JPH0384487A - System and device for monitoring moving body - Google Patents

Abstract

PURPOSE:To monitor whether or not the moving body is within the specific range of the monitoring device by generating a reference signal and a disturbing signal. CONSTITUTION:This system consists of the monitoring device 100 and a moving device 200. In this case, the monitoring device 100 generates the reference signal and disturbing signal. The reference signal and disturbing signal have specific directivity respectively and at least a 1st area where the reference signal and disturbing signal can both be received and a 2nd area where only the reference signal can be received are formed. When the moving body 200 is in the 1st area, the reference signal and disturbing signal are both received, so the reference signal can not be decoded. When the moving body is in the 2nd area, only the reference signal is received, so the reception of the reference signal is sensed. Consequently, the moving body can senses the position about the monitoring device.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention determines whether a moving object is within a predetermined distance from a reference point, particularly whether it is within a predetermined range from the reference point. The present invention relates to a monitoring system and a monitoring device for a mobile body that senses.

(Prior Art) For a moving body whose location changes each time, it is required to sense one position in order to perform necessary operations according to the position. For example, the following method is known as a method for sensing that a moving object has entered a predetermined range (hereinafter referred to as a monitoring range) from a reference point where a monitoring device is placed.

A signal in the form of magnetism, radio waves, or light is emitted from a reference point into space with a constant intensity, and the signal is received by a moving object or the reflected wave from the moving object is received at the reference point. These signals are stronger the closer the moving object is to the reference point, so if the strength of the signal when received is above a certain level, the moving object will move relative to the reference point.
It is determined that the object is within the monitoring range.

(Problem to be Solved by the Invention) However, in this method, it is determined whether a moving object is within the monitoring range based on the magnitude of the reception strength, so Fluctuations in the emission intensity, as well as dirt on the lens of the projector when the signal is light, fluctuations in the transmittance of light due to the medium it passes through, etc. can cause the reception strength to change and the monitoring range to differ from the set value. . Furthermore, the monitoring range is set as a vast space in which the signal from the reference point is attenuated to a certain value, and it is not easy to sense the position of the moving body with respect to the reference point.

The present invention eliminates the drawbacks of the prior art, avoids fluctuations in transmission intensity due to aging of the transmitter, fluctuations in power supply, etc., and the influence of fluctuations in the medium, suppresses fluctuations in the monitoring range, and suppresses fluctuations in the monitoring range. The purpose is to calculate the position relative to the reference point.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a mobile object monitoring system that monitors the position of a mobile object with respect to a monitoring device, in which the monitoring device receives a reference signal having a predetermined directivity. and a reference signal generating means for generating.

and a disturbance signal generating means for generating a disturbance signal having a predetermined directivity and making it difficult to decipher the reference signal, the reference signal generated by the reference signal generation means and the disturbance signal generated by the disturbance signal generation means. and a second region where only the reference signal reaches are formed, and the mobile object receives at least one of the reference signal and the interference signal generated from the monitoring device. By identifying the detected signal, it is sensed whether the mobile object is within a predetermined range with respect to the monitoring device.

Further, according to the present invention, a monitoring device for monitoring the position of a moving object includes a reference signal generating means for generating a reference signal having a predetermined directivity, and a reference signal generating means for generating a reference signal having a predetermined directivity. a first area where both the reference signal generated from the reference signal generation means and the interference signal generated from the interference signal generation means reach, and a first area where only the reference signal reaches. At least a second region is formed to reach the predetermined region, thereby monitoring whether the mobile object is in the predetermined region.

(Function) According to the present invention, in a system composed of a monitoring device and a moving object, the monitoring device generates a reference signal and a disturbance signal. The reference signal and the interference signal each have predetermined directivity, and at least a first region where both the reference signal and the interference signal can be received and a second region where only the reference signal can be received can be formed. When the moving object is in the first area, it receives both the reference signal and the interference signal, so it cannot decipher the reference signal; when it is in the second area, it receives only the reference signal, so it cannot decipher the reference signal. Sense reception. This allows the mobile object to sense its position relative to the monitoring device.

