JP2022059321A - Unmanned carriage - Google Patents

Abstract

To provide an unmanned carriage whose first purpose is to eliminate complicated mechanisms in the wheels themselves, and whose second purpose is to transport a transported object so as to minimize impact shock thereto.SOLUTION: Wheel units 12 to 15 use wheels 21 to support a vehicle body 11 on which a transported object A can be loaded. The wheel units 12 to 15 comprise a driving wheel unit having a traveling drive motor for driving the wheels 21. The wheel units 12 to 15 include steering motors for steering in a respectively travelable direction of the wheel units. The unmanned carriage 10 changes a traveling direction by steering using the steering motors of all wheel units 12 to 15.SELECTED DRAWING: Figure 2

Description

The present invention relates to an automatic guided vehicle.

Automated guided vehicles (AGCs) that move autonomously from the starting point to the target point have been developed. This type of automatic guided vehicle determines a route from the starting point to the target point and moves at high speed based on the route.

The automatic guided vehicle may have restrictions on the width of the movement route, etc., and it is necessary to move not only straight but also in all directions such as backward movement, left-right movement, and rotation. This is generally realized by a mechanism that steers the drive wheels and supports the vehicle body by the driven wheels, or an omnidirectional moving wheel such as an omni wheel or a mecanum wheel (see, for example, Patent Document 1). However, if an omni wheel or a mecanum wheel is used, the wheel itself will be provided with a complicated mechanism that can move in all directions. While this type of automatic guided vehicle can move in all directions, it cannot climb steps or can not be transported without giving an impact to the transported object due to its large vibration.

Japanese Unexamined Patent Publication No. 2013-1207

The present invention has been made in view of the above circumstances, and the first object of the present invention is to enable the wheel itself to be configured without providing a complicated mechanism, and the transported object can be transported without giving an impact as much as possible. The second purpose is to provide an automatic guided vehicle.

In order to achieve the above object, the invention according to claim 1 is provided with at least three wheels of a wheel unit module, and supports a vehicle body configured to be capable of mounting a conveyed object by using wheels. The vehicle body includes a mounted portion on which the above-mentioned three or more wheel unit modules can be mounted.

The wheel unit module is composed of a drive wheel unit all of which are detachably attached to and detachable from the mounted portion and has a drive unit for driving the wheels, and also includes a steering unit for steering in a travelable direction. The direction of travel is changed by steering using the steering section of all wheel unit modules. As a result, the traveling direction of the vehicle body can be changed by changing the steering direction of each wheel of each wheel unit module, and each wheel can be used as a driving wheel to travel in the traveling direction.

Although the automatic guided vehicle can move in all directions, it cannot climb a step due to the nature of the wheel shape, and even if it climbs a step, it causes a large vibration, so it gives an impact when loading a transported object. It may be difficult to carry without it. According to the invention according to claim 2, the wheel of the wheel unit module is provided with a rotating contact surface that rotates in contact with the ground in a curved surface shape, and rotates about a rotation axis inserted through the center of the circular curved surface shape. Therefore, it is possible to travel by using wheels having no unevenness, and it is possible to suppress an impact on a transported object during traveling.

It is a figure explaining one Embodiment, and is the perspective view which shows typically the four-wheel drive automatic guided vehicle. Bottom view schematically showing the orientation of the wheels when the automatic guided vehicle moves sideways Front view showing the main part of the structure of the wheel unit constituting the unmanned carrier Top view showing the main part of the structure of the wheel unit Side view showing the main part of the structure of the wheel unit Electrical configuration diagram of automatic guided vehicle Bottom view schematically showing the orientation of the wheels when the automatic guided vehicle goes straight Bottom view schematically showing the orientation of the wheels when the automatic guided vehicle rotates Side view when an automatic guided vehicle loads and travels a transported object

Hereinafter, some embodiments will be described with reference to the drawings. In addition, as shown in the figure, it will be described using the XY coordinate system. Unless otherwise specified, the XY direction will be considered as the horizontal direction. For convenience of explanation, the XY direction is referred to as a horizontal direction, but the direction is not limited to the horizontal direction.

(First Embodiment)
1 to 8 show explanatory views of the first embodiment. The automatic guided vehicle 10 (corresponding to the main body of the automatic guided vehicle) shown in FIG. 1 is configured to be capable of autonomously traveling in a target range in various facilities, and the wheel units 12 ... 15 are mounted on the vehicle body 11. Consists of. Each wheel unit 12 ... 15 corresponds to a modularized wheel unit module. Further, the wheel units 12 ... 15 are configured to have the same structure as each other, and each is configured as a drive wheel unit provided with a drive source for the wheels 21.

