diagram 3] FIG. 2 is an explanatory diagram illustrating a control system for loading and unloading equipment. [Figure 4] FIG. 11 is an explanatory diagram illustrating self coordinate data; [Diagram 5] 4 is an explanatory diagram illustrating the range finder and a measurement object in FIG. 3; [Figure 6] FIG. 4 is an explanatory diagram illustrating an example of distance data in FIG. 3; [Figure 7] FIG. 1 is a flow diagram illustrating a range finder measurement method. [Figure 8] 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. [Figure 9] 11 is a flow chart illustrating a method for outputting self coordinate data in a control method for cargo handling equipment. FIG. [Figure 10] FIG. 10 is a flow diagram illustrating subroutines (S210) and (S220) of FIG. [Figure 11] FIG. 11 is a flow diagram illustrating a continuation of I in FIG. [Figure 12] 11 is an explanatory diagram illustrating a change in a first contribution rate and a second contribution rate over time. FIG. [Figure 13] 11A and 11B are explanatory diagrams illustrating self coordinate data under conditions that change over time. [Figure 14] 10 is an explanatory diagram illustrating an example of a change in travel speed due to travel control of cargo handling equipment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The control system and method for cargo handling equipment of the present invention will be described below based on the embodiment shown in the drawings. In the drawings, 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 the coordinate system may be an absolute coordinate system.

[0013] The loading equipment 1 illustrated in FIG. 1 may be a crane or a transport vehicle (container truck) that loads and unloads containers or other 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 many objects 2 are stored, in a container terminal. A running road surface 5 with which the running wheels 4 of the loading equipment 1 come into 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, many stopping points are set where the loading equipment 1 performs loading and unloading work, and one of the many stopping points is the target stopping point. For example, when the warehouse facility is a container terminal, many 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 objects 2 are created in advance.

[0014] The map data 20 illustrated in FIG. 2 is a data set that accumulates stopping coordinate data ("(...,...)" in the figure) that indicates target values ​​for the stopping posture of the loading / unloading equipment 1 at multiple stopping points, including points where the loading / unloading equipment 1 performs loading / 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.

[0015] As target values ​​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 spaced apart in the Y-axis direction for one stopping location, it is possible to calculate the orientation at that stopping location as viewed in the Z-axis direction. 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.

[0016] 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 stop point. The stop posture angle obtained from the stop coordinate data of multiple points at one stop point may be different for each stop point, but the storage lane 3 uses the inclination with respect to the X-axis as viewed in the Z direction, and is set to "zero degrees" at multiple stop points. In other words, by stopping the cargo handling equipment 1 in accordance with the stop coordinate data of multiple points at the stop point, there is no deviation in the X-axis direction with respect to the storage position of the cargo 2 at the stop point, and alignment in the X-axis direction is completed. In addition, there is no deviation in the orientation as viewed in the Z direction, and alignment as viewed in the Z direction is completed.

[0017] In an example of map data 20 in FIG. 2, (...,...) indicates 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 cargo handling equipment 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 cargo handling equipment 1 in the Y-axis direction at the stopping location. Point Q indicates the midpoint between points P and R.

[0018] In the loading and unloading operation of the loading and unloading equipment 1, alignment in the Y-axis direction by the traveling of the loading and unloading equipment 1 is not essential. Therefore, it is not essential that the stop coordinate data has 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 as target lines (a set of planar coordinates surrounded by dotted lines in the figure) in one storage lane 3. Controlling the traveling of the loading and unloading equipment 1 along this target line is advantageous in improving the straightness of the traveling of the loading and unloading equipment 1.

[0019] Fig. 3 shows a state in which the cargo handling equipment 1 is traveling from designated number A1 to designated number An according to the map data 20. The solid dots in Fig. 3 indicate points P, Q, and R of the map data 20. The open dots in Fig. 3 indicate points p, q, and r of predetermined locations on the cargo handling equipment 1, and points p, q, and r correspond to points P, Q, and R of the map data 20, respectively.

[0020] 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.

[0021] 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 be such that the coordinate acquisition device 11 and the distance meter 12 are installed in the loading equipment 1, and the calculation device 13 is installed in a location away from the loading equipment 1. Similarly, the coordinate acquisition device 11 and the distance meter 12 may be such that the radio positioning device 14, the internal sensor 15, and the external sensor 17 are installed in the loading equipment 1, and the coordinate calculation device 16 and the distance calculation device 18 are 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 in which the functions of each are integrated.

[0022] The control system 10 executes a driving control process to adjust the rotation speed of the running wheels 4 of the cargo handling equipment 1 based on a large number of stop coordinate data shown in the map data 20 and the own coordinate data 21 of a predetermined location of the cargo handling equipment 1. The control system 10 executes data processing to output the own coordinate data 21 used in the driving control process.

[0023] 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 predetermined location of the loading equipment 1 and the current attitude angle θ (tilt with respect to the X-axis) of the loading equipment 1 as 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.

[0024] The self coordinate data 21 is composed of any 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 have a Y coordinate, although it is not essential that each point has a Y coordinate.

[0025] The coordinate acquisition device 11 illustrated in FIG. 3 is a device that acquires position coordinates of points p and r as predetermined locations of the cargo handling equipment 1, and includes a radio wave 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 wave 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 traveled distance of the cargo handling equipment 1 at each predetermined cycle. In other words, one example of the coordinate acquisition device 11 is configured by a combination of the radio wave positioning device 14 and an odometer (15, 16).

