Transport vehicle

Abstract

To provide a method by which an actuator mounted on a traction truck is driven and controlled while an increase of a total weight of the traction truck is suppressed as low as possible in an unmanned transportation system with an unmanned carrier and a traction truck attracted by the unmanned carrier.SOLUTION: An unmanned carrier 10 has a power storage part 21, traction drive sources 19, 20 driven by power stored by the power storage part 21 to drive the wheels of the unmanned carrier 10, a traction control part 25 to control the drive of the traction drive sources 19, 20, a power supply part 28 to supply the stored power in the power storage part 21 to the traction truck 50 and a power supply control part 26 to control electric power supply by the power supply part 28. The traction truck 50 has a power incoming part 63 to receive power from the power supply part 28 built in the unmanned carrier 10 and an actuator 75 driven by power received from the power incoming part 63 and the power supply control part 26 controls working of the actuator 75 by controlling the power supply to the power incoming part 63 built in the traction truck 50 from the power supply control part 28.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention 、 relates to conveyance car .

Background Art

[0002] Conventionally, Nothing as an example of a human conveyance system, an unmanned conveyance system disclosed in Japanese Unexamined Patent Application Publication No. 2020-044859 (hereinafter referred to as Patent Document 1) is known. In this unmanned conveyance system, a towed cart is connected to an unmanned conveyance vehicle, and the unmanned conveyance vehicle autonomously travels along a route from a starting point set by a user to a destination point, whereby the load loaded on the towed cart is conveyed to the destination point.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the unmanned conveyance system shown in Patent Document 1, for example, it is conceivable to mount a traveling motor (actuator) for travel assistance on the towed cart or to mount a work robot (actuator) for loading and unloading workpieces.

[0005] However, when an actuator is mounted on the towed cart, it is necessary to further mount a power storage unit for supplying power to the actuator and a control device for controlling the operation of the actuator. As a result, there are problems such that the total weight of the towed cart increases and its traveling stability is impaired, or the power of the unmanned conveyance vehicle that towes the towed cart becomes insufficient and it becomes unable to travel.

[0006] The present invention has been made in view of the above circumstances, and aims to provide an unmanned transport system that can drive and control actuators mounted on a towed trolley while suppressing an increase in the total weight of the towed trolley. [Means for solving the problem]

[0007] One aspect of the present invention for solving the aforementioned problems is, An automated guided vehicle (AGV) system comprising an AGV and a towed trolley towed by the AGV, The aforementioned automated guided vehicle (AGV) includes a power storage unit, a drive source that is driven by the power stored in the power storage unit and drives the wheels of the AGV, a drive control unit that controls the drive source, a power supply unit that supplies the power stored in the power storage unit to the towed trolley, and a power supply control unit that controls the power supply by the power supply unit. The towed trolley has a power receiving unit that receives power from the power supply unit provided in the automated guided vehicle, and an actuator that is driven by the power received by the power receiving unit. The power supply control unit is configured to control the operation of the actuator by controlling the power supply from the power supply unit to the power receiving unit provided on the towed trolley in an unmanned transport system.

[0008] In this configuration, the automated guided vehicle (AGV) moves under the control of a driving control unit mounted on the AGV, which controls the AGV's drive source. The power for this drive source is supplied from a power storage unit mounted on the AGV. Meanwhile, the towed carriage is equipped with an electric actuator. This actuator can be, for example, an electric motor that drives the drive wheels of the towed carriage. The AGV is equipped with a power supply unit that supplies power from the power storage unit to a power receiving unit located on the carriage, and the actuator is driven by the power received from the power supply unit at the power receiving unit. The power supply control from the power supply unit to the power receiving unit is performed by a power supply control unit mounted on the AGV. This power supply control includes, for example, control of the timing and amount of power supplied to the power receiving unit. Then, under the control of the power supply control unit, the power supply control from the power supply unit to the power receiving unit is performed, thereby controlling the operating timing and operating speed of the actuator. Therefore, the actuator drive control can be performed without newly installing a power storage unit or control unit for driving the actuator on the towed trolley. This makes it possible to control the actuator drive while suppressing an increase in the total weight of the towed trolley.

[0009] It is preferable that the power supply unit is configured to supply power to the power receiving unit by contactless power supply.

[0010] This configuration allows for contactless power supply from the power supply unit on the automated guided vehicle (AGV) to the power receiving unit on the towed trolley. Therefore, when connecting the towed trolley to the AGV, wiring work to electrically connect the power supply unit and the power receiving unit is unnecessary, reducing the workload on the operator. Furthermore, if the power supply unit and the power receiving unit are connected by wire, there is a risk of the wire bending and breaking each time the AGV turns. However, with the above configuration, by employing contactless power supply, the risk of wire breakage is avoided, and power can be stably supplied from the power supply unit to the power receiving unit.

[0011] Preferably, the power supply surface of the power supply unit and the power receiving surface of the power receiving unit are arranged to face each other with a gap between them in the vertical direction.

[0012] With this configuration, even if the direction of travel of the automated guided vehicle changes, the distance between the power supply surface of the power supply unit and the power receiving surface of the power receiving unit does not change, thus maintaining a constant power supply efficiency.

[0013] Preferably, the actuator provided on the towed trolley includes a travel motor that rotates when power is supplied, and the towed trolley has drive wheels that are rotated by the travel motor.

