Automated guided vehicle system

Abstract

This automated guided vehicle system (100) comprises guide paths (1A, 1B, 1C), a branch point (2), an automated guided vehicle (3), and a control unit (4). The control unit (4) is configured to determine that the automated guided vehicle (3) is on a peripheral member (22A) on the basis of a first detection by sensor units (34A, 34B) and to determine that the automated guided vehicle (3) is on a base point member (21) on the basis of a second detection by the sensor units (34A, 34B) while the automated guided vehicle (3) is traveling straight to the branch point (2) beyond the guide path (1A). Upon determining that the automated guided vehicle (3) is on the base point member (21), the control unit (4) determines to maintain or change the direction of travel of the automated guided vehicle (3). In the case of changing the direction of travel of the automated guided vehicle (3), the control unit (4) causes the automated guided vehicle (3) to stop traveling and spin drive wheels (31A, 31B) about the base point member (21).

Description

Automated Guided Vehicle System

[0001] The present disclosure relates to an automated guided vehicle system in which an automated guided vehicle travels on a guiding path.

[0002] Conventionally, an automated guided vehicle system in which an automated guided vehicle travels on a guiding path has been known. For example, Patent Document 1 discloses an automated guided vehicle that is guided by a travel guide groove. The automated guided vehicle includes a machine base, drive wheels attached to the lower surface of the machine base, a speed reducer and a DC motor for driving the drive wheels, and swivel idler rollers attached to the front and rear portions of the lower surface of the machine base. The automated guided vehicle also includes an electromagnetic central lifting roller unit attached to the central portion of the lower surface of the machine base, and an electromagnetic front lifting roller unit attached to the intermediate portions of the left and right sides of the front portion. The central lifting roller unit has pin-shaped rollers formed at the tip, and is configured such that the pin-shaped rollers are lifted and lowered by electromagnetic force. The front lifting roller unit also has pin-shaped rollers formed at the tip, and is configured to be lifted and lowered by electromagnetic force.

[0003] When the automated guided vehicle is traveling straight, first, the pin-shaped rollers of the central lifting roller unit and the pin-shaped rollers of the front lifting roller unit are lowered, and the respective pin-shaped rollers are inserted into the travel guide groove. Next, the DC motor is rotated at the same speed. As a result, the automated guided vehicle travels straight while the pin-shaped rollers are guided by the travel guide groove. When changing the traveling direction of the automated guided vehicle, the pin-shaped rollers of the central lifting roller unit are further lowered and inserted into the holes formed at the bottom of the travel guide groove to position the automated guided vehicle. Next, the pin-shaped rollers of the front lifting roller unit are raised, and the DC motor is driven in the opposite direction at the same speed. The automated guided vehicle is pivoted around the pin-shaped roller inserted into the hole and then stopped. Then, the pin-shaped rollers of the front lifting roller unit are lowered and inserted into the travel guide groove at the pivoted position. After the change in the traveling direction of the automated guided vehicle is completed, the pin-shaped rollers of the central lifting roller unit are raised and inserted into the travel guide groove to shift to straight travel.

[0004] Japanese Patent Laid-Open No. 8-268270

[0005] However, the technology disclosed in Patent Document 1 includes a central lifting roller section and a front lifting roller section in addition to drive wheels, a reduction gear, a DC motor, and freely driven rollers, which increases the number of components that make up the automated guided vehicle (AGV), resulting in a larger and heavier AGV. In order to operate this AGV, it is necessary to enlarge the AGV system, which may increase manufacturing costs. Furthermore, the increased number of components makes the structure of the AGV more complex, which may increase the maintenance burden on workers. Moreover, since the central lifting roller section and the front lifting roller section are driven each time the vehicle travels in a straight line or changes direction, the control of the AGV may become complicated.

[0006] This disclosure has been made in view of the above, and aims to provide an automated guided vehicle (AGV) system that can simplify the structure and control of the AGV.

[0007] To solve the above-mentioned problems and achieve the objectives, the automated guided vehicle (AGV) system according to this disclosure comprises a plurality of guide paths, branching points connecting the plurality of guide paths, an AGV that drives its drive wheels to travel on the guide paths and branching points, and a control unit that controls the operation of the AGV. The branching point has a base portion that adjusts the direction in which the AGV that has traveled from a guide path moves toward another guide path, a cylindrical base point member provided on the upper surface of the base portion, and a plurality of peripheral members consisting of protrusions provided on the upper surface of the base portion at intervals from the base point member toward each guide path. The AGV has a guide portion that attracts the base point member or the plurality of peripheral members and guides the movement of the AGV on the base portion along the base point member and the plurality of peripheral members, and a sensor portion that detects the base point member and peripheral members attracted by the guide portion. The control unit is configured such that, when the automated guided vehicle (AGV) is traveling straight towards a branching point after crossing a guide path, the first detection by the sensor unit determines that the AGV is on a surrounding member, and the second detection by the sensor unit determines that the AGV is on a base point member. When the control unit determines that the AGV is on a base point member, it decides whether to maintain the AGV's direction of travel or change its direction of travel. If it decides to change the AGV's direction of travel, it stops the AGV's movement and spins the drive wheels around the base point member as an axis.