[0026] The radio wave positioning device 14 acquires its own position coordinates by transmitting and receiving radio waves to and from 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). An example of the radio wave positioning device 14 may 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 IEEE802.11 standard. However, in such devices that use indoor positioning, the range in which radio waves can be transmitted and received to and from 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 a receiver of a global navigation satellite system. It is sufficient that at least one radio wave transceiver 6 exists, and examples of the global navigation satellite system include positioning satellites such as GPS, QZSS, GLONASS, BeiDou, Galileo, and IRNSS.

[0027] The radio positioning device 14p is disposed at one end of the loading equipment 1 in the Y-axis direction, and the radio positioning device 14r is disposed at the other end of the loading equipment 1 in the Y-axis direction. The radio positioning device 14p acquires its own position coordinates (xgp, ygp). The radio positioning device 14r acquires its own position coordinates (xgr, ygr). The radio 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 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 transmitter / receiver 6. When the loading equipment 1 is a crane, the radio positioning device 14 is preferable to install it on the top of the structure of the crane (for example, a girder or a leg).

[0028] The installation positions of the radio positioning devices 14p and 14r on the loading equipment 1 are preferably based on points p and r, respectively. More specifically, it is preferable that the X coordinate of the self-position coordinates acquired by each of the radio positioning devices 14p and 14r approximately coincides when the attitude angle θ of the loading equipment 1 is "zero°". It is preferable 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 preferable 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°".

[0029] 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 various known internal sensors such as a rotary encoder, an inertial measurement unit (IMU: a combination of a gyro sensor and an acceleration sensor), and an attitude and heading reference system (AHRS: a combination of an IMU and a geomagnetic sensor) may be used. 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 traveling speed and traveling 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 that the internal sensor 15 be a sensor that detects any one of the rotation speeds of the running wheels, the rotation speed of the axle, and the rotation speed of the electric motor that is the drive source.

[0030] The coordinate calculation device 16 may be implemented by various known computers. The coordinate calculation device 16 has a central processing unit (CPU), a main storage unit (memory), an auxiliary storage unit (e.g., HDD), and an input / output unit. A predetermined program stored in the auxiliary storage unit is started in the coordinate calculation device 16, and the coordinate calculation device 16 executes each procedure instructed by the started predetermined program. Specifically, the coordinate calculation device 16 executes data processing to calculate a travel distance for each predetermined 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.

[0031] The distance meter 12 may be any of various known distance meters, such as a magnetic induction distance sensor that measures the remaining distance to the stopping point at a predetermined period, 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.

[0032] The distance calculation device 18 may be implemented by various known computers. The distance calculation device 18 has a central processing unit (CPU), a main storage unit (memory), an auxiliary storage unit (e.g., HDD), and an input / output unit. The distance calculation device 18 stores distance data 22 in its storage unit. The distance calculation device 18 executes data processing to output the remaining distance calculated based on the detection state 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 at the timing when the calculated remaining distance becomes zero.

[0033] The arithmetic device 13 may be any of various known computers. The arithmetic device 13 has a central processing unit (CPU), a main storage unit (memory), an auxiliary storage unit (e.g., HDD), and an input / output unit. The arithmetic device 13 is electrically connected to the coordinate acquisition device 11 and the distance meter 12 via the input / output unit. The arithmetic device 13 is also electrically connected to an inverter via the input / output unit. Map data 20 is stored in the auxiliary storage unit.

[0034] The arithmetic device 13 starts a predetermined program stored in the auxiliary storage unit, and executes each procedure according to the started predetermined program to control the traveling of the cargo handling equipment 1. Specifically, when a designated number is designated 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 designated by the higher-level system as a target stopping point, and causes the cargo handling equipment 1 to travel to the target stopping point.

[0035] Next, the rangefinder 12 will be described in detail.

[0036] 5 shows an example of an enlarged view of multiple measurement objects 7 (7p, 7r, 7y) installed at each stopping point 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 executes data processing to calculate the remaining distance to the stopping point based on the detection state of the measurement objects 7 by the external sensors 17.

[0037] The multiple measurement objects 7 are arranged at each of the multiple stopping points. The multiple measurement objects 7 are not particularly limited 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 ferromagnetic material that is magnetized. 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 line, Q line, or R line.

[0038] Each of the measurement objects 7p and 7r extends in the Y-axis direction and is arranged so that the stop 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.

[0039] 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 (e.g., the bottom end in the figure).

[0040] Distance data 22 illustrated in FIG. 6 is stored in the storage unit of distance calculation device 18. Distance data 22 is created for each external sensor 17. Distance data 22 is an accumulation of element numbers given to the plurality of detector elements 19 of each external sensor 17 and distances from the detector elements 19 that are the origin positions (points p and 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 distance calculation device 18 may store in the storage unit a formula using element numbers given to the plurality of detector elements 19 and distances between adjacent detector elements 19 instead of distance data 22.

[0041] FIG. 7 shows an example of a 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 state 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 the point p of the loading equipment 1 to the stopping point P, 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) will be described in detail below.

[0042] 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 when any of the plurality of detection elements 19 of the external sensor 17p detects the object 7p, and to determine that the sensor has not detected the object 7p when none of the plurality of detection elements 19 detects the object 7p. When the external sensor 17p is positioned directly above the object 7p, a predetermined number of detection elements 19 with consecutive element numbers among the plurality of detection elements 19 detect the object 7p. When the external sensor 17p moves away from directly above the object 7p, none of the plurality of detection elements 19 detects the object 7p. The predetermined number of detection 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 strength of the magnetic field of the object 7p and the distance between the adjacent detection elements 19. The predetermined number is preferably a fixed value, and is preferably greater than or equal to three and less than or equal to five.

