JPS58129609A - Controlling system of moving body - Google Patents

Abstract

PURPOSE:To improve the controlling accuracy of movement with a simple constitution and to prevent influences due to the change of external factors by reading out a long scaling body in which signs to indicate a moving passage are drawn by using an optical reader. CONSTITUTION:Tapes 12 in which signs to indicate information controlling the moving action of a moving body 11 are drawn are adhered to appropriate positions of a flower surface 1 along a tape 2 indicating the moving passage. These signs give movement controlling information such as left turn, right turn, slow going, temporary stop, and backdowk by combining characters, marks and figures. The signs drawn on the tapes 12 and the line setting tape 2 are read out by an image sensor 14 through a lens 13 and the output of the sensor 14 is binary-coded by a binary coding circuit 15 to supply the output to a pattern recognizing device 16. Referring information from a tape position detecting part 17, the pattern recognizing device 16 processes the output from the binary coding circuit 15 and sends a signal to a motor controlling circuit 7 to perform a specified movement.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mobile body control system that optically reads information specifying the moving direction and operation of a mobile body and controls the movement of the mobile body according to the reading result. .

Increasingly, unmanned vehicles are used to simplify the transportation of objects within factories. Conventionally, one method of operating such an unmanned vehicle is to trace the travel route using a tape attached to the floor, and detect the relative position between this tape and the vehicle using a photoelectric conversion device mounted on the vehicle. A photoelectric induction method is used to control the moving direction of the moving vehicle according to the detection results.

That is, as shown in FIG.
The travel route is set. The moving body 11 is equipped with the illustrated devices such as a lamp 3, photodetectors 4t, 4R, and the like. The light emitted from the lamp 3 is reflected by the tape 2 and enters the left and right photodetectors 4L and 4R, where the electrical signals photoelectrically converted are input to the left and right amplifiers 5L and 5R, respectively. These input electrical signals are the intensity of the light incident on each detector, ie, the distance X between each detector and the tape 2 as shown in the second diagram.

It corresponds to y. The deviation detector 6 includes amplifiers 5L and 5R.
receives the output of and detects the level difference. The motor control circuit 7 controls the operation of the left and right wheel drive motors 8L and 8R according to the level difference output from the deviation detector 6.

For example, if the amount of light received by the left photodetector 4L is larger than that of the right photodetector, it means that x<y in FIG. 2, and in this case, the rotation speed of the left wheel is The operation of wheel drive motors 8L and 8R is controlled so as to reduce the deviation of X=7.
The state can be approached. The stop position detection circuit 9 detects, for example, that the outputs of the amplifiers 5L and 5R are both below a certain value (the end of the tape), and outputs a stop signal to the motor control circuit 7.

However, the above conventional method has the following drawbacks. First of all, since the configuration detects the difference in the amount of light reflected from the tape, dust or the like may adhere to the photodetector, causing a deviation in the left and right detection sensitivities, or changes over time may cause gain in the left and right amplifiers. If deviations occur, these deviations will become steady errors in the 11 control loops, and in extreme cases, there is a risk that the vehicle will not be pulled into the controllable range and the vehicle will be unable to travel. In addition, in order to improve control accuracy while avoiding the effects of fluctuations in the amount of background light, a lamp with a large amount of light is required, and if the amount of light decreases due to deterioration of the lamp, fluctuations in the amount of background light will continue to affect control accuracy. There is a drawback to be compensated for.

The second drawback of the conventional method is that it is difficult to set a complicated travel route with branches. In other words, if a branch is to be provided in the travel route, in addition to a photoelectric detection device, the moving vehicle must be equipped with a memory circuit that stores control information regarding movement actions such as turning left or slowing down, or some kind of device that indicates the history of the moving vehicle, such as the distance traveled. The device must be equipped with a device for detecting information, making the device complicated. In this case, there is also the problem that detection errors such as the travel distance are accumulated in proportion to the travel distance of the moving vehicle, or that the detection accuracy deteriorates over time.

The present invention has been made in view of the above-mentioned drawbacks of the conventional method.
The purpose is to provide a mobile object control system that has high control accuracy, is less susceptible to fluctuations due to external factors, and can perform various types of movement control with a simple configuration.