Furthermore, since the signal is processed as a digital quantity, it is possible to avoid attenuation of the signal and fluctuation of the monitoring range due to deterioration of the device or changes in the medium.

(Example) Next, an example of the monitoring system according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of a monitoring system according to the present invention. The monitoring device 100 is provided with a reference signal emitter 10 and interference signal emitters 12a and 12b, each of which is composed of an infrared LED. Infrared rays emitted from these reference signal emitters IO and interference signal emitters 12a and 12b are transmitted to the mobile object 20.
0 receiver 20 senses the position of the mobile object 200 relative to the monitoring device ioo.

This system is an example in which a receiver 20 is provided in a moving object 200, and a predetermined range (monitoring range) from the monitoring device is set as an area where only the reference signal can be received.

The reference signal emitter lO is an infrared LED for emitting reference signals.
The electric signal of the reference code sent from the reference code generation circuit 14 is converted into blinking light and emitted into space. In this embodiment, the interference signal emitters 12a and 12b are two infrared LEDs for emitting interference signals, and the interference code generation circuit 1
Similarly, the electric signal of the interference code sent from 6 is converted into flashing lights and emitted into space.

The synchronization circuit 18 outputs a synchronization signal to the reference code generation circuit 14 and the interference code generation circuit 16 to synchronize these signals.

The receiver 20 of the mobile object 200 is a photodiode, and receives the infrared signal emitted from the monitoring device 100.
Convert to electrical signal. The signal receiving circuit 22 includes a receiver 20
The received signal is waveform-shaped. Sign determination circuit 2
4 includes a code generating section that generates the same code as the reference code generating circuit 14, and determines whether the signal sent from the signal receiving circuit 22 is equal to the reference code. Sign determination circuit 24
If it is determined that they are equal, it is determined that the moving object is within the monitoring range.

Reference signal emitter 10 and interference signal emitters 12a, 12
Figure 2 shows an example of the area that the infrared rays emitted from b reach. vessel l
Interfering signal emitters 12a and 12b are installed at reference points 2.3 on the same line as reference point 1, respectively. These emitters l0112a and 12b have directivity as shown in the figure. In this example, each signal emitter 1O11
The area 301 is an area where only the reference signal can be received, and when the moving object 200 is in this area, the moving object 200 receives the reference signal. Receive only signals. Area 302 is an area where only interference signals can be received, and when mobile body 200 is in this area, mobile body 200 receives only interference signals. Area 3
03 is an area where a mixed signal of a reference signal and an interference signal can be received, and when the mobile object 200 is in this area, the mobile object 200 receives a mixed signal of a reference signal and an interference signal. The area 304 is an area where no signal can be received, and when the mobile object 200 is in this area, the mobile object 200
does not receive any signals.

In this example, a region 301 near the reference point l is the monitoring range, and the monitoring device 100 monitors whether the moving object 200 is in this region 301 or not.

FIG. 3 shows an example of the reference signal A emitted from the reference signal emitter IO, the interfering signal B emitted from the interfering signal emitters 12a and 12b, and the signals received in each region 301 to 303. Corresponding to the diagram, the received signal is the same as the reference signal A in the region 301 and the same as the interference signal B in the region 302. Further, in the area 303, a mixed signal of the reference signal A and the interference signal B is received. Note that the pulse train of the mixed signal becomes a pulse train different from both the reference signal A and the interference signal B due to the action of the synchronization circuit 18 shown in FIG.

Next, the operation of the one-piece system will be explained.

In the monitoring device 100, synchronization is achieved by the synchronization signal output from the synchronization circuit 18, and the reference signal A and interference signal B as shown in FIG.
15 and the interference code generation circuit 16, and the reference signal emitter lO and the interference signal emitters 12a and 1, respectively.
Sent to 2b. As a result, a reference signal is emitted from the reference signal emitter 10, and an interfering signal is emitted from the interfering signal emitting devices 12a and 12b.