[0043] 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 in a control method described later by distance calculation device 18, 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).

[0044] In the step (S140) of determining the positional relationship, 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 state of the measurement object 7p by 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. 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.

[0045] In the remaining distance calculation step (S150), data processing is executed 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. When the predetermined number of detector elements 19 that have detected the measured object 7p is an odd number, the remaining distance ΔXp is calculated from the element number given to the detector element 19 located directly above the measured object 7p. When the predetermined number of detector elements 19 that have 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 given to the detector elements 19 adjacent to both sides of the position directly above the measured object 7p.

[0046] In the step (S160) of determining whether the remaining distance ΔXp is zero or not and the step (S170) of outputting a signal, data processing is executed to determine whether the remaining distance ΔXp calculated by the distance calculation device 18 is zero or not, and if it is determined that the remaining distance ΔXp is zero, data processing is executed 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 be omitted. In this case, in the step (S170), data processing is executed 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 (flagA: ON).

[0047] The above steps (S110) to (S170) are always performed when the loading equipment 1 arrives at the target stop point, but may not be performed at all stop points between the starting point and the arrival of the loading equipment 1 at the target stop 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 stop point within a range where it does not come into contact with the storage lane 3 or other loading equipment. In this case, even if the loading equipment 1 passes the stop point, a situation may occur in which the external sensor 17p cannot detect the measurement object 7p at the stop point that it has passed. In addition, even if the travel speed of the loading equipment 1 is high and the external sensor 17p detects the measurement object 7p, a situation may occur in which it cannot detect the timing when the remaining distance ΔXp becomes zero.

[0048] 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.

[0049] 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.

[0050] The method of acquiring the first coordinate data is the same for each of 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 for estimating the first coordinate data for point p based on the accumulated travel distance Lp from the measurement start point and the coordinate data of the 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 for updating the accumulated travel distance Lp to zero and updating the coordinate data of the measurement start point based on the map data 20.

[0051] The cumulative travel distance Lp is a distance obtained by accumulating the travel distance ΔLp measured at a predetermined period from the measurement start point 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 stored in advance in the storage unit of the coordinate calculation device 16. In other words, the cumulative travel distance Lp is accumulated and extended at each measurement period of the internal sensor 15p.

[0052] The measurement start point is the point where the accumulation of the cumulative mileage Lp starts. The measurement start point indicates point P of 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.

[0053] The block diagram illustrated in Fig. 8 shows an example of data processing for calculating first coordinate data (self-coordinate data). 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 storage unit of the coordinate calculation device 16, but each part may be configured by an electronic circuit.

[0054] The accumulator 23 receives the mileage ΔLp measured by the odometer (15p, 16) and the signal S1 transmitted from the odometer 12. The accumulator 23 sequentially accumulates the mileage ΔLp that is input, and outputs the accumulated mileage Lp. When the accumulator 23 receives the signal S1, the accumulator 23 updates the accumulated mileage Lp to zero. In other words, the accumulator 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.

[0055] The selection unit 24 receives 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 a 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.

[0056] The selection unit 24 may use positioning coordinate data of point p calculated based on the self-location coordinate measured by the radio positioning device 14p and the self-location coordinate (xgr) measured by the radio positioning device 14r, instead of the self-location 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-location coordinate (xgp, ygp) acquired by the positioning device 14p and the self-location coordinate (xgr, ygr) acquired by the positioning device 14r.

[0057] Sensitivity is an index of the accuracy of the self-position coordinate, and indicates the degree of influence on the quality of the radio waves transmitted and received between the radio wave positioning device 14p and the radio wave transceiver 6 and the strength of the radio waves that can be received. As the sensitivity, the accuracy degradation rate, the signal strength, the number of satellites used for positioning, etc. can be used, and a value obtained by comprehensively quantifying them may be used. The self-position coordinate acquired in a high sensitivity state has high accuracy, but the self-position coordinate acquired in a low sensitivity state has low accuracy and lacks reliability. The standard level of sensitivity can be set arbitrarily, and it is advisable to take into consideration the constant radio wave conditions in the warehouse facility, the radio wave conditions at a specific location in the warehouse facility, etc. In the figure, a state in which the sensitivity is higher than the standard is called good.

[0058] 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 collated. 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 stop coordinate data that is approximate 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 and unloading equipment 1 at that timing.

[0059] 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.

[0060] The adding unit 27 receives the accumulated travel distance Lp output from the accumulating unit 23 and the coordinate data of the measurement start point output from the setting unit 26. The adding unit 27 outputs a value obtained by adding the accumulated travel distance Lp and the coordinate data of the measurement start point as first coordinate data (xcp) of point p.

[0061] Similarly, the first coordinate data (xcr) of point r is also output. The first coordinate data of points p and r obtained by this acquisition method are input to the arithmetic unit 13. The arithmetic unit 13 performs data processing, which will be described later, and executes travel control processing of the cargo handling equipment 1 using the first coordinate data as its own coordinate data.

[0062] As described above, according to this method of acquiring first coordinate data, the accumulated travel distance and the coordinate data of the measurement start point are reset every 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 accumulated travel distance has a small accumulation error and is highly accurate. In other words, the control system 10 is configured to reduce computational resources by using a very simple method of acquiring first coordinate data (self coordinate data) using the odometer (15, 16), and yet can estimate the first coordinate data (self coordinate data) with high accuracy.

