Unmanned conveyance vehicle

Abstract

An unmanned conveyance vehicle that conveys a carriage comprises: a vehicle body; a detection unit that is provided on the vehicle body and can detect the carriage within a predetermined detection range with respect to the vehicle body; an acquisition unit that acquires a plurality of search locations including a search start location; and a control unit that, after controlling the vehicle body so as to move to the search start location, executes a search process of searching for the carriage via the detection unit, and when the search for the carriage fails at the search start location, controls the vehicle body so as to move to the next search location among the plurality of search locations and repeats execution of the search process at the next search location until the search for the carriage succeeds.

Description

automated guided vehicle

[0001] This specification discloses an automated guided vehicle.

[0002] Conventionally, a mobile robot has been proposed that is equipped with a camera unit that takes pictures of the robot's surroundings and a drive unit attached to the neck or the like that can change the position and orientation of the camera unit.The robot uses the camera to recognize an object, and if it fails to recognize the object, it searches for the object by rotating its head (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2010-221325

[0004] When transporting carts stored in a cart storage area using an automated guided vehicle, it is necessary to ensure that carts can be found reliably, regardless of how they are placed, so that no carts are missed.

[0005] A primary object of the present disclosure is to provide an automated guided vehicle that can more reliably find a carriage to be transported.

[0006] The present disclosure has adopted the following means to achieve the above-mentioned main object.

[0007] The first automated guided vehicle of the present disclosure is an automated guided vehicle that transports a cart, comprising: a cart body; a detection unit provided on the cart body and capable of detecting the cart within a predetermined detection range of the cart body; an acquisition unit that acquires a plurality of search positions including a search start position; and a control unit that controls the cart to move to the search start position, and then executes a search process to search for the cart using the detection unit, and if the search for the cart at the search start position fails, controls the cart body to move to the next search position of the plurality of search positions, and repeats executing the search process at the next search position until the search for the cart is successful.

[0008] In the first automated guided vehicle disclosed herein, if a search for a cart fails at the search start position, the automated guided vehicle moves to the next search position among the plurality of search positions and repeats the search process until the search for the cart is successful. By specifying positions where the cart may be located as the plurality of search positions, it becomes possible to more reliably find a cart in the vicinity even if the cart cannot be detected at the search start position.

[0009] A second automated guided vehicle of the present disclosure is an automated guided vehicle that transports a trolley, comprising: a vehicle body; a detection unit provided on the vehicle body and capable of detecting the trolley within a predetermined detection range of the vehicle body; and a control unit that controls the vehicle body to move to a predetermined search position, and then executes a search process to search for the trolley using the detection unit, and if the search for the trolley at the search position fails, changes at least one of the orientation and position of the vehicle body and executes a re-search process to search for the trolley using the detection unit.

[0010] In the second automated guided vehicle disclosed herein, if the search for the cart at the search position fails, the direction and / or position of the vehicle body is changed and a search process is executed again to search for the cart by the detection unit. This makes it possible to more reliably find a nearby cart even if the cart cannot be detected at the search position.

[0011] 15A and 15B are external perspective views of a plurality of basket trolleys arranged in a trolley storage area of ​​a store or the like, and an automated guided vehicle that transports the basket trolleys. FIG. 15A is an external perspective view of an automated guided vehicle, a basket trolley, and a marker. FIG. 15B is an external perspective view of an automated guided vehicle. FIG. 15B is a side view of an automated guided vehicle. FIG. 15C is a side view of an automated guided vehicle. FIG. 15D is an explanatory diagram showing a state in which an automated guided vehicle has slipped under a basket trolley. FIG. 15E is an explanatory diagram showing a state in which an automated guided vehicle is coupled to a basket trolley. FIG. 15F is a block diagram of a transport system including an automated guided vehicle and a management device. FIG. 15A is a flowchart showing an example of a transport control routine. FIG. 15B is a flowchart showing an example of a search line setting process. FIG. 15C is an explanatory diagram showing an example of a map. FIG. 15D is an explanatory diagram showing an example of a search area, search lines, and search points. FIG. 15E is an explanatory diagram showing another example of an arrangement in which a plurality of basket trolleys are arranged in a trolley storage area. FIG. 15F is an explanatory diagram showing another example of a search area, search lines, and search points. 19A is a flowchart showing an example of a search process. Fig. 19A is an explanatory diagram showing a state where a front is searched at position x, Fig. 19B is an explanatory diagram showing a state where a search is performed by rotating in the CW direction at position x, and Fig. 19C is an explanatory diagram showing a state where a search is performed by rotating in the CCW direction at position x. Fig. 20A is an explanatory diagram showing a state where a front is searched at a position a distance b behind position x, Fig. 20B is an explanatory diagram showing a state where a search is performed by rotating in the CW direction at a position a distance b behind position x, and Fig. 20C is an explanatory diagram showing a state where a search is performed by rotating in the CCW direction at a position a distance b behind position x. Fig. 21A is an explanatory diagram showing a state where a front is searched at a position a distance a ahead of position x, Fig. 21B is an explanatory diagram showing a state where a search is performed by rotating in the CW direction at a position a distance a ahead of position x, and Fig. 21C is an explanatory diagram showing a state where a search is performed by rotating in the CCW direction at a position a distance a ahead of position x.