[0008] The automated guided vehicle (AGV) system described herein has the effect of simplifying the structure and control of the AGV.

[0009] Overall diagram showing the automated guided vehicle according to Embodiment 1 Perspective view showing the guideway and branching point of the automated guided vehicle according to Embodiment 1 Perspective view showing the automated guided vehicle of the automated guided vehicle according to Embodiment 1 Bottom view showing the automated guided vehicle of the automated guided vehicle according to Embodiment 1 Cross-sectional view along the line V-V shown in Figure 1 Block diagram showing the control of the automated guided vehicle according to Embodiment 1 Explanatory diagram showing the state in which the automated guided vehicle has arrived on the first peripheral member in the automated guided vehicle according to Embodiment 1 Explanatory diagram showing the state in which the guide part of the automated guided vehicle has guided the first peripheral member and the base point member in the automated guided vehicle according to Embodiment 1 Explanatory diagram showing the state in which the automated guided vehicle has arrived on the base point member in the automated guided vehicle according to Embodiment 1 An explanatory diagram showing the state in which the components have been guided in. An explanatory diagram showing the state in which the unmanned transport system according to Embodiment 1 has arrived on the second peripheral component after the unmanned transport vehicle has traveled in a straight line. An explanatory diagram showing the state in which the direction of travel of the unmanned transport system according to Embodiment 1 has been changed. An explanatory diagram showing the state in which the guide section has guided the base component and the second peripheral component after the direction of travel of the unmanned transport vehicle has been changed. An explanatory diagram showing the state in which the guide section has guided the base component and the second peripheral component after the direction of travel of the unmanned transport vehicle has been changed. An explanatory diagram showing the state in which the guide section has arrived on the second peripheral component after the direction of travel of the unmanned transport vehicle according to Embodiment 1. An overall diagram showing a modified guide path and branching point of the unmanned transport system according to Embodiment 1. An overall diagram showing the unmanned transport system according to Embodiment 2. An overall diagram showing the unmanned transport system according to Embodiment 3. An overall diagram showing the unmanned transport system according to Embodiment 4.

[0010] The automated guided vehicle (AGV) system according to the embodiments of this disclosure will be described in detail below with reference to the drawings.

[0011] Embodiment 1. Figure 1 is an overall view showing an automated guided vehicle (AGV) system 100 according to Embodiment 1. As shown in Figure 1, the AGV system 100 includes a plurality of guide paths 1A, 1B, and 1C, a branching point 2 connecting the plurality of guide paths 1A, 1B, and 1C, an AGV 3 that travels on the guide paths 1A, 1B, and 1C and on the branching point 2, and a control unit (not shown) that controls the operation of the AGV 3.

[0012] Figure 2 is a perspective view showing the guide paths 1A, 1B, 1C and the branching point 2 of the automated guided vehicle (AGV) system 100 according to Embodiment 1. As shown in Figure 2, each guide path 1A, 1B, and 1C consists of two rails on which the AGV 3 travels, for example, and guides the AGV 3 to its destination. Each guide path 1A, 1B, and 1C has a groove 10 formed therein for the AGV 3 to travel on. Three guide paths 1A, 1B, and 1C are provided via the branching point 2, for example. Note that the guide paths 1A, 1B, and 1C are not limited to the rail-like configuration shown, and other forms are acceptable as long as they can guide the AGV 3 to its destination. Also, the guide paths 1A, 1B, and 1C are not limited to the three shown, but two or more are sufficient.

[0013] Branch point 2 is a point where two or more guideways 1A, 1B, and 1C diverge. In Figure 2, as an example, the point where guideway 1A branches off to guideways 1B and 1C is shown as branch point 2. Branch point 2 has a base portion 20, a base point member 21 consisting of a cylindrical pin, and four peripheral members 22A, 22B, 22C, and 22D consisting of protrusions. The base portion 20 is a travel path for the automated guided vehicle 3, which has traveled from guideway 1A, to adjust its direction toward the other guideways 1B and 1C. The base portion 20 is rectangular as an example, but is not limited to a rectangle and may have other shapes. Guideways 1A, 1B, and 1C are connected to each side of the base portion 20.