[0063] The accuracy of the accumulated mileage obtained by measurement with the odometer (15, 16) is higher as 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 a change in the outer diameter of the running wheels 4. 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 accumulated mileage.

[0064] In this regard, according to the first coordinate data acquisition method, 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, every time the stopping point P is located directly below point p, the control system 10 uses the stopping coordinate data of the P point as the coordinate data of the measurement start point for the next accumulated traveling distance, thereby making it possible to reduce the influence of accumulated errors in the accumulated traveling distance.

[0065] The coordinate data of the measurement start point can be specified using only the first coordinate data estimated based on the cumulative mileage, without using the self-location coordinates acquired by the radio positioning device 14. However, the cumulative mileage includes an accumulated error, and the accuracy of the self-location coordinates acquired by the radio positioning device 14 may be higher than the accuracy of the first coordinate data estimated based on the cumulative mileage. Therefore, the coordinate data of the measurement start point can be specified more accurately by using both the first coordinate data estimated based on the cumulative mileage and the self-location coordinates acquired by the radio positioning device 14 to specify the coordinate data of the measurement start point. In addition, when the sensitivity of the radio wave transmission and reception of the radio wave of the radio positioning device 14 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 specify the coordinate data of the measurement start point even in poor radio wave conditions. Incidentally, the coordinate acquisition device 11 does not necessarily 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.

[0066] In addition, the timing when the remaining distance measured by the distance meter 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 radio waves of the radio wave positioning device 14 is higher than a reference, 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 traveling state of the loading equipment 1, there are cases where the timing when the remaining distance measured by the distance meter 12 becomes zero cannot be detected. For example, there is a case where the loading equipment 1 is traveling 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 target 7 at the stop point that it has passed. There is also a case where the traveling speed of the loading equipment 1 is high, and even if the external sensor 17 detects the measurement target 7, it cannot detect the timing when the remaining distance becomes zero. In such a case, instead of the timing when the remaining distance measured by the distance meter 12 becomes zero, the timing when the positioning coordinate data matches the stop coordinate data can be used as a trigger for updating the coordinate data of the measurement start point. This increases the frequency of updating the coordinate data of the measurement start point and shortens the cumulative travel distance, thereby enabling the accuracy of the self-coordinate data to be improved.

[0067] 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 may store in the storage unit the coordinate data of the measurement start point prior to the coordinate data of the measurement start point updated in the update process and the accumulated mileage before being updated to zero. Then, it is preferable that the coordinate calculation device 16 executes data processing to update the pre-stored outer diameter of the running wheel 4 based on the coordinate data of the updated measurement start point, the coordinate data of the measurement start point prior to the update, and the accumulated 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 traveling 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 accumulated traveling distance before the update, and multiplying the result by the stored outer diameter of the running wheel 4.

[0068] 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 stop coordinate data of the two 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 the 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 accuracy of the first coordinate data.

[0069] In addition, 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 accompanying a change in the total weight of the loading equipment 1 due to the loading of the cargo 2 on the loading equipment 1, it is advisable to update the outer diameter of the running wheels 4 before and after the loading work of the loading equipment 1. For example, when the cargo 2 is loaded on the loading equipment 1, the outer diameter of the running wheels 4 stored in advance by the above-mentioned data processing is updated, and when the loaded cargo 2 is loaded, the outer diameter of the running wheels 4 is restored to the outer diameter stored in advance. 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 accompanying 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.

[0070] 9 to 11 show an example of an embodiment of the control method for the loading equipment 1. The series of flows shown in Fig. 10 and Fig. 11 are detailed flows of the subroutines shown in (S210) and (S220) of Fig. 9. The control method for 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 Fig. 9. Note that the measurement method of the range finder 12 shown in Fig. 6 is performed in parallel with this control method. Also, the method of acquiring the first coordinate data shown in Fig. 8 is performed in the step of (S310) of Fig. 10.

[0071] First, the X coordinates of points p and r are calculated by the arithmetic device 13 to generate self coordinate data 21 (S210, S220). Next, the X coordinate and attitude angle θ of point q are calculated based on the self coordinate data 21 by the arithmetic device 13 (S230), and a travel control process is performed based on the calculated X coordinate and attitude angle θ of point q and 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 point.

[0072] In calculating the X-coordinate of point p (the X-coordinate of point r is calculated in the same manner), first, the coordinate calculation device 16 calculates the first coordinate data (xcp) (S310). Then, the calculation device 13 executes each step (S320 to S350, S410 to S450). Finally, the calculation device 13 continues to execute the steps (S410: NO or S420: NO) until the rangefinder 12 is ready for measurement. 420 If the result of step S440 is NO, the calculation device 13 outputs the first coordinate data (xcp) as the X coordinate of point p (S460). Furthermore, until a predetermined time Ta has elapsed since the rangefinder 12 became capable of measurement (S440: NO), the calculation device 13 outputs the third coordinate data (xcmp) as the X coordinate of point p (S470). Furthermore, 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 contents of each of the steps (S210) to (S240), (S310) to (S350), and (S410) to (S480) will be described in detail below.

[0073] In the step of calculating the X coordinate of point p (S210) and the step of calculating the X coordinate of point r (S220), data processing is executed by the arithmetic device 13 to calculate the X coordinate of each of point p and point r. By these two steps, self coordinate data 21 is created and stored in the memory unit of the arithmetic device 13.

