JPS6015717A - Automatic traveling vehicle - Google Patents

Abstract

PURPOSE:To decrease the processing time of the output signal delivered from a photodetector and to attain the stable steering drive, by processing all of the output signals of plural photodetectors with hardware. CONSTITUTION:The reflected beams given from the objects to be detected such as a floor surface 1, a tape 2, etc. irradiated by a projector 4 are detected by photodetectors 5A-5E. Then the voltage, i.e., the output signals are delivered to a reference value detecting means 10 and a weighting signal value detecting means 11. The means 10 adds each output by an adder 12 and obtains the reference value Y. The means 11 multiplies the signals of photodetectors 5A-5E by the coefficients of X1-X5 by multipliers 13A-13E. At the same time, said coefficients are added together by an adder 14 to obtain the value of the weighting signal X. Then the value of X/Y is obtained by an arithmetic means 15, and coefficient 3 is subtracted from the X/Y value by a subtractor 17 to obtain the value of S. Therefore a truck can always be set at the center position of the tape 2 by controlling a steering device 19 based on the S value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an automatic driving vehicle, and more particularly to an automatic driving vehicle that can perform steering guidance of the vehicle at high speed.

[Background technology]

2. Description of the Related Art In recent years, as manufacturing factories become more labor-saving and unmanned, self-driving conveyance vehicles that convey goods between stations within factories have been put into practical use. Most of the operations of this vehicle, such as starting, stopping, and steering, are automated, and in particular, the steering is automatically controlled so that the vehicle can travel along a preset route within the factory. Figure 1 shows an example of this, in which a light reflective tape 2 is extended on the floor 1 along the route in the factory,
A light projector 4 and a plurality of light receivers 58 to 5E arranged in the width direction are provided at the front of the vehicle 30 body, and the light reflected from the projector 4 has different weight resistance between the light reflective tape 2 and the floor surface 1. Then, the relative position of the vehicle 3 with respect to the light reflective tape 2 is determined by utilizing the difference in the amount of light received by each of the light receivers 58 to 5E, and from this point on, the steering section is automatically controlled to steer the vehicle so that it follows the tape trap. (For example, Japanese Patent Application Laid-Open No. 1983-1999)
(See Publication No. 8758).

By the way, as a conventional control method for this type of vehicle, the present inventor has used the method shown in FIG. 2. In this method, the output signal (voltage) of each photoreceiver 5A=5E is input to comparators 6A to 6E provided individually, and the signal is compared with a comparison voltage 7 at a certain timing to convert the signal into a binary value. become

Comparison voltage 7 is a voltage that corresponds to the output voltage of the light receiver when it receives reflected light with a reflectance between the reflectance of floor surface 1 and tape 2, and therefore the light receiver that currently corresponds to tape 2. The output value of the receiver is different from that of other receivers. Then, by inputting this binary signal to the computer 8 and processing it with a predetermined program, the vehicle 3 for the tape 2 is
The current position in the width direction can be determined, and based on this result, the steering mechanism 9, that is, the light receiver 5C at the center of the vehicle, is steered to correspond to the tape 2.

However, in this method, the reflection of light from the floor or tape is detected by a light receiver, the output signal (voltage) is compared with a comparison voltage, and the binary signal is converted into a binary signal.Then, the binary signal is then used by a computer to calculate the steering amount, etc. As a result, there is a delay in response to the steering due to the time required for the processing, resulting in problems such as undesirable phenomena such as oscillating steering.

Furthermore, if the comparison voltage 7 and the output signals of the respective light receivers 58 to 5E are compared at a certain timing, there will be a period in which the vehicle is in an uncontrolled state, so stable driving cannot be achieved. The inventor has discovered that this is not possible.

[Purpose of the invention]

An object of the present invention is to shorten the processing time of the output signal from the light receiver, thereby achieving faster steering response, preventing problems such as oscillating steering, and achieving stable steering driving. The goal is to provide autonomous vehicles.

