JPH09149475A - Monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the labor of a monitoring person and the operation cost of a system and to accurately grasp an abnormal situation by reproducing monitor information before and after the generation of the abnormal situation in an area to be monitored only at the time of necessity on a monitoring station side. SOLUTION: This system is provided with a station to be monitored 10 transmitting monitor information such as picture data of the area to be monitored and a monitoring station 20 receiving, recording and reproducing monitor information and in addition transfers monitor information and a control signal between the monitoring station 20 and the station to be monitored 10 by radio communication. The station to be monitored 10 generates an abnormality detection signal from a trigger signal based on the abnormal situation generated in the area to be monitored and transmits it to the monitoring station 20. When receiving the abnormality detection signal, the monitoring station 20 reads picture data, etc., in a period before and after the generation of the abnormal situation from a RAM disk 25 and reproduces it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring system for monitoring an area to be monitored by transmitting an image or voice of the area to be monitored to a remote monitoring station by wireless communication.

[0002]

2. Description of the Related Art In general homes, offices, shops, various exhibition halls, outdoors, etc., an image monitoring apparatus is used to remotely monitor the occurrence of intruders, fires, accidents and the like. This type of image monitoring device mainly adopts a real-time monitoring method in which an image of an area to be monitored is captured by a camera and sent to a monitoring station of a security company or the like by a wired or wireless method, and a supervisor of the monitoring station constantly monitors the image. ing.

[0003]

Fortunately, however, if no abnormal situation occurs in the monitored area,
The constant monitoring at the monitoring station is wasted, and much of the labor and system operation costs during that period are wasted. Further, when an abnormal situation occurs, it is desired that the monitoring station can properly understand the situation before and after the abnormal situation.

The present invention has been made in order to solve the above-mentioned problems. The monitoring station side reproduces the monitoring information before and after the occurrence of an abnormal situation in the monitored area only when necessary, so that the labor of the monitoring staff and the operation of the system can be improved. It is intended to provide a monitoring system that can reduce costs and accurately grasp an abnormal situation.

[0005]

In order to solve the above-mentioned problems, the invention according to claim 1 is a monitored station which transmits monitoring information obtained from the monitored area by the monitoring means, and receives and records the monitoring information. In a monitoring system that includes a monitoring station that reproduces and reproduces monitoring information and control signals between the monitoring station and the monitored station by wireless communication, the monitored station is within the monitored area. The abnormality detection signal as a control signal is generated from the trigger signal based on the abnormal situation that has occurred and transmitted to the monitoring station, and when the monitoring station receives the abnormality detection signal, the monitoring station The monitoring information is reproduced.

The invention according to claim 2 is the monitoring system according to claim 1, wherein the monitored station is provided with recording means for recording the monitoring information for a period before and after the occurrence of the abnormal situation, and the monitoring station is When the abnormality detection signal is received, the monitoring information of the period before and after the occurrence of the abnormality is transmitted from the monitored station to record and reproduce.

Further, the invention according to claim 3 is the monitoring system according to claim 1 or 2, wherein the transmission and reception of the monitoring information and the control signal between the monitoring station and the monitored station is performed by a wireless communication by a spread spectrum communication system. It will be done in.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic block diagram showing the overall configuration of this embodiment, which is mainly intended for image monitoring of a monitored area. In the figure, 10 is a monitored station installed in a monitored area such as a general home, office, store, or outdoors. The monitored station 10 includes a monitoring device main body 11 on which various circuit boards described later are mounted. , A camera 12 as a monitoring means for imaging the monitored area, a microphone 13 as a trigger signal generating sensor, and S
And an antenna 14 for S wireless communication.

The monitoring device main body 11 is an image processing board 1 for performing compression processing of image data captured by the camera 12.
5, and a CPU board 16 for controlling the operation of the entire apparatus,
SS communication board 17 that performs modulation and demodulation for SS communication
A digital input board 18 for converting the output signal of the microphone 13 into an abnormality detection signal which is a digital signal and outputting the signal; and a RAM disk 19 for recording image data as necessary as described later.

Reference numeral 20 is a monitoring station installed in a security company or the like, and this monitoring station 20 is an image processing board 22 or C.
A monitoring device body 21 including a PU board 23, an SS communication board 24, and a RAM disk 25, and an image processing board 22.
The CRT 26 connected to the CPU board 23, the numeric keypad 27 connected to the CPU board 23, and the antenna 28 for SS wireless communication. Here, each of the constituent elements 22 to 25 in the monitoring device main body 21 has substantially the same function as the corresponding one on the monitored station 10 side.

Next, the operation of this embodiment will be described. First, in the above configuration, in the monitored station 10, the camera 12 images the monitored area, and the CPU board 16 and the image processing board 15 add a time stamp to the image data. The image data as the monitoring information is monitored by the monitoring station 20.
It is transmitted to the monitoring station 20 side in accordance with control signals such as a transmission start signal and a transmission end signal sent from. The image data and the control signal are transmitted by SS wireless communication via the SS communication boards 17 and 24 and the antennas 14 and 28.