[0012] Next, embodiments of the present disclosure will be described with reference to the drawings.

[0013] FIG. 1 is an external perspective view of a plurality of basket carts 100 arranged in a cart storage area L of a store or the like, and an automated guided vehicle 10 that transports the basket carts 100. FIG. 2 is an external perspective view of the basket carts 100 and the automated guided vehicle 10. FIG. 3 is an external perspective view of the automated guided vehicle 10. FIGS. 4 and 5 are side views of the automated guided vehicle 10. FIG. 6 is an explanatory diagram showing a state in which the automated guided vehicle 10 has slipped under the basket cart 100. FIG. 7 is an explanatory diagram showing a state in which the automated guided vehicle 10 is coupled to the basket cart 100. FIG. 8 is a block diagram of a transport system 1 including the automated guided vehicle 10 and a management device 60.

[0014] 1, a transport system 1 of this embodiment is used in a logistics center, warehouse, store, or the like having a plurality of shelves S, and includes one or a plurality of automated guided vehicles 10 and a management device 60 (see FIG. 8) that manages the operation of the automated guided vehicles 10. The automated guided vehicles 10 are autonomously traveling transport robots (AMR: Autonomous Mobile Robot) that are coupled to a basket cart 100 and transport the automated guided vehicles 10 to a designated shelf S.

[0015] As shown in FIG. 2 , the basket cart 100 has a rectangular, mesh-shaped platform 101 capable of carrying cargo C, and a plurality of (four) casters 110 rotatably attached to the four corners of the underside of the platform 101. A marker M, such as an AR marker, a two-dimensional code, or a barcode, for identifying the basket cart 100 is provided on the platform 101 of the basket cart 100 (in the present embodiment, the center of the outer edge front end surface of the platform 101). By reading the marker M, the automated guided vehicle 10 recognizes the basket cart 100 to be transported (transport target vehicle) and the type of cargo C loaded on the platform 101. The marker M may be attached to the cargo C loaded on the platform 101. The identification information for identifying the basket cart 100 and the cargo C is not limited to the marker M. For example, the identification information may be a unique ID for identifying the basket cart 100. The identification information may also be identification information (such as letters or a picture) written on the outer box of the package C.

[0016] As shown in FIG. 3 , the automated guided vehicle 10 of this embodiment has a low, flat, rectangular parallelepiped appearance. The automated guided vehicle 10 includes a vehicle body 11, a plurality of (e.g., four) wheels 21 rotatably attached to the bottom surface of the vehicle body 11, and a plurality of (e.g., four) drive motors 22 (see FIG. 8 ) that rotate and drive the corresponding wheels 21. In this embodiment, the wheels 21 are configured as Mecanum wheels, each having a plurality of rollers on its outer periphery that can rotate around an axis inclined at 45 degrees relative to the rotation axis of the wheel. The automated guided vehicle 10 can move the vehicle body 11 in all directions and turn (such as by making a pivot turn, a pivot turn, or a gentle turn) by independently controlling the rotation direction and rotation speed of the corresponding wheels 21 using the plurality of drive motors 22. The wheels 21 may also be configured as omniwheels having a plurality of rollers that can rotate around an axis that intersects the rotation axis of the wheel. That is, the plurality of wheels 21 may be any type of wheels as long as they can move the vehicle body 11 in a plurality of directions and turn.