The above and other objects and novel features of the present invention include:
It will become clear from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief overview of typical inventions disclosed in this application is as follows.

That is, there are provided means for extracting the output signals of a plurality of light receivers as they are and using them as reference signals, means for weighting the output signals of each light receiver, and means for performing predetermined calculations from the outputs of both of these means. , and by analog processing the processing in each of these means, all processing is done by hardware, which reduces processing time compared to software and digital processing using a computer. This achieves faster steering response and improved steering stability.

〔Example〕

FIG. 3 is an overall configuration diagram of a steering section of an automatic traveling vehicle which is an embodiment of the present invention, and its external configuration is the same as that shown in FIG. 1. That is, a floodlight 4 made of a fluorescent tube or the like is installed at the front of the vehicle 30 body to illuminate the floor surface approximately evenly across the width of the vehicle.
Five light receivers 58 to 5E are arranged at equal intervals in the 0-width direction and have their light receiving surfaces facing downward. These light receivers 58 to 5E are composed of light receiving elements such as CdS, and have internal resistances that are changed according to the amount of light received, which can be converted into voltage changes and outputted in degrees Celsius. In addition, the center receiver 5C
is positioned at the center in the width direction of the vehicle.

Each of the light receivers 58 to 5E is connected to the reference value detection means 1.
0 and weighting are connected to the signal value detection means 11, respectively. The reference value detecting means JO has an adder 12, and simply adds the output voltages vA to 8 of the light receivers 58 to 5E to add the Y value (Y2, 4,000, 8+Vo+VD+V). On the other hand, the weighted signal value detection means 11 includes five multipliers 13A to 13E, each having a different coefficient, and an adder 14 that adds the outputs of these multipliers. Each of the multipliers 13A to 13E is connected to each of the light receivers 5A to 5EK, and the coefficients are, for example, XI, X2°Xs, X4 . It is set to Xs. Then, the value obtained by multiplying the output signals of the light receivers 58 to 5E by this coefficient is used as a weighted signal, and these are added by the adder 14 to obtain
, ÷3V, +4V, +5■E) are weighted and calculated as signal values.

Furthermore, the reference value detection means 10 and the weighted signal value detection means 11 are connected to the calculation means 15.

This calculation means 15 is equipped with a divider 6 and a subtracter 17, and the divider 16 divides the output Y value of the reference value detection means 10 and the weighting with the output X value of the signal value detection means 11. Ratio X/Y
is calculated, and the subtracter 17 subtracts the value 18 from this X/Y value.
(In this example, the median value of the coefficients is 3) to calculate the S value (S2X/Y-3). The calculation means 15 is connected to a steering device 19 equipped with a feedback control mechanism.

According to the above configuration, the floor surface 1 illuminated by the floodlight 4
The reflected light from the objects to be examined such as the tape 2 and the like are detected by the light receivers 58 to 5g, respectively, and voltages in °C are outputted as output signals to the reference value detection means 1o1 and the weighted signal value detection means 11, respectively. In the reference value detection means 10, each output is added by an adder 12 to obtain the Y value. Weighting is done by signal value detection means 11
Then, the weighting is performed by multiplying the coefficients of the signals KXI to X5 of the respective light receivers 5A to 5E in the multipliers 13A to 13E, and adding these in the adder 14, thereby calculating the signal X value. Then, in the calculation means 15, the divider 16
Find the value of /Y and further subtract the coefficient 3 in the subtracter 17 to calculate the value of S.

The S value determined in this way is 6'' when the center photoreceiver 5C is located directly above the tape 2, and when the photoreceiver is offset to the right or left with respect to the tape, respectively. Becomes a negative or positive value. That is, in the above-mentioned weighting, the average coefficient is found by dividing the signal value The bias of the vessel 5C is detected. Therefore, the relative position of the vehicle 30 in the width direction with respect to the tape 2 can be immediately determined from this S value, and by controlling the steering device 19 based on this, the vehicle 3 can always be set at the center position with respect to the tape 2. be.