[0074] In the step (S230) of calculating the X-coordinate and attitude angle θ of point q, the arithmetic device 13 executes data processing to calculate the X-coordinate of point q as the midpoint of points p and q 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 points p and r and the length Bc of the line segment connecting points p and r. The attitude angle θ indicates the inclination of the normal to the line segment connecting points p and r with respect to the X-axis. The length Bc of the line segment connecting points p and r 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. The length Bc is exemplified by the length between the radio wave positioning devices 14p and 14r, or the length between the external sensors 17p and 17r. The attitude angle θ is calculated by dividing the difference between the X-coordinates of points p and r by the length Bc of the line segment connecting points p and r. -1 ) is calculated as

[0075] In the travel control step (S240), the arithmetic device 13 executes a travel control process for controlling the travel of the cargo handling 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 the travel direction of the cargo handling equipment 1 are adjusted. The travel speed is adjusted by adjusting the deceleration of the cargo handling equipment 1 in the vicinity of the target stopping point based on the deviation of the X-coordinate, and switching is performed between constant acceleration, constant speed, and constant deceleration in other locations. The travel direction is adjusted by adjusting the difference in the travel speed between both ends of the cargo handling equipment 1 in the Y-axis direction based on the attitude angle θ.

[0076] In the step (S310) of calculating the first coordinate data of point p, the coordinate calculation device 16 executes the data processing exemplified in Fig. 8. Specifically, the coordinate calculation device 16 calculates the first coordinate data (xcp) of point p of the cargo handling equipment 1 using the odometers (15p, 16) and the external sensor 17p.

[0077] In the step (S320) of calculating the deviation Δxp, the arithmetic 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 an approximate distance from point p of the cargo handling equipment 1 to point P of the target stopping location.

[0078] In the step (S330) of judging whether the deviation Δxp is equal to or smaller than the predetermined distance ΔL, the calculation device 13 executes data processing to compare the calculated deviation Δxp with the preset predetermined distance ΔL to judge whether the distance meter 12 is ready for measurement. 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 judging 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 showing that the distance meter 12 is ready to measure the remaining distance.

[0079] 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 an 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 the stopping points adjacent to each other in the traveling direction of the loading equipment 1, and is preferably shorter than half the shortest distance, and more preferably within a range of 50 mm to 500 mm.

[0080] In a step (S340) of turning on flag B and a step (S350) of turning off flag B, data processing is executed in which the arithmetic unit 13 sets or clears flag B based on the result of the determination in step (S330). Specifically, when it is determined that the rangefinder 12 is capable of measuring the remaining distance ΔXp by comparing the deviation Δxp with the predetermined distance ΔL (S330: YES), flag B is set (flagB: ON), and when it is determined that the rangefinder 12 is not capable of measuring (S330: NO), flag B is cleared (flagB: OFF).

[0081] In steps (S410, S420) for determining whether flags A and B are on, the arithmetic unit 13 executes data processing for determining whether each flag is on or off. The loading equipment 1 may pass through a plurality of 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. That is, 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 distance meter 12. Therefore, it is possible to determine whether the distance meter 12 is in a state where it can measure by determining the flag B set by comparing the deviation Δxp with the predetermined distance ΔL. 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 measurement target 7p, it can be judged that rangefinder 12 is able to 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 that rangefinder 12 is able to measure remaining distance ΔXp to the target stopping point.

[0082] Each of steps (S120), (S130), (S330) to (S350), (S410), and (S420) constitutes data processing for determining that the distance meter 12 is capable of measuring the remaining distance to the target stopping point. When the accuracy of the deviation Δxp is high, this data processing may be composed of only each of steps (S330) to (S350) and (S410).

[0083] In the step (S430) of calculating the second coordinate data, 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 rangefinder 12. Specifically, the calculation device 13 calculates the second coordinate data (xmp) using the stopping posture coordinate data of the target stopping point, with the remaining distance ΔXp set as the relative distance from point p to point P of the target stopping point. The second coordinate data is calculated by subtracting the remaining distance ΔXp from the X coordinate (xP) of point P of the target stopping point.

[0084] In the step (S440) of determining whether the elapsed time T has exceeded the predetermined time Ta, the arithmetic device 13 executes data processing to compare the elapsed time T that has elapsed since the flag A was turned on with the 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 included in the arithmetic device 13, or may be estimated from the number of periods measured by a counter included in the arithmetic device 13. It is desirable that the predetermined time Ta is set to a time that is shorter than the time from when the flag A is turned on until the traveling of the loading equipment 1 stops, 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 elapsed since the flag B was turned on.

[0085] 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 is immediately switched 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 traveling speed in the traveling control processing when the difference between the first coordinate data and the second coordinate data is large. The sudden change in the traveling speed causes pitching vibration of the loading equipment 1 and swing of the hoisting tool 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, the transition of the coordinate data can be smoothed by using the third coordinate data based on the coordinates of both the first coordinate data and the second coordinate data immediately after the flags A and B are turned on. In this way, the transition of the coordinate data becomes smooth, which is advantageous in suppressing sudden fluctuations in the traveling speed.

[0086] The third coordinate data may be the median (average value) between the first coordinate data and the second coordinate data. It is desirable that the contribution of the first coordinate data to the third coordinate data is decreased as the elapsed time Ta progresses, and conversely, the contribution of the second coordinate data is increased. 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 has a value close to the coordinate data with a higher contribution and a value far from the coordinate data with a lower contribution.

