JPH07232638A - Automated guided vehicle - Google Patents

Abstract

PURPOSE:To run an automated guided vehicle without running off largely from a track line even if the line has large curvature. CONSTITUTION:Axles 3a, 3b are mounted on the underside of an under carriage 1 capably of being swung around vertical shafts (h). (h), one-sided axle 3a is provided with driving wheels 4a, 4b respectively independently rotated by means of two motors 7a, 7b, the other axle 3b is provided with idler wheels 2a, 2a, both axles are energized by the force of springs 8a, 8b, 10a, 10b so as to return to the posture of the under carriage at rectilinearly running, and in addition both axles are connected together through a connecting rod 11 so as to symmetrically move. Further right and left a pair of sensitive bodies 14a, 14b are provided on the axle part near by either of the axle 3a or 3b, and when the right sensitive body 14a does not detect the line on a running surface, the left driving wheel 4b is stopped, meanwhile, when the left sensitive body 14b does not detect the line, the right driving wheel 4a is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unmanned guided vehicle used for carrying an object along a predetermined route in a factory or a warehouse.

[0002]

2. Description of the Related Art An unmanned guided vehicle already exists, and its outline is as shown in FIG.

That is, 1 is an undercarriage, 2 and 2 are idle wheels fixed to the rear portion of the lower surface of the undercarriage 1 in the front-rear direction, and 3 is the undercarriage 1.
Axle mounted on the front part of the lower surface of the so that it can swing about the vertical axis h,
Drive wheels 4a and 4b are mounted on both ends of the axle 3 via horizontal shafts 5a and 5b, and 6 is a line sensor having a pair of left and right sensing bodies 6a and 6b.

At this time, the drive wheels 4a and 4b are independently driven by two motors (not shown), and the one drive wheel 4a is the left sensor 6a.
Is stopped only when the line k on the traveling surface is not detected, and the other driving wheel 4b is stopped only when the right sensor 6b does not detect the line k.

Next, the operation will be described. Now, the chassis 1 is traveling on a straight line portion of the line k, and the left and right sensing bodies 6a, 6b.
If both of them detect the line k, both drive wheels 4a and 4b are rotated, and the chassis 1 moves. During this process, when the chassis 1 approaches the left side f1 and, for example, the left sensor 6a does not detect the line k, only the right drive wheel 4a is stopped. Is forcibly turned in the direction of arrow f2, and the chassis 1 is corrected to the right side f3. On the other hand, when the chassis 1 approaches the right side and, for example, the right side sensor 6b does not detect the line k, only the left drive wheel 4b is stopped. The chassis 1 is turned in the direction opposite to the arrow direction f2, and the chassis 1 is rerouted to the left side f1. When the left and right sensing bodies 6a and 6b are both returned to the state of detecting the line k by such an operation, the chassis 1 advances while the two drive wheels 4a and 4b are both rotated.
After that, such an operation is repeated, so that the chassis 1 always advances along the line k.

[0006]

In the unmanned guided vehicle having the above-mentioned structure, when the curvature of the line k is too large compared to the size of the chassis 1, the chassis 1 travels on the bend of the line k. In the middle, the rear part 1a may be greatly deviated from the line k, which may cause an unexpected collision accident,
Further, due to the fact that the minimum turning radius of the chassis 1 is larger than the size of the chassis 1 from a structural point of view, the response of the track correcting operation of the chassis 1 to the bend of the line k is poor, so that the chassis 1 When the vehicle is stopped on the bend of the line k and is started again, the entire line sensor 6 may come off the line k and the traveling of the chassis 1 may be stopped, and the line sensor 6 and the drive wheels may be stopped. Due to the arrangement relationship of 4a and 4b, there is a disadvantage that only the automatic steering in the forward direction f4 can be performed and the automatic steering in the backward direction cannot be performed.

It is an object of the present invention to provide an unmanned guided vehicle capable of easily solving these problems.

[0008]

In order to achieve the above-mentioned object, the present invention is to mount an axle on each of the front and rear positions of the underside of a chassis so as to be swingable about a vertical axis, and at the left and right ends of either one of the axles. Drive wheels that are independently rotated by two motors are provided in each section, and idle wheels that are freely rotatable are provided at the left and right ends of the other axle, and both axles are driven straight by the spring force by the spring force. Axle that is urged so as to return to the posture and that both axles are connected by a connecting rod so that they can be symmetrically operated, and that the axle is on the side of the chassis traveling direction (any side of the chassis front-rear direction). A front side line sensor having a pair of left and right sensing bodies at appropriate intervals is provided on the axle portion near the central portion in the longitudinal direction of the vehicle, and the sensing bodies on each side are independently associated with the motors on each side. .