[0014] In this configuration, the actuator installed on the towed trolley consists of a travel motor that rotates the drive wheels installed on the towed trolley, and this travel motor is driven by power supplied from the power supply unit of the automated guided vehicle (AGV) to the power receiving unit of the towed trolley. The power supply control unit mounted on the AGV controls the power supply from the power supply unit to the power receiving unit, thereby controlling the operation of the travel motor. Therefore, the drive wheels of the towed trolley can be rotated by the travel motor and its running stability can be improved without installing a power storage unit or control unit on the towed trolley.

[0015] Preferably, the unmanned transport system further includes a tilt detection mechanism for detecting the tilt angle of the towed trolley in a predetermined direction, and the power supply control unit is configured to drive the towed trolley's travel motor by supplying power from the power supply unit to the power receiving unit provided on the towed trolley when the tilt angle of the towed trolley detected by the tilt detection mechanism is greater than or equal to a predetermined amount, while not supplying power from the power supply unit to the power receiving unit when the tilt angle is less than a predetermined amount.

[0016] In this configuration, the tilt detection mechanism detects the tilt angle of the towed trolley in a predetermined direction (e.g., the vehicle width direction). If the tilt angle of the towed trolley in the predetermined direction detected by the tilt detection mechanism is greater than or equal to a predetermined amount, power is supplied from the power supply unit to the power receiving unit of the towed trolley under the control of the power supply control unit. This power is supplied to the travel motor (actuator) installed on the towed trolley, and the drive wheels of the towed trolley are rotated by the power supplied to the travel motor. Therefore, if the tilt angle of the towed trolley is greater than or equal to a predetermined amount, the drive wheels of the towed trolley are driven by the travel motor, stabilizing the unstable running state of the towed trolley and reducing the tilt angle of the towed trolley. On the other hand, if the tilt angle of the towed trolley detected by the tilt detection mechanism is less than a predetermined amount, power is not supplied from the power supply unit of the automated guided vehicle to the power receiving unit of the towed trolley. This prevents the traction motor of the towed trolley from being unnecessarily driven even when the tilt angle of the towed trolley is relatively small, thereby reducing the overall power consumption of the system.

[0017] Preferably, the towed carriage has a left drive wheel and a right drive wheel as the drive wheels, a left drive motor that drives the left drive wheel and a right drive motor that drives the right drive wheel as the travel motor, a left power receiving unit that receives power for driving the left drive motor and a right power receiving unit that receives power for driving the right drive motor, the unmanned transport vehicle has a left power supply unit that supplies power to the left power receiving unit and a right power supply unit that supplies power to the right power receiving unit as the power supply unit, and the power supply control unit is configured to change the power supply ratio between the left power supply unit and the right power supply unit.

[0018] With this configuration, the power supply control unit can change the power supply ratio between the left and right power supply units of the automated guided vehicle (AGV), thereby changing the rotation speed ratio of the left and right drive motors of the towed trolley. For example, when the towed trolley turns in accordance with the AGV's turn, the power supply control unit can control the power supply ratio to control the rotation speed of the left and right drive wheels so that the angular velocity around the turning center remains constant. This suppresses slippage of the left and right drive wheels during turning of the towed trolley, thereby improving its driving stability.

[0019] Preferably, the actuator provided on the towed trolley includes a braking actuator that generates braking force for the towed trolley when power is supplied.

[0020] In this configuration, the towed trolley is equipped with a braking actuator that generates braking force. Under the control of the power supply control unit, when power is supplied from the power supply unit of the automated guided vehicle to the power receiving unit of the towed trolley, the braking actuator is activated, and braking force is applied to the towed trolley. Therefore, when the automated guided vehicle stops, the braking actuator of the towed trolley can be activated by supplying power from the power supply unit to the power receiving unit, thereby preventing insufficient braking force on the towed trolley.

[0021] Preferably, the unmanned transport system further comprises a tilt detection mechanism for detecting the tilt angle of the towed trolley in a predetermined direction, and a weight estimation unit for estimating the load weight of the towed trolley based on the tilt angle of the towed trolley detected by the tilt detection mechanism, wherein the power supply control unit is configured to activate the braking actuator by supplying power from the power supply unit to the power receiving unit when the travel control unit stops the unmanned transport vehicle if the load weight estimated by the weight estimation unit is equal to or greater than a predetermined weight, while not activating the braking actuator by not supplying power from the power supply unit to the power receiving unit when the travel control unit stops the unmanned transport vehicle if the load weight is less than the predetermined weight.

[0022] According to this configuration, based on the tilt angle of the towed cart in a predetermined direction (for example, the vehicle width direction) detected by the tilt detection mechanism unit, the loading weight (weight of the loaded goods) of the towed cart is estimated by the weight estimation unit. When the loading weight of the towed cart estimated by the weight estimation unit is greater than or equal to a predetermined weight, when the travel control unit stops the automated guided vehicle, under the control of the power supply control unit, power supply from the power supply unit to the power receiving unit is executed and the braking actuator operates. Thereby, when the automated guided vehicle stops, it is possible to prevent the towed cart from colliding with the automated guided vehicle due to inertial force. On the other hand, when the loading weight of the towed cart is less than the predetermined weight, power supply from the power supply unit to the power receiving unit when the automated guided vehicle stops is not executed. Therefore, it is possible to prevent unnecessary power supply to the braking actuator even when the loading weight of the towed cart is small, and reduce the power consumption of the entire system.