[0087] 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.

[0088] 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 neither flag A nor flag B is 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 from when both flags A and B are on has not passed a predetermined time Ta, the calculation device 13 outputs the third coordinate data (xcmp). Furthermore, when the elapsed time T from when both flags A and B are on has passed a predetermined time Ta, the calculation device 13 outputs the second coordinate data (xmp).

[0089] Fig. 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 loading equipment 1 in the Y-axis direction, and indicates the side where radio wave positioning device 14p, internal sensor 15p, and external sensor 17p are installed. Point r indicates the other end side of loading equipment 1 in the Y-axis direction, and indicates the side where radio wave positioning device 14r, internal sensor 15r, and external sensor 17r are installed.

[0090] At time t1, flags A and B on the side of point p and the side of point r are both off. The X coordinate of point q at time t1 is calculated as the intermediate coordinate between the first coordinate data (xcp) of point p and the first coordinate data (xcr) of point r.

[0091] 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.

[0092] At time t3, flags A and B on the point p side and the point r side are both on. Also, at time t3, the elapsed times Tp and Tr from when flags B on the point p side and the point r side 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.

[0093] At time t4, the elapsed time Tp on the point p side has passed the predetermined time Ta, and the elapsed time Tr on the point r side 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.

[0094] At time t5, the elapsed times Tp and Tr on the point p side and the point r side have exceeded 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.

[0095] Fig. 14 shows an example of the relationship between the passage of time in the travel control process and the travel speed of the loading and unloading equipment 1. When the self coordinate data 21 is output, the computing device 13 executes the travel control process of the loading and unloading equipment 1 (S240 in Fig. 9). The travel control process adjusts two things: the travel speed of the loading and unloading equipment 1, and the travel direction of the loading and unloading equipment 1 (including the orientation of the loading and unloading equipment 1 when travel stops).

[0096] In the adjustment of the traveling speed, the traveling speed of the cargo handling 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 point Q and the X coordinate of point q of the target stopping point). In the adjustment of the traveling speed, the relationship between the elapsed time from when the cargo handling 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 addition, in the adjustment of 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 point Q and the X coordinate of point q of the target stopping point match) after the traveling speed of the cargo handling equipment 1 is switched to the constant deceleration. That is, constant acceleration, constant velocity, and constant deceleration are switched using the self coordinate data 21 based on the first coordinate data, and deceleration is adjusted using the self coordinate data 21 based on the second coordinate data.

[0097] In adjusting the traveling direction, the difference in traveling speed between both ends of the cargo handling equipment 1 in the Y-axis direction is adjusted based on the attitude angle θ. In adjusting the traveling direction, the traveling speed adjusted by the travel speed control is corrected, and the traveling direction of the cargo handling equipment 1 is adjusted based on the speed difference between both ends in the Y direction. Note that in adjusting the traveling direction when the traveling wheels of the cargo handling equipment 1 are steerable, the steering angle of the cargo handling equipment 1 may be adjusted.

[0098] In the travel control process, in order to further improve the straightness of the travel of the cargo handling equipment 1, it is preferable to adjust the travel speed difference between both ends of the cargo handling equipment 1 in the Y-axis direction based on the deviation amount 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 amount in the Y-axis direction. At each of multiple stopping points that the cargo handling 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 multiple stopping points, but also between stopping points, and may extend over the entire length of the storage lane 3.

[0099] As described above, according to this embodiment, in the vicinity of the target stopping point, the second coordinate data obtained by measurement using the range finder 12 is used as the self coordinate data 21. This second coordinate data is obtained by measuring the measurement target 7 installed at the target stopping point as the measurement target, and is highly accurate. Therefore, the cargo handling equipment 1 can be stopped at the target stopping point with high accuracy by the travel control process using the second coordinate data.

[0100] Furthermore, according to this embodiment, 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 travel road surface 5, making it possible to reduce the installation costs and maintenance thereof.

[0101] That is, in this embodiment, the first coordinate data is used for travel control in a travel section where a certain degree of low accuracy is acceptable, and the highly accurate second coordinate data based on the remaining distance is used for travel control in a travel section where high accuracy is required. In this way, by using the coordinate acquisition device 11 and the distance meter 12 selectively, the low accuracy of the coordinate acquisition device 11 can be compensated for by the distance meter 12, and the high cost required to measure the entire travel range of the loading equipment 1 by the distance meter 12 can be compensated for by the coordinate acquisition device 11. Therefore, this embodiment can stop the loading equipment 1 at the target stop point with high accuracy while suppressing an increase in cost. This makes it possible to ensure an accuracy of ±20 mm or less required 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.

[0102] Furthermore, in this embodiment, 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 multiple stopping points. This eliminates the need for the range finder 12 to obtain absolute position information, and the range finder 12 only needs to be configured to measure 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 multiple stopping points can be minimized.

[0103] In this embodiment, 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 a smooth transition when switching from the first coordinate data to the second coordinate data. Therefore, it is possible to suppress a sudden change in the running speed in the running 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 a sudden change in the running speed does not occur in the running control process even when switching from the first coordinate data to the second coordinate data, it is not necessary to use the third coordinate data. In this case, the steps (S440), (S450), and (S470) of the above control flow can be omitted.