According to this, when the undercarriage goes off the line during its forward traveling, the specific motor associated with the sensor which does not detect the line is stopped and the other motor is kept rotating. Therefore, the axle on the drive wheel side is swung about the vertical axis in the direction to correct the position of the chassis, and this swing causes the other axle to interlock via the connecting rod, and the two axles rotate about the vertical axis. Swung symmetrically to. Such a symmetrical swing of the axle makes the minimum turning radius of the chassis smaller than the swing of only one of the axles, and the swing center of the chassis is located laterally of the center of the chassis. .

In the present invention, in order to enable unmanned operation when traveling in the reverse direction, a pair of left and right sensing devices are provided at appropriate intervals in the chassis portion near the longitudinal center of the axle on the reverse direction side of the chassis. A rear line sensor equipped with a body is fixed, and the sensing body on each side is independently associated with the motor on each side. The line sensor on each of the front and rear sides corresponds to the traveling direction of the chassis, and one of them is connected. One is selected and used.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a view showing the back surface of an unmanned guided vehicle according to the present invention, and FIG. 2 is a plan view showing a state in which the vehicle is running on a line.

In the figure, 3a and 3b are a front axle and a rear axle mounted on the lower surface of the chassis 1 so as to be swingable around a vertical axis h at respective front and rear positions.

Drive wheels 4a are provided at the left and right ends of the front axle 3a.
4b is mounted via a shaft in the direction of the axle 3a, and motors 7a, 7b are fixed near the drive wheels 4a, 4b. In this case, one drive wheel 4a is linked to a motor 7a, and the other drive wheel 4b is linked to another motor 7b.

At the left and right ends of the rear axle 3b, idle wheels 2a,
2a is rotatably mounted via a shaft in the direction of the axle 3b.

Reference numerals 8a and 8b are stretched between locking pins 9 and 9 provided at the center of the lower surface of the chassis 1 and locking pins 9a and 9a provided at each end of the axles 3a and 3b. Tension springs, and 10a and 10b are the locking pins 9,
9 and a locking pin 9 provided at each end of the other axle 3b
b, 9b, which are tension springs stretched between them, and these springs 8a, 8b, 10a, 10b are the vertical axes h, and the axles 3a, 3b swung around h when the chassis 1 is running straight. It is supposed to urge to return to the posture.

Reference numeral 11 denotes a connecting rod that is attached between the one end of the front axle 3a and the other end of the rear axle 3b in a erected manner so that both axles 3a and 3b can be operated symmetrically. belongs to.

Line sensors 13a and 13b are both line sensors for detecting lines provided on the running surface. One of the line sensors 13a is fixed to a portion of the axle 3a slightly forward of the longitudinal center of the front axle 3a. The other one 13b is an axle 3 that is slightly rearward of the longitudinal center of the rear axle 3b.
It is fixed to the portion b and either one of them is selectively used.

At this time, each of the line sensors 13a and 13b is provided with at least a pair of left and right sensing bodies (optical sensor, magnetic sensor, electromagnetic wave sensor, etc.) 14a and 14b which are arranged at appropriate intervals in the left-right direction of the chassis 1. Eggplant

The sensor 14a on one side is related to stop the rotation of the motor 7b on the other side to stop the rotation of the drive wheel 4b in a state where it does not detect the line, and the sensor on the other side is also stopped. 14b is related to stop the rotation of the motor 7a on the other side and stop the rotation of the drive wheel 4a in a state where it does not detect the line.

In this embodiment, these sensors 14a and 14b are used.
Another sensor 14c is provided at the center of the sensor. The sensor 14c functions to temporarily stop the two motors 7a and 7b and stop the traveling of the chassis 1 when the sensor 14c does not detect a line.

An example of use of the product of the present invention configured as described above will be explained. For example, as shown in FIG. 3, the sensors 14a, 14 are placed on a predetermined track on a floor surface F of a warehouse, factory or store.
b, 14c form a line k of material that is sensitive. The line k is formed by adhering a silver-white reflective tape or by applying a reflective paint, and the line k is a discontinuous point m on the line k where the cargo is loaded and unloaded. Is formed.

Then, the chassis 1 is positioned on the line k so that the pair of sensing bodies 14a and 14b of the line sensor 13a or 13b on the traveling direction side can sense the line k.

After that, the start switch of the control device (not shown) is manually operated or input from the outside to drive the vehicle in the arrow direction (forward direction) f4, for example. As a result, both motors 7a and 7b are operated to rotate the two drive wheels 4a and 4b, so that the chassis 1 travels forward.

During this traveling, the chassis 1 meanders and deviates from the line k to the left side f1 or as shown in FIG.
Line sensor 1 when it reaches the bend to the right f3
The sensing body 14b on the left side of 3a does not sense the line k. In this state, the motor 7a stops rotating under the rotating state of one motor 7b, and the axle 3a resists the force of the spring 8b. Then, it is turned in the direction of arrow f2.

