JP2851646B2 - Mobile monitoring system and monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to whether or not a moving object is within a predetermined distance from a reference point, particularly whether or not the moving object is within a predetermined range from the reference point. The present invention relates to a monitoring system and a monitoring device for a moving object, which senses a moving object.

(Prior Art) With respect to a moving body whose location changes each time, it is necessary to sense the position in order to perform necessary operations according to the location. For example, the following method is known as a method for detecting 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 arranged.

A signal is emitted from the reference point in space in a form of magnetism, radio waves, and light with a constant intensity, and the mobile unit receives the signal, or receives a reflected wave from the mobile unit at the reference point side. Since these signals are stronger as the moving body is closer to the reference point, if the strength of the received signal is equal to or higher than a certain strength, it is determined that the moving body is within the monitoring range with respect to the reference point.

(Problems to be Solved by the Invention) However, in such a method, it is determined whether or not the moving object is within the monitoring range based on the magnitude of the reception intensity. Due to fluctuations in the emission intensity, for example, contamination of the lens of the projector when the signal is light, fluctuations in light transmittance due to the passing medium, etc., the reception intensity changes and the monitoring range may differ from the set value. . In addition, the setting of the monitoring range is a wide space where the signal from the reference point attenuates to a certain value, and it is not easy to detect the position of the moving body with respect to the reference point.

The present invention solves such disadvantages of the prior art, avoids fluctuations in transmission intensity due to aging of the transmitter, fluctuations in power supply, and the effects of fluctuations in the medium. The purpose is to calculate the position of the position with respect to the reference point.

(Means for Solving the Problems) In order to solve the above-described problems, the present invention provides a monitoring system for a moving object that monitors the position of the moving object with respect to the monitoring device, wherein the monitoring device includes a reference signal having a predetermined directivity. And a disturbing signal generating means for generating a disturbing signal having a predetermined directivity and making it difficult to decipher the reference signal. At least a first area to which both of the interference signals generated by the signal generating means reach and a second area to which only the reference signal arrives are formed, and the mobile unit detects at least the reference signal and the interference signal generated by the monitoring device. When either of them is received, the monitoring unit detects whether the moving object is within a predetermined range by identifying the received signal.

Further, according to the present invention, a monitoring device that monitors the position of a moving object includes a reference signal generating unit that generates a reference signal having a predetermined directivity, and a decoding device that has a predetermined directivity and is difficult to decode the reference signal. Interfering signal generating means for generating an interfering signal, and only the first region and the reference signal to which both the reference signal generated from the reference signal generating means and the interfering signal generated from the interfering signal generating means reach are provided. At least a second area to be reached is formed, so that it is monitored whether the moving object is in a predetermined area.

(Operation) According to the present invention, in a system including a monitoring device and a moving body, the monitoring device generates a reference signal and an interference signal. Each of the reference signal and the interference signal has a predetermined directivity, and at least a first area that can receive both the reference signal and the interference signal and a second area that can receive only the reference signal can be formed. When the mobile is in the first area, it receives both the reference signal and the interfering signal and cannot decode the reference signal. When it is in the second area, only the reference signal is received, so that the reception of the reference signal is sensed. This allows the mobile to sense its position relative to the monitoring device.

In addition, since signal processing is performed as a digital amount, it is possible to prevent a signal from being attenuated and a monitoring range from fluctuating due to deterioration of a device and a change in a medium.

(Embodiment) Next, an embodiment of a 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 constituted by infrared LEDs. The position of the moving body 200 with respect to the monitoring device 100 is received by the receiver 20 of the infrared moving body 200 emitted from the reference signal emitter 10 and the interference signal emitters 12a and 12b, and the position of the infrared moving body 200 is sensed.

The present system is an example in which the receiver 20 is provided on the moving body 200, and a predetermined range (monitoring range) from the monitoring device is an area where only the reference signal can be received.

The reference signal emitter 10 is an infrared LED for emitting a reference signal, and converts an electric signal of the reference code sent from the reference code generation circuit 14 into blinking light and emits the light into space. In this embodiment, the interference signal emitters 12a and 12b are two infrared LEDs for emitting the interference signal, and similarly convert the electric signal of the interference code sent from the interference code generation circuit 16 into blinking light and emit the light into space. I do. The synchronization circuit 18 outputs a synchronization signal to the reference code generation circuit 14 and the interference code generation circuit 16 and synchronizes these signals.

The receiver 20 of the moving body 200 is a photodiode,
The infrared signal emitted from the monitoring device 100 is received and converted into an electric signal. The signal receiving circuit 22 shapes the waveform of the signal received by the receiver 20. The code determination circuit 24 includes a code generation unit that generates the same code as the reference code generation circuit 14, and determines whether the signal sent from the signal reception circuit 22 is equal to the reference code. If the sign determination circuit 24 determines that they are equal, it is determined that the moving object is within the monitoring range.

FIG. 2 shows an example of an area where the infrared rays emitted from the reference signal emitter 10 and the interference signal emitters 12a and 12b reach.
As shown in the figure, the reference point 1 is a reference point for determining the position of the moving object, and the reference signal emitter 10 is interfered with by the reference point 1 and the reference points 2 and 3 on the same line as the reference point 1. The signal emitters 12a and 12b are installed. These launchers 10, 12a, 12b
Has directivity as shown in FIG. In this example, the directivity of each signal emitter 10, 12a, 12b is assumed to be the same,
The figure shows a receivable plane area for each signal.

