JPH0592811U - Automated guided vehicle - Google Patents

Abstract

(57) [Abstract] [Purpose] To change the traveling direction for pallet transfer, perform lean curve travel. [Configuration] The automatic guided vehicle 1 has one front wheel 1 and two rear wheels. Then, from the G position to the H position, the vehicle travels forward along the guide line L, and from the H position to the I position, the steering control is performed by the control device 6 so that the front wheel 2 passes through the path indicated by the dotted line, and the rear guide sensor 7b. Central part 7b
-1 should pass directly above the guide line L. When the automatic guided vehicle 1 reaches the γ position, it travels backward and stops at a position before the station 10.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an automated guided vehicle, which is devised so that the vehicle can be moved backwards without being wasted to move backwards for transferring pallets.

[0002]

[Prior Art]

 An automated guided vehicle is an unmanned guided vehicle that travels in various factories, warehouses, offices, etc. to transport parts, products, and small items. The unmanned pallet truck that transports pallets among these unmanned transport vehicles is called an unmanned pallet truck.

Now, with reference to FIG. 4, an automated guided vehicle 1 used as an unmanned pallet truck will be described. This automated guided vehicle 1 is a tricycle type having one front wheel 2 for rotational driving and steering, and two rear wheels 3 that are driven wheels, and a pallet transfer device (not shown) is mounted on a vehicle body 4. I have it.

When the pallet is transferred by the automatic guided vehicle 1, traveling steering control as shown in FIG. 5 is performed. That is, the automatic guided vehicle 1 in the position indicated by α in the figure travels forward (indicated by A in the figure), once stops when reaching the position β, and then the front wheel 2 which is in the straight traveling state moves 90 times. ° Steaded up to the position indicated by 2a in the figure. In this state, the front wheels 2 are rotationally driven and spin-turned (indicated by B in the figure). When the position state γ is reached, the front wheel 2 stops and stops the spin turn. After that, the front wheels, which were in the orthogonal state shown by 2a in the figure, are stationary and returned to the straight traveling state shown by 2 in the figure. Thereafter, the automated guided vehicle 1 moves backward (indicated by C in the figure), stops at a position in front of the station 10, transfers the pallet with the station 10, and unloads or unloads the pallet.

The following advantages can be obtained by using the above-described spin turn as the traveling steering control. (1) The control is simple because only the stationary operation of the front wheels 2 in the position states β and γ and the forward / reverse movement are performed. (2) When the position state γ is reached and the position of the front wheels 2 is returned to the straight traveling state, the longitudinal direction (front-rear direction) of the vehicle body 4 and the direction of the front wheels 2 become parallel, and the control for the subsequent reverse C is simplified. Is.

[0006]

[Problems to be solved by the device]

 By the way, in the past, since the spin turn was performed, there were the following drawbacks. (1) Since the vehicle stops once in the position states β and γ, it takes a long time (cycle time) for the automatic guided vehicle 1 to reach the position before the station 10 from the position state α. (2) Since the front wheels 2 are stationary in the position states β and γ, the front wheels 2 are heavily worn.

In view of the above-mentioned conventional technique, the present invention provides an automatic guided vehicle having a short cycle time and less tire wear.

[0008]

[Means for Solving the Problems]

 The configuration of the present invention which solves the above-mentioned problems has one front wheel and two rear wheels, and after traveling forward in a straight line, it travels forward in a straight line in a direction different from the previous forward traveling direction by 90 °. In an unmanned guided vehicle that stops and then travels backward in a straight line, the vehicle moves forward linearly in a direction 90 ° different from the previous forward running direction from the previous linear forward running state. Steering angle data is set in advance to sequentially change the steering angle of the front wheels when traveling forward until the vehicle transitions to the traveling state, and the steering angle data is set during the transition operation. Is provided with a control device for controlling the steering angle of the front wheels.

[0009]

[Action]

 According to the present invention, when shifting from the previous straight forward running to the different straight forward running in the 90 ° direction, lean steering control is performed and the vehicle travels on a curve.

[0010]

【Example】

 Embodiments of the present invention will be described below in detail with reference to the drawings. It should be noted that the same reference numerals will be given to the portions having the same functions as those of the conventional technique.

FIG. 1 shows an automated guided vehicle 1 according to an embodiment of the present invention. The automated guided vehicle 1 has a front wheel 2 and two rear wheels (driven wheels) 3 on a vehicle body 4 and a pallet transfer device 5 to function as a three-wheel type unmanned pallet truck.

