JPH05241658A - Traveling control method for unmanned truck and travel controlling device for realizing the device - Google Patents

Abstract

PURPOSE:To smoothly travel an unmanned truck at the time of either normal travel operations or traverse operations. CONSTITUTION:When traveling an unmanned truck 10 forward and backward (at the time of normal travel operations), front and rear wheels 11 and 12 are torque controlled so that those torques can be made equal. When traveling the unmanned truck 10 to right and left (at the time of traverse operations),the front and rear wheels 11 and 12 are independently speed controlled. Therefore, at the time of normal travel operations, the load balance of driving motors 13 and 14 to drive the front and rear wheels 11 and 12 is made equal and the unmanned truck 10 can be efficiently normally traveled. At the time of traverse operations, the unmanned truck 10 can be traversed over a long distance since the route of the unmanned truck 10 can be adjusted corresponding to speed difference between the front and rear wheels 11 and 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automated guided vehicle (AGV: Automatic) that travels along a guide wire.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guided vehicle) traveling control method and a traveling control device that implements the same.

[0002]

2. Description of the Related Art As an unmanned carrier truck of this type (hereinafter, also simply referred to as a carriage), there is a type having steering drive wheels which are driven to travel in front of and behind the carriage. Here, the steering drive wheels in front of the truck are simply referred to as front wheels, and the steering drive wheels behind the truck are simply referred to as rear wheels. In this type of unmanned guided vehicle, the front-wheel steering mechanism and the rear-wheel steering angle are independently adjusted by the front-wheel steering mechanism and the rear-wheel steering mechanism, respectively. It is possible to travel in the left-right direction (hereinafter also referred to as lateral travel) and to travel in an oblique direction (hereinafter also referred to as oblique travel).

That is, in this type of automatic guided vehicle, normally, the path of the vehicle is adjusted by controlling the steering angles of the front wheels and the rear wheels by the steering mechanism for the front wheels and the steering mechanism for the rear wheels, respectively, and the vehicle is buried in the ground. Travel along the guided wire. Therefore, for example, the turning radius of the bogie can be reduced by controlling the steering angles of the front wheels and the rear wheels in opposite phases. Further, by controlling the steering angles of the front wheels and the rear wheels in the same phase, it is possible to cause the bogie to perform oblique traveling or lateral traveling. Such a method of controlling traveling by adjusting the steering angle is called a steering angle traveling control method.

On the other hand, as a traveling control system different from such a steering angle traveling control system, there is a traveling control system in which traveling drive wheels are installed on both left and right sides of the bogie and the traveling direction of the bogie is controlled by a speed difference between the two traveling drive wheels. is there. Such a travel control system is a system for controlling travel by differential steering, so it is called a differential steering travel control system.

[0005]

The above-described conventional traveling control system has the following drawbacks.

In the conventional steering angle traveling control system, when the carriage is caused to perform the traverse traveling operation, it is impossible to absorb the deviation in the rotating direction of the carriage. For this reason, it is impossible to traverse the carriage over a long distance.

On the other hand, in the conventional differential steering traveling control system,
In order to be applied to the traverse operation, it is necessary to have a mechanism that can control the speeds of both drive wheels independently.
However, if both drive wheels are speed controlled independently,
When causing the bogie to perform a normal traveling operation, an extreme difference may occur in the torque of the drive motor that drives both drive wheels due to differences in the wheel diameters of the two drive wheels. Further, torques in opposite directions are sometimes applied to both drive wheels, which may result in extremely inefficient operation.

Therefore, an object of the present invention is to provide a traveling control method for an unmanned guided vehicle which enables the unmanned guided vehicle to smoothly travel in both normal traveling operation and traverse traveling operation, and a method thereof. It is to provide a traveling control device to be realized.

[0009]

A travel control method for an automated guided vehicle according to the present invention includes front wheels and rear wheels at the front and rear of the automated guided vehicle, and guides by adjusting steering angles of the front wheels and the rear wheels. This is a method of controlling the traveling of an unmanned guided vehicle capable of traveling in the front-rear direction and traveling in the left-right direction along a wire.

According to the present invention, in the traveling control method for the unmanned transportation vehicle, when the unmanned transportation vehicle travels in the front-rear direction (during normal traveling operation), the front wheels and the rear wheels have the same torque. As described above, when the unmanned transport vehicle is driven in the left-right direction by the torque control (during the transverse traveling operation), the speed of the front wheels and the rear wheels is independently controlled.