[0023] The tilt detection mechanism unit preferably includes a predetermined marker provided on the towed cart, an imaging device mounted on the automated guided vehicle for imaging the predetermined marker, a storage unit for storing, as a reference image, an imaging image of the predetermined marker imaged by the imaging device in a state where the towed cart has no tilt, and a tilt angle calculation unit for calculating the tilt angle of the towed cart by comparing the imaging image of the predetermined marker by the imaging device with the reference image.

[0024] According to this configuration, an image of a predetermined marker provided on the towed cart is imaged by an imaging device mounted on the automated guided vehicle, and based on a comparison between the imaging image by this imaging device and a reference image which is an imaging image of the predetermined marker imaged by the imaging device in a state where the towed cart has no tilt in the predetermined direction, the tilt angle of the towed cart in the predetermined direction is calculated by the tilt angle calculation unit. According to this, it is possible to easily detect the tilt angle of the towed cart in a predetermined direction by performing only simple image processing.

Effects of the Invention

[0025] According to the automated guided vehicle system of the present invention, a power supply unit is provided on the automated guided vehicle, and a power receiving unit is provided on the towed trolley to receive power from the power supply unit as power for driving actuators mounted on the towed trolley. By performing power supply control from the power supply unit to the power receiving unit by a power supply control unit mounted on the automated guided vehicle, it is possible to perform drive control of actuators mounted on the towed trolley while minimizing the total weight of the towed trolley. [Brief explanation of the drawing]

[0026] [Figure 1] This is a side view from the left side of a vehicle showing an automated guided vehicle system according to Embodiment 1. [Figure 2] This is a plan view showing the automated transport system according to Embodiment 1. [Figure 3] This is a control block diagram of the automated guided vehicle system according to Embodiment 1. [Figure 4] This is a diagram corresponding to Figure 1, showing Embodiment 2. [Figure 5] This is a diagram corresponding to Figure 2, showing Embodiment 2. [Figure 6] This is a diagram corresponding to Figure 2, showing Embodiment 3. [Figure 7] This is a diagram corresponding to Figure 3, showing Embodiment 3. [Figure 8] This is a diagram corresponding to Figure 1 showing Embodiment 4. [Figure 9] This is a diagram corresponding to Figure 3, showing Embodiment 4. [Figure 10] This is an explanatory diagram illustrating the algorithm for calculating the tilt angle of a trolley by the tilt angle calculation unit of the automated guided vehicle system according to Embodiment 4. [Figure 11] This is a diagram corresponding to Figure 2, showing Embodiment 5. [Figure 12] This is a diagram corresponding to Figure 3, showing Embodiment 5. [Modes for carrying out the invention]

[0027] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

[0028] Embodiment 1 As shown in Figures 1 and 2, the automated guided vehicle (AGV) system 1 of this embodiment comprises an AGV 10 and a trolley 50 (an example of a towed trolley) that is detachably connected to the AGV 10. The AGV 10 travels tracklessly towards a destination point set by an operator, avoiding obstacles. As a result, the cargo loaded on the trolley 50 is transported to the target location. Note that the AGV 10 is not limited to trackless travel; for example, it may travel on tracks while detecting magnetic tape or reflective material laid on the floor.

[0029] The automated guided vehicle (AGV) 10 has a rectangular parallelepiped-shaped transport vehicle body 11 that is long in the longitudinal direction of the vehicle. As shown in Figure 3, which will be described later, the transport vehicle body 11 is equipped with a power storage unit 21, a control device 24, and a power supply device 27. In the following description, "front side" and "rear side" refer to the front and rear sides in the longitudinal direction of the vehicle, and "left side" and "right side" refer to the left and right sides in the width direction of the vehicle.

[0030] As shown in Figure 2, the left drive wheel 12, the right drive wheel 13, the front driven wheel 14, and the rear driven wheel 15 are mounted on the underside of the transport vehicle body 11. The left drive wheel 12 and the right drive wheel 13 are arranged symmetrically on the underside of the transport vehicle body 11, in the center of the vehicle's longitudinal direction, with the center line C1 in the vehicle's width direction in between. The left drive wheel 12 and the right drive wheel 13 are rotationally driven by the left drive motor 19 and the right drive motor 20, which are connected to their respective axles. In this example, each drive motor 19 and 20 is a DC motor and functions as a drive source for travel. In this example, the automated guided vehicle 10 does not have a dedicated steering mechanism, and steering functionality is achieved by the travel control unit 25, described later, which makes the rotation speeds of the left and right drive motors 19 and 20 different.

[0031] The front driven wheel 14 and the rear driven wheel 15 are located on the center line C1 in a plan view. The front driven wheel 14 and the rear driven wheel 15 are composed of caster wheels that can rotate in accordance with the direction of travel of the automated guided vehicle 10.

[0032] A connecting plate 16 (see Figure 1; not shown in Figure 2) extending horizontally toward the rear is connected to the center of the rear side of the transport vehicle body 11 in the width direction. A connecting pin 17 is provided protruding from the rear end of the connecting plate 16. The connecting plate 16 is connected to the connecting plate 56 of the trolley 50 via the connecting pin 17.

[0033] A protruding duct 11a is connected to the upper part of the connecting plate 16 on the rear side of the transport vehicle body 11, projecting horizontally toward the rear. A power supply unit 28, which is part of the power supply device 27, is fixed to the tip of the protruding duct 11a, and wiring connected to the power supply unit 28 is inserted into the protruding duct 11a. The power supply surface 28a of the power supply unit 28 is a vertical surface facing the rear of the unmanned transport vehicle 10. The power supply device 27 supplies a portion of the power stored in the power storage unit 21 to the power receiving unit 63 of the trolley 50, which will be described later, via the power supply unit 28.

