JPH0424266B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of Industrial Application The present invention relates to a method and device for steering an automatic guided vehicle that travels along a set route.

(2) Prior Art A method of driving the drive wheels of an automatic guided vehicle via differential gears is simple and has been commonly used in the past.

However, in the above-described method, the minimum turning radius is verified based on the wheelbase and tread of the automatic guided vehicle, so it has the disadvantage that it cannot be used in cases where spin turns are required in narrow industrial locations.

In addition, automated guided vehicles that can spin and turn by controlling the left and right drive wheels separately are also used, but controlling both the left and right wheels is complicated and requires two precision servo motors, making them expensive. There was also a drawback.

(3) Purpose The present invention was created in view of the above circumstances.
The present invention aims to provide a method and device for steering an automatic guided vehicle that enables spin turns by adding a simple device to a drive mechanism using differential gears.

(4) Configuration The steering method of the present invention is a steering method for an automatic guided vehicle having a steering wheel rotated by a steering motor and two driving wheels driven by a drive motor via a differential gear, During travel, the steering angle is controlled by the drive of the steering motor while traveling by the drive motor, and after stopping travel during a spin turn, the steered wheels are rotated 90 degrees while the differential gear is rotated. The present invention is characterized in that the input shaft is fixed, and further, the rotation is performed by driving a spin-turn motor provided on any one of the drive wheels. In addition, the steering device is
A steering wheel rotated by a steering motor, two drive wheels driven by a drive motor via differential gears, and a detection device that detects a preset route;
a device for controlling the steering angle of the steered wheels based on the output of the detection device; a brake for braking the input shaft of the differential gear; a spin-turn motor; and a device for controlling the spin of any one of the drive wheels. a transmission mechanism that transmits the rotational output of the turn motor in an on/off manner; and the brake based on the spin turn signal.
It is characterized by being equipped with a control device that controls a spin-turn motor transmission mechanism and a steering motor.

(5) Embodiment FIG. 1 is an external perspective view showing an embodiment of the present invention, in which 10 is a truck, 20 is a chassis, 30 is a detection device, and 111 and 112 are drive wheels (drive wheels 112
(shown in Figure 2), 200 is a gearbox, 21
0 is a steering wheel, 220 is a fork, 230 is a steering motor, and 60 is a route formed by pasting tape on the floor. FIG. 2 is a plan view of the chassis 20 seen from below, with drive wheels 111, 112 mounted on bearings 21 fixedly installed on the left and right sides of the chassis 20, respectively.
Drive shafts 121 and 122 are pivotally supported.

One end of the drive shafts 121 and 122 is connected to the differential gear 1
30, and the differential gear 130 is driven by a drive motor 140 via a pinion 142 and a ring gear 131, so that the side gears 132, 133
Rotates via the bevel gear 134 and drives the drive motor 1
40 torque is transmitted to the drive wheels 111,112.

Note that when the automatic guided vehicle turns, the left and right drive wheels 111 and 112 run at rotational speeds corresponding to the turning curve, respectively, according to the known differential gear theory.

In addition to the pinion 142, a brake disc 143 is fixedly attached to the drive shaft 141 of the drive motor 140, and by pressing this disc with the brake 150, the casing of the differential gear 130 is prevented from rotating. Hold.

160 is a spin-turn motor driven by a battery 50 built into the automatic guided vehicle, which is connected in parallel to a solenoid 163 and a contact 16 that turns on and off the spin-turn motor 160.
Contains 4. The contact 164 is provided at the tip of the rod, is normally turned off, and is connected to the solenoid 16.
It is configured to be turned on by energization of step 3.

Further, a pinion 161 is fitted into the drive shaft of the spin turn motor 160. solenoid 1
The pinion 161 is configured to be able to slide onto the drive shaft via the lever 162 when the pinion 63 is energized. and the drive shaft 12 of any one drive wheel.
The gear 123 fixed to the pinion 161
It meshes with the. Spin turn motor 160
When driven, the drive wheel 111 rotates in a predetermined direction at a rotational speed. On the other hand, since the casing of the differential gear 130 is held so as not to rotate as described above, the rotation of the drive wheel 111 is limited to the side gear 13.
2. Rotation with the same rotation speed and opposite direction is transmitted to the drive wheel 112 via the bevel gear 134, the side gear 133, and the drive shaft 122.

Therefore, a spin turn can be performed by steering the steering wheels 210, which will be described later, at right angles as shown by dotted lines.

170 is an encoder that meshes with the ring gear 131.

A steering wheel 210 has a vertical shaft (not shown) erected on the upper surface of a fork 220 that rotatably holds the steering wheel, and is rotated by a steering motor 230 via a gearbox 200 to perform steering.
240 is an encoder that is linked to the steering operation.