The traveling control device for an unmanned carrier vehicle according to the present invention comprises an unmanned carrier vehicle having front and rear wheels at the front and rear, respectively, and a front and rear direction along a guide wire by adjusting the steering angles of the front and rear wheels. Or a traveling control device capable of traveling in either the left or right direction.

According to the first aspect of the present invention, the traveling control device for an unmanned guided vehicle is configured so that the first and second input speed commands for the front wheels and the rear wheels, respectively, and whether the unmanned guided vehicle is forward or backward. A driving direction command indicating which of the left and right directions to travel is received. The traveling control device for the unmanned carrier truck,
A first motor for driving the front wheels; a second motor for driving the rear wheels; a first motor that detects the rotation speed of the first motor and outputs a first rotation speed detection signal Rotation speed detection means; second rotation speed detection means for detecting the rotation speed of the second motor and outputting a second rotation speed detection signal; first input speed command and first rotation speed detection A first speed control unit for receiving a signal and outputting a first input torque command required to bring the front wheels to a speed designated by the first input speed command based on the first rotation speed detection signal. And; necessary for receiving the second input speed command and the second rotation speed detection signal and setting the rear wheels to the speed specified by the second input speed command based on the second rotation speed detection signal. Na second
Second speed control unit for outputting the input torque command of the first motor; and a first torque control for controlling the current of the first motor by controlling the current flowing to the first motor based on the first input torque command. A unit; receives the first input torque command and the second input torque command, and selects the first input torque command when the traveling direction command indicates the front-rear direction, and the traveling direction command indicates the left-right direction. Second if indicated
And a torque command switching unit that outputs the selected torque command; and controls the current flowing through the second motor based on the selected torque command.
And a second torque control unit for controlling the torque of the motor.

According to a second aspect of the present invention, the traveling control device for an unmanned guided vehicle uses the first and second input speed commands for the front wheels and the rear wheels, respectively, and determines whether the unmanned guided vehicle is forward or backward. A traveling direction command indicating which of the left and right directions the vehicle is traveling and a master-slave switching command indicating which of the front wheels and the rear wheels is the main are received. The traveling control device for an unmanned guided vehicle detects the first motor for driving the front wheels; the second motor for driving the rear wheels; the rotation speed of the first motor to detect the first motor; First rotation speed detection means for outputting a rotation speed detection signal; second rotation speed detection means for detecting a rotation speed of the second motor and outputting a second rotation speed detection signal; first A first input torque command required to receive the input speed command and the first rotation speed detection signal and to bring the front wheels to the speed specified by the first input speed command based on the first rotation speed detection signal Receiving a second input speed command and a second rotation speed detection signal, and designating a rear wheel by the second input speed command based on the second rotation speed detection signal. Speed control for outputting a second input torque command necessary for achieving a controlled speed Knit; receiving a first input torque command and the second input torque command,
In response to the traveling direction command and the master-slave switching command, a switching operation between the first input torque command and the second input torque command is performed, and the first input torque command indicates either one of the first and second input torque commands. And a torque command switching unit that outputs a second selected torque command; and a current that flows through the first motor is controlled based on the first selected torque command.
A first torque control unit for controlling the torque of the second motor; and a second torque for controlling the current of the second motor by controlling the current flowing through the second motor based on the second selected torque command. And a control unit.

In the traveling control device for the automatic guided vehicle according to the second aspect, the torque command switching unit includes:
When the first input torque command and the second input torque command are received and the master-slave switching command indicates that the front wheels are the main wheels, the first input torque command is selected, and the master-slave switching command is the rear wheels. And a main-slave switching device that outputs the internal selection torque signal when the second input torque command is selected; When the direction command indicates the front-back direction, the internal selection torque command is selected, and when the traveling direction command indicates the left-right direction, the first input torque command is selected, and the first selected torque command is selected. And a second input torque command and an internal selection torque command, and when the traveling direction command indicates the front-back direction, the internal selection torque command is selected and the traveling direction is selected. The command indicates the left / right direction Case selects the second input torque command, and a second torque command selector for outputting a torque command second selected; it is desirable to have.