Mobile object 200 receives these signals through receiver 20 . The received signal is sent from the receiver 20 to the signal receiving circuit 22, subjected to waveform shaping, and then sent to the sign determination circuit 24. The sign determination circuit 24 determines whether the received signal is the same as the reference signal A shown in FIG. When the moving object is in the area 301, the received signal is the same as the reference signal A as shown in FIG. 3, so it is determined that the moving object is within the monitoring range. In contrast, area 302 or 30
3, the received signal is not the same as the reference signal A as shown in FIG. 3, so it is determined that it is outside the monitoring range.

The size of the monitoring range area 301 shown in FIG. 2 can be easily changed. For example, in FIG. 4A, the interference signal emitters 12a, 1 with respect to the reference signal emitter lO
When the position of 2b is moved from pt to P2 and from P3 to P4, the monitoring range 301 is reduced. In this case, even if the jamming signal emitters 12a and 12b are moved mechanically,
Other jamming signal emitters may be set and switched.

Three or more interference signal emitters 12a, 12b may be provided. Furthermore, it is not always necessary to use a plurality of directional characteristics. For example, as shown in FIG. The monitoring range 301 may also be obtained.

Note that the monitoring range is not limited to the area near the reference point as shown in FIG. 2, but can be set to a predetermined area.

In the above embodiment, the reference signal and the interference signal are emitted by infrared rays, but a medium having directivity other than infrared rays, such as ultrasonic waves, may be used as the carrier wave.

Furthermore, in order to change the directivity of each signal emitter, although the emitting angle is changed or the mounting angle is changed, it is also possible to mechanically rotate the emitter.

In addition, in the above embodiment, the receiver is installed on the moving body, but if the moving body has a part with high reflection efficiency, the monitoring device is equipped with a receiver and the receiver is installed on the moving body. A similar effect can be achieved by the monitoring device receiving infrared radiation.

(Effects of the Invention) According to the monitoring system and monitoring device of the present invention, it is possible to monitor whether a moving object is within a predetermined monitoring range with respect to the monitoring device. Moreover, since the judgment as to whether or not it is within the monitoring range is made by receiving the digital signal and comparing it with the standard code, it is less susceptible to the effects of equipment aging, fluctuations, medium fluctuations, etc. The position of the moving object relative to the reference point can be known without using any special equipment.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a monitoring system according to the present invention, and FIG. 2 is a diagram showing the directivity characteristics and signal receivable areas of the reference signal emitter and interference signal emitter of FIG. 1. FIG. 3 is a diagram showing a signal received by a moving body, and FIGS. 4A and 4B are diagrams showing other examples of directional characteristics of a reference signal emitter and an interfering signal emitter. main . Description of 1 Reference signal emitter Interfering signal emitter Reference code generating circuit Interfering code generating circuit Synchronous circuit Receiver Signal receiving circuit Sign determining circuit Monitoring device Mobile object

Claims (1)

[Claims] 1. A movable object monitoring system that monitors the position of a movable object with respect to a monitoring device, wherein the monitoring device includes a reference signal generating means that generates a reference signal having a predetermined directivity; and a disturbance signal generating means for generating a disturbance signal which makes it difficult to decipher the reference signal, and the reference signal generated by the reference signal generating means and the disturbance signal generated by the disturbance signal generating means. At least a first area where both reach and a second area where only the reference signal reaches is formed, and the mobile object receives at least one of the reference signal and the interference signal generated from the monitoring device. A monitoring system for a mobile object, characterized in that it detects whether or not the mobile object is within a predetermined range with respect to the monitoring device by identifying received signals. 2. In the system according to claim 1, when a second area where only the reference signal reaches is within a predetermined range from the monitoring device, and the mobile body receives only the reference signal, the monitoring device A mobile monitoring system characterized by sensing that the device is within a predetermined range. 3. A monitoring device for monitoring the position of a moving object, which includes a reference signal generating means for generating a reference signal having a predetermined directivity, and an interference device having a predetermined directivity that makes it difficult to decipher the reference signal. a first area where both the reference signal generated from the reference signal generation means and the interference signal generated from the interference signal generation means reach, and only the reference signal; What is claimed is: 1. A monitoring device for a movable body, characterized in that the movable body monitors whether or not the movable body is in a predetermined region by forming at least a second region where the movable body reaches.