Transport facility

Abstract

This transport facility comprises a transport vehicle (2) and a floor surface (31) on which the transport vehicle (2) travels. The transport vehicle (2) transports an object to be transported. The transport vehicle (2) is provided with wheels (222) that roll on the floor surface (31), and a host vehicle position recognition device (23) for recognizing the host vehicle position on the floor surface (31). The transport vehicle (2) is configured to change the direction with reference to a preset reference position on the basis of the recognition result of the host vehicle position obtained by the host vehicle position recognition device (23). The transport vehicle (2) executes direction change position distribution processing to distribute the direction change positions within a set distribution range P in a plurality of direction changes with reference to the same reference position.

Description

TRANSPORT FACILITY

[0001] The present invention relates to a transport facility equipped with a transport vehicle that travels on a floor surface.

[0002] A transport facility equipped with a transport vehicle that travels on a floor surface is utilized. The transport vehicle travels along a set travel path to transport an object to be transported. An example of such a transport facility is disclosed in Japanese Patent Laid-Open Publication No. 2008-168982 (Patent Document 1) below. In the following description of this background art, the reference numerals and names in Patent Document 1 will be cited in parentheses.

[0003] In the conveying equipment of Patent Document 1, a conveying vehicle (plate-like article conveying vehicle 1) is configured to travel along a travelable path (traveling path 2) within a conveying area (clean room) to convey objects to be conveyed (plate-like articles) to each of a plurality of stations (3). Because the conveying vehicle (plate-like article conveying vehicle 1) repeatedly travels on the travelable path (traveling path 2) on the floor surface (floor portion), wear may occur due to friction with the wheels (traveling wheels 5) of the conveying vehicle (plate-like article conveying vehicle 1). Therefore, in the conveying equipment of Patent Document 1, the strength of the floor surface (floor portion) is increased to protect the floor surface (floor portion) from wear due to friction with the wheels (traveling wheels 5) of the conveying vehicle (plate-like article conveying vehicle 1).

[0004] JP 2008-168982 A

[0005] However, in order to increase the strength of the floor surface (floor portion), the cost of the materials that make up the floor surface (floor portion) tends to increase accordingly, which in turn tends to increase the cost of the transport equipment.

[0006] Therefore, it is desirable to realize a transport facility that can effectively protect the floor surface from wear caused by friction with the wheels of the transport vehicle.

[0007] A conveying facility comprising a transport vehicle that transports an object to be transported and a floor surface on which the transport vehicle runs, wherein the transport vehicle is equipped with wheels that roll on the floor surface and a vehicle position recognition device for recognizing the vehicle's position on the floor surface, and the transport vehicle is configured to change direction based on a predetermined reference position based on the recognition result of the vehicle's position by the vehicle position recognition device, and the position at which the transport vehicle changes direction is defined as a change direction position, and the transport vehicle executes a change direction position dispersion process that distributes the change direction positions within a set dispersion range in multiple changes of direction based on the same reference position.

[0008] According to this characteristic configuration, even if the transport vehicle is configured to turn around based on a preset reference position, the turning positions can be dispersed among the multiple turnings based on the reference position, making it less likely that a specific location on the floor surface will be worn out more than other locations due to friction with the wheels. Therefore, according to this configuration, the need to reinforce the floor surface to avoid wear on specific locations on the floor surface can be reduced, while the floor surface can be effectively protected from wear due to friction with the wheels.

[0009] Further features and advantages of the techniques according to the present disclosure will become more apparent from the following description of exemplary and non-limiting embodiments, which proceeds with reference to the drawings.

[0010] Schematic diagram of the conveying facility of the first embodiment. Side view of the conveying vehicle shown in FIG. 1. Front view of the conveying vehicle shown in FIG. 1. Diagram showing the state before the conveying vehicle shown in FIG. 1 changes direction. Diagram showing the state of the conveying vehicle changing direction shown in FIG. 4. Diagram showing the state after the conveying vehicle has changed direction shown in FIG. 5. Diagram showing the relationship between the distance from the reference position to the direction change position within the dispersion range shown in FIG. 4 and the number of direction changes. Diagram showing the dispersion range in the conveying facility of the second embodiment.

[0011] 1. Overview of the Conveying Equipment of the First Embodiment A conveying equipment 1 according to this embodiment will be described with reference to the drawings. As shown in FIG. 1 , the conveying equipment 1 is equipment for conveying objects 10 from a source to a destination. The source and destination include, for example, a station for storing the objects 10 in an automated warehouse (not shown) or for retrieving the objects 10 from the automated warehouse, manufacturing equipment, and a work area. The manufacturing equipment is equipment for manufacturing goods or the like using the objects 10. The work area includes, for example, a shipping work area and a sorting work area. The shipping work area is an area where work for shipping the objects 10 is performed. The sorting work area is a sorting area where sorting of the objects 10 is performed.

[0012] 1 illustrates, as an example of a transfer source, an outgoing station 32 for taking out the transfer object 10 from a warehouse (not shown) in which the transfer object 10 is stored. Also, as an example of a transfer destination, an incoming station 33 for putting the transfer object 10 into the warehouse in which the transfer object 10 is stored.

