JPS63231507A - Method for returning to guiding course for automatically guided unmanned vehicle - Google Patents

Abstract

PURPOSE:To always attain to return to a guided course at a constant angle and to enable an automatically guided travel over a long distance by executing a steering traveling based on a result operated from information detected by the tip of a guide pass detector and the information of an angle to come into the guiding course. CONSTITUTION:At the front part of a truck 11, a guide pass detector 21 is provided and detects a guiding course 1 and detects an automatically guided vehicle 10 and the guiding course 1 and measures the deviation quantity of the automatically guided vehicle 10 and the guiding course 1. To a storage device 310 included in a control device 30, a route necessary for automatically guiding is set, for example, by the coordinates of X-Y system, and the steering angle of a steering wheel 12 and the number of revolutions of driving wheels 13 and 14 at respective positions of axes and the traveling conditions of a stop position, etc., are stored and are controlled through a central processing unit 300. When the automatically guided vehicle deviates from the guiding course 1, one edge of the detector 21 detects the guiding course 1 and the vehicle rushes into the guiding course, and at this time the interval between a rushing angle and the center line of the vehicle of the detector is measured, the steering angle is operated and the automatically guided vehicle is steered.

Description

[Detailed Description of the Invention] The present invention detects a guidance course laid on the floor,
The present invention relates to a steering control method for an automatic guided vehicle that is guided by a detection signal and self-guided on a travel path without a guided course. The present invention relates to a method for returning an autonomously guided automatic guided vehicle to a guided course.

Conventional color chikugoIn the following explanation, independent guidance means that the automatic guided vehicle guides itself based only on its own information set in advance, without relying on external information.

In addition, external information is an optical system that receives and detects the reflected light when specular reflective tape laid on the floor illuminates the optical tape of the retroreflective tape, or detects induced voltage emitted from buried conductive wires. It refers to a detection signal using an electromagnetic method or a pattern method that recognizes placed symbols, etc. Conventionally, in the travel route of an automatic guided vehicle that uses a combination of a self-supporting guidance method and an optical method or an electromagnetic method (hereinafter simply referred to as the guide path method), the guidance course has been cut out in the middle of the travel route due to layout reasons. There may be cases.

Then, the automated guided vehicle steers in the self-guided mode in the deleted section, and when transitioning to the guidance course that is connected to the deleted section and becomes the point where the guide path method restarts, the automatic guided vehicle shifts from self-guided traveling to the guide path method. A guidance method is used.

The sun is shining. However, in the above-mentioned method, errors in position measurement of the automatic guided vehicle in the self-guided system occur due to causes such as the condition of the traveling floor surface and wheel slippage.

When the missing section, or the self-guided traveling section, becomes longer, the error accumulates, and the amount of deviation from the guided course at the point where the guided path method restarts increases (and it becomes difficult to deviate from the guided course at all). It will also happen.

Therefore, in order to eliminate the above-mentioned problems, it is necessary to increase the control accuracy in the self-sustaining guidance system, or to limit the travel distance in the self-sustaining guidance system, and to limit the cumulative error to within a certain range. However, in the former case, the control device becomes complicated, and in the latter case, the layout setting is subject to restrictions.

The present invention was devised in view of the above-mentioned circumstances, and is capable of reliably returning to the guided course even if the traveling section of the automatic guided vehicle is extended by the self-guided system. The purpose is to provide a method.

, a method for controlling the steering of an automated guided vehicle that detects the amount of deviation from a guided course for making a prediction, measures the vehicle body direction, and travels while being steered based on signals from each of the above-mentioned means. The amount is detected by a detector placed in front of the vehicle and perpendicular to the direction of travel, and the vehicle position and direction are calculated by measuring the rotational speed of the drive wheels installed on the vehicle.
In addition, the steering angle of the vehicle body is calculated based on the amount of deviation from the guide course and the detected amount of the vehicle body position/azimuth, and the automatic guided vehicle is steered based on the calculated steering angle.

When the automatic guided vehicle deviates from the guided course and is traveling independently, one end of a detector installed at the front of the vehicle body detects the guided course and enters the guided course. In addition to measuring the entry angle at this time, the distance between the detector that detected the guidance tape and the vehicle body center line is also measured, and the steering angle is calculated based on the above two measurement results. is steered.

Sl± Embodiments of the present invention will be described below based on the drawings.

Figure 1 shows autonomous guided vehicle travel (hereinafter referred to as
FIG. 2 is a schematic perspective view showing the main parts of the automatic guided vehicle used in this embodiment.