In addition, in the monitored area, the microphone 1
When a sound above a certain level is detected by 3, the abnormality detection signal is sent to the SS communication board 17 via the digital input board 18, and is transmitted to the monitoring station 20 side by SS wireless communication.

The monitoring station 20 receives the image data transmitted from the monitored station 10, performs SS demodulation, expansion, etc. processing by the SS communication board 24 and the image processing board 22 and displays it on the CRT 26. It stores in 25 at any time. Here, the maximum recording time on the RAM disk 25 is set to, for example, 10 minutes, and it is controlled to repeatedly overwrite. The maximum recording time can be set arbitrarily.

When an abnormal situation occurs on the monitored station 10 side and a sound above a certain level is detected by the microphone 13, the sound is used as a trigger signal to monitor an abnormality detection signal which is a kind of control signal. It is transmitted to the station 20 side. In the monitoring station 20, the CPU board 23 causes a buzzer (not shown) to ring to notify the occurrence of an abnormal situation.

At this time, the monitor station 20 records the received image data on the RAM disk 25 at any time. However, when the abnormality detection signal is received, at the time of the reception (if the transmission delay is neglected, Image data from 1 minute before to 9 minutes after (when an abnormal situation occurs) is recorded in the RAM disk 25. Note that the recording time after reception is set within the range of the maximum recording time, but the recording may be stopped at any timing by the key operation from the ten-key pad 27.

Thus, when 9 minutes have elapsed after the reception of the abnormality detection signal or when the recording of the image data is stopped by the key operation, the monitoring station 20 sends a control signal to the monitored station 10 to transmit the image data. To stop. While recording the image data when the abnormality detection signal is received, the CRT2
A message to that effect is displayed on 6. At the end of recording the image data, the image at the time of receiving the abnormality detection signal, that is, the image of the monitored area at the moment when the abnormal situation occurs is displayed, and the time is also displayed.

Next, in the monitoring station 20, the numeric keypad 2
The image in the RAM disk 25 is reproduced by the key operation of 7. As shown in FIG. 2 (a), the image to be reproduced is based on the time when the abnormality detection signal is received (when an abnormal situation occurs).
It is an image of a total of 10 minutes from minutes before to 9 minutes later. In addition,
When the abnormality detection signal is not received, the image for 10 minutes from the present time to 10 minutes before is reproduced as shown in FIG.

As the image reproducing function in the monitor station 20, it is desirable to provide a temporary stop function in addition to the continuous reproducing function for the predetermined time. Further, when the monitoring station 20 is playing an image, the imaging on the monitored station 10 side is suspended, and a key operation from the monitoring station 20 sends a control signal to the monitored station 10 side to restart the imaging. good.

In this embodiment, if the input image size on the monitored station 10 side, the display image size on the monitored station 20 and the image data compression rate can be changed in a plurality of steps, respectively, the resolution can be changed appropriately. Therefore, it is possible to obtain an easy-to-see monitoring image according to the situation of the monitored area.
It should be noted that the image has a frame rate of one screen per second and the monitored station 1
Transmission from 0 to the monitoring station 20 is planned, but transmission may be performed at a higher frame rate if the transmission speed can be further increased.

For example, an image taken by the camera 12 is sent to the monitored station 10 at a frame rate of about 30 screens per second.
The RAM disk 19 having a recordable capacity for a minute is provided, and the RAM disk 25 on the monitoring station 20 side is also provided with the same capacity. Then, the monitored station 10 records the captured image while overwriting it on the RAM disk 19 at any time.

Now, an abnormal situation occurs in the monitored station 10,
When the monitoring station 20 receives the abnormality detection signal, the monitoring station 20 sends a control signal to the monitored station 10 and displays images for a total of 10 minutes from 1 minute before to 9 minutes after the reception of the abnormality detection signal. The data is read from the RAM disk 19, transmitted, and recorded in the RAM disk 25 in the monitoring station 20. If the monitoring station 20 reproduces the monitoring image recorded in the RAM disk 25 at an arbitrary timing, the situation of the monitored area before and after the occurrence of the abnormal situation can be grasped in detail and accurately, and the cause of various accidents can be identified. This makes it easier to investigate, understand changes in the situation at the site, and identify criminals.

Next, FIG. 3A shows the structure of the main parts of the SS communication boards 17 and 24 of the monitored station 10 and the monitored station 20, where 171 and 241 are SS modulation / demodulation sections and 172 and 172, respectively.
242 is a PN code (reference signal or pseudo signal) generator,
Reference numeral 243 is a filter including a bandpass filter or the like. Hereinafter, the principle of SS wireless communication according to this embodiment will be briefly described with reference to FIGS.

First, the image data picked up by the camera 12 is Fourier transformed (SS modulated) by the SS modulator / demodulator 171 in the SS communication board 17 using the PN code from the PN code generator 172. In FIG. 3B, the original image data is the SS modulated signal after the Fourier transform. Note that, here, the signal waveforms of image data and the like are shown as analog waveforms for convenience. The SS-modulated signal thus spread over a wide band in this manner is transmitted via the antenna 14 to the SS communication board 24 in the monitoring station 20.
Sent to.