[0017] 3 to 5, the automated guided vehicle 10 also includes a connecting unit 30 that is provided on the upper surface of the vehicle body 11 and that can be connected to the cart 100 when the vehicle body 11 is positioned below the cart 100. The connecting unit 30 includes a flat lift plate 31, connecting pins 32, 33, and 34 that extend upward relative to the lift plate 31, and a lifting device 35 that raises and lowers the lift plate 31. The lift plate 31 covers the upper surface of the vehicle body 11 and has a width that is approximately the same as the width of the vehicle body 11 and a front-to-rear width that is slightly shorter than the front-to-rear width of the vehicle body 11. The connecting pin 32 is provided at the front of the lift plate 31, the connecting pin 33 is provided at the rear of the lift plate 31, and the connecting pin 34 is provided in an intermediate portion between the front and rear of the lift plate 31. 6 and 7 , when the vehicle body 11 is submerged under the cart 100 and the lifting plate 31 is raised by the lifting device 35, at least one of the connecting pins 32, 33, 34 engages with the back side of the loading platform 101 of the cart 100. This connects the automated guided vehicle 10 and the cart 100, and the automated guided vehicle 10 can transport (tow) the cart 100.

[0018] As shown in FIGS. 3 to 5 , contact detection sensors 36 (spring sensors) are provided on both the left and right sides of the lift plate 31 to detect when the connecting portion 30 (connecting pins 32, 33, 34) comes into contact with (connects to) the loading platform 101 of the cart truck 100. The contact detection sensors 36 have a plate that is biased upward by a spring, with its upper end at approximately the same height as the connecting pins 32, 33, 34 relative to the lift plate 31. When the connecting pins 32, 33, 34 engage with the loading platform 101 of the cart truck 100, the plate of the contact detection sensor 36 comes into contact with the loading platform 101, and the spring is compressed as it descends relative to the connecting pins 32, 33, 34. The contact detection sensor 36 detects when the connecting portion 30 comes into contact with (connects to) the loading platform 101 of the cart truck 100 by detecting that the plate has descended relatively.

[0019] As shown in FIG. 8 , the automated guided vehicle 10 further includes a control unit 40 that controls the entire system, a storage unit 41 that stores various information including map information 41a, a communication unit 42 that communicates (wirelessly communicates) with a management device 60, a camera unit 51 as an imaging device, sensors 52 and 53, and a light-emitting unit 54 that illuminates the area ahead of the vehicle body 11. The camera unit 51 is installed on the front of the vehicle body 11 to recognize the area ahead of the vehicle body 11. The sensors 52 and 53 are installed on the front and rear of the vehicle body 11, respectively, to detect surrounding objects. The sensors 52 and 53 detect surrounding objects and the distances to the objects. In this embodiment, the sensors 52 and 53 are LiDAR (Light Detection and Ranging) sensors that scan the surroundings with laser light, receive each reflected light, and measure the time it takes for the reflected light to be received, thereby measuring distance data for each scan angle and obtaining two-dimensional point cloud data of the surroundings. The light emitting unit 54 is installed on the front of the vehicle body 11 and illuminates the area ahead, making it easier for the camera unit 51 to recognize surrounding objects in dark places.

[0020] The control unit 40 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM for storing processing programs, a RAM for temporarily storing data, a timer, etc. As shown in Fig. 8, the control unit 40 receives inputs such as image signals from the camera unit 51, detection signals from the sensors 52 and 53, and detection signals from the contact detection sensor 36. The control unit 40 outputs control signals to the drive motor 22 and the lifting device 35.

[0021] 8, the management device 60 includes a processing unit 61, a storage unit 62, and a communication unit 63 for communicating (wirelessly communicating) with each automated guided vehicle 10. The management device 60 is also connected to an input unit 65 (such as a mouse or a keyboard), a display unit 66 (such as a liquid crystal display or an organic EL display), a printer, and the like. The processing unit 61 is configured as a microprocessor centered around a CPU, and includes, in addition to the CPU, a ROM for storing processing programs, a RAM for temporarily storing data, and the like. The storage unit 62 is a storage device such as an HDD or SSD, and stores various information such as map information 62a and destination information 62b.