[0034] As shown in Figure 3, the energy storage unit 21 is composed of, for example, a rechargeable battery or a capacitor. The energy storage unit 21 is connected to the left-side travel motor 19 and the right-side travel motor 20 via drivers 22 and 23 so as to be able to supply power. The energy storage unit 21 is also connected to the control device 24 and the power supply device 27 so as to be able to supply power.

[0035] The power supply device 27 is configured to supply power to the power receiving unit 63 of the power receiving device 62 mounted on the trolley 50 in a non-contact manner via the power supply unit 28. Power is supplied from the power supply unit 28 to the power receiving unit 63 by means of electromagnetic induction, for example, but is not limited to this, and may also be supplied by radio waves, electric field resonance, or magnetic field resonance.

[0036] Returning to Figures 1 and 2, the bogie 50 has a rectangular bogie body 51 that is long in the longitudinal direction of the vehicle. The bogie body 51 is equipped with a power receiving device 62 (see Figure 3) that receives power from the power supply device 27, and has a storage space inside that can accommodate loads such as workpieces.

[0037] The underside of the bogie body 51 is fitted with a drive wheel 70, a left driven wheel 71, and a right driven wheel 72. The drive wheel 70 is located at the front end of the vehicle at the center of the bogie body 51 in the vehicle width direction. The drive wheel 70 is driven by a running motor 75 (an example of an actuator) connected to its axle. In this example, the running motor 75 is a DC motor. The left driven wheel 71 and the right driven wheel 72 are located symmetrically on either side of the center line C2 in the vehicle width direction at the rear end of the bogie body 51. Each driven wheel 71 and 72 is a caster wheel that can pivot in the direction of travel of the bogie 50.

[0038] A connecting plate 56 (see Figure 1; not shown in Figure 2) extending horizontally toward the front is connected to the center of the front side of the trolley body 51 in the width direction. An engagement hole (not shown) is formed at the front end of this connecting plate 56. By rotatably engaging this engagement hole with a connecting pin 17 provided on the connecting plate 16 of the automated guided vehicle 10, the automated guided vehicle 10 and the trolley 50 are connected via both connecting plates 16 and 56.

[0039] A protruding duct 51a is connected to the upper part of the connecting plate 56 on the front side of the bogie body 51, projecting horizontally toward the front. A power receiving section 63, which is part of the power receiving device 62, is fixed to the tip of the protruding duct 51a. The power receiving surface 63a of the power receiving section 63 is a vertical surface facing the front side of the bogie 50. This power receiving surface 63a and the power supply surface 28a of the power supply section 28 provided on the automated guided vehicle 10 are parallel to each other when the automated guided vehicle 10 is traveling in a straight line (when the center line C1 of the automated guided vehicle 10 and the center line C2 of the bogie 50 are on the same straight line in a plan view).

[0040] As shown in Figure 3, the power receiving device 62 includes a power receiving unit 63 that receives power supplied from the power supply unit 28 of the automated guided vehicle 10, and a power receiving circuit 64 that smooths the power received by the power receiving unit 63, converts it into DC power, and then supplies it to the travel motor 75.

[0041] Power supply control from the power supply unit 28 of the automated guided vehicle 10 to the power receiving unit 63 of the trolley 50 is performed by a control device 24 mounted inside the guided vehicle body 11.

[0042] As shown in Figure 3, the control device 24 includes a driving control unit 25 and a power supply control unit 26. The control device 24 is composed of a computer including a CPU, RAM, ROM, etc., and the functions of the driving control unit 25 and the power supply control unit 26 are realized by computer programs and they perform the processes described later.

[0043] The driving control unit 25 executes a program based on the SLAM (Simultaneous Localization And Mapping) method, for example, which simultaneously performs self-position estimation and environmental map creation. The driving control unit 25 then calculates the driving path from the current position of the automated guided vehicle (AGV) 10 to the destination point, and controls the rotational speed of the left driving motor 19 and the right driving motor 20 via drivers 22 and 23 to drive the AGV 10 along the calculated driving path. Specifically, when the driving control unit 25 moves the AGV 10 in a straight line based on the calculated driving path, it rotates the left driving motor 19 and the right driving motor 20 at the same speed, and when the AGV 10 turns, it rotates both motors 19 and 20 at different speeds according to the turning direction and turning radius of the AGV 10.

[0044] The power supply control unit 26 determines whether the traction mode of the trolley 50 is set based on operation signals from an operation panel (not shown) located on the side of the automated guided vehicle 10. If it determines that the traction mode is set, it controls the power supply from the power supply unit 28 of the power supply device 27 to the power receiving unit 63. Specifically, the power supply control unit 26 obtains the running status of the automated guided vehicle 10 from the running control unit 25. If it determines that the automated guided vehicle 10 is running, it supplies power from the power supply unit 28 to the power receiving unit 63. If it determines that the automated guided vehicle 10 is stopped, it stops supplying power from the power supply unit 28 to the power receiving unit 63. When the power supply control unit 26 determines that the automated guided vehicle 10 is running and supplies power from the power supply unit 28 to the power receiving unit 63, it controls the power supplied from the power supply unit 28 to the power receiving unit 63 so that the trolley 50 and the automated guided vehicle 10 run at the same speed.

[0045] On the other hand, the power supply control unit 26 does not perform the power supply control if it determines, based on the operation signal from the operation panel located on the side of the automated guided vehicle 10, that the traction mode is not set. In this case, the power from the power storage unit 21 is supplied only to the travel motors 19 and 20 of the automated guided vehicle 10.