[0014] The base point member 21 is provided approximately in the center of the upper surface of the base portion 20. The peripheral members 22A, 22B, and 22C are provided on the upper surface of the base portion 20 at regular intervals from the base point member 21 in the direction of each guideway 1A, 1B, and 1C. Among the multiple peripheral members 22A, 22B, 22C, and 22D, there may be peripheral members 22D that are provided even if there is no corresponding guideway. Peripheral members 22A, 22B, 22C, and 22D are cylindrical pins as an example of a protruding shape. The base point member 21 and the peripheral members 22A, 22B, 22C, and 22D are, for example, the same shape and size. However, the base point member 21 and each peripheral member 22A, 22B, 22C, and 22D do not necessarily have to be the same shape and size, and their shapes and sizes may differ. The peripheral members 22A, 22B, 22C, and 22D are not limited to a cylindrical shape, but may be, for example, prismatic. The base member 21 and the peripheral members 22A are spaced apart so that the peripheral members 22A do not interfere with the components of the automated guided vehicle 3 when the automated guided vehicle 3 spins around the base member 21. The same applies to the spacing between the base member 21 and the other peripheral members 22B, 22C, and 22D.

[0015] Figure 3 is a perspective view showing the automated guided vehicle 3 of the automated guided vehicle system 100 according to Embodiment 1. Figure 4 is a bottom view showing the automated guided vehicle 3 of the automated guided vehicle system 100 according to Embodiment 1. Figure 5 is a cross-sectional view taken along the line V-V shown in Figure 1. Figure 6 is a block diagram showing the control of the automated guided vehicle system 100 according to Embodiment 1. As shown in Figures 3 to 5, the automated guided vehicle 3 has a body 30, two drive wheels 31A, 31B, four driven wheels 32A, 32B, 32C, 32D, a guide section 33, and two sensor sections 34A, 34B. The body 30 is, for example, substantially rectangular parallelepiped, but may have other shapes.

[0016] As shown in Figures 3 and 4, the two drive wheels 31A and 31B are positioned approximately in the center of the side of the vehicle body 30, and are provided so as to protrude partially from the underside of the vehicle body 30. The drive wheels 31A and 31B are driven by a drive mechanism (not shown). The drive mechanism is, for example, a motor and a reduction gear. As shown in Figure 6, the drive mechanism 35 is controlled by a control unit 4. The driven wheels 32A, 32B, 32C, and 32D are positioned on the side of the vehicle body 30, in front of and behind the drive wheels 31A and 31B in the direction of travel, and are provided so as to protrude partially from the underside of the vehicle body 30. As shown in Figure 1, the automated guided vehicle 3 moves in a straight line along the guide paths 1A, 1B, and 1C with its drive wheels 31A, 31B and driven wheels 32A, 32B, 32C, and 32D fitted into grooves 10 provided in the guide paths 1A, 1B, and 1C, and changes direction of travel at branching point 2. The guidance of the automated guided vehicle 3 is such that the drive wheels 31A, 31B and driven wheels 32A, 32B, 32C, and 32D are fitted into grooves 10 provided in the guide paths 1A, 1B, and 1C, and the automated guided vehicle 3 moves in a straight line along the grooves 10.

[0017] The automated guided vehicle (AGV) 3 moves forward when both drive wheels 31A and 31B rotate in the forward direction at the same speed. The AGV 3 moves backward when both drive wheels 31A and 31B rotate in opposite directions at the same speed. The AGV 3 changes direction of travel by spinning the drive wheels 31A and 31B so that they rotate in opposite directions at the same speed. The body 30 of the AGV 3 is supported by the driven wheels 32A, 32B, 32C, and 32D to maintain its posture when stopped, moving straight, and changing direction of travel. The number of drive wheels 31A and 31B and the number of driven wheels 32A, 32B, 32C, and 32D can be changed within the range that enables the above functions.

[0018] As shown in Figures 3 to 5, the guide section 33 is provided on the underside of the vehicle body 30. The guide section 33 guides the base member 21 or the peripheral members 22A, 22B, 22C, 22D, and guides the movement of the automated guided vehicle 3 on the base section 20 along the base member 21 and the multiple peripheral members 22A, 22B, 22C, 22D. The guide section 33 is composed of two rail members that are spaced apart and extend in the direction of travel of the automated guided vehicle 3. The guide section 33 guides the base member 21 and the peripheral members 22A, 22B, 22C, 22D between the two rail members. As shown in Figure 5, the underside of the guide section 33 is located below the upper surfaces of the base member 21 and the peripheral members 22A, 22B, 22C, 22D. As a result, the automated guided vehicle 3 can use the guide section 33 to guide the base member 21 or the surrounding members 22A, 22B, 22C, and 22D.