The details of the present invention will be explained below with reference to Examples.

FIG. 3 is a block diagram showing the configuration of an embodiment of the present invention. Elements in this figure labeled with the same reference numerals as in FIG. 1 are the same elements as those already explained in connection with FIG.

In this embodiment, a tape U depicting a sign indicating information for controlling the moving operation of the moving body 11 is drawn at an appropriate location on the floor l along the tape 2 specifying the moving route.
is pasted. This sign consists of appropriate letters, symbols, figures, or an appropriate combination of these, and tells the moving object 11 to turn left, turn right, slow down, or temporarily stop.

Provides movement control information such as retreat.

The mark drawn on the tape 12 and the route setting tape 2 are read by the image sensor 14 through the lens 13. This image sensor 14 is a conventional device in which photoelectric conversion elements are arrayed one-dimensionally or two-dimensionally, and the number of arrayed elements is determined as appropriate depending on the required resolution based on the complexity of the label to be read, etc. A value is selected. Image sensor 1
It is also possible to adopt a configuration in which the scanning of the sign according to No. 4 is carried out by the traveling of the moving object, but a unique scanning function may be provided to enable scanning while moving slowly or in a stopped state.

The output from the image sensor 14 is binarized by a binarization circuit 15 and supplied to a pattern recognition device 16 .

The pattern recognition device 16 is composed of a conventional and appropriate device, and reads the binarized signal into nine shift registers arranged two-dimensionally, for example, with reference to information from a tape position detection section 17, which will be described later. Then, in the pattern matching method, for example, the image is compared with a pre-stored mark. When the content of the label read by the image sensor 14 is detected by matching, nine motor control signals are supplied to the motor control circuit 7 in response. The motor control circuit 7 controls the wheel drive motors 8L and 8R according to the supplied control signal.
control. This causes the moving object 11 to turn left.

Carry out the actions specified by the signs, such as slowing down.

The above-mentioned correspondence between the nine signs and control actions is such that when the number "3" is read, slow down, and when the number "l" is read, K means turn left.
A configuration in which K is associated may be used. Alternatively, the control operation to be performed at each position on the route may be stored in advance in a memory circuit mounted on the moving body, and the position on the route at which the moving body is currently located may be indicated by a sign. Good too.

On the other hand, the output of the binarization circuit is also supplied to the tape position detection circuit 17.
4, i.e. tape 2.
Detects which cell is imaged on the nine cells arranged perpendicularly to the tape, and calculates the center cell position when the image is formed over a plurality of cells. Next, the tape position detection circuit 17 outputs a signal proportional to the difference between the calculated nine cell position and a predetermined cell position to the motor control circuit 7 together with the polarity of the difference O.

Upon receiving this, the motor control circuit 7 controls the wheel drive motor 8 so that the moving body 11 is moved in the direction specified by the polarity of the difference by an amount proportional to the absolute value of the difference.
Supply control signals to L and 8R.

An example in which the image sensor 14 in the above embodiment is arranged one-dimensionally and consists of nine cells will be explained with reference to FIG. In the figure, Shu is Ton in the field of view of the image sensor 14 consisting of a plurality of cell groups.

This is time 1. ．． 1. and t to the positions indicated by the same reference numerals in the figure. At time t, the tape 2 is imaged into three cells gj1gm and 2n. The position detection circuit 17 detects this and detects the center cell g.
The motor control circuit 7 is supplied with a difference between m and a predetermined cell position 21 and 1, that is, a difference of four cells, and a polarity indicating the direction of the deviation (in this case, positive polarity). Based on this, the motor control circuit 7 supplies a control signal to the wheel drive motors 8L and 8R to rotate the left wheel at a high speed as well as the right wheel. As a result, the moving body 11
turns to the right and at time t2 cells 2h and 2i
The loop 2 is imaged at 2j and 2j, and the difference signal output from the position detection circuit 17 becomes zero. As a result, the motor control circuit 7 thereafter supplies a control signal to the wheel drive motors 8L and 8R to rotate both the left and right wheels at a constant speed, and the moving body 11 continues to move straight. At time t1, the image sensor 14
Exactly the same operation is performed when the field of view of the tape 2 is shifted in the opposite direction. However, in this case, position detection circuit 1
A differential signal of negative polarity is output from the terminal, and the moving body 11 changes its direction to the left.

