JP2007188436A - Theft alarm unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a theft alarm unit capable of issuing a highly precise alarm. <P>SOLUTION: A frequency-modulated transmission wave is transmitted to receive a reflected wave reflected by a detected object 4, a distance up to the detected object 4 and a size thereof are detected based on the transmission wave and the reflected wave, and the distance up to the detected object 4 and the size thereof are stored in a memory 16. The alarm is issued from a speaker 18, when the detected object 4 excepting the detected object 4 having the distance and the size same to those of the detected object 4 stored therein is detected within a warning area, after stored. The warning area comprises the first warning area, and the second warning area including the first warning area and wider than the first warning area, the alarm is issued when the detected object 4 is detected within the first warning area, and a preliminary alarm is issued when the detected object 4 is detected within the second warning area until a preset time lapses. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a theft alarm device that issues an alarm when a detected object enters a warning area.

Conventionally, as a device that issues a warning when a detected object enters a warning area, as disclosed in Patent Document 1, a detection sensor detects a detected object in a warning area and issues a warning. Are known. Further, in this apparatus, the output increases as the distance between the detection sensor and the detected object becomes shorter, so the type of alarm is changed according to the output level.
JP 2003-89346 A

  In such a conventional device, an infrared sensor or a Doppler sensor is used as the detection sensor, and an alarm can be issued by detecting the intrusion of the detected object into the alert area or the movement of the detected object in the alert area. . However, there is a problem in that even if the vehicle passes only a part of the warning area, an alarm is issued and it is difficult to issue a highly accurate alarm.

  An object of the present invention is to provide a theft alarm device capable of issuing a more accurate alarm.

In order to achieve this problem, the present invention has taken the following measures in order to solve the problem. That is,
Detecting means for transmitting a frequency-modulated transmission wave, receiving a reflected wave reflected by the detected object, and detecting at least a distance from the transmitted wave and the reflected wave to the detected object; and In the theft alarm device comprising alarm means for issuing an alarm when the detected object to be detected is in the alert area,
The detection means can detect the distances of the plurality of detected objects,
In addition, it comprises ambient information storage means for storing the distance to the detected object detected by the detection means,
And when the alarm means is detected by the detection means within the alert area, the detected object excluding the detected object that is the same as the distance of the detected object stored in the surrounding information storage means, This is a burglar alarm device characterized by issuing the alarm.

  The detection means can further detect the size of the detected object, and the ambient information storage means stores the distance to the detected object detected by the detection means and the size of the detected object. And when the detected object except the detected object having the same distance and size of the detected object stored in the surrounding information storage means is detected by the detecting means within the warning area. In addition, the alarm may be issued. The alarm means includes a first alarm means for issuing an alarm when the detected object is detected in the first warning area by the detection means; and the detected object is detected by the detection means. It may be configured to include a second alarm unit that issues a preliminary alarm when it is detected until a preset time elapses in a second alert area that includes the area and is wider than the first alert area.

  The burglar alarm device of the present invention stores a distance to the detected object as a detected object in advance, such as a fixed object around it, detects the distance to the detected object, and stores the detected detected object. Since the alarm is issued when the object to be detected is in the alert area, it is possible to distinguish between the object to be detected in the vicinity and the object to be detected that has entered, and the distance to the object to be detected is detected. Since the determination is made, there is an effect that a highly accurate alarm can be issued. Further, even when the surrounding environment is different, it can be distinguished from the intruding detected object by storing it as the detected object, and the accuracy can be improved. Furthermore, detection accuracy can be further increased by detecting the size of the detected object.

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
As shown in FIG. 1, reference numeral 1 denotes an antenna that transmits and receives radio waves, and an FM transmitter 2 is connected to the antenna 1. The FM transmitter 2 is a transmitter whose frequency changes linearly at a constant period, and transmits a frequency-modulated transmission wave from the antenna 1. In the present embodiment, as indicated by a solid line in FIG. 6A, the transmission wave from the FM transmitter 2 is a triangular wave modulation wave having a period Tm (= 1 / fm) and a frequency deviation width Δf.

  The transmission wave radiated from the antenna 1 is reflected by the detection object 4, and the reflected wave is input to the mixer 6 via the antenna 1. A part of the transmission wave from the FM transmitter 2 is input to the mixer 6, and the mixer 6 extracts the frequency difference between the transmission wave and the reflected wave and outputs it to the beat signal amplifier 8.