[0022] The destination information 62b is information that associates the type of luggage with the destination of the luggage, and is registered in advance by the operator. Furthermore, the management device 60 creates a unique marker M for each type of luggage at the operator's instruction and prints (issues) the created marker M using a printer. The operator then attaches the printed marker M to a specified location on the cart 100 or to the luggage loaded on the cart 100. In this way, the automated guided vehicle 10 can recognize the type of luggage to be transported by reading the marker M with the camera unit 51, and can obtain the destination (destination) of the cart 100 (transport target vehicle) loaded with the luggage based on the recognized type of luggage.

[0023] Next, the operation of the transport system 1 of this embodiment configured as described above will be described. In particular, as shown in Fig. 1, the operation of the automated guided vehicle 10 when transporting a plurality of basket carts 100 arranged in a cart storage area L one by one to their respective destinations will be described. Fig. 9 is a flowchart showing an example of a transport control routine executed by the control unit 40 of the automated guided vehicle 10. This process is executed when an instruction to transport a basket cart 100 (baggage) is received from the management device 60.

[0024] When the transport control routine is executed, the control unit 40 first acquires a search line or the first search point on the search line that has been set in advance in the carriage storage area L (S100), and controls the drive motor 22 to move to the acquired first search point (S102). The search line is set in advance by executing a search line setting process by the processing unit 61 (CPU) of the management device 60. Figure 10 is a flowchart showing an example of the search line setting process. The description of the transport control routine will be interrupted below, and the search line setting process will be described.

[0025] In the search line setting process, the processing unit 61 of the management device 60 first displays a map (S150) and accepts the designation of a search area on the map (S152). An example of this map is shown in FIG. 11 . The operator operates the input unit 65 (mouse) to designate a rectangular search area at any position and size on the map. For example, the operator operates the input unit 65 to designate two points on the map, thereby designating a rectangular search area with the two points as diagonal corners. Next, the processing unit 61 sets a search line for the accepted search area (S154). The search line is set within the search area so as to extend longitudinally of the search area, as shown in FIG. 12 . Furthermore, multiple search lines are set so as to be aligned in the width direction according to the width of the search area. For example, as shown in Figures 13 and 14, when the basket carts 100 are arranged in three rows in the cart parking area L, by specifying a rectangular search area to encompass the area in which the three rows of basket carts 100 are arranged, three search lines are set in the search area, arranged in the width direction with a predetermined width e between them.

[0026] Next, the processing unit 61 sets the search direction as the direction from the start end to the end end of each search line, with the end closest to the waiting position P of the AGV 10 on the map (e.g., a charging position where the AGV 10 can be charged) as the start end and the other end as the end end (S156). Next, the processing unit 61 sets the position of each search line on the start end side of the search direction as the first search point (S158). The processing unit 61 then registers search information 62c including the search line, search direction, and first search point in the storage unit 62 (S160), and ends the search line setting process. After registering the search information 62c, the processing unit 61 transmits the search information 62c to the control unit 40 of the AGV 10. The search line setting process has been described above.

[0027] Returning to the transport control routine, when the control unit 40 moves to the first search point, it executes a cart search process to search for a nearby cart 100 at the search point (S104), and determines whether or not the cart 100 has been found (S106). The search for the cart 100 (cart search process) is performed, for example, by capturing an image of the area around the vehicle body 11 with the camera unit 51, and processing the captured image to determine whether or not the marker M attached to the cart 100 has been recognized. If the control unit 40 is successful in recognizing the marker M, it determines that the cart 100 has been found, and if the control unit 40 fails to recognize the marker M, it determines that the cart 100 has not been found. Details of the cart search process will be described later.

[0028] If the control unit 40 determines that the cart 100 has not been found, it acquires its own position (current position) and determines whether it has reached the vicinity of the end of the search line (the distance from the current position to the end of the search line is less than the interval d described below) (S108). The control unit 40 acquires its own position by grasping the shape of the surroundings based on point cloud data measured by the sensor units 52 and 53 (LiDAR), and comparing (collating) the grasped shape of the surroundings with the map information 41a stored in the memory unit 41 to recognize the current location of the cart. If the control unit 40 determines that it has not reached the vicinity of the end of the search line, it sets a position on the search line that is the interval d away in the search direction as the next search point (S110), moves to the next search point (S112), returns to S104, and executes the cart search process at the next search point.