[0013] The transport facility 1 includes a transport area 3, which is an area where the transport object 10 is transported, a transport vehicle 2 that transports the transport object 10, and a control system (not shown) that controls the transport vehicle 2. The transport vehicle 2 travels on a floor surface 31 that constitutes the transport area 3, transporting the transport object 10 from the source to the destination. One or more transport vehicles 2 travel within the transport area 3. Specifically, the floor surface 31 may be a floor surface 31 provided inside a building or a floor surface 31 provided in a certain area outdoors, and may be flat. A transport vehicle 2 traveling on such a floor surface 31 has a larger travel area than a ceiling transport vehicle that travels along rails suspended from the ceiling or a track-guided vehicle that travels along a track arranged on the floor surface 31. This provides a significant effect by efficiently protecting the floor surface 31.

[0014] The following describes the transport vehicle 2, the transport area 3, and the control system. For ease of explanation, one of the two directions along the floor surface 31 is referred to as the "first direction D1," and the other of the two directions along the floor surface 31 is referred to as the "second direction D2." The direction intersecting the "first direction D1" and the "second direction D2" is referred to as the "up-down direction D3."

[0015] 2. Transfer Area The transfer area 3 includes an unloading facility as the transfer source, an inloading facility as the transfer destination, auxiliary facilities (not shown) that assist the travel of the transfer vehicle 2, a travel area 34 formed by a floor surface 31 on which the transfer vehicle 2 travels, and a reinforcing member 4. The reinforcing member 4 is a member for reinforcing the floor surface 31 of the travel area 34. The transfer area 3 illustrated in FIG. 1 represents one floor inside a factory or warehouse building.

[0016] In this embodiment, a travel area 34 is provided in a position adjacent to the carry-in facility and the carry-out facility. The transport vehicle 2 travels on a floor surface 31 provided in the travel area 34. Therefore, friction occurs between the floor surface 31 and the wheels 222 (described later) of the transport vehicle 2 at points on the floor surface 31 that come into contact with the wheels 222. The friction between the floor surface 31 and the wheels 222 may cause wear on the floor surface 31. The reinforcing member 4 prevents wear from occurring at points on the floor surface 31 that come into contact with the wheels 222. In the following description, the path of contact on the floor surface 31 by the wheels 222 of the transport vehicle 2 traveling along the traversable path 23R is referred to as the wheel path WT.

[0017] The reinforcing members 4 are arranged at specific locations on the wheel trajectory WT where wear due to friction between the wheels 222 and the floor surface 31 is greater than at other locations. Here, the magnitude of wear due to friction between the wheels 222 and the floor surface 31 is determined according to at least one of the magnitude of the frictional force acting on the floor surface 31 and the frequency with which the frictional force acts. In detail, as the frictional force acting on the floor surface 31 increases, wear occurring on the floor surface 31 increases. Also, as the frequency with which the frictional force acts on the floor surface 31 increases, wear occurring on the floor surface 31 increases.

[0018] The specific locations include locations where the wheels 222 frequently come into contact with the floor surface 31 and locations where the transport vehicle 2 changes direction. By disposing the reinforcing members 4 at the specific locations, the wheels 222 of the transport vehicle 2 passing through the specific locations come into contact with the reinforcing members 4. As a result, the reinforcing members 4 come into contact with the wheels 222 instead of the floor surface 31, thereby preventing wear due to friction between the floor surface 31 and the wheels 222 at the specific locations.

[0019] 3. Transport vehicle The transport vehicle 2 carries out the object 10 at the source and carries the object 10 to the destination. To perform this function, the transport vehicle 2 is equipped with a transfer device 21, a traveling device 22, and a vehicle position recognition device 23, as shown in Figures 2 and 3.

[0020] The transfer device 21 is a device that supports the object 10 to be transferred and transfers the object 10 at the source and destination. In this embodiment, the transfer device 21 moves the object 10 in the vertical direction D3. Specifically, when the transport vehicle 2 is positioned at an output station 32, which is an example of the source, the transfer device 21 receives the object 10 that is positioned at the warehouse or output station 32. On the other hand, when the transport vehicle 2 is positioned at an input station 33, which is an example of the destination, the transfer device 21 moves the object 10 that is positioned at the warehouse or input station 33 to a position in the warehouse or input station 33 where the object 10 will be handed over.

[0021] The transfer device 21 may include, for example, a lifting mechanism (lifter) that raises and lowers the target object in the vertical direction D3. The transfer device 21 may also include a fork-type or conveyor-type transfer mechanism or a pressing mechanism (pusher) that moves the target object in the first direction D1 or the second direction D2. Alternatively, the transfer device 21 may include a mechanism that moves the target object in both the vertical direction D3 and the first direction D1 or the second direction D2, such as a fork-type transfer machine.