[0015]

In the present invention, when the unmanned transport vehicle is moved in the front-rear direction (during normal traveling operation), the front wheels and the rear wheels are
Torque control is performed so that those torques become equal.
As a result, the load balances of the drive motors that drive the front wheels and the rear wheels are equalized, and the unmanned guided vehicle can efficiently travel normally. Further, when the unmanned guided vehicle is to be moved in the left-right direction (during the transverse traveling operation), the speeds of the front wheels and the rear wheels are independently controlled. As a result, the path of the unmanned transport vehicle can be adjusted by the speed difference between the front wheels and the rear wheels, so that the unmanned transport vehicle can be traversed over a long distance.

[0016]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 shows a traveling drive system of an automated guided vehicle to which a traveling control system according to an embodiment of the present invention is applied.

The automated guided vehicle 10 has traveling drive wheels, that is, front wheels 11 and rear wheels 12, respectively in front of and behind it.
Have. The front wheels 11 and the rear wheels 12 are respectively the first
It is driven by the traveling motor 13 and the second traveling motor 14. Further, the steering angles of the front wheels 11 and the rear wheels 12 are independently adjusted (controlled) by the first steering motor 15 and the second steering motor 16, respectively.

The first traveling motor 13 and the second traveling motor 14 are traveling-controlled by a traveling servo controller 17. The detailed configuration of the traveling servo controller 17 will be described later. First steering motor 1
Reference numeral 5 is steering-controlled by the first steering servo controller 18, and second steering motor 16 is steering-controlled by the second steering servo controller 19. The traveling servo controller 17 and the first and second steering servo controllers 18 and 19 perform traveling control and steering control according to a command from the vehicle control controller 20 described later. That is, the trolley controller 20 includes the servo controllers 17, 18 and 1
9 is used to cause the automated guided vehicle 10 to perform a desired traveling operation.

In the ground where the automated guided vehicle 10 is transported,
A guide wire 21 for traveling guide and a guide wire for traverse guide (which will be described later) for guiding the automatic guided vehicle 10 are buried. Electromagnetic waves are emitted from these guide wires. First and second traveling pickup devices 22 and 23 for detecting electromagnetic waves emitted from the traveling guide wire 21 are attached to the front wheel 11 and the rear wheel 12, respectively. The first and second traveling pickup devices 22 and 23 are
The first and second traveling guidance signals TI1 and TI2 are sent to the vehicle control controller 20, respectively. Further, first and second traverse pickup devices 24 and 25 for detecting electromagnetic waves emitted from the traverse guide wire are attached to the left and right sides of the unmanned transport vehicle 10, respectively. First and second
Of the traverse pickup devices 24 and 25 of the first and second traverse induction signals SI1 and SI, respectively.
2 is sent to the vehicle control controller 20.

The trolley controller 20 responds to the guidance signals TI1, TI2, SI1 and SI2 from the pickup devices 22, 23, 24 and 25 to the servo controllers 17, 18 and 19 as described below. By issuing a command, the automated guided vehicle 10
To perform a desired traveling operation.

More specifically, when the automated guided vehicle 10 is caused to travel forward in the direction indicated by the arrow A in FIG. 1, the vehicle control controller 20 causes the first traveling pickup device 22 to guide the first traveling vehicle. In response to the signal TI1, the first and second input speed commands V1 and V2 for the front wheels 11 and the rear wheels 12 and the traveling direction command TC indicating the front-rear direction
And are sent to the traveling servo controller 17. The traveling servo controller 17 uses the first and second input speed commands V1 and V2 and the traveling direction command TC indicating the front-rear direction.
In response to the front wheel 11 and the rear wheel 1 as described below.
The unmanned guided vehicle 10 is caused to travel forward by controlling the torque of No. 2 so that their torques become equal.

Further, as shown in FIG. 1, it is assumed that the traveling guide wire 21 is curved to the left. In this case, the carriage control controller 20 uses the received first traveling guidance signal TI1 to guide the traveling guide wire 21.
Is judged to curve to the left. According to this determination result, the carriage control controller 20 determines that the first and second
By sending the first and second steering commands S1 and S2 to the steering servo controllers 18 and 19, the front wheels 11 and the rear wheels 12 are rotated as shown by arrows B1 and B2 in FIG. 1, respectively. The steering control is performed so as to rotate in the clockwise direction and the clockwise direction, and the automatic guided vehicle 10 is curved to the left along the guide wire 21 for guiding the travel.