[0029] 15A and 15B are explanatory diagrams showing how the cart cart 100 is searched for. As shown in FIGS. 15A and 15B , the automated guided vehicle 10 searches for the cart cart 100 by sequentially moving along the search line to positions (next search points) at intervals d in the search direction and executing a cart search process until the cart cart 100 is found or the automated guided vehicle 10 reaches the vicinity of the end of the search line. The interval d is determined based on the range searchable by the camera unit 51. This allows the cart cart 100 located within the search area to be found more reliably. Furthermore, the operator simply needs to specify the search area on a map, allowing the automated guided vehicle 10 to search for the cart cart 100 with a simple operation.

[0030] When the control unit 40 determines in S108 that it has reached the vicinity of the end of the search line, it determines whether there are other search lines to be searched (S114). If it determines that there are other search lines to be searched, the control unit 40 moves to the first search point of the other search line (S116), returns to S104, and executes the cart search process.

[0031] FIG. 16 is an explanatory diagram showing how a cart cart 100 is searched for when multiple search lines are set in a search area. As shown in the figure, when the automated guided vehicle 10 reaches the vicinity of the end of one search line, it retreats along that search line and moves to the first search point of another search line that has not yet been searched. The automated guided vehicle 10 then searches for the cart cart 100 by sequentially moving along the other search lines to positions (next search points) spaced a distance d apart in the search direction and executing a cart search process until the cart cart 100 is found or the automated guided vehicle 10 reaches the vicinity of the end of the other search line. This allows for more reliable detection of cart carts 100 arranged in multiple rows. Furthermore, the operator simply specifies a search area on a map, and multiple search lines corresponding to the width of the area are set. This allows the automated guided vehicle 10 to search for the cart cart 100 with a simple operation.

[0032] When the control unit 40 determines in S104 that a basket cart 100 has been found, it couples the basket cart 100 (cart to be transported) to the cart (cart to be transported) (S118). This process is performed as follows. That is, the control unit 40 first recognizes the two casters 110 of the cart to be transported using the sensor unit 52. Next, the control unit 40 controls the drive motor 22 so that the control unit 40 moves between the two recognized casters 110 and under the cart to be transported. Then, the control unit 40 raises the connecting pins 32, 33, 34 using the lifting device 35 so that they engage with the loading platform 101 of the cart to be transported, thereby coupling the cart to the cart to be transported.

[0033] When the control unit 40 couples with the transport target vehicle, it acquires its own position and stores the acquired own position in the storage unit 41 as the vehicle coupling position (S120). The control unit 40 then sets a destination and starts transporting the transport target vehicle (S122). The destination is set by recognizing the type of cargo C loaded on the transport target vehicle from the recognized marker M, acquiring a destination for the cargo C corresponding to the recognized type of cargo C, and setting the destination. The destination is acquired by receiving from the management device 60 a destination derived from destination information 62b based on the recognized type of cargo C. Furthermore, the transport target vehicle is transported by acquiring a transport route and controlling the drive motor 22 to start transport from the vehicle storage area L to the destination according to the acquired transport route. The transport route is acquired by recognizing the current location of the vehicle and searching for a route based on the recognized current location and the specified destination using map information 41a. The transport route may also be acquired by recognizing the current location and transmitting it to the management device 60, and receiving a transport route generated by the management device 60 based on the current location.

[0034] When the control unit 40 starts transporting the cart to be transported, it acquires its own position (S124) and determines whether it has arrived at the destination (S126). If the control unit 40 determines that it has not arrived at the destination, it returns to S124. If it determines that it has arrived at the destination, it stops traveling (S128) and releases the coupling from the cart to be transported (S130). Then, the control unit 40 moves to the nearest cart coupling position among the cart coupling positions stored in S120 (S132), and then returns to S104. This allows the control unit 40 to sequentially find the multiple carts 100 lined up in the cart storage area L and transport the carts 100 to their respective destinations.

[0035] After executing the cart search process, the control unit 40 determines in S104 that the cart 100 could not be found. If the control unit 40 subsequently determines in S106 and S114 that the cart 100 has reached the vicinity of the end of the search line and there are no other search lines to be searched, it determines that there are no remaining carts 100 to be transported to the cart storage area L, and terminates the transport control routine. In this manner, a search line is set in a search area designated in advance for the cart storage area L, and carts 100 are searched along the search line. This makes it possible to more reliably find and transport multiple carts 100 placed in the search area. Furthermore, even if an obstacle F is installed in the cart storage area L and multiple carts 100 lined up in the search direction are spaced apart to avoid the obstacle F, as shown in FIG. 16 , the automated guided vehicle 10 can reliably find the cart 100 by sequentially searching along the search line.