[0022] The traveling device 22 is a device for traveling the transport vehicle 2. The traveling device 22 includes a chassis 221 and wheels 222 that roll on the floor surface 31. Various devices for transporting the target transported object are mounted on the chassis 221. The wheels 222 are supported rotatably relative to the chassis 221. The wheels 222 illustrated in FIGS. 1 to 3 are arranged below the chassis 221.

[0023] In this embodiment, the traveling device 22 includes a plurality of wheels 222. The plurality of wheels 222 includes a drive wheel W1 that is rotationally driven by a drive source such as a motor. The chassis 221 can move by the rotation of the drive wheel W1. In addition, in this embodiment, the plurality of wheels 222 includes a driven wheel W2. The driven wheel W2 is a wheel 222 that rotates to follow the movement of the chassis 221, which moves in conjunction with the rotation of the drive wheel W1.

[0024] In this embodiment, the plurality of wheels 222 includes a pair of drive wheels W1 and four driven wheels W2. The pair of drive wheels W1 are arranged at a distance from each other in the width direction (second direction D2 in FIG. 2 ) at the bottom of the chassis 221. The driven wheels W2 are also arranged at the bottom of the chassis 221, similar to the drive wheels W1. The four driven wheels W2 are respectively arranged at the four corners of the chassis 221.

[0025] In this embodiment, the driven wheels W2 have a direction-changing function for changing the direction of the transport vehicle 2. Each driven wheel W2 changes its posture so as to change the inclination angle with respect to the first direction D1 as viewed in the up-down direction D3, based on the rotation axis as viewed in the up-down direction D3, thereby changing the traveling direction of the transport vehicle 2. Hereinafter, for convenience of explanation, changing the inclination angle with respect to the first direction D1 as viewed in the up-down direction D3 by the driven wheels W2 in order to exert the direction-changing function will be referred to as "the driven wheels W2 changing their posture."

[0026] In this embodiment, as shown in Figures 4 to 6, the guided vehicle 2 sets a direction change position based on a reference position, and changes direction around a turning axis WX that passes through the direction change position and runs along the up-down direction D3. That is, the turning axis WX of the guided vehicle 2 when turning is determined by the arrangement of the multiple wheels 222 as viewed in the up-down direction D3. The turning axis WX illustrated in Figures 4 to 6 is a position where the distances from the four driven wheels W2 are equal as viewed in the up-down direction D3.

[0027] In this embodiment, the transport vehicle 2 changes direction at a stopped position. When the transport vehicle 2 illustrated in Figures 2 and 3 changes direction, the transport vehicle 2 in a stopped state changes its posture so that the four driven wheels W2 face the destination of the turn. After the postures of the four driven wheels W2 are changed, the pair of drive wheels W1 rotates, allowing the transport vehicle 2 to travel toward the destination of the turn.

[0028] The vehicle position recognition device 23 is a device for recognizing the position of the vehicle on the floor surface 31. The vehicle includes a transport vehicle 2 to which the vehicle position recognition device 23 is attached, and a transport vehicle 2 whose position is to be recognized by the control system. The vehicle position on the floor surface 31 is determined by coordinates in a coordinate system set based on a reference position provided on the floor surface 31, or the distance to a wall or equipment arranged in the transport area 3.

[0029] The transport vehicle 2 is configured to change direction based on a preset reference position, based on the result of recognition of the vehicle's position by the vehicle position recognition device 23. Therefore, the transport vehicle 2 changes direction when it reaches the preset position.

[0030] In this embodiment, as shown in FIG. 3 , the vehicle position recognition device 23 includes a detected portion 231 that serves as a reference position for setting a drivable route 23R on which the transported vehicle 2 can travel, and a detection portion 232 that detects the detected portion 231. The detection portion 232 is mounted on the chassis 221, and the detected portion 231 is installed in the transport area 3. In this embodiment, the reference position is the position of each of the multiple detected portions 231 arranged on the floor surface 31. As shown in FIG. 1 , the transported vehicle 2 is configured to travel along a route (drivable route 23R) that is set to connect the multiple detected portions 231. In the example shown in FIG. 1 , the detected portions 231 are regularly spaced apart on the floor surface 31 of the travel area 34.

[0031] In this embodiment, the detectable portion 231 includes, for example, a magnetic material or an identification code such as a one-dimensional code or a two-dimensional code. If the detectable portion 231 is a magnetic material, the detecting portion 232 is configured with a detector or the like that detects the magnetic material. If the detectable portion 231 is an identification code, the detecting portion 232 is configured with a code reader or the like that reads the identification code. However, as long as the detecting portion 232 can detect the detectable portion 231, the detecting portion 232 and the detectable portion 231 are not limited to such configurations. For example, the detectable portion 231 may be configured with an IC (Integrated Circuit) tag, and the detecting portion 232 may be configured with an IC tag reader. Alternatively, the detectable portion 231 may be configured with a mark that is detected by being imaged by the detecting portion 232.