FIG. 5 shows nine time series of binarized patterns input to the pattern recognition device 16 in the embodiments shown in FIGS. 3 and 4. The moving body 11 is controlled to move at a substantially constant speed along the tape 2, and as a result,
A correct binarized pattern as shown in FIG. 5 is taken into the pattern recognition device 16, and based on this, pattern recognition is executed by an appropriate method such as a pattern matching method or a feature extraction method.

When the position of the moving body 11 deviates from the tape 2 to a large circle, and therefore a part of the sign protrudes from the field of view of the image sensor 14, pattern recognition is prohibited to avoid erroneous recognition.

This prohibition signal is sent to the pattern recognition device 1 when the difference signal from the position detection circuit wI17 exceeds a predetermined value of a predetermined polarity.
It is created for 6 yen.

In addition, if the image 7 t14 reads both the image of the tape 2 and the image of the sign, there will be multiple Jirin cell areas, but assuming that there is no sudden route change, the image of the previous tape 8 will be read. Using the image as a reference, the one with the least change can be identified as the one on tape 2. Note that a new route may be estimated after checking the pattern recognition device 16 to see if there is a sudden route change such as a right turn or left turn.

In the above-described embodiment, the marker is installed at a position apart from the route setting tape 8, but the marker can also be installed on the tape 2. In this case, if the tape is binarized into 8 rounds and 1 black signal, it is necessary to binarize the sign into 1 white signal.
Although there is an inconvenience that the area of tape 2 including the marker is cut by a 1 white area in the processing of the tape position detection unit 17, it is inconvenient that the area of tape 2 containing the marker is cut in a 1 white area. In this case, the above-mentioned disadvantage can be solved by inverting a 1-white area surrounded by a ``black'' area into a 1-black area in the tape position detection section 17.

In the above embodiment, a tape is used to set the moving route.
As long as the reflectance of light is different from that of the floor, it may be a robe, wire, or any long object painted on the floor.

As described in detail above, the present invention reads an elongated object that specifies a moving route using an optical reader, and scans the elongated object so that the read image of the elongated object exists at a predetermined position within the field of view. Since it is configured to control the moving direction of the sensor, there is no steady-state error caused by sensitivity differences or aging, unlike in conventional systems, and control accuracy is greatly improved. Furthermore, since it is not affected by background light, extremely stable control is possible. Furthermore, the present invention is configured to optically read signs installed along the travel route to perform pattern recognition, and perform predetermined control operations according to the recognition results. Fine control operations can be performed without accumulating errors.

Furthermore, the present invention has a configuration in which both the route setting information and the operation designation information are read by a common optical reading device, so there is an advantage that the configuration is simple and inexpensive.・

[Brief explanation of the drawing]

1 and 2 are block diagrams and plan views for explaining the conventional system, FIG. 3 is a block diagram of a configuration of an embodiment of the present invention, and FIGS. 4 and 95 are a block diagram of the configuration shown in the third figure. It is a conceptual diagram explaining operation. l... Floor surface, 8... Tape, 7... Motor control circuit, 8L, 8R... Wheel drive motor, 11... Moving object, ■... Tape with a sign drawn on it, 14 ... Image sensor, 15 ... Binarization circuit, 16 ... Pattern recognition device, 17 ... Tape position detection section. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] A predetermined movement path for a movable body is specified by a long body installed on the floor, and the movable body optically detects the positional relationship with the long body and uses the detection result. In the mobile object control system, a sign specifying a predetermined movement of the mobile object is installed along the predetermined movement route, and the elongated object and the sign are optically attached to the mobile object. a common optical reading device that reads the sign; a position detection circuit that detects the position of the read long body within the field of view of the optical reading device; a pattern recognition device that recognizes the read mark;
and controlling the moving direction of the moving body so that the elongated body exists at a predetermined position within the field of view of the optical reading device based on the detection result of the position detection circuit, and the pattern-recognized mark. 1. A mobile object control system comprising: a control circuit that performs a predetermined control operation based on the contents of the mobile object control system.