JPS62225421A - Unmanned vehicle - Google Patents

Abstract

PURPOSE:To ensure a stable running performance even in either a straightforward running mode or a lateral spin turn mode, by providing two drive wheels provided with running drive devices and steering devices, and one driven wheel, and by controlling at least one of the drive wheels. CONSTITUTION:There are provided running drive wheels 7a, 7b, running drive devices 8a, 8b, steering devices 9a, 9b and a universal driven wheel 10. With this arrangement the directional control either for rectilinear running or lateral running may be made by controlling the steering of only one axle of the running drive wheel 7b, and it is sufficient to similarly control the steering of the running drive wheel 7b alone even for spin turn. Further, the steering direction of the running drive wheel 7a is made straightforward for rectilinear running and spin turn while the drive wheel 7a is fixed in the lateral direction for lateral running. Further, the control of difference in rotational speed between both drive wheels 7a, 7b may be suitable made in accordance with the steering angle of the running drive wheel 7b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an automatic guided vehicle mainly used in a factory.

(Prior art) In general, in automatic transportation within a factory using a conveyance vehicle, a receiving stage Z1 is not provided in contact with the conveyance route 1-1, or a sufficient space for passing through a curved portion is not provided. Due to constraints on the travel route of the Ikasa, the conveyance vehicle may be required to have the capability of traveling viA. Hereinafter, a conventional transport vehicle that is capable of traveling sideways will be explained. FIGS. 5 and 6 are configuration diagrams showing the wheel arrangement of a conventional transport vehicle, respectively. In each of these figures, there is tF3, and the vehicle bodies 1a and 1b include traveling drive wheels 2a, 2b, 2c, and 2d, and a traveling drive device 3a.
.

3b, 3c, 3d, steering devices 4a, 4b, iJc.

4d and swivel driven wheels 5a, 5b, 5c, 5d are attached. The transport vehicle shown in FIG. 5 has drive wheels 2a,
2b are arranged diagonally on the vehicle body, and the transport vehicle shown in FIG.
, 2d, so (δru).

(Problems to be Solved by the Invention) When the conveyance vehicle shown in FIG.
There are two methods, one is to control either one of b, and the other is to control both at the same time. For example, if only the driving wheels on the front side with respect to the traveling direction are controlled, an inner wheel difference occurs when traveling on a curved portion, resulting in a problem that a large amount of space is required to pass through the curved portion. Furthermore, when traveling on a straight section after traveling on a curved section, the vehicle must travel a certain distance after passing through the curved section until the center line in the traveling direction of the vehicle body 1a becomes parallel to the traveling line within an allowable range. Therefore, there was a problem that a receiving station could not be provided near the curved section.

On the other hand, the above-mentioned problem can be greatly improved by a method of controlling both the traveling and driving wheels at the same time.

Hereinafter, both traveling drive wheels 2a will be explained with reference to FIG.

A case will be described in which the steering control is performed simultaneously on the steering wheels 2b and 2b.

If the steering angle is selected so that the intersection point 01 of the center lines of the two driving wheels 2a and 2b is located on the center line in the width direction of the vehicle body, l11, the space for passing through the curved portion will be reduced compared to the above-mentioned method. However, this method has the problem that the correspondence between the steering angles and rotational speeds of the two running wheels 2a and 2b and the increasing control system of the controlled equipment become complicated.

Furthermore, if the carrier performs a spin turn, which is not shown in FIG. 5, yet another problem will arise.

Hereinafter, problems when performing 4T spin turns will be explained with reference to FIG. When performing a spin turn, the wheel center lines of the two running drive wheels 2a and 2b coincide, so if the rotation speeds of the running drive wheels are different, the spin turn center o2 will be on the running drive 111 wheel center line 12. It shifts.

Therefore, it is necessary to strictly control the rotational speed υ of the driving wheels 2a and 2b during a spin turn, and if a delay or error occurs in the control, an error in body position after the spin turn will occur.

