JPS63158616A - Guide device for optical unattended carriage - Google Patents

Abstract

PURPOSE:To perform the branching operation along a guide line by mounting a picture processing device, which discriminates and recognizes the pattern of a reflection tape, on an unattended carriage to entirely abolish autonomous running of the unattended carriage. CONSTITUTION:An unattended carriage 1 on which a picture processing device 7 is mounted runs along a guide line A while performing the picture processing of the output of an image sensor 5 to discriminate and recognize the pattern of the reflection tape. When the carriage 1 comes to a branch point P, reflection tapes 13 and 15 different in pattern forming the guide line are simultaneously detected. If a branch command is preliminarily given, the carriage 1 runs while detecting the reflection tape 13. But otherwise, the carriage 1 runs while detecting the reflection tape 15. Thus, autonomous running of the unattended carriage is entirely abolished to perform the branching operation along the guide line.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic guided vehicle that optically detects a guide line installed on a floor surface and travels along the guide line.

(Conventional technology) Generally, optical automatic guided vehicles using image sensors are
As shown in No. 7rj4, the reflective tape 21 as a guide line installed on the floor is detected by an image sensor, and the image is processed based on the detection signal to distinguish and recognize the pattern (wi stripe) of the reflective tape and follow it. The branching operation of the automatic guided vehicle 22 is performed autonomously without relying on the reflective tape 21 forming the guide line. That is, when traveling from guide line 8 to guide line C, for example, when the image sensor detects the branch mark 23, the reflective tape 2
1, the vehicle autonomously travels at a preset steering angle and speed, and after traveling a certain distance, it searches for the reflective tape 21 again to perform follow-up travel. Similarly, when traveling straight from Li 4 line A to word line B, the vehicle autonomously travels in a straight line after the branch mark 23 is detected.

(Problem to be Solved by the Invention) However, in the conventional device that performs the above-mentioned branching operation autonomously without relying on a guidance line, if the driving center wheel slips during autonomous driving, the traveling direction may deviate. I ended up
There are problems such as not being able to detect the reflective tape that should be followed after the branch, or even if it is detected, the vehicle body swinging sideways when starting to follow again, and because the branch mark is detected before the branch. In addition, if the detection timing of the branch mark is out of order, problems similar to the above-mentioned slip may occur.

Therefore, in view of the above-mentioned problems, an object of the present invention is to provide a II device that completely abolishes autonomous travel during unmanned transportation and can perform branching operations in the form of follow-up travel using a guidance line. .

(Means for solving the problem) The technical means for solving the above problem is to detect the reflective tape as a guide line installed on the floor using an image sensor, and process the image based on the detection signal to reflect the In an automatic guided vehicle that travels by following a tape pattern while discriminating and recognizing it, the reflective tapes forming each line at the branching part of the guide line are formed with different patterns, and the vehicle has at least two types of reflective tapes. It is equipped with an image processing device that can distinguish and recognize the patterns of the reflective tape, so that it can distinguish and recognize the reflective tape that corresponds to the given command and follow it.

(Function) An automatic guided vehicle equipped with an image processing device capable of distinguishing between two or more types of reflective tape patterns processes the detection signal of the image sensor and moves to the W2J line while distinguishing and recognizing the reflective tape patterns. It travels along the line, and when it reaches a fork, it forms a guiding line.
Multiple reflective tapes with different patterns are detected at the same time, but if a branching command is given in advance from the central control device on the ground, the switch is switched to detect the reflective tape on the branching guidance line, and if the branching guidance line is When a command is given, the vehicle is switched to detect the reflective tape on the straight-ahead guide line, and follows the reflective tape guide line that corresponds to the command.

(Example) Hereinafter, an example of the present invention will be specifically described based on the drawings. As shown in FIGS. 3 and 4, the automatic guided vehicle 1 is
A pair of left and right drive wheels 3 that are individually rotationally driven by a pair of left and right drive motors 2, and 4 that are arranged on the front, rear, left and right sides.
The vehicle is equipped with several casters 4, and is steered by changing the rotational speed of the drive wheels 3. Further, an image sensor 5 and a light beam 6 are installed at the front and rear of the vehicle body, respectively, for detecting guidance lines placed on the floor surface.

FIG. 2 is a block diagram of the automatic guided vehicle travel 41' IIJ circuit. As shown in the figure, the traveling control circuit includes an image sensor 5 that detects the reflective tape, processes an image signal of the reflective tape detected by the image sensor 5, and
An image processing device 7 that can distinguish and recognize at least two types of reflective tape patterns, a steering controller 8 that provides speed commands necessary for steering, and a steering controller 8 that controls the rotational speed of the left and right drive motors 2 based on the commands from the steering controller 8. a drive controller 9 for individual control;
A servo amplifier 10 for supplying current necessary for speed control to the drive motor 2, an image processing device 7, and a steering controller 8 for controlling the running of the automatic guided vehicle 1.
, and a host controller 11 that gives commands to the drive controller 9, and can be mounted on the unmanned carrier vehicle 1. Then, while the image processing device 7 calculates and determines the amount of lateral deviation of the vehicle body relative to the reflective tape, the left and right drive motors 2 are operated to change the speed in order to reduce the amount of lateral deviation to zero, and the type of reflective tape is determined. , it is designed to follow the guidance line corresponding to the command.