[0032] 4. Control System The control system controls one or more transport vehicles 2. Specifically, the control system moves the transport vehicle 2 to a designated location including a source and a destination, and causes the transport vehicle 2 to perform operations for handing over the transported object 10 at the designated location. In the example of control of the transport vehicle 2 by the control system shown in FIG. 1 , the controlled transport vehicle 2 moves from the outgoing station 32 in a first direction D1 and changes direction to travel in a second direction D2. The control system then moves the changed direction transport vehicle 2 to the receiving station 33. Note that, for ease of explanation, the transported object 10 transported by the transport vehicle 2 is not shown in FIG. 1 . Also, hereinafter, for ease of explanation, the control system's control of the travel of the transport vehicle 2 will simply be referred to as the transport vehicle 2 traveling.

[0033] The control system calculates multiple candidates for the travelable route 23R along which the transport vehicle 2 will travel in order to move the transport vehicle 2 to the designated location. The control system sets a travel route 23A along which the transport vehicle 2 will actually travel from the multiple calculated travelable routes 23R. Then, the control system causes the transport vehicle 2 to travel along the travel route 23A, thereby moving the transport vehicle 2 to the designated location.

[0034] The control system assigns a transport task for transporting the object 10 to each of the multiple transport vehicles 2. The transport task includes an instruction to transport the object 10 from the origin to the destination. Each transport vehicle 2 assigned a transport task by the control system transports the object 10 from the origin to the destination in accordance with the transport task. The transport task also includes an instruction for a travel route 23A of the transport vehicle 2 to which the transport task is assigned. As a result, the transport vehicle 2 travels along a route (travel route 23A) selected from preset drivable routes 23R based on the recognition result of the vehicle's own position by the vehicle position recognition device 23.

[0035] The control system includes, for example, a host control device (not shown) that manages the entire conveyance facility 1, and a vehicle control device (not shown) that controls each conveyance vehicle 2. The host control device and the vehicle control device are configured to communicate with each other. The host control device assigns conveyance tasks to the vehicle control devices (conveyance vehicles 2). The vehicle control devices assigned with conveyance tasks control various devices and the like provided therein according to the conveyance tasks. The host control device and the vehicle control device each include, for example, a processor such as a microcomputer, peripheral circuits such as memory, and the like. Each process or function is realized by cooperation between this hardware and a program executed on a processor of a computer or the like.

[0036] 5. Operation of the Transport Vehicle The traveling operation of the transport vehicle 2 will now be described with reference to FIGS.

[0037] As shown in FIG. 4 , the guided vehicle 2 travels along the travelable path 23R toward a position within the dispersion range P that is set based on the reference position. In reality, the guided vehicle 2 travels along a travel path 23A of the travelable path 23R that overlaps with the reference path, or a travel path 23A that deviates slightly from the reference path. Here, the reference path is an ideal path for the guided vehicle 2 that is set to connect two reference positions. For example, the reference path is set to connect the positions where the two detectable parts 231 are located in a straight line.

[0038] The dispersion range P is a position where the transport vehicle 2 changes direction. In this embodiment, the position where the transport vehicle 2 changes direction is determined based on the rotation axis WX. The transport vehicle 2 changes direction at a position where the rotation axis WX is located within the dispersion range P when viewed in the vertical direction D3. Note that the portion of the transport vehicle 2 that serves as the reference for changing direction is not limited to the rotation axis WX of the transport vehicle 2, but may be determined appropriately depending on the structure and use of the transport vehicle 2. For example, the portion that serves as the reference for the transport vehicle 2 to change direction may be a corner position or a center position of the chassis 221 when viewed in the vertical direction D3. Hereinafter, for convenience of explanation, "the portion of the transport vehicle 2 that serves as the reference for changing direction is located within the dispersion range P when viewed in the vertical direction D3" will be referred to as "the transport vehicle 2 is located within the dispersion range P."

[0039] The dispersion range P is set around the reference position. The reference position may be located within the dispersion range P or may be set outside the dispersion range P. The dispersion range P is set taking into consideration factors that affect wear due to friction between the wheels 222 of the transport vehicle 2 and the floor surface 31. For example, the dispersion range P is set taking into consideration the number of times the transport vehicle 2 changes direction, the manner of direction changes, the strength of the floor surface 31, etc. Supplementally, the manner of direction changes is a concept that includes, for example, whether the transport vehicle 2 turns or performs another operation, and the angle of the direction change. The dispersion range P illustrated in FIG. 4 is the range inside a circle centered on the reference position.

[0040] The guided vehicle 2 performs a direction change position distribution process for multiple direction changes based on the same reference position. The direction change position distribution process is a process for distributing direction change positions within a set distribution range P. The direction change position distribution process may distribute the direction change positions uniformly within the distribution range P, or may distribute the direction change positions stochastically within the distribution range P. Specifically, the direction change position distribution process for uniformly distributing direction change positions within the distribution range P includes a process in which multiple direction change positions are pre-determined within the distribution range P so that the number of times the guided vehicle 2 actually changes direction at each direction change position is approximately the same. On the other hand, the direction change position distribution process for stochastically distributing the direction change positions within the distribution range P includes a process in which the guided vehicle 2 randomly sets direction change positions with a certain probability. For example, the guided vehicle 2 may set direction change positions evenly throughout the entire distribution range P, or may set direction change positions so that the number of times they are set in a certain range close to the reference position is relatively high.