  The beat signal amplifier 8 amplifies the beat signal output from the mixer 6 and outputs it to the low-pass filter 10. The low-pass filter 10 attenuates the high frequency component of the beat signal and outputs the attenuated high frequency component to the A / D converter 12, thereby limiting the maximum detection distance. This maximum detection distance is set to a distance equivalent to a second warning area described later or a distance corresponding to a wider area. In this embodiment, the antenna 1, the FM transmitter 2, the mixer 6, the beat signal amplifier 8, and the low-pass filter 10 constitute a known FM-CW radar.

  As shown by a broken line in FIG. 6A, when there is no relative velocity between the detected object 4 and the detected object 4, the waveform indicating the change of the reflected wave is the waveform of the transmitted wave in the right direction of the horizontal axis. The distance R can be calculated by calculating the difference in frequency between the transmitted wave and the reflected wave.

  From the mixer 6, a beat signal fb having a frequency deviation width of Δf / C · fm · R is obtained. Here, Δf is the frequency deviation width of the triangular wave, and fm is the modulation frequency. Further, when the relative speed with respect to the detected object 4 is not 0, that is, when the detected object 4 is moving, the frequency of the transmission wave changes in proportion to the relative speed at the time of reception due to the Doppler effect. As shown in FIG. 6C, the waveform of the reflected wave is a waveform obtained by translating the waveform of the transmission wave to the right in the horizontal axis and in the vertical axis.

  Therefore, when the frequency difference between the transmitted wave and the reflected wave is obtained, a beat signal fb in which the frequencies fb1 and fb2 appear alternately as shown in FIG. 6D is obtained. Then, the distance R and the relative speed V to the detected object 4 can be calculated from the beat signal fb thus obtained by using the proportional constants K1 and K2 as follows.

R = K1 · (fb1 + fb2) / 2
V = K2 · (fb1−fb2) / 2
The A / D converter 12 converts the analog signal from the low-pass filter 10 into a digital signal and outputs it to the CPU 14. The CPU 14 processes the digital signal from the A / D converter 12 according to a preset program and stores it in the memory 16 or issues an alarm from the speaker 18.

Next, the operation of the burglar alarm device of this embodiment will be described with reference to FIG. 2 together with the surrounding information storage process executed by the CPU 14.
First, a frequency-modulated transmission wave from the FM transmitter 2 is radiated from the antenna 1. The transmitted wave is reflected by the detected object 4 and the reflected wave received by the antenna 1 is input to the mixer 6, and the mixer 6 extracts the frequency difference between the transmitted wave and the reflected wave to obtain a beat signal amplifier as a beat signal. 8 is output. The beat signal amplifier 8 amplifies the beat signal and outputs the amplified signal to the low-pass filter 10, and the analog signal with the high frequency component attenuated is converted into a digital signal by the A / D converter 12.

  First, the CPU 14 executes ambient information storage processing, reads the digital signal converted by the A / D converter 12 (step 50), performs frequency analysis by Fourier transform, and performs a frequency analysis for each of the plurality of detected objects 4. The distance and size are detected (step 52).

  When there are a plurality of detected bodies 4, a plurality of reflected waves having a time T shift according to the distance R to each detected body 4 are received, and each detected body 4 is included in the beat signal fb. The signal of the frequency component according to is superimposed. The beat signal fb is subjected to frequency analysis by Fourier transform, separated into signals for each detected object 4, and a distance R for each detected object 4 is detected. Further, the amplitude of the signal of each detected body 4 is proportional to the magnitude, and the magnitude of the detected body 4 can be detected by detecting the amplitude.

  Next, the detected distances and sizes for the plurality of detected bodies 4 are stored in the memory 16 (step 54). Then, it is determined whether or not a predetermined time T0 has elapsed (step 56). When the predetermined time T0 has not elapsed, the processing from step 50 onward is repeatedly executed to detect the detected object. The distance and size of every 4 are stored in the memory 16, and when the predetermined time T0 has elapsed, this ambient information storage processing is once terminated.

  The surrounding information storage process may be executed at the place where the burglar alarm device is installed, at the initial stage of installation, or at regular intervals. By executing the surrounding information storage process, the surrounding information in which the burglar alarm device is installed is stored in the memory 16. That is, the information of the detected object 4 around the burglar alarm device is stored. For example, when a burglar alarm device is installed in a house, plants, gates, pillars, and the like around the house are used as the detected body 4, and furniture is used as the detected body 4 in the house. The distances from the burglar alarm devices to the plurality of detected bodies 4 and the size of the detected bodies 4 are stored in the memory 16 for each detected body 4.

  After executing the surrounding information storage process, a warning process is executed. At that time, similarly to the above, the frequency-modulated transmission wave from the FM transmitter 2 is radiated, the reflected wave is input to the mixer 6, and the mixer 6 outputs the beat signal to the beat signal amplifier 8. . The signal processed by the beat signal amplifier 8 and the low-pass filter 10 is converted into a digital signal by the A / D converter 12.