[0036] Next, the details of the carriage search process in S104 will be described. Figures 17 and 18 are flowcharts showing an example of the carriage search process.

[0037] In the trolley search process, the control unit 40 first sets the current position to position x (S200) and searches for the basket trolley 100 using the camera unit 51 in front of position x (S202, FIG. 19A). The search for the basket trolley 100 is performed by capturing an image of the area in front of the vehicle body unit 11 at position x using the camera unit 51 and processing the captured image to recognize a marker M. If the control unit 40 is successful in recognizing the marker M, it determines that the basket trolley 100 has been found (YES in S204), and if the control unit 40 fails to recognize the marker M, it determines that the basket trolley 100 has not been found (NO in S204). When the control unit 40 determines that the basket trolley 100 has been found (YES in S204), it ends the trolley search process.

[0038] If the control unit 40 determines that the basket trolley 100 has not been found (NO in S204), it then moves to a position rotated by an angle θ in a clockwise (CW) direction relative to the position x (S206) and searches for the basket trolley 100 using the camera unit 51 (S208, FIG. 19B). The search for the basket trolley 100 is performed, for example, by capturing multiple images with the camera unit 51 while rotating clockwise, processing each captured image, and recognizing the marker M in each image. If the control unit 50 succeeds in recognizing the marker M in any of the images, it determines that the basket trolley 100 has been found (YES in S210). If the control unit 40 fails to recognize the marker M in any of the images, it determines that the basket trolley 100 has not been found (NO in S210). If the control unit 40 determines that the basket trolley 100 has been found (YES in S210), it terminates the trolley search process.

[0039] If the control unit 40 determines that the basket trolley 100 has not been found (NO in S210), it then moves to a position rotated counterclockwise (CCW) by an angle θ relative to the position x (S212) and searches for the basket trolley 100 using the camera unit 51 (S214, FIG. 19C). The search for the basket trolley 100 is performed, for example, by capturing multiple images with the camera unit 51 while rotating counterclockwise, processing each captured image, and recognizing the marker M in each image. If the control unit 50 succeeds in recognizing the marker M in any of the images, it determines that the basket trolley 100 has been found (YES in S216). If the control unit 40 fails to recognize the marker M in any of the images, it determines that the basket trolley 100 has not been found (NO in S216). If the control unit 40 determines that the basket trolley 100 has been found (YES in S216), it terminates the trolley search process.

[0040] If the control unit 40 determines that the basket trolley 100 has not been found (NO in S216), it then moves to a position rearward by a distance b from position x (S218) and searches for the basket trolley 100 in front of the rearward position using the camera unit 51 in the same manner as in S202 (S220, FIG. 20A). If the control unit 40 determines that the basket trolley 100 has been found (YES in S222), it ends the trolley search process. If the control unit 40 determines that the basket trolley 100 has not been found (NO in S222), it then moves to a position rotated by an angle θ in a clockwise (CW) direction from the position rearward by a distance b from position x (S224) and searches for the basket trolley 100 using the camera unit 51 in the same manner as in S208 (S226, FIG. 20B). When the control unit 40 determines that the basket cart 100 has been found (YES in S228), it ends the cart search process. When the control unit 40 determines that the basket cart 100 has not been found (NO in S228), it next moves to a position rotated by an angle θ in a counterclockwise (CCW) direction from a position that is a distance b behind position x (S230), and searches for the basket cart 100 using the camera unit 51 in the same way as in S214 (S232, FIG. 20C). When the control unit 40 determines that the basket cart 100 has been found (YES in S234), it ends the cart search process.

[0041] If the control unit 40 determines that the basket trolley 100 has not been found (NO in S234), it then moves to a position that is the distance a forward from position x (S236) and searches for the basket trolley 100 in front of the forward position using the camera unit 51 in the same manner as in S202 (S238, FIG. 21A). If the control unit 40 determines that the basket trolley 100 has been found (YES in S240), it ends the trolley search process. If the control unit 40 determines that the basket trolley 100 has not been found (NO in S240), it then moves to a position that is rotated by an angle θ in the clockwise (CW) direction from the position that is the distance a forward from position x (S242) and searches for the basket trolley 100 using the camera unit 51 in the same manner as in S208 (S244, FIG. 21B). When the control unit 40 determines that the basket cart 100 has been found (YES in S246), it ends the cart search process. When the control unit 40 determines that the basket cart 100 has not been found (NO in S248), it next moves to a position rotated by an angle θ in a counterclockwise (CCW) direction from a position that is a distance a forward from position x (S250), and searches for the basket cart 100 using the camera unit 51 in the same manner as in S214 (S252, FIG. 21C). When the control unit 40 determines that the basket cart 100 has been found (YES in S254), it ends the cart search process.

