JPH0652449A - Intruding body detecting device - Google Patents

Abstract

PURPOSE:To provide the intruding body detecting device which is reduced in power consumption and prolongs the life of an ultrasonic vibrator. CONSTITUTION:A transmitting means 2 intermittently send an ultrasonic wave to a detection space and a receiving means 3 receives its reflected wave for a certain time after the transmission and outputs reception data corresponding to the reflected wave; and a microprocessor 4 as a deciding means decides whether or not there is an intruding body on the basis of the reception data. Therefore, the ultrasonic wave need not continuously and successively be sent and received, and consequently the power consumption is reducible, the life of the ultrasonic vibrator is prolonged, and even intrusion which is low in moving speed can be detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intruding object detecting apparatus suitable for, for example, a vehicle anti-theft device. The present invention relates to a device for detecting an intruding object.

[0002]

2. Description of the Related Art As an anti-theft device for a vehicle, there is an intruding object detecting device which detects intrusion of a suspicious person into the vehicle by utilizing ultrasonic waves.

This detection device is activated when the owner of the vehicle locks the vehicle and leaves the vehicle, and transmits ultrasonic waves from an ultrasonic wave transmitter / receiver provided at an appropriate position such as the ceiling in the vehicle. The intruder uses the Doppler effect that the frequency of the reflected wave is changed when the ultrasonic wave is continuously transmitted and received and the ultrasonic wave is reflected by hitting an object moving in the vehicle, that is, a suspicious intruder. Is detected and the horn is sounded to issue an alarm.

FIG. 12 shows an example of the transmission wave and the reflection wave of such a conventional Doppler ultrasonic wave. FIG. 12A shows the transmission wave and FIG. 12B shows the velocity of a moving object. Shows a reflected wave when the object is slow, and FIG. 7C shows a reflected wave when the speed of the moving object is high.

[0005]

However, in such a Doppler type detecting device, while the detecting device is activated, as shown in FIG. 12, ultrasonic wave transmission / reception is continuously continued. Has to be done, it consumes a lot of power,
Especially in the case of car theft prevention, because it is driven by the battery with the car engine stopped,
There is a drawback that the battery goes up, and there is also a drawback that the life of the ultrasonic transducer that transmits and receives ultrasonic waves is shortened. Moreover, it is difficult to invade at a slow moving speed or to invade a position away from the ultrasonic wave transmitter / receiver.

The present invention has been made in view of the above points, and reduces the power consumption, prolongs the life of the ultrasonic transducer, and detects an intruding object that can easily detect an intrusion with a slow moving speed. The purpose is to provide a device.

[0007]

In order to achieve the above-mentioned object, the present invention is constructed as follows.

That is, the present invention is an intruding object detecting apparatus for detecting an object intruding into a detection space, the transmitting means intermittently transmitting ultrasonic waves to the detection space, and the transmitting means after transmitting by the transmitting means. Receiving means for receiving a reflected wave over a fixed period and outputting received data corresponding to the reflected wave,
And a determining unit that determines the presence or absence of an intruding object based on the received data output from the receiving unit.

[0009]

According to the above structure, ultrasonic waves are transmitted intermittently, reflected waves are received for a certain period after the transmission, and intrusion of an object is detected based on the received data obtained. As in the example, it is not necessary to continuously transmit and receive ultrasonic waves, and this makes it possible to reduce power consumption and extend the life of the ultrasonic transducer.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings.

Example 1 FIG. 1 is a block diagram of an embodiment of the present invention. In this embodiment, description will be made by applying it to a vehicle antitheft device.

The antitheft device 1 of this embodiment is the same as the device 1
After being activated, it detects an intrusion of a suspicious person or the like into the vehicle and sounds a horn as an alarm device (not shown) to issue an alarm, and basically has the following configuration.

That is, the anti-theft device 1 includes transmitting means 2 for transmitting ultrasonic waves in the vehicle as a detection space intermittently at a time interval of 0.5 to 1 second, and transmitting means 2 for transmitting the ultrasonic waves. Every time, the receiving means 3 receives the reflected wave for a certain period after the transmission and outputs the reception data corresponding to the reflected wave, and the receiving means 3 at every reception for the certain period.
The microcomputer 4 that has a function as a determination unit that determines the presence or absence of an intruding object by comparing the previous data and the current data received from the microcomputer 4 that controls each unit.
It has and.

The transmitting means 2 is provided with an ultrasonic transducer 5 which is installed on a ceiling in a vehicle and transmits ultrasonic waves, and a drive circuit 6 which drives the ultrasonic transducer 5, as shown in FIG. A)
As shown in, the ultrasonic waves are transmitted intermittently.