As shown in FIG. 1, the vehicle body 11 is composed of a rectangular box-shaped body as a whole. The vehicle body 11 includes a mounted portion 11a to which the wheel units 12 ... 15 can be mounted. The wheel units 12 ... 15 support the vehicle body 11 by using the wheels 21, so that the automatic guided vehicle 10 can travel in the passage in the facility. The wheel units 12 to 15 are configured to have at least three or more, and it is sufficient that the vehicle body 11 can be stably controlled to travel by contacting three or more points with the passage. Here, an example in which four wheel units 12 ... 15 are incorporated will be described.

The safety laser scanners 18 and 19 are composed of non-contact sensors capable of recognizing at least front, rear, left and right obstacles of the automatic guided vehicle 10, and are composed of, for example, a radar unit called LIDAR. The safety laser scanners 18 and 19 are provided on the vehicle body 11 so as to be capable of sensing all horizontal directions of the vehicle body 11.

For example, the safety laser scanners 18 and 19 may be installed at two diagonal corners of the four horizontal corners of the vehicle body 11. Then, the safety laser scanners 18 and 19 can efficiently sense 270 degrees in the horizontal direction from the diagonal positions of the vehicle body 11. The installation locations of the safety laser scanners 18 and 19 are not limited to these installation positions, and may be installed in any position as long as the object can be detected in all directions of front, back, left, and right. As a result, the safety laser scanners 18 and 19 can detect an object such as an obstacle such as a pillar or a wall over the front, rear, left, and right directions of the vehicle body 11.

As shown in FIG. 2 is a bottom view of the automatic guided vehicle 10, the wheel units 12 ... 15 are each equipped with wheels 21. The individual wheel units 12 ... 15 are drive wheel units having the same structure as each other, and all of them are configured to be detachably attached to the mounted portion 11a.

Hereinafter, the structure of the wheel unit 12 will be described with reference to FIGS. 3 to 5, and the description of the other wheel units 13 ... 15 will be omitted. As shown in FIGS. 3 to 5, the wheel 21 of the wheel unit 12 has a rotary contact surface that rotates in contact with the ground in a curved surface shape, and rotates about a rotation axis inserted through the center of the circular curved surface shape. It is configured to do. The wheel unit 12 is configured as a drive wheel unit including a traveling drive motor 33 for driving the wheels 21. The wheel unit 12 mainly serves as a safety control device, as a safety encoder 35 as a speed detecting unit for detecting the speed in the traveling direction of each wheel 21, and as a steering angle detecting unit for detecting the steering angle of the wheels 21. A safety non-contact switch 28 and an electromagnetic brake 36 as a braking device for braking the rotation of the wheel 21 are incorporated.

The wheel unit 12 is composed of a fixing plate 22 as a fixing portion fixed to the mounted portion 11a of the vehicle body 11 and a movable portion 23 that can rotate horizontally with respect to the fixing plate 22. On the fixing plate 22, a pulleys 24 and 25 rotatably installed along the upper surface of the fixing plate 22 and a timing belt 26 connecting the pulleys 24 and 25 are installed. A steering motor 27 as a steering unit is connected to the shaft of the pulley 24. The steering motor 27 is capable of rotating the pulley 25 in conjunction with the timing belt 26 by rotationally driving the pulley 24 via the motor shaft. The steering motor 27 can rotate the wheels 21 in the horizontal direction and can steer in a travelable direction. Further, the encoder 34 is engaged with the timing belt 26 via the pulley 43, so that the steering angle can be detected.

A safety non-contact switch 28 is fixed to the fixing plate 22 by using bolts, nuts, and the like. The safety non-contact switch 28 is used to improve the safety performance, and is used as a steering angle detecting unit for detecting the steering angle of the wheel 21. As illustrated in FIG. 4, the safety non-contact switch 28 penetrates from above to below the fixing plate 22 and its tip extends to the side of the frame 30. At the tip of the safety non-contact switch 28, an induction detection coil that outputs a magnetic field using an oscillation circuit is installed. The safety non-contact switch 28 functions as an inductive proximity switch together with the protrusions 31 and 32 provided on the frame 30 described later. Any method may be used as long as the steering angle can be detected by a method conforming to the safety standard.

A bearing 29 is installed on the lower surface of the fixing plate 22. A frame 30 is connected to the lower side of the bearing 29. The frame 30 is fixed to the bearing 29 using screws.

The movable portion 23 is configured with the frame 30 as a base material, and is directly or indirectly connected to the frame 30, with protrusions 31, 32, wheels 21, traveling drive motors 33, encoders 34, safety encoders 35, and electromagnetic waves. A brake 36 is provided. In addition, the movable portion 23 also includes a rotating shaft 21a and the like. The movable portion 23 is configured to be rotatable in the horizontal direction by integrating the components 30 ... 36 with respect to the fixing plate 22 through the bearing 29.