[0046] With the automated guided vehicle (AGV) system 1 configured as described above, when the AGV 10 starts moving toward a target point with the towing mode set on the AGV 10's control panel, power is supplied from the AGV 10's power supply unit 28 to the trolley 50's power receiving unit 63 under the control of the power supply control unit 26. The supplied power is converted to DC power via the power receiving circuit 64 and then supplied to the trolley 50's drive motor 75. The trolley 50's drive wheels 70 are then rotated by the power supplied to the trolley 50's drive motor 75. On the other hand, when the AGV 10 stops moving, the power supply control unit 26 stops the power supply from the power supply unit 28 to the power receiving unit 63, and as a result, the rotation of the trolley 50's drive motor 75 also stops.

[0047] As described above, according to this embodiment, while the automated guided vehicle 10 is in motion, the trolley 50 is driven by the power of the trolley motor 75. Therefore, the trolley 50's stability can be sufficiently ensured in situations where its stability is easily compromised, such as when the automated guided vehicle 10 is turning. Moreover, the power to drive the trolley motor 75 on the trolley 50 is supplied from the power storage unit 21 mounted on the automated guided vehicle 10 via the power supply device 27, and the control device 24 that controls this power supply device 27 is also mounted on the automated guided vehicle 10. Therefore, the trolley 50 does not need to be equipped with a power storage unit or control device to drive the trolley motor 75, thus suppressing an increase in the total weight of the trolley 50. Thus, problems such as a decrease in running stability and insufficient power for the automated guided vehicle 10 caused by an increase in the total weight of the trolley 50 can be avoided.

[0048] Furthermore, the power supply unit 28 of the automated guided vehicle 10 is configured to supply power to the power receiving unit 63 of the trolley 50 in a non-contact manner.

[0049] With this configuration, when connecting the trolley 50 to the automated guided vehicle 10, there is no need to perform wiring work to electrically connect the power supply unit 28 and the power receiving unit 63. Furthermore, if the power supply unit 28 and the power receiving unit 63 were connected by wiring, there would be a risk of the wiring bending and breaking each time the automated guided vehicle 10 turns. However, with the above configuration, by employing contactless power supply, the risk of wire breakage can be avoided and power can be stably supplied from the power supply unit 28 to the power receiving unit 63.

[0050] Embodiment 2 Figures 4 and 5 show Embodiment 2. In this embodiment, the configuration of the power supply unit 28 and the power receiving unit 63 differs from that of Embodiment 1. However, other than this point, the configuration is the same as that of Embodiment 1, and in the following embodiments, the same reference numerals are used for the same components as in Embodiment 1, and their detailed descriptions are omitted.

[0051] In other words, in this embodiment, the power supply surface 28a of the power supply unit 28 and the power receiving surface 63a of the power receiving unit 63 are both composed of horizontal planes and are arranged to face each other in the vertical direction. The power supply surface 28a and the power receiving surface 63a are circular in shape when viewed from above and are arranged coaxially with each other. Furthermore, the axis A1 of the power supply surface 28a and the power receiving surface 63a is coaxial with the axis A2 of the connecting pin 17.

[0052] In this embodiment, since the power supply surface 28a of the power supply unit 28 and the power receiving surface 63a of the power receiving unit 63 face each other in the vertical direction, the distance between the power supply surface 28a of the power supply unit 28 and the power receiving surface 63a of the power receiving unit 63 can be kept constant even when the direction of travel of the automated guided vehicle 10 changes. Therefore, the power supply efficiency from the power supply unit 28 to the power receiving unit 63 can be kept constant regardless of the direction of travel of the automated guided vehicle 10.

[0053] Furthermore, since the axes A1 of the power supply surface 28a and the power receiving surface 63a are coaxial with the axis A2 of the connecting pin 17, even if the angle of the trolley 50 around the connecting pin 17 changes when the automated guided vehicle 10 turns, the area of ​​the opposing portions of the power supply surface 28a and the power receiving surface 63a remains constant. Therefore, the power supply efficiency from the power supply unit 28 to the power receiving unit 63 can be reliably kept constant.

[0054] Embodiment 3 Figures 6 and 7 show Embodiment 3. This Embodiment 3 differs from Embodiment 1 in the wheel configuration of the trolley 50, as well as in the configuration of the power supply unit 28 and the power receiving unit 63.

[0055] First, the wheel configuration of the bogie 50 will be explained with reference to Figure 6. The bogie 50 has a left drive wheel 52, a right drive wheel 53, a front driven wheel 54, and a rear driven wheel 55. The left drive wheel 52 and the right drive wheel 53 are arranged symmetrically on either side of the center line C2 in the width direction of the bogie body 51 in the front-rear direction. The front driven wheel 54 and the rear driven wheel 55 are arranged on the center line C2 in a plan view. The left drive wheel 52 and the right drive wheel 53 are driven by a left running motor 60 and a right running motor 61 connected to their respective axles.

[0056] Next, the configurations of the power supply unit 28 and the power receiving unit 63 will be described with reference to Figures 6 and 7. The power supply unit 28 provided on the automated guided vehicle 10 consists of a left power supply unit 28L and a right power supply unit 28R. The power receiving unit 63 provided on the trolley 50 consists of a left power receiving unit 63L that receives power from the left power supply unit 28L and a right power receiving unit 63R that receives power from the right power supply unit 28R.