[0042] When the control unit 40 determines that the basket cart 100 has not been found (NO in S254), it determines that the basket cart 100 is not present (S254) and ends the cart search process.

[0043] As described above, in this embodiment, at the search point, the control unit 40 searches for the basket trolley 100 at position x, a position rotated clockwise from position x, and a position rotated counterclockwise from position x. This allows the search range to be expanded to the left and right, and the basket trolley 100 in the vicinity of position x to be more reliably found. Furthermore, at the search point, the control unit 40 also searches for the basket trolley 100 at a position a distance b behind position x, a position rotated clockwise from the position a distance b behind position x, and a position rotated counterclockwise from the position a distance b behind position x. This allows the search range to be expanded to the front, back, left, and right. For example, if a part of the car body 11 is hidden under the basket trolley 100 and cannot be searched by the camera unit 51, the car body 11 can be moved backward to recognize the basket trolley 100. Furthermore, at the search point, the control unit 40 also searches for the basket cart 100 at a position a distance a forward from position x, a position rotated clockwise from the position a forward from position x, and a position rotated counterclockwise from the position a forward from position x. This makes it possible to expand the search range in the front, back, left, and right directions. For example, if the search range of the camera unit 51 does not reach the basket cart 100 by a little, the car body unit 11 can be moved forward to recognize the basket cart 100.

[0044] In this embodiment, the control unit 40 searches for the basket trolley 100 using the camera unit 51 in a frontal, clockwise rotated, and counterclockwise rotated position at each of position x, a position a distance b behind position x, and a position a distance a ahead of position x. However, the control unit 40 may also search for the basket trolley 100 using the camera unit 51 in a frontal, clockwise rotated, and counterclockwise rotated position only at position x. Furthermore, the control unit 40 may also search for the basket trolley 100 using the camera unit 51 only in a frontal position at each of position x, a position a distance b behind position x, and a position a distance a ahead of position x.

[0045] Here, the correspondence between the main elements of the embodiment and the main elements of the present disclosure described in the claims will be described. That is, the cart 100 of the present embodiment is an example of a cart of the present disclosure, the vehicle body 11 is an example of a vehicle body, the camera unit 51 is an example of a detection unit, the control unit 40 that executes the process of S100 of the transport control routine is an example of an acquisition unit, and the control unit 40 that executes the process of S102-S132 of the transport control routine is an example of a control unit.

[0046] It goes without saying that the present disclosure is not limited to the above-described embodiments, and can be embodied in various forms as long as they fall within the technical scope of the present disclosure.

[0047] For example, in the above-described embodiment, the control unit 40 terminates the transport control routine if the basket cart 100 cannot be found on any of the search lines, but if the basket cart 100 is placed in a plurality of different cart parking areas, if the basket cart 100 cannot be found in one cart parking area, it may move to another cart parking area and search for the basket cart 100.

[0048] In the embodiment described above, the automated guided vehicle 10 engages the connecting pin 34 of the connecting portion 30 with the loading platform portion 101 of the basket cart 100 to tow the basket cart 100. However, the automated guided vehicle 10 may also be configured to lift the basket cart 100 with the connecting portion 30 and transport it.

[0049] As described above, in the first automated guided vehicle of the present disclosure, if a search for a cart fails at the search start position, the automated guided vehicle moves to the next search position among the plurality of search positions and repeats the search process until the search for the cart is successful. By specifying positions where the cart may be located as the plurality of search positions, it becomes possible to more reliably find a cart in the vicinity even if the cart cannot be detected at the search start position.