The protrusions 31 and 32 are fixed around the frame 30 in a predetermined angle step (for example, 90 ° step), and are integrally rotatable in the horizontal direction together with the frame 30. Therefore, when the movable portion 23 rotates in the horizontal direction, which is the rotation direction of the bearing 29, the protrusions 31 and 32 are displaced or coincide with the tip position of the safety non-contact switch 28. The safety non-contact switch 28 fixed to the fixed plate 22 detects the proximity state to the protrusions 31 and 32 by the magnetic field generated by the induction detection coil at the tip thereof, so that the wheel 21 can be stepped in a specific direction, for example, 90 ° step. , Steering state can be detected. Thereby, it can be determined which direction the wheel 21 is facing at an angle with respect to the traveling direction, for example, which direction is front, rear, left, or right.

The traveling drive motor 33 is used as a drive unit for driving the wheels 21. The traveling drive motor 33 can drive the wheels 21 in forward and reverse rotations, and enables the wheels 21 to travel in one direction, for example, in the Y direction, the X direction, or other directions in the drawing. In the present embodiment, the traveling drive motor 33 is provided integrally with the safety encoder 35 and the electromagnetic brake 36. These may be composed of separate parts.

The traveling drive motor 33 is fixed to the frame 30, and the rotating shaft 21a of the traveling drive motor 33 is directly connected to the wheels 21. The safety encoder 35 detects the rotation speed of the wheel 21. The number of revolutions may be detected by converting the gear ratio. As a result, the safety encoder 35 is used as a speed detection unit that detects the speed of each wheel unit 12 ... 15 in the traveling direction.

The electromagnetic brake 36 is provided integrally with the traveling drive motor 33 and the safety encoder 35, and is used as a braking device for braking the rotation of the wheels 21. The electromagnetic brake 36 brakes the rotation of the wheel 21 through the rotating shaft 21a. As shown in FIG. 3, an electric wiring 42 connecting various electric configurations is installed along the rotation axis of the bearing 29.

FIG. 6 illustrates an electrical configuration. The automatic guided vehicle 10 is equipped with a wheel unit 12 ... 15, a safety laser scanner 18 and 19 as an environment recognition unit, a control unit 50, and an emergency stop switch 55. The control unit 50 is configured by combining a travel control controller 51, a safety controller 52, a contactor 53, and a drive circuit 54a mounted on the control board 54.

Further, as described above, the safety laser scanners 18 and 19 are mounted on the vehicle body 11. The safety laser scanners 18 and 19 are electrically connected to the safety controller 52 of the control unit 50. Each wheel unit 12 ... 15 includes an encoder 34 in addition to the steering motor 27, a safety non-contact switch 28, a traveling drive motor 33, a safety encoder 35, and an electromagnetic brake 36 described above. The encoder 34 can detect the steering angle of the wheel 21 in detail for traveling control.

The travel control controller 51 is mainly composed of a microcomputer that is responsible for travel control. The travel control controller 51 is realized by the CPU executing a program stored in a ROM or the like. That is, although it is realized by software, the drive control controller 51 may be realized by hardware.

The travel control controller 51 drives the travel drive motor 33 through the drive circuit 54a mounted on the control board 54, and also drives the steering motor 27 to control the rotation of each wheel 21 of the wheel units 12 ... 15. At this time, the travel control controller 51 detects the detailed steering angle of each wheel 21 by the encoder 34 and performs feedback control to control the travel of the automatic guided vehicle 10.

The safety controller 52 is a controller mainly responsible for safety control and is composed of a PLC. The safety controller 52 determines information on the surrounding environment such as the presence or absence of an obstacle and the distance to the obstacle within the scan detection range of the safety laser scanners 18 and 19. The safety controller 52 can send and receive information to and from the travel control controller 51, and can transmit information on the surrounding environment acquired from the safety laser scanners 18 and 19 to the travel control controller 51. The travel control controller 51 can autonomously travel by controlling in cooperation with the safety controller 52.

Further, the safety controller 52 directly inputs the signals of the safety non-contact switch 28 and the safety encoder 35. The safety controller 52 can detect the steering state of each wheel unit 12 ... 15 in a specific direction by the safety non-contact switch 28 of each wheel unit 12 ... 15. Further, the safety controller 52 can detect the speed of each wheel unit 12 ... 15 by the safety encoder 35 of each wheel unit 12 ... 15. As a result, the safety controller 52 can detect various states of the automatic guided vehicle 10.

Although the safety controller 52, safety laser scanners 18 and 19, safety non-contact switch 28, safety encoder 35, and electromagnetic brake 36 are not used as the main body of driving control, they are necessary equipment to meet the safety standard ISO3691-4. It is configured as a safety device with safety certification. The speed monitoring function and steering detection function are certified as safety category 3 and performance level D as defined by ISO13849.