In the monitor station 20, it is assumed that the received signal contains noise from peripheral equipment and an interference wave due to multipath fading, as shown in the figure. This received signal is input to the SS modulator / demodulator 241 and subjected to inverse Fourier transform (correlation processing) using the PN code from the PN code generator 242 that is the same as and synchronized with the transmitter side, and becomes an SS demodulated signal as shown in the figure .

At this time, since the noise and the interference wave are not subjected to the SS modulation, the band width is diffused by the SS demodulation processing from to, and the noise and the power density are converted into the noise. On the other hand, although the power density of the image data itself is small, it has a large level in a narrow band. Therefore, by passing this SS demodulated signal through the filter 243, it is possible to take out only the transmitted image data as shown in. The above-described operation is performed by the monitoring station 2 and the abnormality detection signal sent from the monitored station 10 to the monitoring station 20.
The same applies to the transmission start signal, the transmission end signal, etc. sent from 0 to the monitored station 10.

According to the SS wireless communication system described above, the influence of multipath fading can be eliminated on the receiving side, and the power density of the transmission signal is small, so that it can be applied to various electronic and electric devices existing in the vicinity. On the other hand, there is no inconvenience such as noise source or crosstalk.
In addition, according to the specification of the SS wireless communication in this embodiment,
The direct spread method is adopted as the modulation method, and the antenna power is set to 10 mW / M or less using the frequency band of 2.4 GHz.

In the above-described embodiment, the occurrence of an abnormal situation in the monitored station 10 is recognized from the detection sound from the microphone 13 and an abnormality detection signal is sent to the monitoring station 20.
The occurrence of an abnormal situation may be recognized by detecting any trigger signal other than the sound generated thereby. That is,
An optical sensor, smoke sensor, gas sensor, magnetic sensor, infrared sensor, ultrasonic sensor, voltage / current sensor, mechanical switch, etc. are installed in the monitored station 10 and abnormal signals are output from these various sensors (that is, trigger signals). The occurrence of a situation may be detected and the abnormality detection signal may be generated.

By changing the transmission frequency band of SS wireless communication, it is possible to easily construct a system for monitoring a plurality of monitored stations by a single monitoring station. Further, a wireless communication system other than the SS wireless communication may be used for transmitting the monitoring information and the control signal.

In the above embodiment, the monitoring station 20 has a function of detecting the occurrence of an abnormal situation by detecting a temporal change of the image data sent from the monitored station 10 by comparing the images image by image. Is also good. Furthermore, although the case where image data is transmitted as the monitoring information has been described here, the present invention is directed to a case where the monitored station 10 collects and transmits audio data as the monitoring information and the monitoring station 20 records and reproduces the voice data. Of course, it is applicable.

[0030]

As described above, according to the present invention, since the monitoring station can record and reproduce the monitoring information before and after the occurrence of the abnormal condition, the burden on the monitor is reduced as compared with the case of constant monitoring, and the labor is reduced. It is possible to understand the contents and situation of the abnormal situation in detail and accurately, and it becomes easier to investigate the cause of various accidents, to grasp the situation change of the site, and to identify the criminal. Further, by overwriting control so that only the monitoring information for a certain period is recorded in the monitoring station and the monitored station, the capacity of the recording device can be small and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram of image data reproduced by a monitoring station in the embodiment.

FIG. 3 is an explanatory diagram of an SS wireless communication system in the embodiment.

[Explanation of symbols]

 10 Monitored Station 11, 21 Monitoring Device Main Body 12 Camera 13 Microphone 14, 28 Antenna 15, 22 Image Processing Board 16, 23 CPU Board 17, 24 SS Communication Board 18 Digital Input Board 19, 25 RAM Disk 20 Monitoring Station 26 CRT 27 Numeric keypad 171,241 SS modulator / demodulator 172,242 PN code generator 243 Filter

Claims (3)

[Claims] 1. A monitored station for transmitting monitoring information obtained from a monitored area by a monitoring means, and receiving and recording the monitoring information,
In a monitoring system that includes a monitoring station that plays back and that sends and receives monitoring information and control signals between the monitoring station and the monitored station by wireless communication, the monitored station is located within the monitored area. An abnormality detection signal as a control signal is generated from a trigger signal based on the abnormal situation that has occurred and transmitted to the monitoring station. When the monitoring station receives the abnormality detection signal, the monitoring station monitors the period before and after the occurrence of the abnormal situation. A surveillance system characterized by reproducing information. 2. The monitoring system according to claim 1, wherein the monitored station includes recording means for recording monitoring information of a period before and after occurrence of an abnormal situation, and the monitoring station receives the abnormality detection signal. In addition, the monitoring system is characterized in that the monitored information is transmitted, recorded, and reproduced from the monitored station during the period before and after the occurrence of the abnormal situation. 3. The monitoring system according to claim 1, wherein the monitoring information and the control signal are transmitted and received between the monitoring station and the monitored station by wireless communication using a spread spectrum communication method. Monitoring system.