[0057] As shown in Figure 6, the rear side of the transport vehicle body 11 of the automated guided vehicle 10 has a left-side protruding duct 11c and a right-side protruding duct 11d that are spaced apart in the vehicle width direction. The left-side protruding duct 11c and the right-side protruding duct 11d are arranged symmetrically on either side of the center line C1 in the vehicle width direction in a plan view, with the left-side power supply unit 28L fixed to the tip of the left-side protruding duct 11c and the right-side power supply unit 28R fixed to the tip of the right-side protruding duct 11d.

[0058] On the front side of the bogie body 51, a left-side protruding duct 51c and a right-side protruding duct 51d are provided, spaced apart in the width direction of the vehicle. In a plan view, the left-side protruding duct 51c and the right-side protruding duct 51d are arranged symmetrically on either side of the center line C2 in the width direction of the vehicle, with the left-side power receiving unit 63L fixed to the tip of the left-side protruding duct 51c and the right-side power receiving unit 63R fixed to the tip of the right-side protruding duct 51d.

[0059] The power supply surfaces 28a of each power supply unit 28L, 28R and the power receiving surfaces 63a of each power receiving unit 63L, 63R face each other in the front-rear direction of the vehicle when the automated guided vehicle 10 is moving in a straight line (as shown in Figure 6).

[0060] As shown in Figure 7, the power receiving device 62 has a power receiving circuit 67 connected to the left power receiving unit 63L and a power receiving circuit 68 connected to the right power receiving unit 63R. Power supplied from the left power supply unit 28L of the automated guided vehicle 10 to the left power receiving unit 63L of the trolley 50 is converted to DC power in the power receiving circuit 67 (see Figure 7) and then supplied to the left travel motor 60. Power supplied from the right power supply unit 28R of the automated guided vehicle 10 to the right power receiving unit 63R of the trolley 50 is converted to DC power in the power receiving circuit 68 and then supplied to the right travel motor 61.

[0061] Then, when executing power supply control, the power supply control unit 26 controls the speed ratio between the left-side power supply unit 28L and the right-side power supply unit 28R, thereby controlling the speed ratio between the left-side travel motor 60 and the right-side travel motor 61 of the trolley 50. Specifically, the power supply control unit 26 obtains the travel status of the automated guided vehicle 10 from the travel control unit 25, and based on the obtained status, if it determines that the automated guided vehicle 10 is traveling in a straight line (forward or backward), it sets the power supply ratio between the left-side power supply unit 28L and the right-side power supply unit 28R to 1:1, thereby driving the left-side travel motor 60 and the right-side travel motor 61 of the trolley 50 at the same speed. On the other hand, if the power supply control unit 26 determines that the automated guided vehicle 10 is turning, it adjusts the power supplied to the left power supply unit 28L and the right power supply unit 28R according to the turning radius of the trolley 50, thereby creating a speed difference between the left travel motor 60 and the right travel motor 61 of the trolley 50 and matching the turning angular velocity of the left drive wheel 52 and the right drive wheel 53.

[0062] In this embodiment, the power supply control unit 26 is configured to change the power supply ratio between the left power supply unit 28L and the right power supply unit 28R. This allows the rotational speed ratio between the left travel motor 60 and the right travel motor 61 to be controlled when the trolley 50 is turning, thereby improving its running stability.

[0063] Embodiment 4 Figures 8 and 9 show Embodiment 4. This embodiment differs from Embodiment 1 in that it includes a tilt detection mechanism 35 that detects the tilt angle of the trolley 50 in the vehicle width direction (an example of a predetermined direction), and that the power supply control unit 26 performs power supply control based on the tilt angle of the trolley 50 detected by the tilt detection mechanism 35.

[0064] In other words, the automated guided vehicle system 1 of this embodiment includes, as a tilt detection mechanism 35, an imaging device 29 mounted on the automated guided vehicle 10, a predetermined marker 30 attached to the trolley 50, and a reference image storage unit 32 and a tilt angle calculation unit 33 provided in the control device 24, which will be described later.

[0065] The designated marker 30 is attached to the center of the front side of the trolley body 51 in the width direction. In this example, the designated marker 30 is a square-shaped graphic marker. The imaging device 29 is composed of, for example, a CCD camera and is attached to the rear side of the transport vehicle body 11. The imaging device 29 captures an image of the designated marker 30 and transmits the captured image to the tilt angle calculation unit 33. The designated marker 30 is not limited to a square shape, but may be triangular or rhombus-shaped, for example, and is not limited to a graphic marker, but may be a letter marker, for example.

[0066] As shown in Figure 9, the control device 24 includes a driving control unit 25, a power supply control unit 26, a reference image storage unit 32, and a tilt angle calculation unit 33. The tilt angle calculation unit 33, like the driving control unit 25 and the power supply control unit 26, is implemented by a computer program, and the reference image storage unit 32 is implemented by a storage medium such as ROM.

[0067] The reference image storage unit 32 has in advance stored an image of a predetermined sign 30 captured by the imaging device 29 when the trolley 50 is not tilted in the width direction, as the reference image g2.

[0068] As shown in Figure 10, the tilt angle calculation unit 33 calculates the tilt angle of the bogie 50 in the vehicle width direction (tilt angle in the vehicle width direction relative to the vertically upward direction) by comparing the captured image g1 from the imaging device 29 with the reference image g2 stored in the reference image storage unit 32. Specifically, the power supply control unit 26 calculates the tilt angle θ of the captured image g1 relative to the reference image g2, and calculates the tilt angle of the bogie 50 in the vehicle width direction corresponding to the calculated tilt angle θ. Here, the tilt angle of the bogie 50 corresponding to the tilt angle θ of the captured image g1 may be calculated, for example, by geometric theoretical calculation, or it may be calculated based on measurement data showing the correlation between the tilt angle θ of the captured image g1 and the tilt angle of the bogie 50. In the latter case, the measurement data is stored in advance in a storage unit such as a ROM.