The detection device 30 detects a preset route 60 of the automatic guided vehicle, and includes light receiving elements 311, 31.
Contains 2.

FIG. 3 is a block diagram explaining the operation of the control device 40, in which the central processing unit 400, the storage device 41
0, addition circuit 420, switching circuit 450,
Contains 460 etc. Light receiving elements 311, 312
The detected path signal is input to the central processing unit 400 via the adder circuit 420 and the A/D converter 421, and is processed according to a processing routine stored in the storage device 410 in advance. If steering is necessary, synchronization circuit 430, D/A changer 43
1. A steering signal is input to the steering motor 230 via the control circuit 433, and the steered wheels 210 are rotated at a predetermined angle. A running signal is applied from the central processing unit 400 to the drive motor 140 via a synchronization circuit 440, a D/A converter 441, a control circuit 442, and a switching circuit 443, and is applied to the drive wheels 111, 112 via the differential gear 130. is driven.

When the central processing unit 400 determines that the curve of the route obtained by the detection device is smaller than the minimum turning radius stored in the storage device 410, the central processing unit 400 outputs a spin turn signal instructing the spin turn to be performed. be done. This signal activates the switching circuit 443 to stop the drive motor 140. Furthermore, the switching circuit 450 is activated to drive the brake 150, press the disk 143, and hold the casing of the differential gear 130 from rotating via the pinion 142 and ring gear 131. Further, the spin turn signal is also applied to the control circuit 433, which drives the steering motor 230 to rotate the steered wheels 210 by 90 degrees.

On the other hand, the spin turn signal is also applied to the switching circuit 460, and the solenoid 163 is energized. The operation of this solenoid 163 causes the pinion 161 to slide onto the drive shaft of the spin-turn motor 160 via the lever 162, while the gear 16
It meshes with 3. Due to the operation of solenoid 163,
The contact 164 is turned on, and the spin turn motor 160 is connected to the battery 50. The spin turn motor 160 starts rotating, and as described above, the spin turn motor 160 starts rotating and drives the drive wheels 111 and 11 through the side gears 132 and 133 as described above.
2 are rotated in opposite directions at the same rotation speed, and the automatic guided vehicle performs a spin turn.

Furthermore, the outputs of encoders 240 and 170 are passed through pulse counters 434 and 444 to respective synchronization circuits 430 and 440 and central processing unit 40.
It is fed back to 0 and used for stabilizing control and measuring the steering angle.

In this embodiment, the drive during spin turns is transmitted to one of the drive wheels, but both the left and right drive wheels may be driven separately, and the transmission mechanism of the pinion of the spin turn motor may also be used. is not limited to this example.

(6) Effects of the Invention According to the present invention, an automatic guided vehicle capable of spin-turning can be realized by adding some simple devices without significantly changing the structure of a conventional automatic guided vehicle.

Furthermore, the steering control of automated guided vehicles is simpler and more economical than when the left and right drive wheels are driven by separate drive sources, and it also helps improve the efficiency of space utilization in factories. .

[Brief explanation of drawings]

FIG. 1 is an external perspective view showing an embodiment of the present invention, FIG. 2 is a plan view showing the bottom surface of the chassis, and FIG. 3 is a block diagram. 10... Trolley, 20... Chassis, 30... Detection device, 40... Control device, 50... Battery,
111, 112... Drive wheel, 130... Differential gear, 140... Drive motor, 150... Brake, 160... Spin turn motor, 210...
...steering wheel.

Claims (1)

[Claims] 1. A method for steering an automatic guided vehicle having a steering wheel rotated by a steering motor and two driving wheels driven by a drive motor via a differential gear,
When traveling, the steering angle is controlled by driving the steering motor while traveling by driving the drive motor, and after stopping traveling during a spin turn,
While rotating the steering wheel by 90 degrees, the input shaft of the differential gear is fixed, and further, a spin turn motor provided on one of the drive wheels is driven to rotate the steering wheel. A method for steering an automated guided vehicle, characterized by: 2. A steering wheel rotated by a steering motor, two driving wheels driven by a drive motor via a differential gear, a detection device that detects a preset route, and a detection device that detects a preset path, and a steering wheel that is rotated by a steering motor, and a detection device that detects a preset path. a device for controlling a steering angle, a brake for braking an input shaft of the differential gear, a spin-turn motor, and a rotational output of the spin-turn motor to any one of the drive wheels. What is claimed is: 1. A steering device for an automatic guided vehicle, comprising: a transmission mechanism that enables transmission of signals; and a control device that controls the brake, the spin-turn motor transmission mechanism, and the steering motor based on a spin-turn signal.