[0050] In such an automated guided vehicle disclosed herein, if the control unit fails to search for the bogie at the search start position, the control unit may execute a re-search process in which at least one of the orientation and position of the vehicle body is changed and the detection unit searches for the bogie again, and if the search for the bogie fails even after the re-search process, the control unit may control the vehicle body to move to a next search position among the plurality of search positions until the search for the bogie is successful, and execute the search process at the next search position, and if the search for the bogie at the next search position fails, the re-search process may be executed repeatedly. This eliminates missed searches and makes it possible to more reliably find nearby bogies.

[0051] Furthermore, in the automated guided vehicle disclosed herein, the control unit may, as the re-search process, change the orientation of the vehicle body in both forward and reverse rotation directions within a predetermined angle range and search for a bogie using the detection unit. This allows the search range to be expanded left and right. In this case, the control unit may, as the re-search process, change the position of the vehicle body forward or backward in the direction of travel, and search for a bogie using the detection unit by changing the orientation of the vehicle body in both forward and reverse rotation directions within the predetermined angle range before and after the change in position of the vehicle body. This allows the search range to be expanded forward, backward, left and right.

[0052] In the automated guided vehicle according to the present disclosure, the control unit may perform the re-search process by changing the position of the vehicle body forward or backward in the traveling direction and searching for the bogie using the detection unit. In this way, the search range can be expanded forward and backward.

[0053] In the second automated guided vehicle of the present disclosure, if the search for the cart at the search position fails, the direction and / or position of the vehicle body is changed and a search process is executed again to search for the cart by the detection unit. This makes it possible to more reliably find a nearby cart even if the cart cannot be detected at the search position.

[0054] The present disclosure is applicable to the automated guided vehicle manufacturing industry and the like.

[0055] 1 conveying system, 10 unmanned guided vehicle, 11 vehicle body, 21 wheels, 22 drive motor, 30 connecting portion, 31 lifting plate, 32, 33, 34 connecting pin, 35 lifting device, 36 contact detection sensor, 40 control unit, 41 memory unit, 41a map information, 42 communication unit, 51 camera unit, 52, 53 sensor unit, 54 light emitting unit, 60 management device, 61 processing unit, 62 memory unit, 62a map information, 62b transport destination information, 63 communication unit, 65 input unit, 66 display unit, 100 basket cart, 101 loading platform unit, 110 caster, L cart storage area, M marker, S shelf, W wall, F obstacle.

Claims

1. An unmanned guided vehicle that transports a cart, comprising: a car body; a detection unit provided on the car body and capable of detecting the cart within a predetermined detection range of the car body; an acquisition unit that acquires a plurality of search positions including a search start position; and a control unit that controls the car body to move to the search start position, and then executes a search process to search for the cart using the detection unit, and if the search for the cart at the search start position fails, controls the car body to move to a next search position among the plurality of search positions, and repeats the execution of the search process at the next search position until the search for the cart is successful.

2. An unmanned guided vehicle as described in claim 1, wherein, when the control unit fails to search for the trolley at the search start position, the control unit executes a re-search process in which at least one of the orientation and position of the vehicle body is changed and the detection unit searches for the trolley, and when the re-search process also fails to search for the trolley, the control unit controls the vehicle body to move to a next search position among the multiple search positions until the search for the trolley is successful, and executes the search process at the next search position, and when the search for the trolley at the next search position fails, the re-search process is repeatedly executed.

3. An automated guided vehicle according to claim 2, wherein the control unit, as part of the re-search process, changes the orientation of the vehicle body in both forward and reverse rotation directions within a predetermined angle range and searches for a bogie using the detection unit.

4. An unmanned guided vehicle as described in claim 3, wherein the control unit, as part of the re-search process, changes the position of the vehicle body forward or backward in the direction of travel, and changes the orientation of the vehicle body in both forward and reverse rotation directions within the specified angle range before and after the change in the position of the vehicle body, thereby searching for a bogie using the detection unit.

5. An unmanned guided vehicle according to claim 2, wherein the control unit, as part of the re-search process, changes the position of the vehicle body forward or backward in the direction of travel and searches for a bogie using the detection unit.

6. An unmanned guided vehicle that transports a cart, comprising: a car body; a detection unit that is provided on the car body and is capable of detecting the cart within a predetermined detection range of the car body; and a control unit that controls the car body to move to a predetermined search position, and then executes a search process to search for the cart using the detection unit, and if the search for the cart at the search position fails, executes a re-search process to change at least one of the orientation and position of the car body and search for the cart using the detection unit.

Images