[0069] The power supply control unit 26 is configured to supply power from the power supply unit 28 of the automated guided vehicle 10 to the power receiving unit 63 of the trolley 50 if the inclination angle in the vehicle width direction of the trolley 50 calculated by the inclination angle calculation unit 33 is equal to or greater than a predetermined amount, while not supplying power from the power supply unit 28 to the power receiving unit 63 if the inclination angle is less than a predetermined amount.

[0070] In this configuration, if the tilt angle of the bogie 50 detected by the tilt detection mechanism 35 is greater than or equal to a predetermined amount, power is supplied from the power supply unit 28 to the power receiving unit 63 of the bogie 50 under the control of the power supply control unit 26. The supplied power is converted to DC power in the power receiving circuit 64 and then supplied to the running motor 75 of the bogie 50, and the driving wheels 70 are rotated by the running motor 75 that has received the power supply. In this way, when the tilt angle of the bogie 50 in the width direction exceeds a predetermined amount, the driving wheels 70 of the bogie 50 rotate, improving its running stability and consequently reducing the tilt angle of the bogie 50.

[0071] On the other hand, if the tilt angle of the trolley 50 detected by the tilt detection mechanism 35 is less than the predetermined amount, the power supply control unit 26 does not supply power from the power supply unit 28 of the automated guided vehicle 10 to the power receiving unit 63 of the trolley 50. Therefore, it is possible to prevent the trolley 50's travel motor 75 from being driven unnecessarily even when the trolley 50's tilt angle is relatively small, and consequently, to reduce the power consumption of the entire automated guided vehicle system 1.

[0072] Embodiment 5 Figures 11 and 12 show Embodiment 5. This embodiment differs from Embodiment 4 in that the actuator mounted on the trolley 50 is composed of an electromagnetic brake 69, and the control device 24 has a weight estimation unit 34.

[0073] In other words, in this embodiment, the trolley 50 is not equipped with a running motor 75 as in Embodiment 1, and all three wheels 71 to 73 are driven wheels. An excitation-operated electromagnetic brake 69 that applies a deceleration force to the trolley 50 is attached to the front driven wheel 73. The electromagnetic brake 69 has an electromagnetic coil 69a, and the electromagnetic force generated by energizing the electromagnetic coil 69a presses a friction member (not shown) against the driven wheel 73 to generate braking force. In the example in Figure 11, the electromagnetic brake 69 is attached only to the front driven wheel 73, but this is not the only option, and the electromagnetic brake 69 may be attached to all three driven wheels 71 to 73.

[0074] The control device 24 of the automated guided vehicle 10 further includes a weight estimation unit 34 that estimates the weight of the load placed on the trolley 50.

[0075] The weight estimation unit 34 estimates the weight of the load on the trolley 50 based on the tilt angle in the vehicle width direction of the trolley 50, which is calculated by the tilt angle calculation unit 33 when the trolley 50 is turning. For this estimation, for example, correlation data that has been measured in advance regarding the correlation between the weight of the load on the trolley 50 and the tilt angle in the vehicle width direction when the trolley 50 is turning may be used. Alternatively, for example, the tilt angle calculation unit 33 may calculate the maximum value of the tilt angle in the vehicle width direction of the trolley 50 that occurs when the automated guided vehicle 10 is moving in a straight line, and the weight of the load on the trolley 50 (load weight) may be estimated based on the calculated maximum value of the tilt angle.

[0076] Furthermore, the power supply control unit 26 is configured such that, if the load weight of the trolley 50 estimated by the weight estimation unit 34 is equal to or greater than a predetermined weight, when the travel control unit 25 stops the automated guided vehicle 10, it supplies power from the power supply unit 28 of the automated guided vehicle 10 to the power receiving unit 63 of the trolley 50, thereby energizing the electromagnetic coil 69a and activating the electromagnetic brake 69. On the other hand, if the load weight of the trolley 50 estimated by the weight estimation unit 34 is less than the predetermined weight, the travel control unit 25 does not supply power from the power supply unit 28 to the power receiving unit 63 when stopping the automated guided vehicle 10.

[0077] Therefore, according to the automated guided vehicle system 1 of this embodiment, when the load weight of the trolley 50 is greater than or equal to a predetermined weight, power is supplied from the power supply unit 28 of the automated guided vehicle 10 to the power receiving unit 63 of the trolley 50 when the automated guided vehicle 10 stops, and the electromagnetic brake 69 is activated. This prevents the trolley 50 from colliding with the rear of the automated guided vehicle 10 due to its inertial force when it stops. On the other hand, when the load weight of the trolley 50 is less than the predetermined weight, power is not supplied from the power supply unit 28 to the power receiving unit 63. Therefore, it is possible to prevent the electromagnetic brake 69 from activating unnecessarily even when the load weight of the trolley 50 is relatively small, thereby preventing an increase in the overall power consumption of the system.

[0078] Other embodiments In the above embodiment, a travel motor 75 and an electromagnetic brake 69 were described as examples of actuators mounted on the trolley 50, but the invention is not limited to these. The actuators may also be, for example, a work robot mounted on the trolley 50 or an electric lifter for lifting objects.