The area 301 is an area where only the reference signal can be received, and when the mobile 200 is in this area, the mobile 200 receives only the reference signal. The area 302 is an area where only the interference signal can be received, and when the mobile 200 is in this area, the mobile 200 receives only the interference signal. An area 303 is an area where a mixed signal of a reference signal and an interfering signal can be received.
When 200 is in this area, mobile 200 receives a mixed signal of a reference signal and an interfering signal. The area 304 is an area in which no signal can be received, and when the mobile 200 is in this area, the mobile 200 does not receive any signal.

In this example, an area 301 near the reference point 1 is a monitoring range, and the monitoring device 100 monitors whether the moving body 200 is in this area 301.

FIG. 3 shows a reference signal A emitted from the reference signal emitter 10 and an interference signal B emitted from the interference signal emitters 12a and 12b.
And examples of signals received in the respective areas 301 to 303. In correspondence with FIG. 2, the received signal is the same as the reference signal A in the area 301 and the same as the interference signal B in the area 302. In the area 303, a mixed signal of the reference signal A and the interference signal B is received. The pulse train of the mixed signal is different from the reference signal A and the disturbance signal B due to the operation of the synchronization circuit 18 shown in FIG.

 Next, the operation of the present system will be described.

In the monitoring apparatus 100, synchronization is achieved by the synchronization signal output from the synchronization circuit 18, and the reference signal A and the interference signal B as shown in FIG. And sent to the reference signal emitter 10 and the jammer signal emitters 12a and 12b, respectively. As a result, the reference signal is emitted from the reference signal emitter 10, and the interference signal is emitted from the interference signal emitters 12a and 12b.

The mobile unit 200 receives these signals by the receiver 20. The received signal is sent from the receiver 20 to the signal receiving circuit 22, the waveform is shaped, and then sent to the sign determination circuit 24. The sign determination circuit 24 determines whether or not the received signal is the same as the reference signal A in FIG. The moving object is area 301
, The received signal becomes the same as the reference signal A as shown in FIG. On the other hand, when the signal is in the region 302 or 303, the received signal is not the same as the reference signal A as shown in FIG.

The size of the monitoring range area 301 shown in FIG. 2 can be easily changed. For example, in FIG. 4A, when the positions of the interfering signal emitters 12a and 12b with respect to the reference signal emitter 10 are respectively shifted from P1 to P2 and from P3 to P4, the monitoring range 301 is reduced. In this case, the jamming signal emitters 12a and 12b may be moved mechanically, or may be switched by setting another jamming signal emitter.

Three or more interference signal emitters 12a and 12b may be provided. In addition, there is no need to always include a plurality. For example, as shown in FIG. 4B, a reference signal emitter 10 and one interfering signal emitter 12
The different directional characteristics a may be combined to obtain a highly sensitive monitoring range 301 in a specific direction.

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

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, for example, an ultrasonic wave may be used as the carrier.

Further, although the description has been made by changing the firing angle or the mounting angle in order to change the directivity of each signal emitter, the application of mechanically rotating the emitter is also easy.

Further, in the above-described embodiment, the description has been made assuming that the receiver is installed on the moving body. However, when the moving body has a portion having high reflection efficiency, the receiver is provided in the monitoring device, and the light is reflected from the moving body. A similar effect can be obtained by receiving infrared rays by the monitoring device.

(Effect of the Invention) According to the monitoring system and the monitoring device of the present invention, it is possible to monitor whether the moving object is within a predetermined monitoring range with respect to the monitoring device. Moreover, since the determination as to whether or not it is within the monitoring range is made by receiving the digital signal and comparing it with the reference code, it is hardly affected by aging deterioration of the device, fluctuation, medium fluctuation, etc. It is possible to know the position of the moving object with respect to the reference point without using a simple device.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a monitoring system according to the present invention. FIG. 2 is a diagram showing the directional characteristics of a reference signal emitter and an interfering signal emitter of FIG. 1 and an area where signals can be received. FIG. 4A and FIG. 4B are diagrams showing signals received by the body, and FIG. 4B and FIG. 4B are diagrams showing examples of other directivity characteristics of the reference signal emitter and the interference signal emitter. Explanation of Signs of Main Parts 10 Reference Signal Emitting Device 12 Interference Signal Emitting Device 14 Reference Code Generating Circuit 16 Interference Code Generating Circuit 18 Synchronizing Circuit 20 Receiver 22 Signal Receiving Circuit 24 …… Sign judgment circuit 100 …… Monitoring device 200 …… Moving body

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiromi Ando 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (56) References JP-A-60-252282 (JP, A) Showa 60-158171 (JP, U) Minoru Okada, “Avionics <Revised Edition”, published by Nikkan Kogyo Shimbun, January 30, 1978, p. 140 to p. 141 (58) Field surveyed (Int.Cl. ⁶ , DB name) G01S 1/00-1/68 G01S 7/00-7/42 G01S 13/00-13/95

Claims (3)

(57) [Claims] A first signal generating means for generating a first signal including a first code in a first area; and a first area in a second area partially overlapping the first area. A second signal generating means for generating a second signal different from the first signal and including a second code which makes it difficult to decode the first code; In a region where both can be received, a mixed signal of the first signal and the second signal is received, and in a region where the second signal cannot be received and the first signal can be received, the second signal is received. And a moving body that receives the signal of the first moving object, wherein a position of the moving body is recognized by decoding a code in the signal received by the moving body. 2. The system according to claim 1, wherein said first and second signals are synchronized with each other. 3. A first signal generating means having a predetermined directivity and generating a first signal having a first code, and a first signal generating means having a predetermined directivity and decoding the first code. A second signal generating means for generating a second signal having a second code that makes it difficult, a first area capable of receiving both the first signal and the second signal, and Monitoring at least a second area which cannot receive the second signal and which can receive the first signal, thereby monitoring whether or not the mobile is in a predetermined area; apparatus.