The receiving means 3 is installed on the ceiling of the vehicle or the like, and has an ultrasonic transducer 7 for receiving reflected waves, and an ultrasonic transducer 7
Of the output of the amplifier circuit 8, a detection circuit 9 for detecting the output of the amplification circuit 8, and an output of the detection circuit 9
The receiver circuit 3 is provided with an A / D converter 10 that outputs the D-converted data as reception data. In the reception circuit 3, as shown in FIG. The wave is received, amplified by the amplification circuit 8, and then detected by the detection circuit 9.
The detection is performed as shown in (C), and the detection output is shown in FIG.
As shown in (D), the A / D converter 10 performs A / D conversion and outputs.

A microcomputer 4 having a function as a judging means is a ROM 1 in which a program is stored.
1, a RAM 12 as a storage unit in which the received data from the receiving means 3 is updated and stored as described later, and a determination process of presence or absence of an intruding object and other control processes as described later based on the received data. It has a CPU 13 for performing.

In the antitheft device 1 having the above structure,
As shown in FIG. 3 (A), the transmitting means 2 does not perform continuous transmission and reception of ultrasonic waves continuously as in the conventional Doppler system, but as shown in FIG. At the same time, the receiving means 3 receives the reflected wave over a period T3 after the end of the transmission.

Microcomputer 4 as judging means
Updates and stores the received data (A / D conversion output) based on the reflected wave received in the period T3, for example, as shown in FIG.
By comparing the previous reception data shown in (B) with the present reception data shown in FIG. 3 (C), it is determined whether or not an intruding object into the vehicle, that is, a suspicious intruder is detected. In this embodiment, as shown in FIG. 3D, FIG. 3B and FIG.
When the difference in area of the figure from (C) exceeds a predetermined level, it is determined that there is an intruder.

Next, the above processing operation will be described with reference to the flowchart of FIG.

First, it is judged whether or not the period T2 of FIG. 3 has elapsed (step n1). When the period T2 has elapsed, ultrasonic waves are transmitted over the period T1 of FIG. 3 (step n2), and after the transmission is completed, The receiving means 3 is activated to start reception of the reflected wave (step n3), the received data (A / D converted value) is sequentially stored (step n4), and it is determined whether or not the period T3 in FIG. 3 has elapsed. (Step n5).

When the period T3 has elapsed, the receiving means 3
(Step n6), the reception data of this time is compared with the previous reception data stored (step n7), and the presence or absence of intrusion is determined based on the difference in area as described above ( In step n8), when it is determined that there is an intrusion, an intrusion detection output is given to the alarm means (step n9), and when it is determined that there is no intrusion, the current data is updated and stored as the previous data (step n10).

Since the intruder is detected in the vehicle in this manner, unlike the conventional Doppler system, it is not necessary to continuously transmit and receive ultrasonic waves, and to reduce power consumption. As a result, unlike the conventional example, the battery of the vehicle does not run out to drive the anti-theft device, and the life of the ultrasonic transducers 5 and 7 of the transmitting / receiving means is extended. Moreover, it is possible to detect an intrusion with a slow moving speed.

In this embodiment, the previous data and the current data of the received data are compared, but the comparison is not limited to the previous data and the current data.
It is also possible to compare the last-minute batch and the current batch.

Example 2. In the first embodiment described above, the received data for a certain period of time, that is, the A / D conversion output is stored as it is, but as another embodiment of the present invention, in order to reduce the memory capacity, the following process is performed. You may comprise.

That is, as shown in FIG.
In the same manner as in Example 1, ultrasonic waves are transmitted intermittently,
The reflected wave is received for a certain period, and the center of gravity G1 of the figure based on the previous reception data shown in FIG.
The barycentric point G2 of the figure based on the previous received data shown in FIG. 5C is compared, and when the positional deviation exceeds a predetermined level, it is determined that there is an intrusion.

The coordinates X and Y of the center of gravity are calculated according to the following equation, for example.

X = Σ (An × n) / ΣAn (1) Y = Σ (An × n) / Σn (2) An: A / D conversion value of the nth time (n> 0) By calculating and comparing, the memory capacity can be reduced as compared with the case where the received data is stored as it is. For example, when n is 100, 1
If the A / D conversion value of bytes is stored as it is, a capacity of 100 bytes or more is required. In this embodiment for comparing the centers of gravity, Σ (An × n) is calculated every A / D conversion. Then, it is sufficient to update and store it, and the capacity of about 3 bytes will suffice.

The other structure is the same as that of the first embodiment.

FIG. 6 is a flow chart for explaining the operation of this embodiment.