In FIG. 2, 10 is an automatic guided vehicle, and 11 is an automatic guided vehicle 100 truck, which is equipped with a steering wheel 12 at the front and drive wheels 13 and 14 on the left and right sides of the rear of the truck.

The steered wheels 12 are configured to freely turn around a vertical axis by a steering motor 15 via a speed reduction mechanism (not shown).

Further, the drive wheels 13 and 14 are driven by the travel motor 16 via a differential speed reduction mechanism using differential gears (not shown), and are configured to perform forward and backward movement and spin turns.

l is the guidance course that forms the travel route, and this is AI SUS, etc., specular reflective tape, retroreflective tape, electromagnetic guidance wire, symbol mark, etc. laid on the floor, and the automatic guided vehicle is preset and memorized. It may also be travel route information.

For information detection, the configuration differs depending on the type of guidance course 1, such as an optical sensor or a guidance sensor, but in the following explanation, for convenience, the guidance course 1 using the guide path method uses a mirror tape, and the guidance course 1 using the self-supporting method uses a memorized tape. Based on the travel route information provided.

A guide path detector 21 is provided at the front of the truck 11. The guide path detector 21 detects the guide course 1, detects the automatic guided vehicle 10 and the guided course 1, and detects the automatic guided vehicle 10 and the guided course 1.
0 and the guidance course 1, and includes a light irradiation means for irradiating light onto the guidance course 1, and a light reception detection means (both not shown) for receiving and detecting the irradiated and reflected light. The automatic guided vehicle 10 is configured to travel along the guidance course 1 by controlling the steering motor 15 via the control device 30 based on the detection output of the light reception detection means.

The drive shaft of the drive motor 15 is connected to an angle detector, such as a potentiometer 23, via a timing belt 22. Thus, the potentiometer 23 rotates according to the rotation of the steering wheel 12, generates an output voltage according to the rotation speed, and inputs it to the control device 30.

Further, the drive shaft of the drive wheel 13.14 is connected to an angle detection means, for example, an encoder 2 via a timing belt 24.25.
It is connected to 6.27. Therefore, the encoder 26.
27 rotates according to the rotation of the drive wheels 13 and 14, generates pulses according to the rotation speed, and inputs them to the control device 30. The reason why the encoders 26 and 27 are arranged on the left and right sides is to make it possible to cope with the case where the rotational speed of either of the drive wheels 13 or 14 differs due to slipping or the like.

The control device 30 performs guidance control for guiding the automatic guided vehicle IO and controls each motor.

Guidance control includes a function of counting the number of pulses output from the encoders 26 and 27 to measure the position and orientation of the bogie 11, and performing self-supporting guidance, as well as deviation amount information of the guidance course 1 output from the guide path detection device 21. and a function to perform guidance to return to the guidance course 1 based on the measured position and orientation of the bogie 11 and deviation amount information of the guide path detection device. are doing.

Further, each motor has a function of controlling the running speed of the driving wheels 13 and 14, and a function of controlling the steering angle of the steered wheel 12 based on the output of the potentiometer 23.

FIG. 3 is a block diagram of the control device 30 showing control of the automatic guided vehicle 10.

In the storage device 310 included in the control device 30, a route necessary for self-sustaining guidance is set, for example, using coordinates of the x-y axes, and the steering angle of the steering wheels 12 and the driving wheels 13, 14 at each coordinate position are stored. Running conditions such as rotation speed and stop position are stored and controlled via central processing unit 300.

In the guide path method, the detection signal from the guide course 1 detected by the guide bus detector 2 is sent to the adder circuit 320.
, is input to the central processing unit 300 via the A/D converter 321, processed and outputted as a steering signal, and is used to steer the steering motor 15 via the synchronization circuit 330, the D/A converter a 331, and the control circuit 332. do.

On the other hand, the drive signal to the travel motor 16 is sent to the central processing unit 30.
0 to the travel motor 16 via the synchronization circuit 340, D/A converter 341, control circuit 342, and switching circuit 343, and the automatic guided vehicle 10 travels.

Each output signal of the encoders 26 and 27 is sent to the pulse counter 3.
44 and 345, and input them to the central processing unit 300.

Note that the input circuit 350 inputs signals from the position sensor 2 that detects symbols arranged on the route or self-sustaining guidance traveling conditions to the central processing unit 300.

Next, the operation of the present invention will be explained.

First, as described above, the driving conditions are stored in the central processing unit 300, and if there is an instruction to start, the driving starts, and in the guide path method, the detection signal from the guidance course 1 is read and the steering is performed along the guidance course 1. I'm running around.