  As shown in FIG. 3, the CPU 14 executes a warning process, reads the digital signal converted by the A / D converter 12 (step 60), performs frequency analysis by Fourier transform, and detects a plurality of detected objects. The distance and size for every 4 are detected (step 62).

  Next, it is determined whether or not the detected body 4 to be detected is within the first alert area (step 64). Whether the detected object 4 is in the first warning area by comparing the detected distance of the detected object 4 with the preset first warning area by executing the processing of steps 60 and 62. Judging. At that time, when the distance and size of the detected object 4 stored in the memory 16 by the surrounding information storage process described above match, the detected detected object 4 is excluded.

  When the detected object 4 that does not match the detected object 4 stored in the memory 16 is within the first warning area, an alarm signal is output to the speaker 18 and an alarm is issued from the speaker 18 (step 66).

  When the detected object 4 that does not match the detected object 4 stored in the memory 16 is not in the first warning area, it is next determined whether or not the detected detected object 4 is in the second warning area. (Step 68).

  Whether or not the detected object 4 is in the second warning area by comparing the distance of the detected detected object 4 with the preset second warning area by executing the processing of steps 60 and 62. Judging. At that time, when the distance and size of the detected object 4 stored in the memory 16 by the surrounding information storage process described above match, the detected detected object 4 is excluded.

  The second warning area includes the first warning area described above and is wider than the first warning area. For example, when a burglar alarm device is installed in a house, for example, the first warning area is an area including the house, or an area including the vicinity of the house and the outside of the house, and the second warning area is a surrounding area including a wider garden. It is preset as an area.

  The detected object 4 that does not match the detected object 4 stored in the memory 16 is a suspicious person or a suspicious object that has entered the first alert area, and issues an alarm to notify the resident of the house. When it is determined that the detected object 4 is present in the first alert area, the detected object 4 is not a fixed object such as furniture but a newly detected detected object 4 (suspicious person or suspicious object). is there. In addition, it has entered the vicinity of the house or the first alert area in the house, and in that case, an alarm is immediately issued and notified.

  If the detected object 4 is in the second alert area, it is determined whether or not a predetermined time T1 has passed (step 70). If the predetermined time T1 has not elapsed, it is determined whether or not the detected object 4 is approaching (step 72). When the detection object 4 is not approaching, the processing after step 60 is repeatedly executed. When the detected object 4 remains in the second warning area until the predetermined time T1 elapses, a preliminary warning signal is output to the speaker 18 and a preliminary warning is issued from the speaker 18 (step 74).

  Even when the predetermined time T1 has not elapsed, when the detected object 4 is approaching, similarly, a preliminary alarm signal is output to the speaker 18 and a preliminary alarm is issued from the speaker 18 (step 74).

  The detected object 4 that does not coincide with the detected object 4 stored in the memory 16 is in the second warning area outside the first warning area, and the detected object 4 is kept until a predetermined time T1 elapses. Is in the second warning area, it is moving around the house, the grounds such as the garden, or stays for a long time. At that time, a preliminary warning is issued from the speaker 18 to alert the resident.

  Even before the predetermined time T1 has elapsed, when the detected object 4 is approaching, similarly, a preliminary warning is issued from the speaker 18 to alert the resident. However, when the detected object 4 leaves the second alert area before the predetermined time T1 elapses, for example, it is determined that it is a simple passerby, a newspaper delivery person, etc., and no preliminary alarm is issued.

If the detected object 4 is neither in the first warning area nor in the second warning area, the processing from step 60 onward is repeatedly executed.
In the present embodiment, the well-known FM-CW radar using the antenna 1, the FM transmitter 2, the mixer 6, the beat signal amplifier 8, and the low-pass filter 10 and the execution of the processing in steps 60 and 62 serve as detection means, and ambient information Execution of the storage process serves as ambient information storage means, and execution of the processes of steps 64 to 74 serves as alarm means.

  As described above, in the present embodiment, prior to the execution of the warning process, the surrounding information storage process is executed, and a fixed object or the like in the surroundings is set as the detected body 4 in advance, and the distance to the detected body 4 and its Remember the size. When executing the warning process, if it is determined that the detected objects 4 other than the stored detected object 4 are in the first warning area and the second warning area, an alarm and a preliminary warning are issued.

  At this time, at least the distance to the detected object 4 may be stored, and it may be determined whether the detected object 4 is in the first warning area or the second warning area based on the distance. However, the detection accuracy can be further improved by detecting the size of the detected object 4.