[0041] As shown in Fig. 4, the transport vehicle 2 travels toward a predetermined reference position. The transport vehicle 2 illustrated in Fig. 4 travels in a first direction D1. When the transport vehicle 2 reaches a dispersion range P set near the predetermined reference position, it changes direction within the dispersion range P. In the example shown in Fig. 5, the transport vehicle 2 stops once at the direction change position (direction change position), and performs a rotation operation in which the transport vehicle 2 rotates around the rotation axis WX as the center of rotation while the rotation axis WX does not move when viewed in the up-down direction D3. The rotation operation changes the travel direction of the transport vehicle 2 from the first direction D1 to the second direction D2.

[0042] The guided vehicle 2 that has completed the direction change at the direction change position within the dispersion range P starts traveling again, as shown in Fig. 6. Because the direction change position is located slightly off the reference path, the guided vehicle 2 that has completed the direction change travels on a travel path 23A that is slightly off the reference path. The travel path 23A merges with the reference path at a position away from the detected portion 231. The guided vehicle 2 illustrated in Fig. 6 travels on the travel path 23A that merges with the reference path along the second direction D2.

[0043] When the transport vehicle 2 repeatedly changes direction at the same reference position by the direction change position distribution process described above, the position of the wheel trajectory WT shifts each time the transport vehicle 2 changes direction, so that the floor surface 31 can be effectively protected from friction with the wheels 222. Hereinafter, several examples of aspects of the direction change position distribution process that can more effectively protect the floor surface 31 will be described. Note that the examples shown below may be applied alone to the direction change position distribution process described above, or may be applied in combination as long as no contradictions arise.

[0044] [Example 1] As described above, reinforcing members 4 are placed on the floor surface 31 of the transport area 3, as shown in Fig. 1. Wear due to friction between the wheels 222 and the floor surface 31 occurs more significantly at the direction change positions than at other positions, so placing the reinforcing members 4 at the direction change positions can effectively protect the floor surface 31. Therefore, as shown in Fig. 4, it is preferable to place the reinforcing members 4 at positions on the floor surface 31 that include the positions of the wheels 222 of the transport vehicle 2 in the reference position.

[0045] In this example, the dispersion range P is set so that the wheels 222 of the transport vehicle 2 do not extend beyond the surface of the reinforcing member 4 during a change of direction. In this embodiment, the reinforcing member 4 is disposed on the floor surface 31 at a position where the driven wheels W2 change their posture when the transport vehicle 2 changes direction. The reinforcing member 4 illustrated in FIG. 5 is disposed at a position where the transport vehicle 2, having stopped temporarily to perform a turning operation, changes the posture of the driven wheels W2. Specifically, in FIG. 5 , the reinforcing member 4 is disposed at four locations around the reference position. The dispersion range P is set so that the position where the posture of the driven wheels W2 changes when the transport vehicle 2 turns overlaps with the reinforcing member 4 when viewed in the vertical direction D3. According to this configuration, when the transport vehicle 2 changes direction, the driven wheels W2 change their posture while in contact with the surface of the reinforcing member 4. Additionally, when the transport vehicle 2 repeatedly changes direction, the position where the posture of the driven wheels W2 changes on the reinforcing member 4 shifts with each change of direction, thereby reducing wear caused by friction between the reinforcing member 4 and the wheels 222.

[0046] [Example 2] The processing capacity of a processing system varies depending on the specifications of the transport equipment 1. If the processing capacity of the processing system is not very high, it may be better to determine the direction change position within the dispersion range P according to a simple rule. In this example, an example of such a rule is shown.

[0047] In this example, in the direction change position distribution processing, the transport vehicle 2 pre-sets a set number of direction change positions relative to the same reference position. The transport vehicle 2 determines the direction change positions by sequentially adopting the set number of direction change positions each time it changes direction relative to the reference position. In particular, if the set number is N (N is a natural number), N direction change positions are set relative to the same reference position, and the N direction change positions are sequentially adopted so that the N consecutive direction change positions are all different positions.

[0048] FIG. 4 illustrates an example in which the number of settings is five. In this case, the transport vehicle 2 sets five positions within the dispersion range P. In FIG. 4, a first position P1, a second position P2, a third position P3, a fourth position P4, and a fifth position P5 are set within the dispersion range P. The first position P1, the second position P2, the third position P3, the fourth position P4, and the fifth position P5 are, for example, arranged clockwise around a reference position. In the example illustrated in FIG. 4, the distances from the reference position of the first position P1 to the fifth position P5 are different from each other. Each time the transport vehicle 2 enters the dispersion range P and changes direction, it stops at the positions listed in the order of the first position P1, the second position P2, the third position P3, the fourth position P4, and the fifth position P5 and changes direction. In the example illustrated in FIG. 5, the transport vehicle 2 entering the dispersion range P after passing the second position P2 is depicted. The transport vehicle 2 illustrated in FIG. 5 is changing direction at a third position P3.