When the unmanned transport vehicle 10 is moved backward, the vehicle control controller 20 sends the second traveling guidance signal TI from the second traveling pickup device 23.
In response to 2, the operation similar to that during the forward traveling is performed.

With reference to FIG. 2, an operation of the unmanned transport vehicle 10 when it is traversed will be described. In this case, the carriage control controller 20 first sends the first and second steering commands S1 and S2 to the first and second steering servo controllers 18 and 19,
Both the front wheels 11 and the rear wheels 12 are steering-controlled so as to rotate in the counterclockwise direction by 90 degrees as shown in FIG. The automatic guided vehicle 1 in the direction indicated by the arrow Aa in FIG.
When 0 is traversed to the left, the carriage control controller 20 outputs the first transverse guidance signal SI1 that detects the electromagnetic wave emitted from the transverse guidance guide wire 21a from the first pickup device 24 for transverse travel. In response, first
And the second input speed commands V1 and V2 and the traveling direction command TC indicating the left-right direction, and the traveling servo controller 1
Send to 7. The traveling servo controller 17 is the first
And in response to the second input speed commands V1 and V2 and the traveling direction command TC indicating the left-right direction, as will be described later,
The front wheels 11 and the rear wheels 12 are independently speed-controlled to drive the unmanned transport vehicle 10 to the left.

When the automated guided vehicle 10 is traversed to the right, the vehicle controller 20 is operated by the second controller.
In response to the second traverse guidance signal SI2 from the traverse pickup device 25, the same operation as that for the leftward traveling is performed.

1 and 2, the automatic guided vehicle 1 is shown.
0 to the left front, right front, right rear, and left rear of driven wheels 26-1, 26-2, 26-3, and 2 respectively.
6-4 are provided.

FIG. 3 shows a traveling control device for an automatic guided vehicle according to the first embodiment of the present invention. The traveling control device for an unmanned carrier vehicle detects the rotation speeds of the traveling servo controller 17, the first and second traveling motors 13 and 14, and the first traveling motor 13 to determine the first rotation speed. Detection signal R
The first rotation speed meter 27 that outputs D1 and the rotation speed of the second traveling motor 14 are detected, and the second rotation speed detection signal R is detected.
And a second tachometer 28 for outputting D2.

In general, the front wheels 11 and the rear wheels 12 do not always have the same wheel diameter due to factors such as wear. Therefore, it should be noted that the actual peripheral speeds of the front wheels 11 and the rear wheels 12 do not match even if the rotation speeds of the first and second traveling motors 13 and 14 match each other. ..

As described above, the traveling servo controller 17 controls the first and second input speed commands V1 and V.
2 and a traveling direction command TC indicating whether the unmanned transport vehicle 10 (FIG. 1) is traveling in the front-rear direction or the left-right direction.

The traveling servo controller 17 has a front wheel traveling driver 29, a rear wheel traveling driver 30, and a torque command switching unit 31.

The front wheel traveling driver 29 receives the first input speed command V1 and the first rotation speed detection signal RD1, and based on the first rotation speed detection signal RD1 the front wheels 11 (FIG. 1).
Based on the first input torque command IT1 and a first speed control unit 32 that outputs a first input torque command IT1 necessary to bring the speed to a speed designated by the first input speed command V1. A first torque control unit 33 for controlling the current flowing to the first traveling motor 13 to control the torque of the first traveling motor 13, and a first traveling motor under the control of the first torque control unit 32. It has a first motor driving power unit 34 for supplying a current to the motor 13, and a first current detector 35 for detecting the current flowing in the first traveling motor 13 and outputting a first current detection signal CD1. ..

The first speed control unit 32 subtracts the first rotation speed detection signal RD1 from the first input speed command V1 and outputs a first speed deviation signal representing the deviation between them. -1, and a speed compensator 32-1 that outputs a first input torque command IT1 in response to the first speed deviation signal.
2 and. The first input torque command IT1 corresponds to the first torque control unit 33 and the torque command switching unit 31.
And supplied to.

The first torque control unit 33 subtracts the first current detection signal CD1 from the first input torque command IT1 and outputs a first current deviation signal representing the deviation between them. 1 and a current compensator 33-2 that outputs a first current command in response to the first current deviation signal. The first current command is supplied to the first motor driving power unit 34.