First, similarly to the first embodiment, it is judged whether or not the period T2 has passed (step n1). When the period T2 has passed, ultrasonic waves are transmitted over the period T1 (step n).
2) After the transmission is completed, the receiving means 3 is activated to start receiving the reflected wave (step n3), and n = 1 is set (step n).
4), Σ (A / D converted value) and Σ (A / D converted value x)
n) is calculated (steps n5 and n6), 1 is added to n (step n7), and it is determined whether or not n is equal to K (step n8). Note that K is A / D conversion time ×
It is determined that K is the above-mentioned period T3.

When n is not equal to K, the process returns to step n5, and when it is equal, reception by the receiving means 3 is stopped (step n9), and the current center of gravity point is determined by the above equations (1) and (2). Calculated based on the above, and compared with the previous center of gravity point (step n10), the presence / absence of the intrusion is determined based on the displacement of the center of gravity point (step n11). When it is determined that there is no intrusion, the current data is stored as the previous data (step n1).
3).

According to this embodiment, in addition to the effect of the first embodiment, the memory capacity can be reduced.

Example 3. Generally, the intensity of a reflected wave from an object at a long distance is weakened, so that the detection sensitivity of an object at a long distance is lowered. Therefore, in this embodiment, the following configuration is adopted so that the intrusion can be detected with uniform sensitivity regardless of the distance.

That is, although the received data from the receiving means 3 is stored as it is in the first embodiment and the determination process is performed, the ultrasonic wave is transmitted as shown in FIG. 7A in this embodiment. Then, the received data shown in FIG. 7 (B) obtained by receiving the reflected wave, that is, the A / D converted output is not stored as it is, but is stored in FIG. The weighting coefficient shown in C) is used for weighting, that is, the correction is performed according to the distance to obtain the reception data shown in FIG. 7D, and the corrected reception data is stored. Similar to the first embodiment, the received data is compared with the current data and the previous data to detect the presence or absence of intrusion.

Therefore, in the case of this embodiment, the microcomputer 4 receives the received data according to the distance.
That is, it has a function as a correction unit that performs weighting and correction according to the passage of time from the start of reception.

As the weighting coefficient, for example, FIG.
The coefficient as shown in (E) may be used to particularly enhance the detection sensitivity of a specific position, for example, the driver's seat.

The other structure is the same as that of the first embodiment.

FIG. 8 is a flow chart for explaining the operation of this embodiment.

First, similarly to the above-described embodiment, it is judged whether or not the period T2 has passed (step n1), and when it has passed, ultrasonic waves are transmitted over the period T1 (step n).
2) After the transmission is completed, the receiving means 3 is activated to start receiving the reflected wave (step n3), and n = 1 is set (step n).
4) Read the weighting coefficient for n (step n
5), the A / D converted value is multiplied by the weighting coefficient and stored in the memory (step n6), and 1 is added to n (step n).
7), it is determined whether n has become equal to K (step n8). Note that K is A / A as in the second embodiment.
The D conversion time × K is determined so as to be the above-mentioned period T3.

When n is not equal to K, the process returns to step n5, and when it is equal, the reception by the receiving means 3 is stopped (step n9), and the corrected reception data of this time and the previous correction stored. The received data is compared (step n10), and the presence or absence of intrusion is determined based on the area difference (step n11). When it is determined that there is intrusion, an intrusion detection output is given to the alarm means (step n12). ), If it is determined that there is no intrusion, the corrected reception data of this time is updated and stored as the previous data (step n13).

According to this embodiment, in addition to the effect of the first embodiment, it is possible to detect with a uniform sensitivity regardless of the distance or to detect a specific position with a high sensitivity.

Example 4. In general, ultrasonic waves may fluctuate in reflected waves when there is wind inside the vehicle, which is the detection space, and may be erroneously determined to have entered.

Therefore, in this embodiment, the above-mentioned first embodiment is used.
In addition to the above configuration, when the anti-theft device 1 is activated, it is first determined whether or not the reflected wave is stable, and when it is determined that the reflected wave is stable, the determination process is started.

That is, in this embodiment, the microcomputer 4 has a function as a determining means for determining whether or not the reflected wave is stable, and one of the two built-in timers can stabilize the reflected wave. Is measured, and when this stable period exceeds a predetermined period α,
When the judgment process is started and the other timer does not start the judgment process because the reflected wave is not stable even after the predetermined period β (β> α) has passed since the device was started, the intrusion detection is performed. I'm trying to stop the operation of.

FIG. 9 is a flow chart for explaining the operation of this embodiment.

First, when the anti-theft device is activated, the two timers 1 and 2 are cleared (step n1) and it is determined whether the reflected wave is stable (step n2). This determination is made, for example, by comparing the previous data and the current data of the reception data output from the receiving means 3 and determining that the data is stable when there is almost no difference.