[0049] [Example 3] It may be preferable to relatively increase the number of direction changes of the transport vehicle 2 at a specific position. For example, if the strength of the floor surface 31 varies depending on the position, a direction in which the number of direction changes of the transport vehicle 2 at a position on the floor surface 31 that is relatively strong can reduce wear due to friction between the floor surface 31 and the wheels 222.

[0050] In this example, the guided vehicle 2 is configured to determine a direction change position according to a specific distributed algorithm. As shown in FIG. 8 , the distributed algorithm determines a direction change position so that, for multiple direction changes based on the same reference position, the distribution of the number of direction changes at each direction change position relative to the distance between the reference position and the direction change position is a normal distribution. In the graph shown in FIG. 8 , the distance from the reference position to the direction change position is plotted on the horizontal axis, and the number of direction changes at that direction change position is plotted on the vertical axis. In FIG. 8 , the direction change position that coincides with the reference position is set as the median of the normal distribution. In other words, the number of direction changes is set to be greatest at the direction change position that coincides with the reference position, and the number of direction changes is set to be smaller at positions farther from the reference position.

[0051] In addition, the guided vehicle 2 may periodically change the orientation of the direction change positions relative to the reference position. For example, although not shown, the guided vehicle 2 may set 36 direction change positions, each of which is at an angle of 10° around the reference position. The guided vehicle 2 may then change direction at each of the 36 direction change positions, each of which is at a different angle of 10°, completing one rotation 36 times.

[0052] 6. Conveying Facility of Second Embodiment A conveying facility 1 of a second embodiment will be described with reference to FIG. 8. In the first embodiment, the vehicle position was determined based on the detected part 231. However, depending on the application of the conveying facility 1, it may not be possible to install a dedicated detected part 231 for determining the reference. Therefore, there may be a need for a vehicle position recognition device 23 that can recognize the vehicle position without installing the detected part 231.

[0053] The conveying facility 1 of the second embodiment differs from the conveying facility 1 of the first embodiment in that the vehicle recognition device of the conveying vehicle 2 can recognize the vehicle position without detecting the detection target portion 231. Hereinafter, differences between the conveying facility 1 of the second embodiment and the conveying facility 1 of the first embodiment will be mainly described, and descriptions of other points will be omitted.

[0054] The vehicle position recognition device 23 includes a detector 233 that detects components 35 in the carry-out area that are arranged around the transport vehicle 2, and a calculation device 234. Here, the components 35 in the transport area 3 are, for example, walls that partition the transport area 3, devices installed in the transport area 3, etc. The calculation device 234 creates map information based on the detection results of the detector 233. Then, the calculation device 234 identifies the vehicle's position on the map represented by the map information.

[0055] The detector 233 detects whether or not a structure 35 is placed within a certain range around the vehicle. In this embodiment, the detector 233 is attached to the chassis 221. Therefore, when the detector 233 attached to the transport vehicle 2 transporting the vehicle in the travel area 34 detects that a structure 35 is placed within a certain range around the vehicle, the calculation device 234 obtains the positional relationship between the structure 35 and the transport vehicle 2 as a detection result.

[0056] In this embodiment, the calculation device 234 creates map information representing a map of the transportation area 3 based on the positional relationship (detection result of the detector 233) between the transportation vehicle 2 traveling in the transportation area 3 and the structure 35. The map information includes a coordinate system set based on a specific structure 35. The calculation device 234 expresses the vehicle position using coordinates in the coordinate system included in the map information.

[0057] As in the first embodiment, the guided vehicle 2 travels along a travel route 23A that is set from among a plurality of candidate travel routes 23R calculated by the control system. In this embodiment, the travel route 23R is determined based on a map represented by map information. For example, the travel route 23R is set based on a reference position that is set based on the position where the structure 35 is located on the map represented by the map information.

[0058] Preferably, the detector 233 is a sensor that measures the distance from an object placed around the vehicle to the vehicle's position. With this configuration, the positional relationship between the structure 35 and the guided vehicle 2 can be obtained with high accuracy. Therefore, the calculation device 234 can obtain map information that represents a map with high accuracy of positions and distances. As a result, the guided vehicle 2 traveling along the travel path 23A experiences little positional deviation from the travel path 23A determined by the control system. The detector 233 illustrated in FIG. 8 is a laser rangefinder.

[0059] 7. Other Embodiments Next, other embodiments of the conveying equipment 1 will be described.

[0060] (1) In the present embodiment, the traveling device 22 has been described as having a pair of drive wheels W1. However, the number of drive wheels W1 is not limited to one pair. For example, the traveling device 22 may have one or more than one pair of drive wheels W1. Also, in the present embodiment, four driven wheels W2 have been described as being disposed at the bottom of the chassis 221. However, the number of driven wheels W2 may be other than four. Furthermore, the driven wheels W2 may be disposed at a location other than the bottom of the chassis 221.

[0061] (2) In the present embodiment, the plurality of wheels 222 of the traveling device 22 are described as including the driving wheels W1 and the driven wheels W2. However, all of the plurality of wheels 222 of the traveling device 22 may be the driving wheels W1.