[0019] The guide section 33 is configured to be Y-shaped in plan view, with its front and rear ends inclined outward in the direction of travel of the automated guided vehicle 3 so as to widen the gap between the rail members. This allows the automated guided vehicle 3 to grip the base point member 21 or surrounding members 22A, 22B, 22C, and 22D by guiding them with the left and right rail members. In the case of an automated guided vehicle system 100 in which the automated guided vehicle 3 travels in only one direction, the guide section 33 may be configured so that only the front end or only the rear end in the direction of travel of the automated guided vehicle 3 is inclined outward so as to widen the gap between the rail members. Furthermore, while it is desirable for the guide section 33 to be inclined outward at both the front and rear ends in the direction of travel of the automated guided vehicle 3 so as to widen the gap between the rail members, this configuration is not necessarily required.

[0020] The length of the guide section 33 in the direction of travel of the automated guided vehicle 3 is greater than or equal to the length from the base point member 21 to the peripheral member 22A, 22B, 22C, 22D that is furthest from the base point member 21. As a result, the automated guided vehicle 3 can simultaneously guide the base point member 21 and one of the peripheral members 22A, 22B, 22C, 22D with the guide section 33, thereby correcting the orientation of the vehicle body 30.

[0021] As shown in Figures 3 to 5, the two sensor units 34A and 34B detect the base point member 21 or the surrounding members 22A, 22B, 22C, and 22D when the automated guided vehicle 3 travels over the base point member 21 or the surrounding members 22A, 22B, 22C, and 22D. The sensor units 34A and 34B are respectively attached to the rail members that constitute the guide unit 33. As an example, the sensor units 34A and 34B are through-beam photosensors. Of the two sensor units 34A and 34B, one is the light-receiving sensor unit 34A, and the other is the light-emitting sensor unit 34B. Note that the sensor units 34A and 34B are not limited to through-beam photosensors, and may be, for example, magnetic sensors or proximity sensors. The sensor units 34A and 34B are positioned at the center of the spin when the automated guided vehicle 3 spins to change its direction of travel.

[0022] As shown in Figure 5, the sensor units 34A and 34B are positioned below the upper surfaces of the base point member 21 and the peripheral members 22A, 22B, 22C, and 22D. This allows the light-receiving sensor unit 34A to detect when the light emitted by the light-emitting sensor unit 34B is blocked by the base point member 21 or the peripheral members 22A, 22B, 22C, and 22D, and the control unit 4 to determine when the automated guided vehicle 3 has reached the base point member 21 or the peripheral members 22A, 22B, 22C, and 22D.

[0023] As shown in Figure 6, the control unit 4 controls the drive mechanism 35 of the drive wheels 31A and 31B based on the detections of the sensor units 34A and 34B to perform actions such as straight-line travel, stopping, and spinning of the automated guided vehicle 3. The functions of the control unit 4 are realized by a processing circuit. The processing circuit may be dedicated hardware or a processing unit that executes a program stored in a memory device. For example, the control unit 4 may be configured to instruct control based on a program held by the automated guided vehicle 3, or it may be provided as a separate device from the automated guided vehicle 3, with a program held by that device making decisions and wirelessly instructing the automated guided vehicle 3 to control.

[0024] Next, referring to Figures 1 and 7 through 9, the flow from when the automated guided vehicle (AGV) 3 enters the branching point 2 from the guideway 1A and stops on the base point member 21 will be explained. As shown in Figure 1, when the AGV 3 is traveling along the guideway 1A from left to right in Figure 1, the light receiving sensor unit 34A monitors the light receiving status. The AGV 3 begins to enter the branching point 2 while guiding the surrounding members 22A with the guide unit 33.

[0025] Figure 7 is an explanatory diagram showing the state in which the automated guided vehicle (AGV) 3 has arrived on the first peripheral member 22A, in the automated guided vehicle system 100 according to Embodiment 1. As shown in Figure 7, when the light-receiving sensor unit 34A detects the first instance of light blocking while the AGV 3 is traveling straight towards the branching point 2 after crossing the guide path 1A, the control unit 4 determines that the AGV 3 is on the peripheral member 22A. At this point, the AGV 3 does not stop but continues to travel straight.

[0026] Figure 8 is an explanatory diagram showing the state in which the guide section 33 of the automated guided vehicle 3 has guided the first peripheral member 22A and the base point member 21, in an automated guided vehicle system 100 according to Embodiment 1. After the state shown in Figure 7, as shown in Figure 8, the automated guided vehicle 3, while guiding the peripheral member 22A with the guide section 33, simultaneously guides the base point member 21 with the guide section 33. At this time, even if the automated guided vehicle 3 deviates in the direction of travel due to a speed difference between the drive wheels 31A and 31B at the branching point 2, the guided vehicle 3 can correct the deviation in the direction of travel by driving straight while guiding the base point member 21 with the front end of the guide section 33 which is inclined outward, thereby eliminating the deviation in the direction of travel.