At this time, since the signal processing from the light receivers 58 to 5E to the steering device 19 is analog processing by hardware,
The processing time is extremely short, and since the S value can be converted to the steering device, the steering response can be performed at high speed. This prevents oscillating steering and improves the stability of one steering. Furthermore, according to this signal processing, since the same signal is used for the reference value and the signal value, normal operation can be performed even if the reflectance of the floor IJP tape 20 is different. There is no need to adjust the comparison voltage 7 according to the difference in reflectance.

〔effect〕

+11 The standard value is calculated from the output signal of the light receiver, and the weighted signal value is calculated, and both values are calculated to detect the bias of the vehicle with respect to the tape. Based on this, automatic steering is performed, so the light reception hardware processing of the output signal of the device,
Since the steering control will be performed using analog processing, the computer
It is possible to achieve higher processing speeds compared to software processing and digital processing that uses software, thereby speeding up the responsiveness of automatic steering and improving steering stability.

(2) Both the reference value and the weighted signal value are calculated from the receiver signal, so even if the reflectance of the floor or tape differs, or the yc amount of the emitter changes, There is no need to change or set the reference value (and accurate steering can be performed at all times.

Hereinafter, the invention made by the present inventor has been specifically explained based on examples, but the present invention is not limited to the above-mentioned examples, and it is understood that various changes can be made without departing from the gist of the invention. Needless to say. For example, the photoreceiver may utilize elements other than CdS (and is not limited to light-reflecting tape; it may also be possible to use a magnetic tape instead of a photoreceptor, such as passing a current through a wire or using a magnetic tape). Further, the coefficient in the multiplier for weighting may be any other value, as long as it has a correlation with the subtracted value in the arithmetic means.

However, when the coefficient of the multiplier 13C for the central light receiver 50 is set to "0", the subtraction value 18 also becomes "0", and therefore the subtracter 17 becomes unnecessary.

[Application field]

In the above explanation, we mainly explained the case where the invention made by the present inventor is applied to automatic guided vehicles in factories, which is the background field of application, but the invention is not limited to this. It can be applied to automatic driving vehicles for various purposes.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the main parts of an automatic driving vehicle, Fig. 2 is a schematic diagram of the current steering system, and Fig. 3 is a diagram of the steering section of the vehicle of the present invention. : It is a q-composition diagram. 1...floor surface, 2...tape, 3...vehicle, 4...
・Emitter, 58~5E...Receiver (receiver), 10・
...Reference value detection means, 11... Signal value detection means for weighting, 12... Adder, 13A to 13E... Multiplier,
14... Adder, 15... Arithmetic means, 16... Divider, 17... Subtractor, 9... Steering device. -11 groans-

Claims (1)

[Scope of Claims] 1. In an automatic driving vehicle that can run while automatically steering along a test object extended on the floor surface, light and magnetic fields arranged in the width direction of the vehicle a plurality of receivers for detecting a signal value, a reference value detection means for calculating a reference value from the output signals of these receivers, and a weighting method for weighting the signal value using a different coefficient for each output signal of the receiver. 1. An automatic driving vehicle, comprising: a signal value detection means; and a calculation means for calculating the output of the rain detection means to detect deviation of the vehicle in the left and right direction. 2. The automatic driving vehicle according to claim 1, wherein the receiver is a light receiver that detects light having different reflectances from the floor surface and the object to be inspected, and comprises a light receiving element such as CdS. 3. The reference value detection means has an adder that simply adds the output signals of the receiver, and the weighted signal value detection means has a plurality of multipliers that multiply the output signals of the receiver by respective coefficients, and these multipliers. 2. The automatic driving vehicle according to claim 1 or 2, wherein the calculating means includes at least a divider for calculating the ratio of the outputs of both the means. .