[0062] (3) In the present embodiment, the vehicle position recognition device 23 is described as including the detecting unit 232 and the detected unit 231. However, the vehicle position recognition device 23 may have any configuration as long as it can recognize the vehicle's position on the floor surface 31. For example, the vehicle position recognition device 23 may be a position recognition device that uses radio waves, such as a GPS (Global Positioning System). In this case, the vehicle's position on the floor surface 31 is determined by coordinates in a coordinate system that is set based on a reference position provided on the floor surface 31. With this configuration, there is no need to place a reference for the transport vehicle 2 to travel in the travel area 34, thereby simplifying the entire transport facility 1.

[0063] (4) In the present embodiment, the driven wheel W2 has been described as having a turning function. However, the driving wheel W1 may have the turning function instead of the driven wheel W2. In addition, both the driven wheel W2 and the driving wheel W1 may have the turning function.

[0064] (5) In the present embodiment, the reference path has been described as, for example, a path that linearly connects two different detectable portions 231. However, the reference path may be a path that connects two different detectable portions 231 in a curved line, or a path that is formed by combining a path that linearly connects two different detectable portions 231 with a path that curvedly connects two different detectable portions 231.

[0065] (6) In the present embodiment, the guided vehicle 2 has been described as performing a turning operation to change direction. However, the direction change performed by the guided vehicle 2 is not limited to a turning operation as long as it is an operation for changing the traveling direction of the guided vehicle 2. For example, the guided vehicle 2 may perform a curved run in which the path is gradually changed while traveling to change direction. In addition, curved run refers to a traveling mode of the guided vehicle 2 in which the center position of the guided vehicle 2 changes direction while moving as viewed in the up-down direction D3. When the guided vehicle 2 performs a curved run, the direction change position is the start position of the direction change or the center (center of the arc) of the arc-shaped traveling trajectory of the guided vehicle 2.

[0066] (7) In this embodiment, the dispersion range P includes a range inside a circle centered on the reference position. However, the dispersion range P may also be a range inside a circle centered on a position other than the reference position. Furthermore, the boundary of the dispersion range P is not limited to a circle and may be a polygon, etc., as long as a certain range can be defined. The dispersion range P may be set to the same range for all of the multiple reference positions installed on the floor surface 31, or a different range may be set for each reference position. In addition, the setting of the dispersion range P may be configured to be changeable. This configuration allows the dispersion position to be changed appropriately taking into account the condition of the floor surface 31, thereby enabling flexible operation of the guided vehicles 2. For example, even when changing the facility layout by installing new equipment within the already set dispersion range P, simply changing the setting of the dispersion range P allows the guided vehicles 2 to avoid the new equipment while traveling.

[0067] (8) In the present embodiment, the first position P1 to the fifth position P5 are arranged clockwise as an example of the positions at which the direction is changed when the preset number is set. However, the multiple direction change positions set by setting the preset number are not limited to being arranged clockwise around the reference position. For example, the multiple direction change positions may be arranged counterclockwise around the reference position, or may be arranged randomly within the dispersion range P.

[0068] (9) In this embodiment, the distribution algorithm uses the median of the normal distribution as the reference position. However, the median of the normal distribution may be set at a position away from the reference position.

[0069] (10) The configurations disclosed in the above-described embodiments can be applied in combination with configurations disclosed in other embodiments, as long as no contradictions arise. Regarding other configurations, the embodiments disclosed in this specification are merely examples in all respects. Therefore, various modifications can be made as appropriate within the scope of the present disclosure.

[0070] 8. Summary of the Present Embodiment The following provides a summary of the above-described embodiment of the conveyance equipment.

[0071] The conveying equipment is equipped with a conveying vehicle that conveys the object to be conveyed and a floor surface on which the conveying vehicle runs, and the conveying vehicle is equipped with wheels that roll on the floor surface and a vehicle position recognition device that recognizes the vehicle's position on the floor surface, and the conveying vehicle is configured to change direction based on a predetermined reference position based on the recognition result of the vehicle's position by the vehicle position recognition device, and the position at which the conveying vehicle changes direction is set as a direction change position, and the conveying vehicle executes a direction change position distribution process that distributes the direction change positions within a set distribution range in multiple direction changes based on the same reference position.

[0072] According to this characteristic configuration, even if the transport vehicle is configured to turn around based on a preset reference position, the turning positions can be dispersed among the multiple turnings based on the reference position, making it less likely that a specific location on the floor surface will be worn out more than other locations due to friction with the wheels. Therefore, according to this configuration, the need to reinforce the floor surface to avoid wear on specific locations on the floor surface can be reduced, while the floor surface can be effectively protected from wear due to friction with the wheels.

[0073] In addition, it is preferable that the transport facility be such that the transport vehicle sets the direction change position based on the reference position and changes direction using an axis that passes through the direction change position and runs in the vertical direction as a rotation axis.