[0027] Figure 9 is an explanatory diagram showing the state in which the automated guided vehicle 3 has arrived on the base point member 21, in the automated guided vehicle system 100 according to Embodiment 1. The automated guided vehicle 3 continues to travel in a straight line even after the state shown in Figure 8. As shown in Figure 9, when the light-receiving sensor unit 34A detects a second instance of light blocking, the control unit 4 determines that the automated guided vehicle 3 has arrived on the base point member 21. When the control unit 4 determines that the automated guided vehicle 3 is on the base point member 21, it maintains or changes the direction of travel of the automated guided vehicle 3.

[0028] Next, with reference to Figures 10 and 11, the flow of the automated guided vehicle (AGV) entering the guideway 1B after arriving on the base member 21 will be described. Figure 10 is an explanatory diagram of the AGV system 100 according to Embodiment 1, showing the AGV 3 traveling in a straight line and the guide unit 33 guiding the base member 21 and the second peripheral member 22B. After arriving on the base member 21, the AGV 3 continues to travel in a straight line. As shown in Figure 10, while the AGV 3 is guiding the base member 21 with the guide unit 33, the guide unit 33 simultaneously guides the peripheral member 22B as well. At this time, even if the automated guided vehicle 3 deviates in the direction of travel at the branching point 2 due to a difference in speed between the drive wheels 31A and 31B, the vehicle corrects the deviation in the direction of travel by continuing to travel in a straight line while guiding the surrounding members 22B with the front end of the guide section 33 which is tilted outwards.

[0029] Figure 11 is an explanatory diagram of the automated guided vehicle (AGV) system 100 according to Embodiment 1, showing the state after the AGV 3 has traveled in a straight line and arrived on the second peripheral member 22B. The AGV 3 continues to travel in a straight line even after the state shown in Figure 10. As shown in Figure 11, the control unit 4 determines that the AGV 3 has arrived on the peripheral member 22B when the light-receiving sensor unit 34A detects the third instance of light blocking. Furthermore, if the AGV 3 continues to travel in a straight line, it can enter the guide path 1B. At this time, since the AGV 3 has corrected the deviation in its direction of travel just before entering the guide path 1B, it does not deviate from the guide path 1B and can reliably enter the guide path 1B.

[0030] Next, referring to Figures 12 to 14, the flow of the automated guided vehicle (AGV) 3 after arriving on the base point member 21 and then changing its direction of travel before entering the guideway 1C will be described. Figure 12 is an explanatory diagram showing the AGV 3 in a state where its direction of travel has been changed, in the AGV system 100 according to Embodiment 1. In Figure 9, the AGV 3 stops traveling when it arrives on the base point member 21. After this, as shown in Figure 12, the AGV 3 spins 90 degrees counterclockwise. This spin may be performed by rotating the drive wheels 31A and 31B for a predetermined time and then stopping, or by attaching a gyro sensor to the AGV 3 to detect when the spin angle reaches 90 degrees and stop the spin. After the spin is completed, the AGV 3 resumes straight-line travel.

[0031] Figure 13 is an explanatory diagram showing the automated guided vehicle (AGV) system 100 according to Embodiment 1, in which the guide section 33 guides the base member 21 and the second peripheral member 22C after changing the direction of travel of the AGV 3. As shown in Figure 13, the AGV 3 is in a state where the guide section 33 is guiding the base member 21, and at the same time the guide section 33 is also guiding the peripheral member 22C. At this time, even if the AGV 3 deviates from the direction of travel due to an excess or deficiency of the spin angle relative to 90 degrees, or a difference in speed between the drive wheels 31A and 31B during straight-line travel after spinning, the AGV 3 can correct the deviation by traveling straight while guiding the peripheral member 22C with the front end of the guide section 33 which is inclined outward, thereby eliminating the deviation in the direction of travel.

[0032] Figure 14 is an explanatory diagram of the automated guided vehicle (AGV) system 100 according to Embodiment 1, showing the state after the AGV 3 has changed direction and arrived on the second peripheral member 22C. The AGV 3 continues to travel in a straight line even after the state shown in Figure 13. As shown in Figure 14, the control unit 4 determines that the AGV 3 has arrived on the peripheral member 22C when the light-receiving sensor unit 34A detects the third instance of light blocking. However, because the AGV 3 stops in a position close to the peripheral member 22D immediately after completing its spin, the light-receiving sensor unit 34A may mistakenly detect the third instance of light blocking when it arrives on the base member 21 again. In this case, false detection can be prevented by disabling the light blocking detection function of the light-receiving sensor unit 34A for a certain period of time after the AGV 3 has completed its spin and started traveling in a straight line. Then, if the automated guided vehicle 3 continues to travel in a straight line, it will be able to enter the taxiway 1C. At this time, since the automated guided vehicle 3 corrects any deviation in its direction of travel just before entering the taxiway 1C, it will not deviate from the taxiway 1C and will be able to enter the taxiway 1C with certainty.