The rear wheel traveling driver 30 receives the second input speed command V2 and the second rotation speed detection signal RD2, and based on the second rotation speed detection signal RD2, the rear wheels 12 (FIG. 1).
Selection control supplied from a second speed control unit 36 that outputs a second input torque command IT2 necessary to bring the speed to a speed designated by the second input speed command V2, and a torque command switching unit 31 described later. Torque command S
Under the control of the second torque control unit 37 that controls the current flowing through the second traveling motor 14 based on T to control the torque of the second traveling motor 14, and the control of the second torque control unit 37. A second motor driving power unit 38 for supplying a current to the second traveling motor 14 and a second current for detecting a current flowing in the second traveling motor 14 and outputting a second current detection signal CD2. And a detector 39.

The second speed control unit 36 subtracts the second rotation speed detection signal RD2 from the second input speed command V2 and outputs a second speed deviation signal indicating the deviation between them. -1, and a speed compensator 36 that outputs the second input torque command IT2 in response to the second speed deviation signal-
2 and. The second input torque command IT2 is supplied to the torque command switching unit 31.

The second torque control unit 37 subtracts the second current detection signal CD2 from the selected torque command ST and outputs a second current deviation signal representing the deviation between them and a subtractor 37-1. , And a current compensator 37-2 that outputs a second current command in response to the second current deviation signal. The second current command is supplied to the second motor driving power unit 38.

The torque command switching unit 31 has a first
Input torque command IT1 and second input torque command IT2
And are supplied. Further, the torque command switching unit 31
Further, a traveling direction command TC is supplied from the vehicle control controller 20 (FIG. 1). The torque command switching unit 31 selects the first input torque command IT1 when the traveling direction command TC indicates the front-back direction, and the second input when the traveling direction command TC indicates the left-right direction. Select the torque command IT2 and select the selected torque command ST
Is output.

More specifically, the torque command switching unit 31 has a first movable contact a to which a first input torque command IT1 is supplied and a second movable contact a to which a second input torque command IT2 is supplied. b and the selected torque command ST
And a contactor 31-1 for connecting the fixed contact to either the first movable contact a or the second movable contact b in response to the traveling direction command TC. When the traveling direction command TC indicates the front-rear direction, the torque command switching unit 31 brings the contactor 31-1 into contact with the first movable contact a side, so that the fixed input contacts the first input torque command IT.
1 is output as the selected torque command ST. When the traveling direction command TC indicates the left-right direction, the torque command switching unit 31 brings the contact 31-1 into contact with the second movable contact b side and selects the second input torque command IT2 from the fixed contact. The torque command ST is output.

Hereinafter, referring to FIGS. 1, 2 and 3,
The operation of the traveling control device for the automatic guided vehicle according to the first embodiment of the present invention will be described.

Both drive wheels of the front wheel 11 and the rear wheel 12 are mechanically connected via the floor surface. Therefore, the front wheel 11
And each of the rear wheels 12 rotates at a rotational speed according to the ratio of the wheel diameters.

First, during normal running (when running in the front-back direction)
The operation will be described. In this case, the carriage control controller 20 outputs a signal indicating the front-rear direction as the traveling direction command TC. Running direction command TC indicating this front-back direction
In response to this, the torque command switching unit 31 brings the contactor 31-1 into contact with the first movable contact a side and outputs the first input torque command IT1 from the fixed contact as the selected torque command ST. .. As a result, both the first torque control unit 33 of the front wheel traveling driver 29 and the second torque control unit 33 of the rear wheel traveling driver 30 output from the first speed control unit 32 of the front wheel traveling driver 29. The current flowing into the first and second traveling motors 13 and 14 is controlled based on the generated first input torque command IT1. As a result, during normal traveling operation, the first traveling motor 13 that drives the front wheels 11 and the second traveling motor 14 that drives the rear wheels 12 are torque-controlled so that they have the same torque. In other words, the rear wheels 12 are torque-controlled so as to output the same torque as the front wheels 11. Further, since the front wheel traveling driver 29 for driving the front wheels 29 constitutes a speed control system, the speed of the front wheels 29 is controlled so as to reach the speed designated by the first input speed command V1.