The encoder 34 detects the steering angle of the wheel 21 in detail for traveling control. For example, the safety non-contact switch 28 is provided as an indispensable device for detecting a specific direction as described above. .. Further, if the driving force of the traveling drive motor 33 becomes small, or if the power of the traveling drive motor 33 fails to be cut off due to some trouble, the electromagnetic brake 36 is used to safely and surely stop the automatic guided vehicle 10. Is assembled.

The contactor 53 is an electromagnetic switch that opens and closes the power supply according to the control of the safety controller 52. The contactor 53 is configured to be able to energize the electromagnetic brake 36 with the electric power required for the braking action according to the control of the safety controller 52.

Further, the contactor 53 is capable of transmitting and disconnecting a power source that is energized to the control board 54 according to the control of the safety controller 52. The emergency stop switch 55 is a switch that can be operated by an external user, is electrically connected to the safety controller 52, and can be instructed to stop from the outside in an emergency.

Even while the travel control controller 51 is autonomously controlling travel through the drive circuit 54a using the drive motor 33 for travel, the steering motor 27, and the encoder 34, the emergency stop switch 55 is turned on to turn on the safety controller 52. , The power supply energized in the drive circuit 54a can be cut off through the contactor 53. As a result, autonomous driving control can be stopped.

Further, the safety controller 52 collates the state of the wheel units 12 ... 15 of the automatic guided vehicle 10 with the information of the surrounding environment of the automatic guided vehicle 10, and can secure a certain distance or more from the obstacles existing in the vicinity. For example, when the automatic guided vehicle 10 is colliding with an obstacle, the safety controller 52 can brake the automatic guided vehicle 10 by energizing the electromagnetic brake 36 with a power source through the contactor 53.

The travel control controller 51 drives and controls the travel drive motors 33 of the wheel units 12 ... 15, so that the wheels 21 of the wheel units 12 ... 15 can be driven in forward and reverse rotations.

Therefore, as shown in FIG. 2, the control unit 50 can laterally move the vehicle body 11 by steering the wheels 21 of all the wheel units 12 ... 15 in the X direction. Further, as shown in FIG. 7, the control unit 50 can steer the wheels 21 of all the wheel units 12 ... 15 in the Y direction to allow the vehicle body 11 to go straight.

Further, as shown in FIG. 8, the control unit 50 can rotate the automatic guided vehicle 10 around its vertical axis by inclining the wheels 21 of all the wheel units 12 ... 15 in the XY directions. As a result, the automatic guided vehicle 10 can be moved in any direction in the horizontal direction, and the automatic guided vehicle 10 can be driven in all directions by 360 °.

FIG. 9 shows a side view of the automatic guided vehicle 10 when the automatic guided vehicle 10 is mounted and travels. The wheel 21 of the unmanned transport carriage 10 is provided with a rotating contact surface that rotates in contact with the ground in a curved surface shape, and rotates about a rotation axis inserted through the center of the circular curved surface shape. The wheel unit 12 can travel using the wheels 21 having no unevenness, and can suppress an impact on the conveyed object A during traveling.

(Other embodiments)
The embodiment is not limited to the above, and for example, the following modifications or extensions are possible.
The wheel units 12 ... 15 show a form in which only four wheels are mounted, but the present invention is not limited to this, and may be three wheels, five wheels, or six wheels.

Although the present invention has been described in accordance with the above-described embodiment, it is understood that the present invention is not limited to the embodiment or structure. The present invention also includes various modifications and variations within a uniform range. In addition, various combinations and forms, as well as other combinations and forms including one element, more, or less, are within the scope and scope of the invention.

In the drawing, 10 is an unmanned transport trolley, 11 is a vehicle body, 11a to 11d are mounted parts, 12 to 15 are wheel units (wheel unit modules), 21 are wheels, 27 is a steering motor (steering part), and 33 is for traveling. A drive motor (drive unit) is shown.

Claims (3)

A wheel unit module (12 to 15) having at least three wheels or more that supports a vehicle body configured to be capable of mounting a transported object by using wheels (21), and a wheel unit module (12 to 15).
The vehicle body (11) having a mounted portion to which the wheel unit module of three or more wheels can be mounted is provided.
The wheel unit module is
All of them are configured to be mountable on the mounted portion, and are composed of a drive wheel unit having a drive unit (33) for driving the wheels, and also have a steering unit (27) for steering in a direction in which the wheels can travel. ,
An automatic guided vehicle that changes the direction of travel by steering using the steering unit of all the wheel unit modules. The unmanned transport trolley according to claim 1, wherein the wheel of the wheel unit module is provided with a rotating contact surface that rotates in contact with the ground in a curved surface shape, and rotates about a rotation axis inserted through the center of the circular curved surface shape. .. The automatic guided vehicle according to claim 1 or 2, wherein the wheel unit module is mounted on the vehicle body with only four wheels.

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