  By detecting and storing the detected object 4 in advance, a highly accurate alarm can be issued using advanced detection means such as FM-CW radar. Further, the surrounding environment differs depending on the location where the burglar alarm device is installed, and the detected object 4 such as a fixed object that reflects the transmission wave differs. Even in that case, it is possible to distinguish from the newly intruded detected body 4 by executing the surrounding information storing process and detecting and storing the detected object 4 in the surroundings in advance, and a highly accurate alarm is generated. Can be emitted.

  In the embodiment described above, the case where the burglar alarm device is installed in a house is taken as an example. Next, the case where the burglar alarm device is installed in a car will be described. In the case of installation in an automobile, the warning process shown in FIG. 4 may be executed instead of the warning process shown in FIG. The same processing as the above-described warning processing is denoted by the same step number, and detailed description thereof is omitted.

  In the case of an automobile, the surrounding information storage process described above may be executed every time the automobile is moved and parked. The surrounding information storage process is executed to detect and store the surrounding detected object 4, and then the warning process is executed. Thereby, even if a parking place differs, the surrounding detected body 4 can be detected again, and the detected body 4 of the parking place can be newly memorize | stored.

  In the alert process, the first alert area is set as the inside of the automobile, and the second alert area is set as an area including the outer periphery of the automobile. When the detected object 4 is detected in the first alert area by executing the processing in steps 60 to 66, an alarm is immediately issued.

  When it is determined that there is a detected body 4 other than the detected body 4 stored in the second alert area (step 68), it is determined whether or not the detected body 4 is moving (step 69). . When the detected object 4 is moving, it is in the state of passing through the vicinity of the automobile, so at that time, the processing of step 60 and subsequent steps is repeated again without issuing an alarm.

  If the detected object 4 remains in the second warning area for a predetermined time T1, the behavior is suspicious and the car may be unlocked. A preliminary alarm signal is output to 18 to issue a preliminary alarm (step 74). Note that an alarm signal may be transmitted to a mobile phone or the like together with an alarm and a preliminary alarm by the speaker 18 or in place of the speaker 18.

  Further, in the present embodiment, frequency analysis by Fourier transform is performed in order to detect a plurality of detected objects 4, but instead of this, a comb filter 20 may be used as shown in FIG. The comb filter 20 is a known filter in which narrow band filters are arranged in a comb shape, and an A / D converter 12 is provided for each narrow band filter. Thereby, since a frequency changes for every distance of the some to-be-detected body 4, the some to-be-detected body 4 can be detected.

  The present invention is not limited to such embodiments as described above, and can be implemented in various modes without departing from the gist of the present invention.

It is a block diagram which shows the structure of the burglar alarm apparatus as one Embodiment of this invention. It is a flowchart which shows the surrounding information storage process performed with CPU of this embodiment. It is a flowchart which shows the alert process performed with CPU of this embodiment. It is a flowchart which shows the alert process performed by CPU as another embodiment. It is a block diagram which shows the structure of the burglar alarm device as another embodiment. It is explanatory drawing which shows the relationship between the transmission wave and reflected wave of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Antenna 2 ... FM transmitter 4 ... Detected object 6 ... Mixer 8 ... Beat signal amplifier 10 ... Low pass filter 12 ... A / D converter 14 ... CPU
16 ... Memory 18 ... Speaker 20 ... Com Filter

Claims (3)

Detecting means for transmitting a frequency-modulated transmission wave, receiving a reflected wave reflected by the detected object, and detecting at least a distance from the transmitted wave and the reflected wave to the detected object; and In the theft alarm device comprising alarm means for issuing an alarm when the detected object to be detected is in the alert area,
The detection means can detect the distances of the plurality of detected objects,
In addition, it comprises ambient information storage means for storing the distance to the detected object detected by the detection means,
And when the alarm means is detected by the detection means within the alert area, the detected object excluding the detected object that is the same as the distance of the detected object stored in the surrounding information storage means, A burglar alarm device that emits the alarm. The detection means can further detect the size of the detected object,
The ambient information storage means stores the distance to the detected object detected by the detecting means and the size of the detected object,
When the detected object except the detected object having the same distance and size as the detected object stored in the surrounding information storage means is detected by the detecting means within the warning area, The theft alarm device according to claim 1, wherein the alarm is issued. The alarm means includes
First alarm means for issuing an alarm when the detected object is detected in the first alert area by the detection means;
When the detection means detects the detected object until a preset time elapses in a second warning area that includes the first warning area and is wider than the first warning area, a preliminary warning is issued. 2 alarm means;
The burglar alarm device according to claim 1 or 2, further comprising:

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