[0033] Figure 15 is an overall view of the automated guided vehicle system 100 according to Embodiment 1, showing modified examples of the guide paths 1A, 1B, 1C and the branching point 2. The multiple guide paths 1A, 1B, 1C are not limited to the configuration shown in Figure 1 where they are arranged at approximately 90-degree intervals, but may be arranged at any angle as shown in Figure 15. However, the automated guided vehicle 3 is not configured to spin at 90 degrees, but rather needs to spin at an angle corresponding to the direction of the branched guide paths 1B, 1C.

[0034] Incidentally, conventional automated guided vehicles (AGVs) systems use a guided material such as magnetic tape, light-reflective tape, or electromagnetic induction cable to guide the AGV. Such AGV systems require sensors for the AGV to detect the guided material, a steering mechanism necessary for steering the AGV, or a guide line control device for curved roads. In other words, in addition to the drive mechanism that drives the AGV's drive wheels, other drive mechanisms are required, which increases the number of parts and can lead to a larger AGV system and increased manufacturing costs. Furthermore, the increased complexity of the AGV structure may increase the maintenance burden on workers. Moreover, controlling the AGV may become more complex.

[0035] Therefore, the automated guided vehicle system 100 according to Embodiment 1 comprises a plurality of guide paths 1A, 1B, 1C, a branching point 2 connecting the plurality of guide paths 1A, 1B, 1C, an automated guided vehicle 3 that drives its drive wheels 31A, 31B to travel on the guide paths 1A, 1B, 1C and the branching point 2, and a control unit 4 that controls the operation of the automated guided vehicle 3. The branching point 2 comprises a base portion 20 that adjusts the direction in which the automated guided vehicle 3, which has traveled from guide path 1A, moves toward the other guide paths 1B, 1C, a cylindrical base point member 21 provided on the upper surface of the base portion 20, and a plurality of peripheral members 22A, 22B, 22C consisting of protrusions provided on the upper surface of the base portion 20 at intervals from the base point member 21 in the direction toward each of the guide paths 1A, 1B, 1C. The automated guided vehicle (AGV) 3 has a guide unit 33 that attracts the base member 21 or a plurality of peripheral members 22A, 22B, 22C and guides the movement of the AGV 3 on the base unit 20 along the base member 21 and the plurality of peripheral members 22A, 22B, 22C, and sensor units 34A, 34B that detect the base member 21 and peripheral members 22A, 22B, 22C attracted by the guide unit 33. The control unit 4 is configured such that when the AGV 3 is traveling straight towards the branching point 2 after crossing the guide path 1A, the first detection by the sensor units 34A, 34B determines that the AGV 3 is on the peripheral member 22A, and the second detection by the sensor units 34A, 34B determines that the AGV 3 is on the base member 21. When the control unit 4 determines that the automated guided vehicle 3 is on the base point member 21, it determines whether to maintain the direction of travel of the automated guided vehicle 3 or change the direction of travel. If it decides to change the direction of travel of the automated guided vehicle 3, it stops the movement of the automated guided vehicle 3 and spins the drive wheels 31A and 31B around the base point member 21 as an axis.

[0036] In other words, in the first embodiment of the automated guided vehicle (AGV) system 100, the movement of the AGV 3 on the base portion 20 is guided by the base point member 21 and a plurality of peripheral members 22A, 22B, 22C simply by driving the drive wheels 31A, 31B of the AGV 3. When changing the direction of travel of the AGV 3, the drive wheels 31A, 31B are spun around the base point member 21 detected by the sensor units 34A, 34B. Therefore, in addition to the drive mechanism 35 that drives the drive wheels 31A, 31B of the AGV 3, there is no need to provide, for example, a dedicated drive mechanism for changing the direction of travel of the AGV 3. Thus, in the first embodiment of the AGV system 100, the structure of the AGV 3 can be simplified, the weight of the AGV 3 can be reduced, and the burden of maintenance on the AGV 3 by workers can also be reduced. Furthermore, since the automated guided vehicle 3 can be made to move straight, stop, and spin simply by driving the drive wheels 31A and 31B of the automated guided vehicle 3, the control of the automated guided vehicle 3 can be simplified.

[0037] The guide section 33 is configured to simultaneously guide the base point member 21 and any one of the multiple peripheral members 22A, 22B, 22C, and 22D. After maintaining or changing the direction of travel of the automated guided vehicle 3, the control unit 4, when the automated guided vehicle 3 travels in a straight line from the base point member 21, uses the guide section 33 to simultaneously guide the peripheral members 22A, 22B, 22C, and 22D and the base point member 21, thereby correcting the posture of the automated guided vehicle 3 toward the guidance paths 1A, 1B, and 1C.