[0074] According to this configuration, since the transport vehicle turns around a vertical axis at the direction change position, wear on the floor surface is likely to be greater at the wheel trajectory of the turning vehicle at the direction change position than at other locations. Therefore, the effect of protecting the floor surface by executing the direction change position distribution process is high.

[0075] Furthermore, it is preferable that the reference position of the conveying equipment is the position of each of a plurality of detectable parts arranged on the floor surface, the conveying vehicle is configured to travel along a route set to connect the plurality of detectable parts, and the vehicle position recognition device is configured to recognize the vehicle position based on detecting each of the detectable parts.

[0076] This configuration allows for a relatively simple conveyance facility that can move a conveyance vehicle to a target location. Furthermore, this configuration allows for highly accurate setting of a direction change position based on the position of the detected part. Therefore, if the direction change position distribution process is not performed, the floor surface at the direction change position is likely to suffer greater wear than other locations. Conversely, by performing the direction change position distribution process, it becomes easier to appropriately distribute the direction change positions for multiple direction changes that use the same reference position as a reference.

[0077] Furthermore, the conveying equipment has a sheet-like reinforcing member having a surface that is more wear-resistant than the floor surface arranged at a position on the floor surface that includes the position of the wheels of the conveying vehicle at the reference position, and it is preferable that the dispersion range is set to a range that does not allow the wheels of the conveying vehicle to protrude from the surface of the reinforcing member during the direction change.

[0078] With this configuration, the reinforcing members can be placed in areas of the floor surface where friction with the wheels is likely to be greater than in other areas, thereby providing adequate protection for areas of the floor surface that are likely to be worn down due to friction with the wheels.

[0079] In addition, it is preferable that the conveying equipment determines the direction change position by setting a set number of direction change positions for the same reference position in advance in the direction change position distribution processing, and adopting the set number of direction change positions in order each time the conveying vehicle makes a direction change based on the reference position.

[0080] According to this configuration, it is possible to appropriately distribute the turning positions in a plurality of turning operations based on the same reference position by using a relatively simple calculation process.

[0081] Furthermore, it is preferable that the conveying equipment is configured such that the conveying vehicle determines the direction change position according to a specific distributed algorithm, and the distributed algorithm determines the direction change position so that the distribution of the number of direction changes at each direction change position relative to the distance between the reference position and the direction change position for multiple direction changes based on the same reference position is a normal distribution.

[0082] According to this configuration, when multiple direction changes are made using the same reference position as a reference, the variation in the direction change positions relative to the reference position can be kept relatively small, while the direction change positions when multiple direction changes are made using the same reference position as a reference can be appropriately distributed.

[0083] The technology disclosed herein can be used in a transport facility equipped with a transport vehicle that travels on a floor surface.

[0084] 1: Conveying equipment 2: Conveying vehicle 4: Reinforcing member 10: Conveying object 23: Vehicle position recognition device 31: Floor surface 222: Wheel 231: Detected part 232: Detecting part D3: Up-down direction P: Dispersion range WX: Swivel axis

Claims

1. A transport facility comprising: a transport vehicle for transporting an object to be transported; and a floor surface on which the transport vehicle travels; wherein the transport vehicle has wheels that roll on the floor surface and a vehicle position recognition device for recognizing its own position on the floor surface; the transport vehicle is configured to change direction based on a predetermined reference position based on the recognition result of the vehicle position by the vehicle position recognition device; the position at which the transport vehicle changes direction is defined as a direction change position; and the transport vehicle executes a direction change position distribution process that distributes the direction change positions within a set distribution range in multiple direction changes based on the same reference position.

2. The conveying equipment according to claim 1, wherein the conveying vehicle sets the direction change position based on the reference position, and changes direction using an axis that passes through the direction change position and runs vertically as a rotation axis.

3. A conveying facility as described in claim 1 or claim 2, wherein the reference position is the position of each of a plurality of detectable parts arranged on the floor surface, the conveying vehicle is configured to travel along a route set to connect the plurality of detectable parts, and the vehicle position recognition device is configured to recognize the vehicle position based on detecting each of the detectable parts.

4. A conveying facility as described in claim 1 or claim 2, wherein a sheet-like reinforcing member having a surface more wear-resistant than the floor surface is placed on the floor surface at a position that includes the position of the wheels of the conveying vehicle at the reference position, and the dispersion range is set to a range that prevents the wheels of the conveying vehicle from protruding from the surface of the reinforcing member during the change of direction.

5. A conveying facility as described in claim 1 or claim 2, wherein the conveying vehicle, in the direction change position distribution processing, pre-sets a set number of direction change positions for the same reference position, and determines the direction change position by sequentially adopting the set number of direction change positions each time the conveying vehicle makes a direction change based on the reference position.

6. The conveying equipment according to claim 1 or claim 2, wherein the transport vehicle is configured to determine the direction change position in accordance with a specific distributed algorithm, and the distributed algorithm is configured to determine the direction change position so that the distribution of the number of direction changes at each direction change position relative to the distance between the reference position and the direction change position for multiple direction changes based on the same reference position is a normal distribution.

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