Next, the operation during lateral traveling (horizontal traveling) will be described. In this case, first, the carriage control controller 20 sends the first and second steering command S1 to the first and second steering servo controllers 18 and 19.
And S2 are sent to rotate the steering angles of the front wheels 11 and the rear wheels 12 by 90 degrees as shown in FIG. In this state, as will be described later, the course of the automated guided vehicle 10 is adjusted by the speed difference between the driving wheels of the front wheels 11 and the rear wheels 12.

That is, the trolley controller 20
Outputs a signal indicating the left-right direction as the traveling direction command TC. In response to the traveling direction command TC indicating the left-right direction, the torque command switching unit 31 has its contactor 31-
1 is brought into contact with the side of the second movable contact b, and the second input torque command IT2 is selected from the fixed contact thereof.
Output as T. As a result, the front wheels 11 and the rear wheels 12
Can be speed-controlled independently by the front wheel traveling driver 29 and the rear wheel traveling driver 30, respectively.

As shown in FIG. 2, it is assumed that the vehicle laterally travels to the left. In this case, the transverse guide wire 21a
The deviation amount from is detected by the first traverse pip-up device 24. The first traverse pip-up device 24 is
A first transverse guiding signal SI1 representing this amount of deviation is sent to the carriage control controller 20. The trolley control controller 20 takes the displacement amount represented by the first transverse guiding signal SI1 into consideration, and the traveling servo motor controller 17
A first input speed command V1 for the front wheels 11 and a second input speed command V2 for the rear wheels 12 to be transmitted to the front wheels 11 are determined.

The method of shifting from normal traveling to transverse traveling is not limited here, but the following two methods are conceivable, for example.

First, the first transfer method will be described. From the normal traveling to the traverse traveling, the traveling of the automatic guided vehicle 10 is temporarily stopped. In this stopped state, the front wheel 11 and the rear wheel 12 are rotated 90 degrees as shown in FIG. 2 by the first and second steering motors 15 and 16, and the front wheel 11 and the rear wheel 12 are rotated at this 90 degree position. To fix. After that, the vehicle moves to traverse. On the contrary, in the first transition method, the transition from the transverse traveling to the normal traveling can be performed in the same manner.

Next, the second transfer method will be described. At the time of transition, the speed of the unmanned guided vehicle 10 is reduced to a low speed, and the steering angle of the front wheels 11 is controlled so that the front wheels 11 follow the traverse guiding guide wire 21a. On the other hand, the steering angle of the rear wheels 12 is set so as not to be equal to the steering angle of the front wheels 11.
2 is controlled so as to have the same phase and the same angle as the front wheel 11. When both of these drive wheels rotate 90 degrees, the steering angle is fixed at 90 degrees, and the vehicle moves to traverse.

In the traveling control device for the automatic guided vehicle according to the first embodiment shown in FIG. 3, the first speed control unit 32 of the front wheel traveling driver 29 is always used as the speed control unit during normal traveling. In other words, always front wheel 1
One side is used as the main side and the rear wheel 12 side is used as the sub side. However, depending on the traveling direction (forward or backward), etc., the first speed control unit 32 of the front wheel traveling driver 29 or the second speed control of the rear wheel traveling driver 30 is instructed by the carriage control controller 20. Either of the units 36 may be used.

FIG. 4 shows a traveling control device for an unmanned guided vehicle according to a second embodiment capable of such switching between master and slave. The traveling control device for the automated guided vehicle according to the second embodiment differs from that according to the first embodiment (FIG. 3) in the following points.

First, in the traveling control device for the automatic guided vehicle according to the second embodiment, the traveling servo controller 17a is used.
However, not only the first and second input speed commands V1 and V2 and the traveling direction command TC but also the master-slave switching command MS indicating which of the front wheel 11 and the rear wheel 12 is to be the main is received from the vehicle control controller 20. That is. Also, the configuration of the torque command switching unit is different. Therefore,
The torque command switching unit is shown at 31a. In the traveling control device for the unmanned guided vehicle according to the first embodiment, the first torque control unit 33 of the front wheel traveling driver 29 is supplied with the first input torque command IT1 from the first speed control unit 32. On the other hand, in the traveling control device for the automatic guided vehicle according to the second embodiment, the first torque control unit 33 is supplied with the first selected torque command ST1 described later from the torque command switching unit 31a. Is to live. Therefore, the front wheel drive driver is shown at 29a. Further, the second torque control unit 37 is supplied with a second selected torque command ST2 described later from the torque command switching unit 31a.