As described above, the transport vehicle shown in FIG. 5 in which the drive wheels are arranged diagonally on the vehicle body has various problems. On the other hand, in the conveyance vehicle shown in FIG. 6 in which drive wheels are arranged on either the left or the right front and rear, the above-mentioned problem is improved. This will be explained below with reference to FIG. In the conveyance vehicle shown in FIG. 6, if the front and rear driving wheels 2c and 2d are steered at the same angle, the turning center will be set at the center line in the vehicle width direction when passing through a curved section.
3, and has the further advantage that there is no need to provide a rotational speed difference between the two driving wheels 2c and 2d. However, when the conveyance vehicle travels sideways as shown in FIG. 3, the control form for direction fl and direction II control must be changed. 1. In other words, when the vehicle is traveling in the longitudinal direction of the vehicle, directional control is basically performed by steering, whereas when traveling sideways, it is controlled by the difference in rotational speed between the two driving wheels 2c and 2d. As a result, the control system becomes complicated and the running stability of the traversing vehicle 11 deteriorates.

The present invention has been made to solve the above-mentioned problems, and provides an automated guided vehicle that improves controllability and has high running stability in any of the straight, lateral, and spin-turn running modes. With the goal.

(Structure of the Invention) (Means for Solving the Problems) The present invention configures a traveling device with two driving wheels equipped with a traveling drive device and a steering device, and one subordinate wheel, and One of the drive wheels and the driven wheel are disposed at the front and rear of either one, and the other drive wheel is disposed at the center of the other left and right sides of the vehicle body to configure the unmanned conveyance system. By steering at least one of the backs of the two driving wheels, the direction of the guided vehicle is controlled and the guided vehicle is driven straight, sideways, or in a spin turn, resulting in an automated guided vehicle with excellent running stability. Wear.

(Example) Hereinafter, an example of the present invention will be described with reference to the corrected drawings.

In the following description of the drawings, the same scents are given the same reference numerals to avoid illustration of the same in the description.

FIG. 1 is a plan view showing the configuration of an embodiment according to the present invention. The vehicle body 6 has driving wheels 7a.

7b, traveling drive device i! (8a, sb, steering gear 619
a.

9b and a swivel driven wheel 10. Travel drive 4
(2) The wheel 7a is disposed on one side in the width direction of the central portion of the vehicle body, and the travel drive wheel 7b and the freely driven wheel 10 are disposed on the opposite side, at the front and rear of the vehicle body, respectively.

The operation of the above embodiment will be explained below with reference to FIGS. 2 to 4. FIG. 2 is a plan view showing a state in which the driving wheels 7b of the automatic guided vehicle shown in FIG. 1 are steered. In this state, the vehicle body 6 can turn around the intersection 04 of the center lines of the two driving wheels 7a and 7b. Now, if the steering angle of the driving wheel 7b is equal to the steering angle of the driving wheels 2c and 2d of the automatic guided vehicle shown in FIG. 9, and the structural dimensions of the vehicle bodies are the same, then It does not show the same curved trajectory as that shown in Figure 9. Therefore, the transport vehicle shown in FIG. 9 has two driving wheels 2c,
2d, according to the embodiment of the present invention, in order to follow the same curved travel trajectory 196, only one running drive wheel yb needs to be steered. Jj, if the distances between the steering centers of the driving wheels 7a and 7b and the intersection o4 of the wheel center line are A and B, respectively, and the rotational speeds of the driving wheels 7a and 7b are n and nb, respectively, then n8 is always n8: J: The number of revolutions of the driving wheels 7a and 7b that satisfies nb=A:B. It becomes possible to run the vehicle.

When the automatic guided vehicle turns in the opposite direction to the case shown in FIG. 2, it is sufficient to steer only the travel drive wheels 7b in the opposite direction.

FIG. 3 is a plan view showing a state in which the automatic guided vehicle according to this embodiment is traveling sideways. When direction control is performed using the deviation signal from the steering wheel for traversing 011, it is sufficient to control the steering of either one of the two driving wheels 7a and 7b, and in this case, the turning of the automatic guided vehicle The center is the intersection of the center lines of the two traveling drive wheels 7a, 7b and 4 as described above.
[ru.