The front wheels 2 are rotationally driven by the drive motor Md and are steered by the operation of the steering motor M s. The amount of rotation of the front wheels 2 is detected by a traveling sensor Sd such as an encoder, and the steering angle of the front wheels 2 is detected by a steering angle sensor Ss. The control device 6 controls the driving of the motors Md and Ms and receives the signals detected by the sensors Sd and Ss. Further, in order to detect the guide line installed along the traveling path, the front and rear portions of the vehicle body 4 are provided with guide sensors 7f and 7b, and the detection signals from the sensors 7f and 7b are also control devices. Sent to 6.

The control device 6 is preliminarily set with steering angle data as shown in FIG. 2 in order to perform a curve running without waste when transferring pallets.

Next, with reference to FIG. 3, a traveling control state performed for pallet transfer will be described. As shown in FIG. 3, the automated guided vehicle 1 that has departed from the position G travels forward while detecting the guide line L by the guide sensor 7f, reaches the position indicated by α in the figure, and further linearly reaches the position H. Drive forward.

When the guidance sensor 7f reaches the position H, the guidance by the guidance sensor 7f is stopped, and instead, the control device 6 controls the steering of the front wheels 2 based on the steering angle data shown in FIG. In other words, the steering speed is controlled so that the vehicle speed becomes constant and the steering angle shown in FIG. 2 is obtained according to the elapsed time from the time when the position H is started. When the guidance sensor 7f reaches the position I, the sensor 7f detects the guidance line L again and travels straight ahead.

When the steering control is performed in this manner, the front wheel 2 passes through the path indicated by the dotted line in the drawing from the position H to the position I, but the central portion 7b-1 of the rear-side inductive sensor 7b moves from the position H to the position H. It is located right above the guide line L when moving to the position I. Conversely speaking, the steering data shown in FIG. 2 is set so that the sensor central portion 7b-1 is directly above the guide line L even between H 1 and I 2. The radius of curvature of the guide line L in the curved portion is determined in consideration of the fact that the path indicated by the dotted line in the figure projects.

The automated guided vehicle 1 stops when the position state γ is reached. At this time, the direction of the vehicle body 4 and the direction of the front wheels 2 become parallel. Then, the automated guided vehicle 1 travels straight backward and stops at a position before the station 10. Then, the pallets are transferred to and from the station 10.

Next, how to obtain the steering angle data shown in FIG. 2 will be described. To obtain the steering angle data, in FIG. 3, the automatic guided vehicle 1 is started from the γ position, and the guide line L is detected by the rear guide sensor 7b, and the guide line L is moved to the positions I → H → G. At this time, the path (indicated by the dotted line in the figure) through which the central portion 7f-1 of the front induction sensor 7f passes between I and H is obtained by simulation or actual measurement, and the data obtained by plotting this path is used as steering angle data. And

Although the steering angle according to the time is set as shown in FIG. 2 in the above embodiment, the steering angle may be set according to the traveling distance.

[0020]

[Effect of the device]

 According to the present invention, as described in detail with reference to the above embodiments, the direction can be changed by 90 ° without stopping, the cycle time is shortened, and the front wheels 2 are not stationary, so that tire wear does not occur. Decrease.

[Brief description of drawings]

FIG. 1 is a block diagram showing an automatic guided vehicle according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing steering angle data.

FIG. 3 is a plan view showing a traveling state of the embodiment.

FIG. 4 is a configuration diagram showing a conventional automated guided vehicle.

FIG. 5 is a plan view showing a conventional traveling state.

[Explanation of symbols]

 1 Automated guided vehicle 2 Front wheel 3 Rear wheel 4 Car body 5 Pallet transfer device 6 Control device 7f, 7b Inductive sensor 10 Station

Claims (1)

[Scope of utility model registration request] 1. A vehicle having one front wheel and two rear wheels, traveling forward in a straight line, and then 90 ° with respect to a previous traveling direction.
In an unmanned guided vehicle that travels straight ahead in different directions, stops, and then travels backward in a straight line, an unmanned guided vehicle moves 90 ° from the previous straight ahead traveling direction from the previous straight forward traveling direction. Steering angle data for sequentially changing the steering angle of the front wheels according to the traveling is set in advance when traveling forward until the state in which the vehicle travels linearly in different directions is changed. At this time, the automatic guided vehicle is provided with a control device for controlling the steering angle of the front wheels according to the steering angle data.