The torque command switching unit 31a has a first
Input torque command IT1 and second input torque command IT2
In response to the traveling direction command TC and the master-slave switching command MS, the switching operation between the first input torque command IT1 and the second input torque command IT2 is performed, and the first and second input torque commands are received. First and second selected torque commands ST1 and S indicating either one of IT1 and IT2
Outputs T2. The first and second selected torque commands ST1 and ST2 are supplied to the first and second torque control units 33 and 37, respectively.

The first torque control unit 33 controls the current of the first traveling motor 13 based on the first selected torque command ST1 to control the torque of the first traveling motor 13. The second torque control unit 37 is
The torque of the second traveling motor 37 is controlled by controlling the current flowing through the second traveling motor 37 based on the second selected torque command ST2.

Next, the structure of the torque command switching unit 31a will be described in detail. The torque command switching unit 31a has a master-slave switching unit 31a-0 and first and second torque command switching units 31a-1 and 31a-2.

The master-slave switching device 31a-0 receives the first input torque command IT1 and the second input torque command IT2, and indicates that the master-slave switching command MS mainly uses the front wheels 11 (FIG. 1). In this case, the first input torque command IT1 is selected, and when the master-slave switching command indicates that the rear wheels 12 (FIG. 1) are mainly selected, the second input torque command IT2 is selected, and the internal selection is performed. Output a torque signal.

The first torque command switch 31a-1 is
When the first input torque command IT1 and the internal selection torque command are received and the traveling direction command TC indicates the front-rear direction, the internal selection torque command is selected, and the traveling direction command TC indicates the left-right direction. Is the first input torque command IT
1 is selected and the first selected torque command ST1 is output.

The second torque command switch 31a-2 is
When the second input torque command IT2 and the internal selection torque command are received and the traveling direction command TC indicates the front-rear direction, the internal selection torque command is selected, and the traveling direction command TC indicates the left-right direction. The second input torque command IT
2 is selected and the second selected torque command ST2 is output.

[0058]

As described above, according to the present invention, when the unmanned carrier is run in the front-rear direction (during normal running operation), the front wheel and the rear wheel are torque-controlled so that their torques become equal. is doing. Therefore, the load balances of the drive motors that drive the front wheels and the rear wheels are equalized, and the unmanned guided vehicle can efficiently travel normally. Further, when the unmanned transport vehicle is run in the left-right direction (during the transverse running operation), the speeds of the front wheels and the rear wheels are independently controlled. As a result, the path of the unmanned transport vehicle can be adjusted by the speed difference between the front wheels and the rear wheels, so that the unmanned transport vehicle can be traversed over a long distance.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a traveling drive system to which a traveling control method for an automated guided vehicle according to an embodiment of the present invention is applied.

FIG. 2 is a diagram showing a state where the steering angles of front wheels and rear wheels are set to 90 degrees in the traveling drive system shown in FIG.

FIG. 3 is a block diagram showing a configuration of a traveling control device for an automated guided vehicle according to a first embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a travel control device for an automated guided vehicle according to a second embodiment of the present invention.

[Explanation of symbols]

 11 front wheel (travel drive wheel) 12 rear wheel (travel drive wheel) 13,14 traveling motor 15,16 steering motor 17,17a traveling servo controller 18,19 steering servo controller 20 vehicle control controller 21 traveling guidance Guide wire 21a Traverse guide wire 22,23 Traveling pickup device 24,25 Traverse pickup device 26-1, 26-2, 26-3, 26-4 Driven wheel 27, 28 Rotation meter 29, 29a For front wheel Traveling driver 30 Rear wheel traveling driver 31, 31a Torque command switching unit 32 Speed control unit 33 Torque control unit 34 Motor drive power unit 35 Current detector 36 Speed control unit 37 Torque control unit 38 Motor drive power unit 39 Current detector

Claims (4)