[0104] In the case of a loading device 1, such as a crane, in which the traveling direction is controlled by the speed difference between both ends in the Y-axis direction, the time when flag B turns on and the time required for flag A to turn on after flag B turns 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 (the p-point side and the 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 in the Y-axis direction of the loading device 1. Note that even if the loading device 1 is a crane, there are cases in which the self-coordinate data 21 is not estimated for each of both ends. 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 calculated from the X coordinate of point p and the X coordinate of point r and the posture angle θ are calculated as the respective coordinate data.

[0105] 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 the specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention.

[0106] The loading / unloading equipment 1 is not limited to a crane that travels across the storage lane 3. The loading / unloading equipment 1 may be a crane that handles loading / unloading from a ship berthed at a quay of a container terminal or an overhead crane that handles loading / unloading in a warehouse facility. The loading / unloading equipment 1 may be a transport vehicle that travels in a warehouse facility such as a container terminal. Furthermore, the cargo 2 that the loading / 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.

[0107] The multiple stopping points may include points other than the points where the loading and unloading work is performed by the loading and unloading equipment 1. Examples of such points include points where the loading and unloading equipment 1 stops on the way to the point where the loading and unloading work is performed, and points where the traveling direction is changed. Specifically, when the loading and unloading equipment 1 is a crane, an example of such a point is a predetermined point on a connecting road used for lane changing. Also, when the loading and unloading equipment 1 is a transport vehicle, an example of such a point is a point where the transport vehicle stops temporarily or turns right or left at a container terminal. Furthermore, examples of such a point include a point where the loading and unloading equipment 1 is maintained or inspected, and a point where the energy of the drive source of the loading and unloading equipment 1 is replenished.

[0108] The control system 10 may have a different configuration depending on the type of cargo handling equipment 1 to be controlled. When the cargo handling equipment 1 is a transport vehicle, the coordinate acquisition device 11 may have one radio wave positioning device and one odometer, and the odometer 12 may have one external sensor.

[0109] The coordinate acquisition device 11 does not have to have both the radio positioning device 14 and the odometer (15, 16), and may be composed of only the radio positioning device 14 when the sensitivity of the radio wave transmission and reception of the radio waves of the radio positioning device 14 is always high. Also, the coordinate acquisition device 11 may be composed of only the odometer (15, 16) and the inertial navigation system (autonomous navigation system) when the sensitivity of the radio wave transmission and reception of the radio waves of the radio positioning device 14 is always low.

[0110] The self-position coordinates acquired by the radio wave positioning device 14 may have low accuracy because they are affected by dynamic attitude changes (e.g., pitching vibration) of the loading equipment 1. Therefore, it is desirable to apply a filter to the self-position coordinates acquired by the radio wave positioning device 14 by the coordinate calculation device 16 to remove noise including pitching vibration.

[0111] Specifically, this filter may be a known Kalman filter capable of removing noise including pitching vibration. The Kalman filter is set based on an observation equation in which the self-position coordinates and the rotation speed of the motor for traveling of the cargo handling equipment 1 are the observation values, a state equation in which the self-position coordinates and the rotation speed of the motor for traveling are the state quantities, and a pitching vibration system is incorporated by assuming that the dynamic characteristic in which the rotation speed of the motor for traveling reaches the target rotation speed is a one-time delay characteristic with a predetermined time constant, and the noise covariance of the observation equation and the noise covariance of the state equation. Applying such a filter to the self-position coordinates is advantageous in improving the accuracy of the self-position coordinates.

[0112] It is also preferable that the computing device 13 executes travel control based on the dynamic change in the attitude of the loading equipment 1. This travel control is a control that generates a speed command that makes the residual vibration of the pitching vibration a one-degree-of-freedom vibration system zero, and adjusts the rotation speed of the motor for travel based on the speed command. The speed command that makes the residual vibration zero can be generated by input shaping that performs convolution integral between a first impulse train based on the natural frequency and damping ratio of the pitching vibration and a target rotation speed. By using such travel control, it is possible to suppress the dynamic change in the attitude of the loading equipment 1, which is advantageous for improving the accuracy of the self-position coordinates acquired by the radio wave positioning device 14.

[0113] In order to improve the accuracy of the self-position coordinate of the radio wave positioning device 14, it is effective to apply a filter by the coordinate calculation device 16 and to implement driving control by the calculation device 13 to suppress dynamic attitude changes. By using both the application of a filter and driving control to suppress dynamic attitude changes, it is possible to improve the accuracy of the first coordinate (e.g., xcp) obtained from the self-position coordinate of the radio wave positioning device 14. Therefore, when the coordinate acquisition device 11 is composed of only the radio wave positioning device 14 and the coordinate calculation device 16, it is possible to make the gap when switching from the first coordinate to the second coordinate smaller.

[0114] When the cargo handling equipment 1 handles cargo 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 cargo handling equipment 1, or may be a portable device carried by a driver who boards the cargo handling 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 preferable that the coordinate calculation device 16 and the calculation device 13 are configured as a computer connected to the portable device so as to be able to communicate with each other.

[0115] Based on a signal S1 indicating that the remaining distance measured by the distance meter 12 has become zero, the coordinate acquisition device 11 updates the accumulated travel distance to zero and executes an update process to update the coordinate data of the measurement start point, but the signal S1 may be sufficient as long as it can time when the stopping point is located directly below a predetermined point of 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 detect the measurement object when it is located directly above the measurement object. However, by timing the update process using the measurement result of the distance meter 12, it is possible to obtain a highly accurate accumulated travel distance.

[0116] 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.