[0038] In other words, the automated guided vehicle system 100 according to Embodiment 1 does not require a drive mechanism to correct the orientation of the automated guided vehicle 3 in the direction of the guide paths 1A, 1B, and 1C, in addition to the drive mechanism 35 that drives the drive wheels 31A and 31B of the automated guided vehicle 3. Therefore, the number of parts is reduced, and the structure of the automated guided vehicle 3 can be simplified. As a result, the weight of the automated guided vehicle 3 can be reduced, and the burden of maintenance on the automated guided vehicle 3 can also be reduced.

[0039] Furthermore, the guide section 33 has two rail members that are spaced apart and extend along the direction of travel of the automated guided vehicle 3, and is configured to guide the base member 21 and peripheral members 22A, 22B, 22C, and 22D between the two rail members.The guide section 33 is configured such that the rail members are inclined outward so that the spacing between the rail members widens at at least one of the front end and rear end in the direction of travel of the automated guided vehicle 3.As a result, the automated guided vehicle 3 can grip the base member 21 or peripheral members 22A, 22B, 22C, and 22D by guiding them with the left and right rail members, thereby enabling smooth travel on the base section 20.

[0040] Embodiment 2. Next, the automated guided vehicle system 101 according to Embodiment 2 will be described. Note that components identical to those in Embodiment 1 are denoted by the same reference numerals, and their descriptions are omitted as appropriate. Figure 16 is an overall view showing the automated guided vehicle system 101 according to Embodiment 2. In the automated guided vehicle system 101 according to Embodiment 2, when the light-receiving sensor unit 34A detects a peripheral member 22A, the control unit 4 switches the speed of the automated guided vehicle 3 to a low speed.

[0041] Specifically, when the control unit 4 detects the first instance of light blocking by the light-receiving sensor unit 34A while the automated guided vehicle (AGV) 3 is traveling straight towards the branching point 2 after crossing the guideway 1A, and determines that the AGV 3 is on the surrounding member 22A, it temporarily stops the AGV 3 and then makes it travel at a lower speed than the speed it traveled on the guideway 1A, or decelerates the AGV 3 to travel at a lower speed. At this time, as shown in Figure 16, the AGV 3 travels at high speed within the high-speed travel area X1 and at low speed within the low-speed travel area X2. In other words, the speed at which the AGV 3 travels from the surrounding member 22A to the base member 21 becomes low. As a result, the time from when the light-receiving sensor unit 34A detects the second instance of light blocking until the AGV 3 stops is shortened, which can prevent the AGV 3 from stopping beyond the base member 21, and ensure that the AGV 3's direction of travel is changed by spinning. Furthermore, when the automated guided vehicle 3 is spun to change its direction of travel, the center of the spin can be brought closer to the base member 21, thereby suppressing situations in which the body 30 of the automated guided vehicle 3 interferes with, for example, surrounding members 22C during the spinning operation.

[0042] Embodiment 3. Next, the automated guided vehicle system 102 according to Embodiment 3 will be described. Note that components identical to those in Embodiment 1 are denoted by the same reference numerals, and their descriptions are omitted as appropriate. Figure 17 is an overall view showing the automated guided vehicle system 102 according to Embodiment 3.

[0043] As shown in FIG. 17, in the unmanned transport system 102 according to the third embodiment, the shapes of the peripheral members 23A, 23B, 23C, and 23D are different from those in the configurations of the first and second embodiments. For other configurations, they are the same as those in the first or second embodiment. The peripheral members 23A, 23B, and 23C are configured as plate-like members extending along the directions of the surrounding guide paths 1A, 1B, and 1C from the base member 21. Among the plurality of peripheral members 23A, 23B, 23C, and 23D, there may be a peripheral member 23D that is arranged even if there is no corresponding guide path. The peripheral members 23A, 23B, 23C, and 23D shown in FIG. 17 are rounded rectangular in shape when viewed in plan. Although not shown, the peripheral members 23A, 23B, 23C, and 23D may be rectangular in shape when viewed in plan, or may be configured such that only one end side facing the guide paths 1A, 1B, and 1C is rounded. Thereby, since the light shielding time when the light receiving side sensor unit 34A detects the first light shielding becomes longer in the unmanned transport system 102, even if the unmanned transport vehicle 3 travels at high speed, the light receiving side sensor unit 34A can surely detect the light shielding. Further, in the unmanned transport system 102, when guiding any of the peripheral members 23A, 23B, 23C, and 23D into the guide unit 33, the direction of the unmanned transport vehicle 3 can be corrected only by the respective peripheral members 23A, 23B, 23C, and 23D. Therefore, even after the unmanned transport vehicle 3 leaves the base member 21, it can more surely enter the guide paths 1A, 1B, and 1C without deviating from the guide paths 1A, 1B, and 1C.

[0044] Embodiment 4. Next, the unmanned transport system 103 according to the fourth embodiment will be described. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. FIG. 18 is an overall view showing the unmanned transport system 103 according to the fourth embodiment.

