JPH0343805A - Guide material detecting device for self-traveling carrier - Google Patents

Abstract

PURPOSE:To attain the stable detection of a guide material for a self-traveling carrier regardless of the change of photodetecting value and the change of sensitivity of a sensor by discriminating the guide material based on the difference between the detection value of the guide material and that of the floor surface. CONSTITUTION:Plural sensors are prepared so that the detection value of a floor surface 3 is always obtained, and the reading level of a guide material 4 is automatically set in accordance with the detection value of the surface 3. That is, the detection value of the guide material 4 is evaluated by the reading level set automatically in response to the detection value of the surface 3 not by a reading level set previously. Then the guide material 4 is discriminated based on the difference between the detection value of the guide material 4 and that of the surface 3. Thus the guide material 4 is stably detected regardless of the change of the photodetecting value and the change of sensitivity of the sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a self-propelled guided vehicle that detects a guided vehicle running zero along a traveling line or marker point formed by a guided body provided on a floor surface. This invention relates to a derivative detection device.

Conventional technology A guide detection device for an optically guided self-propelled vehicle irradiates light onto a traveling floor surface that has a guide, receives reflected light from the floor surface with a light receiving element, and detects it using an electrical signal from the light receiving element. However, the transport vehicle can run unmanned.

The principle at this time is that, as shown in Figure 4 (al, (bl), there is a difference between the electrical signal value of the reflected light from the running floor surface and the electrical signal value of the reflected light from the highly reflective dielectric. There is a difference.

By setting a threshold value between these differences, it is possible to determine whether the light is reflected from the floor or from the guide, allowing the guided vehicle to travel unmanned.

Problems to be Solved by the Invention Conventionally, the above-mentioned threshold value has been fixedly set using a configuration as shown in FIG. As a result, the following problems occurred.

■ If a tilt occurs between the floor surface and the light-receiving element, the amount of reflected light will decrease, and the detection of the dielectric may become impossible.

■ Detection becomes impossible when the sensitivity of the light emitting part and the light receiving part undergoes physical changes such as changes in temperature or aging.

- The reflectance of the conductor itself decreases due to dirt, etc., and it is necessary to replace the conductor.

SUMMARY OF THE INVENTION An object of the present invention is to provide a guide detection device for a self-propelled guided vehicle that can detect a guide without being influenced by the guide, the floor environment, the characteristics of the guided vehicle itself, and the like.

Means for Solving the Problems In order to achieve the above object, the present invention arranges a plurality of detection sensors so that detection values of the floor surface can be obtained at all times,
The present invention is characterized in that the reading level of the derivative is automatically set according to this detected value.

The detected value of the derivative and the detected value of the floor are evaluated by evaluating the detected value of the derivative not by the preset readable level value but by the readable level value that is automatically set according to the detected value of the floor surface. Since the derivative can be determined using the difference between

Embodiment FIG. 1 is an explanatory diagram of an electric circuit of an inductor detection device for a self-propelled guided vehicle in an embodiment of the present invention.

The operating principle is that the electrical signal modulated by the oscillation circuit 1
2, the floor surface 3 (see FIGS. 2 and 3) is irradiated as an optical signal. The irradiated optical signal is reflected by the floor surface 3 or the dielectric 4, and the light receiving element (photo diode) 5
and is extracted as an electrical signal. These LED2
The light-receiving element 5 constitutes a dielectric detection section 9 . By amplifying and rectifying this electrical signal, a floor detection comparison signal (a) can be obtained. At the same time, this floor detection comparison signal fat is input to the floor level detection circuit 6, which passes through a minimum value selection circuit 7, extracts the minimum value, and compares the value obtained by multiplying that value by a certain constant. threshold signal (b
It is set as l. By comparing and detecting this comparison threshold signal tb+ and the aforementioned floor detection comparison signal (al) in the comparator circuit 8, it is determined whether the floor 3 or the dielectric 4 is present.

FIG. 3 shows an example of the arrangement of the above-mentioned dielectric detection section 9 with respect to the dielectric 4. In FIG. During normal running, the right line detection section 9a and the left line detection section 9a detect the running guide 4a, and unmanned guided running is performed. Next, the numerical control signals necessary for this unmanned guided travel are detected by the right marker detection section 9b and the left marker detection section 9b on the marker guides 4b attached to the left and right sides of the travel guide 4a, and the vehicle travels. Such a detection section 9a
.

If there is a pair of 9b for each of the derivatives 4a and 4b, one of the detection parts 9a and 9b corresponds to the derivative 4a.

If it deviates from 4b, it is possible to extract it as the above-mentioned minimum comparison threshold signal, but if all the detection parts 9a and 9b are on the dielectrics 4a and 4b, there will be no comparison value. You will not be able to drive.

Therefore, by providing a dummy detection section 9c separate from the left and right running guide detection sections 9a and the marker guide detection section 9b, it becomes possible to always extract the comparison threshold signal from one of the points. . Next, the positional relationship of these derivative detection parts 9a to 9C is shown in FIG. It is installed at a position outside of the dielectrics 4a and 4b.Thereby, the dielectric detection device can select the optimum comparison threshold value for any relationship between the floor surface 3 and the dielectrics 4.

In this example, if the reflectance of the floor surface 3 is very low, if the amount of light reflected from the floor surface 3 is simply multiplied by a constant and set as the threshold value, a slight difference in light amount will cause the difference between the light amount and the dielectric 4. In order to prevent judgment, a limit is placed so that the threshold value does not fall below a certain value.

By using the above-mentioned derivative detection device, the floor surface 3
An optically guided self-propelled vehicle that can run without being affected by the inclination between the guide 4 and the guide detecting section 9, changes in the physical characteristics of the guide detecting section 9, and malfunctions due to deterioration of the guide. It can be a transport vehicle.

Effects of the Invention According to the present invention, it is possible to identify the derivative by using the difference between the detected value of the derivative and the detected value of the floor surface, so regardless of changes in the amount of received light or changes in the sensitivity of the detection sensor Derivatives can be detected stably.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a guide body detection device for a self-propelled guided vehicle according to an embodiment of the present invention, FIG.
is a layout diagram of the dummy detection unit in the same device, and Figure 4 (al.
4 is an explanatory diagram of the reading level in the conventional example, and FIG. 5 is a circuit diagram in the conventional example. 3...Floor surface, 4a... ...driving derivative,
4b... Marker dielectric, 6... Floor level detection circuit, 7... Minimum value selection circuit, 8...
... Comparison circuit, 9a ... Line detection section,
9b... Marker detection section, 9c... Dummy detection section.

Claims (1)

[Claims] A plurality of detection sensors for detecting the derivative and the floor surface are arranged so that the detection value of the floor surface can be obtained at all times by one of these detection sensors, and the reading level of the derivative is automatically adjusted according to the detected value. A guide body detection device for a self-propelled guided vehicle, characterized in that the device is configured to set.