Next, FIG. 4 is a plan view showing the shape f& of the driving wheels when the unmanned transport 'B1 is spin-turned, which is not shown in FIG. 1. That is, when making a spin turn of the automated guided vehicle T, the driving wheels 7b are steered so that the extension line of the center line of the 11 driving wheels 7b is located in the direction passing through the vehicle body center 05 (spin turn turning center). If it is covered, J: will be lifted, and moreover, the center of rotation will be uniquely determined by this. For this reason, compared to when the automatic guided vehicle shown in Fig. 5 spins and turns as shown in Fig. 8, the deviation of the center of rotation during spin turns due to control lag and rotational speed error of the traveling drive wheels. This makes it possible to perform stable spin-turns.

In the third embodiment described above, for example, direction control during lateral travel in FIG. 3 can be performed by steering only the travel drive wheels 7b. Therefore, direction control in both straight-ahead travel and lateral travel requires steering control of only one axis of the driving wheel 7b, and similarly for spin turns, only the driving wheel 7b needs to be steered. In addition, the steering direction of the driving wheel 7a is fixed in the straight direction for straight-ahead travel and spin turns, as shown in FIG. 1, and in the transverse direction for transverse travel, as shown in FIG. 3. The rotation speed difference control between the two driving wheels 7a and 7b may be performed in accordance with the steering angle of the driving wheels 7b.

Thus, according to this embodiment, direct and traverse direction control (11) including spin turns can be performed by steering control of the single axis of the middle wheel driving the vehicle, and the control system can be implemented as an IFfIA control system. For example, if the rotation speed of the running drive wheel (7a in Figure 1) placed in the center of the vehicle body is constant, the rotation speed of the other running drive wheel (7b in Figure 1) It can be determined in part depending on the steering angle of the drive wheels.

Furthermore, since the turning center is uniquely determined by the steering angle of the driving wheels when traveling on curves, the turning center is less likely to shift even if there is a delay in control or an error in the rotational speed of the two driving wheels. .

The present invention is not limited to the above-mentioned embodiments, and various modifications are possible. For example, in an automatic guided vehicle that does not require a traversing function, the steering device shown in FIG. 1 can be omitted.

〔Effect of the invention〕

As described above, in the present invention, the first drive wheel with the steering position υ is disposed at either the front or rear of the left or right side of the vehicle body, and the steering device is further placed at the center of the other left or right side of the small body. A second driving wheel is provided, and either one of the first or second driving wheels described in 11η is controlled by steering i1+lJ to make the automatic guided vehicle go straight, sideways, or spin and turn. J3 in any driving mode, traversal, or spin turn.
However, it is possible to provide an automatic guided vehicle that can achieve stable running performance on a 1:1 basis.

[Brief explanation of drawings]

Fig. 1 is a plan view showing the configuration of one embodiment of the present invention;
4 to 4 are plan views for explaining the operation of the same embodiment, FIG. 5 is a plan view of the configuration of a conventional automatic guided vehicle, and FIG.
This figure is a plan view of the configuration of a conventional automatic guided vehicle for black people, and FIGS. 7 to 9 are plan views for explaining the operation of a conventional guided vehicle for black people. 6...Small body, 7a, 7b...Traveling drive wheel, 8a,
8b... Travel drive device, 9a, 9b... Steering device,
10...Freely driven wheel. Applicant's agent Yubi Sato 1 Figure 2 Island 2 Figure 3 Figure 4 Figure 2b 55 Tob 6 Figure 7

Claims (1)

[Claims] 2 drive wheels with traveling drive and steering device and 1
One of the drive wheels and the driven wheel are arranged at the front and rear of either the left or right of the vehicle body, and the other of the drive wheels is arranged in the center of the other left or right of the vehicle body. An automatic guided vehicle, characterized in that the automatic guided vehicle performs direction control during traveling by controlling the steering of at least one of the drive wheels.