Note that the rotational speed of the drive motor 2 is fed back to the drive controller 9 via the tacho generator 12.

FIG. 1 shows the structure of the branching part of the guide line on which the automatic guided vehicle 1 travels, and as shown in the figure, the branch guide line B is partially parallel to the straight guide line 8. In this embodiment, a part of the branching guide line B is formed by reflective tape 13 having a different pattern (vertical stripes). That is, the branching guide line B has a branching reflective tape 13 disposed at a certain distance from the branching point P, and a pattern different from that of the branching reflective tape 13, and the branching reflective tape 13 has a pattern different from that of the branching reflective tape 13. 13 and a reflective tape 14 disposed continuously. On the other hand, as shown in the figure, the straight guiding line A is formed by a reflective tape 15 having the same pattern as the reflective tape 14, but this may be a slightly different pattern.

Next, the travel control operation of the automatic guided vehicle 1 will be explained based on the flowchart shown in FIG. Center of the ground i, I
It is determined whether or not a travel command has been output from the JIII device (not shown) to the travel control circuit (step 1). If a travel command has been output, the process proceeds to step 2, where an image is captured by the image sensor 5. is started, and then the reflective tape is recognized by the image processing device 7 (step 3).Subsequently, in step 4, it is determined whether or not there is a guiding line A for going straight, and if the line A is present, the process proceeds to step 5. The vehicle then proceeds to determine whether there is a branching guidance line B. If there is no line B, the vehicle advances to step 7 and travels following the straight-ahead guidance line A. If there is a travel command in that state, the vehicle advances to step 10.C Return to step 1. That is, until the automatic guided vehicle 1 reaches the branch point P shown in FIG.
Then, when the automatic guided vehicle 1 reaches the branch point P, the image sensor 5 detects the reflective tape 15 constituting the straight guiding line 8 and the branching point P. The branching reflective tape 13 on line B will be detected at the same time. Therefore, in step 5, it is determined that there is a branching guide line B, and the process proceeds to step 6. In this case, if a branching command has not been issued from the central controller, the image processing device 7 Reflective tape on guide line 15
Detection continues and the process proceeds to step 7, where the unmanned transport i1 continues to travel along the straight guide line A.

On the other hand, if a branching command has been issued from the central control device, the image processing device 7 switches the detection target from the straight reflective tape 15 to the branching tape 13 with a different pattern, and proceeds to step 9. The automatic guided vehicle 1 travels while detecting the reflective tape 13 for branching. Then, until the automatic guided vehicle 1 reaches the end of the branching reflective tape 13,
It runs while repeating steps 1 to 4, step 8, step 9, and step 10, and when it passes the branching reflective tape 13, it detects a reflective tape 14 with a different pattern from this, and then runs along this reflective tape 14. It will be followed.

In addition, if it is determined in step 4 and step 8 that there is no line, it is determined that there is a derailment accident (
Step 11), the automatic guided vehicle 1 stops.

FIG. 6 shows another embodiment of the invention. That is, this embodiment is an example in which the running direction is divided into three directions, and the three directions are divided by providing reflective tapes 16 and 17 with different patterns at a certain distance from the branching point P, respectively, regarding the branching guide lines B and C. This makes it possible to branch in direction.

In the description of the embodiment, the case where vertical stripes, which are the pattern of the reflective tape, are continuous is illustrated, but as long as it is within the range that can be recognized by the image processing device 7, it can be seen intermittently at a constant pitch. There may be no problem, and the branching guide line B or C may be a type of reflective tape over its entire length.

(Effects of the Invention) As described in detail above, according to the present invention, an image processing device mounted on a vehicle that can discriminate and recognize patterns of at least two kinds of reflective tapes can be used to generate images from a central control device on the ground. It is possible to select the guidance line corresponding to the command based on the command and perform branching operation by following that guidance line. Reliable and safe branching can be achieved by solving various problems caused by slips or deviations in detection timing of branching marks. Further, according to the present invention, since a branch mark is not required, a branch mark detection device is not required.
This will be effective in reducing control m + equipment costs to n elements.

[Brief explanation of the drawing]

Figures 1 to 6 show embodiments of the present invention, Figure 1 is a configuration diagram of a reflective tape at a branch part of a guide line, and Figure 2 is a water circuit lock for automatic guided vehicle travel IT and IJ control circuits. figure,
Fig. 3 is a schematic plan view of the automatic guided vehicle, Fig. 4 is a side view thereof, Fig. 5 is a flowchart showing the travel control operation, and Fig. 6 is a schematic plan view of the automatic guided vehicle.
The figure is a configuration diagram of a reflective tape showing another embodiment, and FIG. 7 is an explanatory diagram illustrating a branching operation by a conventional device. 1...Automated guided vehicle 5...Image sensor 7...Image processing device 13-17...Reflective tape A...Direction guide line B, C...Branch guide line

Claims (1)

[Claims] In an automatic guided vehicle that detects a reflective tape as a guide line installed on the floor using an image sensor, processes the image based on the detection signal to distinguish and recognize the pattern of the reflective tape, and travels by following it. The reflective tape that makes up each line at the branching part of the guide line is formed with different patterns, and the vehicle is equipped with an image processing device that can distinguish and recognize at least two types of reflective tape patterns. An optical automatic guided vehicle guidance device that distinguishes and recognizes the corresponding reflective tape and follows it.