[0117] 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 travel 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 an absolute type linear scale. 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 the maintenance cost is higher than that combination, the combination of the measurement object 7 and the external sensor 17 can also be a combination of a mark installed on the travel 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.

[0118] 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 less than a predetermined number of detector elements 19 detect the measurement object 7, the remaining distance may be calculable 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.

[0119] The map data 20 is not limited to a data set in which stopping coordinate data of a plurality of points of one stopping position is accumulated. The map data 20 may be a data set in which stopping coordinate data of one point of one stopping position and an attitude angle at that point are accumulated. Similarly, the self coordinate data 21 may be composed of X coordinate data of one point of the cargo handling equipment 1 and an attitude angle θ. [Explanation of symbols]

[0120] 1. Cargo handling equipment 6 Radio transmitter / receiver 7 Measurement Object 10. Control System 11 Coordinate acquisition device 12 Rangefinder 13 Arithmetic unit 14 Radio-based positioning device 15 Internal Sensors 16 Coordinate Calculation Unit 17 External Sensors 18 Distance calculation device 19 Detector element 20 Map Data 21 Self-coordinate data 22 Distance Data

Claims

1. 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, The system is equipped with a coordinate acquisition device that sequentially acquires position coordinates of a predetermined location of the loading and unloading equipment, a distance meter that sequentially measures a remaining distance from the predetermined location to one of the multiple stopping locations when the loading and unloading equipment approaches the stopping location, and a calculation device, and the distance meter has an external sensor that detects a measurement object installed at each of the multiple stopping locations, The calculation device executes the following data processing: data processing to output self-coordinate data based on the position coordinates acquired by the coordinate acquisition device until the rangefinder is able to measure the remaining distance to the target stopping point among the multiple stopping points; data processing to determine that the rangefinder is able to measure the remaining distance to the target stopping point based on the position coordinates and whether or not the object to be measured is detected by the external sensor; and data processing to output self-coordinate data based on the remaining distance measured by the rangefinder after determining that the rangefinder is able to measure the remaining distance to the target stopping point.

2. The loading equipment control system of claim 1, wherein the calculation device performs data processing to output self-coordinate data based on both the position coordinates and the self-coordinate data based on the remaining distance until a predetermined time has elapsed since the rangefinder determined that it is able to measure the remaining distance to the target stopping point.

3. 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, a coordinate acquisition device which sequentially acquires position coordinates of a predetermined location of the loading and unloading equipment, a distance meter which sequentially measures a remaining distance from the predetermined location to one of the multiple stopping locations when the loading and unloading equipment approaches the stopping location, and a calculation device, The calculation device executes the following data processing to output self coordinate data based on the position coordinates acquired by the coordinate acquisition device until the rangefinder is able to measure the remaining distance to a target stopping point among the multiple stopping points; data processing to determine that the rangefinder is able to measure the remaining distance to the target stopping point based on the position coordinates; data processing to output self coordinate data based on both the self coordinate data based on the position coordinates and the self coordinate data based on the remaining distance measured by the rangefinder until a predetermined time has elapsed since the rangefinder determined that it is able to measure the remaining distance to the target stopping point; and data processing to output self coordinate data based on the remaining distance after the predetermined time has elapsed.

4. A control method for controlling travel of a loading / unloading device based on map data in which stop 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, comprising: A coordinate acquisition device sequentially acquires position coordinates of a predetermined location of the loading and unloading equipment; using a distance meter having an external sensor for detecting a measurement object installed at each of the plurality of stopping points, when approaching one of the plurality of stopping points, the remaining distance from the predetermined point to the stopping point is measured sequentially; a calculation device processes the position coordinates acquired by the coordinate acquisition device to output self-coordinate data based on the position coordinates, and determines that the range finder is able to measure the remaining distance to a target stopping point among the multiple stopping points based on the position coordinates and the presence or absence of detection of the measurement object by the external sensor; A control method for loading and unloading equipment, characterized in that after it is determined that the range finder is able to measure the remaining distance, the remaining distance measured by the range finder is processed by the arithmetic device, and self-coordinate data based on the remaining distance is output.

5. A control method for loading and unloading equipment as described in claim 4, in which the arithmetic device outputs self-coordinate data based on both self-coordinate data based on the position coordinates and self-coordinate data based on the remaining distance until a predetermined time has elapsed after the rangefinder has determined that it is able to measure the remaining distance to the target stopping point.

6. A control method for controlling travel of a loading / unloading device based on map data in which stop 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, comprising: A coordinate acquisition device sequentially acquires position coordinates of a predetermined location of the loading and unloading equipment; using a distance meter to sequentially measure the remaining distance from the predetermined point to one of the multiple stopping points when the vehicle approaches the stopping point; a calculation device processes the position coordinates acquired by the coordinate acquisition device to output self-coordinate data based on the position coordinates, and identifies that the rangefinder is able to measure the remaining distance to a target stopping point among the multiple stopping points based on the position coordinates; outputting self-coordinate data based on both self-coordinate data based on the position coordinates and self-coordinate data based on the remaining distance by processing the position coordinates and the remaining distance measured by the rangefinder by the arithmetic unit until a predetermined time has elapsed since it was determined that the rangefinder has become capable of measuring the remaining distance to the target stopping point; A method for controlling loading and unloading equipment, characterized in that after the specified time has elapsed, the remaining distance measured by the distance meter is processed by the arithmetic device, and self-coordinate data based on the remaining distance is output.

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