In the self-sustaining guidance method, the position and orientation of the automatic guided vehicle 10 is measured according to the rotational speed from the encoders 26 and 27, and the automatic guided vehicle 10 is steered and travels according to a pre-stored course. Hereinafter, the aforementioned steering operation will be referred to as dead reckoning navigation.

Next, a case will be described in which the automatic guided vehicle 10 returns to the guided course 1 from autonomous travel by dead reckoning navigation.

In FIG. 1, when returning to guidance course 1 from dead reckoning navigation, automatic guided vehicle 10 changes its guidance method to a guide bus method instead of following a pre-stored guidance course.

The automatic guided vehicle 10 enters the guidance course 1 at an angle ΔθC,
A light-receiving sensor R at the tip of the guide bus detector 21 (leftmost in the figure) detects the guide course 1 and detects information ds.

This information ds is based on the center line of the automatic guided vehicle 10 and the light receiving sensor R.
The distance ds is the same as that of the sensor on the left side of the vehicle.
<O, and ds>0 for the right sensor.

The reference direction measured by the automatic guided vehicle 10 in the dead reckoning navigation is A1, the preset reference direction is B, and the tread center point P of the drive wheels 13, 14 and the guide bus detector 2.
1, the angle between the PQ and the reference direction is θ, the angle between the reference direction B and the guidance course 1 is θc1, the distance between the PQ is Ws, and the distance between the tread center point P and the guidance course 1 is Xd. For example, X5=-sinΔθc−dscosΔθ
-(1) Δθ=θ−θC.

Therefore, since the angle θ is obtained from the traveling route information of the automatic guided vehicle 10, the position of the tread center point P is calculated by the central processing unit 300 as Xd=−WssinΔθc−dscosΔθC based on the information ds and the information θ. .

However, the automatic guided vehicle 10 is guided by the guidance course 1 from dead reckoning navigation.
The steering angle φ to return to
5, the automatic guided vehicle 10 returns to the guidance course 1.

Note that even if the automatic guided vehicle 10 passes through the guide course 1 due to coasting and then deviates from the guide course 1, it is steered in the same manner as described above and continues to travel while wrapping around the guide course 1.

In this embodiment, the encoders 26.27 are provided on each of the left and right drive wheels 13.14 to measure the rotation speed of the left and right drive wheels, but the average value of the rotation speed of each drive wheel is calculated. It is also possible to do so.

It is also possible to directly connect one set of encoders to the travel motor 16 and calculate the average rotational speed of the driving wheels.

As explained above, according to the present invention, the vehicle is steered based on the result calculated from the information detected by the tip of the guide bus detector and the information about the angle at which the vehicle enters the guidance course. There are two. Therefore, even if the automated guided vehicle deviates from the guided course when it completes self-guided travel,
It is possible to always return to the guided course at a constant angle.

Therefore, it becomes possible to perform self-supporting guided travel over long distances, and the layout can be extremely flexible.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a situation in which the automatic guided vehicle returns to the guided course from a deviation state, FIG. 2 is a schematic perspective view showing the main parts of the automatic guided vehicle, and FIG. 3 is a control block diagram. 10...Automated guided vehicle, 12...Steering wheel, 13.14
...Drive wheel, 21...Guide bus detector, 23...
・Potentiometer, 26.27...encoder,
30...control device.

Claims (3)

[Claims] (1) A method for controlling the steering of an automated guided vehicle that detects the amount of deviation from a guided course, measures the position and orientation of the vehicle body, and travels while being steered based on the respective signals, wherein the detection of the amount of deviation is performed by detecting the amount of deviation from the vehicle body. This is done with a detector placed in front and perpendicular to the direction of travel, and the vehicle body position and orientation are calculated by measuring the rotational speed of the drive wheels installed on the vehicle body.
and a steering angle of the vehicle body is calculated based on the amount of deviation from the guidance course and the detected amount of vehicle body position/direction, and the automatic guided vehicle is steered based on the calculated steering angle. How to return an unmanned guided vehicle to a guided course. (2) The self-guided unmanned vehicle according to claim 1, wherein the measurement of the vehicle body position and orientation is calculated by measuring the rotational speed of each drive wheel provided on the left and right sides of the vehicle body. How to return the guided vehicle to the guided course. (3) The self-guided unmanned transport system according to claim 1, wherein the vehicle body position and orientation are measured and calculated by measuring the average rotational speed of drive wheels provided on the left and right sides of the vehicle body. How to return a car to a guided course.