This turning operation is transmitted to the other axle 3b via the connecting rod 11, the axle 3b is swung in the direction of arrow f5 against the force of the spring 10b, and both axles 3a, 3b are at one point. As shown by the chain lines n1 and n2, they are displaced in a symmetrical arrangement. Thus, the chassis 1 is turned to the right side f3 with a smaller turning radius than in the case where only one axle is swung, and the turning center is turned to the right side f3 with the turning center existing laterally of the central portion of the chassis 1. The pair of sensing bodies 14 of the line sensor 13a are moved.
Both a and 14b are returned to the positions where the line k is sensed.

On the other hand, when the chassis 1 meanders and deviates from the line k to the right side or reaches the bend to the left side of the line k, the sensing body 14a on the right side of the line sensor 13a does not sense the line k. In this state, the motor 7b is rotated under the rotating state of the one motor 7a, contrary to the previous case.
Is stopped rotating, the axle 3a is turned in the direction opposite to the arrow f2, and both axles 3a, 3b are arranged in a symmetrical arrangement opposite to the previous one against the force of the spring 8a according to the above description. It is rocked. Therefore, also in this case, the chassis 1 is swung to the left with a smaller turning radius than in the case where only one axle is swung, and the turning center thereof is located laterally of the central portion of the chassis 1, and Sensor 14
Both a and 14b are returned to the positions where the line k is sensed.

At this time, the springs 8a, 8b, 10
Reference characters a and 10b prevent excessive swinging of the axles 3a and 3b, and impart a restoring force to the swiveled axles 3a and 3b toward the straight posture of the chassis 1.
The rocking motion of b is stable.

Thus, the chassis 1 always moves on the line k during traveling, and the idle wheels 2a, 2a during traveling on a curve.
Tends to travel along the traveling loci of the drive wheels 4a and 4b.

Then, the chassis 1 is at a loading / unloading point A.
Alternatively, when the line sensor 13a reaches the line B, the line sensor 13a indicates the line k.
When the vehicle chassis 1 is stopped, the two motors 7a and 7b are stopped by sensing the discontinuous point m of the. After that, the operator loads and unloads the luggage, and re-operates the start switch as necessary, whereby the two drive wheels 4a and 4b are appropriately rotated by the function of the control device to proceed, After the sensors 14a and 14b of FIG. 6 sense the line k again, the above-described control is performed and the chassis 1 travels along the line k.

When the chassis 1 is driven in the reverse direction, the reverse switch of the control device (not shown) is operated.
As a result, the chassis 1 moves in the direction opposite to the arrow direction f4 (reverse direction).

In this case, instead of the line sensor 13a, the other line sensor 13b on the traveling direction side is line k.
Is detected and the two motors 7a and 7b are controlled, and the chassis 1 automatically travels along the line k in accordance with the above description.

In the above embodiment, the drive wheels 4a and 4b are defined as the forward traveling direction, but conversely, the idle wheels 2a and 2a are set forward.
Setting the side as the forward direction does not make a substantial difference. It should be noted that the drive wheels may be configured to include the idler wheels 2a and 2a.

[0033]

According to the present invention constructed as described above, since the minimum turning radius of the chassis becomes smaller and the center of rotation of the chassis is located laterally of the central portion thereof, the chassis can be swung relative to the sensing of the sensor. The responsiveness of the operation is improved, and the chassis can accurately travel on a line with a large curvature. A corner station is also possible.

According to the second aspect of the present invention, automatic steering can be performed regardless of whether the chassis is traveling in the front or rear direction.

[Brief description of drawings]

FIG. 1 is a diagram showing a back surface of an unmanned guided vehicle according to the present invention.

FIG. 2 is a plan view showing a state in which the transport vehicle travels on a line.

FIG. 3 is a diagram showing an example of use of the carrier.

FIG. 4 is a plan view operation explanatory view showing a conventional example.

[Explanation of symbols]

 1 chassis 2a idler wheels 3a and 3b axles 4 vertical axes 4a and 4b drive wheels 7a and 7b motors 8a, 8b, 10a and 10b springs 11 connecting rods 13a and 13b line sensors 14a and 14b sensor

Claims (2)

[Claims] 1. An axle is attached to each of the front and rear positions of a bottom surface of a chassis so as to be swingable about a vertical axis, and drive wheels independently rotated by two motors are provided at left and right ends of one of the axles. , The left and right ends of the other axle are provided with rotatable idle wheels, and both axles are urged by spring force so as to be returned to the posture when the chassis is in a straight running state. Front line sensor having a pair of left and right sensing bodies which are connected to each other by a connecting rod so as to be symmetrically operable, and which are provided with a pair of left and right sensing bodies at appropriate intervals on an axle portion near a central portion in the longitudinal direction of the axle on the chassis traveling direction side. An unmanned guided vehicle, characterized in that a sensor on each side is independently associated with a motor on each side. 2. A rear line sensor having a pair of left and right sensing elements provided at appropriate intervals is also provided on an axle portion near a central portion in the longitudinal direction of the axle on the reverse direction side, and each sensing element on each side is provided. Independently associated with each side motor,
The unmanned guided vehicle according to claim 1, wherein one of the line sensors on each of the front and rear sides is selected and used according to the traveling direction of the chassis.