[0079] Furthermore, in the above embodiment, power supply control by the power supply control unit 26 is performed only when the traction mode of the traction mode of the trolley 50 is set via the operation panel. However, this is not the only option. For example, wireless communication units may be provided in both the power supply device 27 and the power receiving device 62, and power supply control by the power supply control unit 26 may be performed when communication (e.g., infrared communication) is established between the wireless communication units.

[0080] Furthermore, in the above embodiment, a non-contact power supply method is used as the power supply method from the power supply unit 28 to the power receiving unit 63, but this is not the only option, and a contact power supply method may also be used.

[0081] Furthermore, the present invention includes any combination of the above embodiments.

[0082] The above-described embodiments are illustrative and not restrictive in all respects. Modifications and alterations are readily possible for those skilled in the art. The scope of the present invention is defined by the claims, not by the embodiments described above. Furthermore, the scope of the present invention includes modifications from the claims and equivalent embodiments. [Explanation of symbols]

[0083] 1. Automated Guided Vehicle (AGV) System 10. Automated Guided Vehicles 12. Left-side drive wheel (wheel of automated guided vehicle) 13. Right-side drive wheel (wheel of automated guided vehicle) 19. Left-side drive motor (driving source) 20 Right-side drive motor (driving source) 21 Energy Storage Unit 25. Driving control unit 26 Power supply control unit 28 Power supply section 28L Left-side power supply unit 28R Right side power feed section 28a Power supply plane 29. Imaging device (tilt detection mechanism) 30. Sign (tilt detection mechanism) 32 Reference image storage unit (storage unit, tilt detection mechanism unit) 33. Tilt Angle Calculation Unit (Tilt Detection Mechanism Unit) 34 Weight estimation section 35 Tilt detection mechanism 40 Control device 50 trolleys 52 Left-side drive wheel (drive wheel) 53 Right-side drive wheel (drive wheel) 60 Left-side drive motor (actuator) 61 Right-side drive motor (actuator) 63 Power receiving section 63L Left side power receiving section 63R Right side power receiving section 63a Power receiving surface 69. Electromagnetic brake (actuator, braking actuator) 70 Drive wheels 75. Driving motor (actuator) g1 Acquired image g2 reference image

Claims

1. The energy storage unit, A drive source that is driven by the electricity stored in the aforementioned power storage unit and drives the wheels, A travel control unit that controls the aforementioned travel drive source, A transport vehicle comprising a power supply unit that supplies the power stored in the power storage unit to other vehicles, The aforementioned other vehicle has an actuator that operates when power is supplied, The power supply unit is configured to supply the power stored in the power storage unit to the actuator provided in the other vehicle. The transport vehicle is further characterized in that it includes a power supply control unit that controls the operation of an actuator provided on another vehicle by controlling the power supply from the power supply unit to the actuator.

2. The transport vehicle according to claim 1, characterized in that the power supply unit is configured to supply power by contactless power supply.

3. The other vehicle has a power receiving unit that receives power from the power supply unit, The transport vehicle according to claim 2, characterized in that the power supply surface of the power supply unit and the power receiving surface of the power receiving unit are arranged to face each other with a gap between them in the vertical direction.

4. The aforementioned other vehicle has a drive motor as an actuator and drive wheels that are rotationally driven by the drive motor, The system further includes a tilt detection mechanism that detects the tilt angle of the other vehicle in a predetermined direction, The transport vehicle according to claim 1, characterized in that the power supply control unit is configured to drive the drive motor of the other vehicle by supplying power from the power supply unit to the drive motor provided on the other vehicle when the tilt angle of the other vehicle detected by the tilt detection mechanism unit is greater than or equal to a predetermined amount, while not supplying power from the power supply unit to the drive motor when the tilt angle is less than the predetermined amount.

5. The aforementioned other vehicle has a drive motor as an actuator and drive wheels that are rotationally driven by the drive motor, The aforementioned other vehicle has a left drive wheel and a right drive wheel as its drive wheels, and has a left drive motor that drives the left drive wheel and a right drive motor that drives the right drive wheel as its drive motors. The transport vehicle according to claim 1, characterized in that the power supply control unit is configured to change the power supply ratio between the left-side travel motor and the right-side travel motor.

6. The other vehicle has a braking actuator which generates braking force for the other vehicle by receiving a power supply, A tilt detection mechanism for detecting the tilt angle of the other vehicle in a predetermined direction, The system further includes a weight estimation unit that estimates the load weight of the other vehicle based on the tilt angle of the other vehicle detected by the tilt detection mechanism, The transport vehicle according to claim 1, characterized in that the power supply control unit is configured to activate the braking actuator by supplying power when the transport vehicle is stopped by the travel control unit if the load weight estimated by the weight estimation unit is equal to or greater than a predetermined weight, while not activating the braking actuator by not supplying power by the power supply unit when the transport vehicle is stopped by the travel control unit if the load weight is less than the predetermined weight.

7. The tilt detection mechanism is provided with a predetermined sign on the other vehicle, The transport vehicle is equipped with an imaging device that captures images of the predetermined sign, and a storage unit that stores the image of the predetermined sign captured by the imaging device as a reference image when the other vehicle is not tilted in the predetermined direction. The transport vehicle according to claim 6, further comprising a tilt angle calculation unit that calculates the tilt angle of the other vehicle by comparing the image of the predetermined sign captured by the imaging device with the reference image.

Images