[0045] As shown in FIG. 18, in the unmanned transport system 103 according to the fourth embodiment, the structures of the base member 21 and the peripheral members 22A, 22B, 22C, and 22D are different from those in the first to third embodiments. For other configurations, they are the same as those in the first to third embodiments.

[0046] The base point member 21 is a cylindrical pin, just as in the configuration of Embodiment 1. Similarly, the peripheral members 22A, 22B, 22C, and 22D are also cylindrical pins, just as in the configuration of Embodiment 1. The curved surfaces of the base point member 21 and the peripheral members 22A, 22B, 22C, and 22D are each configured to rotate like cam followers. This allows the automated guided vehicle (AGV) system 103 to reduce friction between the base point member 21 and the peripheral members 22A, 22B, 22C, and 22D and the guide section 33 when the AGV system 103 guides any of the base point member 21 or peripheral members 22A, 22B, 22C, and 22D with the guide section 33. Furthermore, the AGV system 103 can reduce friction between the base point member 21 and the guide section 33 when changing the direction of travel of the AGV 3 by spinning around the base point member 21 as an axis. These measures make it possible to suppress, for example, wear and tear on parts, generation of foreign matter due to wear, and snagging of the automated guided vehicle 3 due to friction.

[0047] The configurations shown in the above embodiments are merely examples and can be combined with other known technologies, or the embodiments themselves can be combined. Furthermore, it is possible to omit or modify parts of the configuration without departing from the gist of the invention.

[0048] 1A, 1B, 1C Guideway, 2 Branch point, 3 Automated guided vehicle, 4 Control unit, 10 Groove, 20 Base unit, 21 Base point member, 22A, 22B, 22C, 22D, 23A, 23B, 23C, 23D Peripheral members, 30 Vehicle body, 31A, 31B Drive wheels, 32A, 32B, 32C, 32D Driven wheels, 33 Guide unit, 34A, 34B Sensor unit, 35 Drive mechanism, 100, 101, 102, 103 Automated guided vehicle system.

Claims

1. The system comprises: a plurality of guide paths; branching points connecting the plurality of guide paths; an automated guided vehicle (AGV) whose drive wheels are driven to travel on the guide paths and branching points; and a control unit that controls the operation of the AGV, wherein the branching point has: a base portion that adjusts the direction in which the AGV traveling from one of the guide paths moves toward another guide path; a cylindrical base point member provided on the upper surface of the base portion; and a plurality of peripheral members consisting of protrusions provided on the upper surface of the base portion at intervals from the base point member toward each of the guide paths, wherein the AGV has: a guide portion that attracts the base point member or the plurality of peripheral members and guides the AGV's movement on the base portion along the base point member and the plurality of peripheral members; and a sensor portion that detects the base point member and the peripheral members attracted by the guide portion, wherein the control unit is An automated guided vehicle (AGV) system characterized in that, while the AGV is traveling straight towards the branching point beyond the guide path, the system determines, based on a first detection by the sensor unit, that the AGV is on the surrounding member, and based on a second detection by the sensor unit, that the AGV is on the base point member, and when it determines that the AGV is on the base point member, it determines whether to maintain or change the direction of travel of the AGV, and if it changes the direction of travel of the AGV, it stops the AGV from traveling and spins the drive wheels around the base point member as an axis.

2. The automated guided vehicle system according to claim 1, characterized in that the guide portion is configured to simultaneously guide the base member and any one of the plurality of peripheral members, and the control unit causes the peripheral members and the base member to be simultaneously guided by the guide portion when the automated guided vehicle is traveling in a straight line on the base portion, thereby correcting the posture of the automated guided vehicle toward the guide path.

3. The automated guided vehicle system according to claim 1 or 2, characterized in that the guide portion has two rail members arranged at intervals and extending along the direction of travel of the automated guided vehicle, and is configured to guide the base member and the peripheral member between the two rail members, and the rail members are inclined outward at least one of the front end and rear end in the direction of travel of the automated guided vehicle, the distance between the rail members widens at the front end and the rear end.

4. The automated guided vehicle system according to any one of claims 1 to 3, characterized in that, when the control unit determines, based on the first detection of the sensor unit, that the automated guided vehicle is on the surrounding member while the automated guided vehicle is traveling straight toward the branching point beyond the guideway, the control unit temporarily stops the automated guided vehicle and then makes it travel at a lower speed than the speed at which it traveled on the guideway, or decelerates the automated guided vehicle and makes it travel at a lower speed.

5. The unmanned transport system according to any one of claims 1 to 4, characterized in that the peripheral member is configured to be plate-shaped and extends from the base member in the direction of the guide path.

6. The unmanned transport system according to any one of claims 1 to 4, characterized in that the peripheral member is cylindrical, and the curved surface of the base member and the curved surface of the peripheral member are configured to rotate.

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