[Claims] 1. An unmanned carrier is provided with front wheels and rear wheels, respectively, and front and rear traveling and left and right traveling are performed along a guide wire by adjusting steering angles of the front and rear wheels. In a possible method of controlling the traveling of the unmanned transport vehicle, when the unmanned transport vehicle is run in the front-rear direction, the front wheel and the rear wheel are torque-controlled so that their torques become equal to each other. However, when the unmanned guided vehicle travels in the left-right direction, the traveling control method for the unmanned guided vehicle is characterized in that the speeds of the front wheels and the rear wheels are independently controlled. 2. An unmanned guided vehicle having front and rear wheels, respectively, on the front and rear sides, is moved along the guide wire in either the front-back direction or the left-right direction by adjusting the steering angles of the front wheels and the rear wheels. In the traveling control device capable of controlling the traveling speed of the front wheel and the rear wheel, the traveling control device controls the first and second input speed commands for the front wheel and the rear wheel, respectively. A first motor for driving the front wheels, a second motor for driving the rear wheels, and a rotation speed of the first motor are received in response to a travel direction command indicating which direction to travel. A first rotation speed detecting means for detecting and outputting a first rotation speed detection signal; and a second rotation detecting a rotation speed of the second motor and outputting a second rotation speed detection signal. A number detecting means, and the first A first necessary for receiving an input speed command and the first rotation speed detection signal and for setting the front wheel to the speed specified by the first input speed command based on the first rotation speed detection signal. Receiving a second input speed command and the second rotation speed detection signal, and driving the rear wheel based on the second rotation speed detection signal. A second speed control unit that outputs a second input torque command required to achieve a speed specified by the second input speed command; and the first motor based on the first input torque command. A first torque control unit that controls the current flowing through the first motor to control the torque of the first motor; and the first input torque command and the second input torque command. When showing the front-back direction A torque command switching unit that selects the first input torque command, selects the second input torque command when the traveling direction command indicates the left-right direction, and outputs the selected torque command; And a second torque control unit for controlling the current of the second motor based on the selected torque command to control the torque of the second motor. apparatus. 3. An automated guided vehicle having front and rear wheels, respectively, on the front and rear sides, is made to travel in the front-rear direction or the left-right direction along a guide wire by adjusting the steering angles of the front wheels and the rear wheels. In the traveling control device capable of performing the traveling control device, the traveling control device may control the first and second input speed commands for the front wheel and the rear wheel, respectively, and the unmanned transport vehicle in the front-rear direction or the left-right direction. A first motor for driving the front wheels, which receives a traveling direction command indicating which one of the front wheel and the rear wheel is the main, and a first motor for driving the front wheels; A second motor for driving a wheel; a first rotation speed detection unit that detects a rotation speed of the first motor and outputs a first rotation speed detection signal; and a second motor of the second motor. The number of rotations is detected and Second rotation speed detection means for outputting a rotation speed detection signal, the first input speed command and the first rotation speed detection signal, and the front wheel based on the first rotation speed detection signal. A first speed control unit that outputs a first input torque command required to bring the speed to a speed designated by the first input speed command, the second input speed command, and the second rotation speed. A second input torque command for receiving the detection signal and receiving the second input torque command to bring the rear wheel to the speed designated by the second input speed command based on the second rotation speed detection signal. Of the speed control unit, the first input torque command and the second input torque command, and in response to the traveling direction command and the master-slave switching command, the first input torque command and the first input torque command. Switching operation with the input torque command of 2 A torque command switching unit that outputs a first and second selected torque command indicating one of the first and second input torque commands, and the torque command switching unit that outputs the torque command based on the first selected torque command. A first torque control unit for controlling the current flowing through the first motor to control the torque of the first motor; and controlling the current flowing through the second motor based on the second selected torque command. And a second torque control unit for controlling the torque of the second motor. 4. The torque command switching unit receives the first input torque command and the second input torque command, and when the master-slave switching command indicates that the front wheels are the main wheels. When the first input torque command is selected and the master-slave switching command indicates that the rear wheel is the main, the second input torque command is selected and the master-slave that outputs the internal selection torque signal is selected. A switching device, the first input torque command and the internal selection torque command are received, and when the traveling direction command indicates the front-back direction, the internal selection torque command is selected, and the traveling direction command is A first torque command switch that selects the first input torque command and outputs the first selected torque command when the left and right direction is indicated; the second input torque command; Internal selection A torque command, the internal selection torque command is selected when the traveling direction command indicates the front-rear direction, and the second input is selected when the traveling direction command indicates the left-right direction. The travel control device for an unmanned carrier vehicle according to claim 3, further comprising a second torque command switching device that selects a torque command and outputs the second selected torque command.