When it is determined in step n2 that the reflected wave is stable, the timer 1 starts the measurement (step n3), and it is determined whether or not the period measured by the timer 1 is equal to or longer than the predetermined period α. (Step n4) and when it is determined that the period measured by the timer 1, that is, the stable period of the reflected wave is equal to or longer than the predetermined period α, the determination process according to the first embodiment described above is started. .

In step n4, when the period measured by the timer 1, that is, the stable period of the reflected wave is not longer than the predetermined period α, the timer 2 starts the measurement (step n5). It is determined whether or not the measured period is equal to or longer than a predetermined period β (step n6). When the period measured by the timer 2 is not equal to or larger than the predetermined period β, the process returns to step n2 and the predetermined period β is set. When the period becomes β or more,
Despite the passage of the period β, the intrusion detection is stopped because the reflected wave is not stable (step n7). When it is determined in step n2 that the reflected wave is not stable, the timer 1 is cleared (step n8).

According to this embodiment, in addition to the effect of the first embodiment, it is possible to prevent erroneous detection when the reflected wave is not stable.

As another embodiment of the present invention, in the determination processing, the received data when it is determined that the reflected wave is stable rather than comparing the received data for the previous time and the received data for this time. The reference data may be used as a reference data and the presence or absence of detection may be determined by sequentially comparing with the reference data.

Example 5. In each of the above-mentioned embodiments, when the reflected wave of the ultrasonic wave changes beyond the predetermined judgment level as compared with the previous reflected wave, it is configured to give an alarm that there is intrusion, that is, theft. As another embodiment of the present invention, a plurality of judgment levels are provided, and, for example,
When the first judgment level is exceeded, a first alarm with a short warning period is issued because of the suspicion of theft, and when the second judgment level is exceeded, a second alarm with a long warning period is issued as a theft. It may be configured to emit, and instead of detecting theft only with ultrasonic waves, other sensors such as a tilt sensor, impact sensor, door switch, etc. may be added,
The outputs of these sensors may be determined together.

FIG. 10 is a schematic block diagram of another embodiment of the present invention. In the figure, 15 is an ultrasonic sensor,
The ultrasonic sensor 15 includes, for example, the above-described transmitting means 2 and receiving means 3 of the first embodiment. 16
Is a tilt sensor, 17 is a controller that detects an intrusion based on the outputs of the ultrasonic sensor 15 and the tilt sensor 16, and 18 is an alarm device that emits an alarm sound.

FIG. 11 is a flow chart for explaining the operation of this embodiment.

First, similarly to the above-described embodiment, the ultrasonic sensor 15 detects the difference X between the previous and the present reflected waves (step n1), and the difference X is in a predetermined range γ to δ. If it is within the predetermined range, it is determined that there is a suspicion of theft, and t1 is set as the alarm time t (step n3), and within the predetermined range. If not, the difference X between the reflected wave last time and this time
Is greater than or equal to a predetermined value δ (step n13), and if greater than or equal to the predetermined value δ, the alarm time t
Is set to t2 (t2> t1) (step n1
4).

Next, when the inclination sensor 16 detects an abnormality (step n4), this is the first time (step n4).
5), while starting the timer (step n15),
It is determined that there is a suspicion of theft, and the alarm time t1 is set (step n16). If it is not the first time, that is, if the timer is operating, the warning number counter counts (step n6), and when the timer times up (step n11), the tilt sensor 16 detects an abnormality during the time-up operation. It is determined whether or not the number of times exceeds a specific value N (step n8). When the number of times exceeds the specific value N, it is determined to be theft and an alarm time t2 is set (step n).
9) If it is less than the specific value N, the warning number counter is cleared (step n10), and it is determined whether the alarm time is set to a value other than 0 (step n11).
Otherwise, the alarm is turned on (step n12), and if not, the alarm is turned off (step n17).

As described above, two kinds of alarms having different alarm times are provided by the plurality of determination levels and the outputs of the plurality of sensors 15 and 16 depending on whether there is a suspicion of theft or when it is determined to be theft. Since it is emitted, it is possible to prevent erroneous detection and prevent omission of detection.

[0057]

As described above, according to the present invention, ultrasonic waves are transmitted intermittently, reflected waves are received for a certain period after this transmission, and an intrusion of an object based on the received data obtained. Since it is not necessary to continuously transmit and receive ultrasonic waves as in the conventional example, it is possible to reduce power consumption and extend the life of the ultrasonic transducer. Moreover, an intrusion with a slow moving speed can be detected.

[Brief description of drawings]

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

FIG. 2 is a signal waveform diagram of each part of the embodiment of FIG.

FIG. 3 is a signal waveform diagram for explaining the operation of the embodiment of FIG.

FIG. 4 is a flowchart for explaining the operation of the embodiment of FIG.

FIG. 5 is a signal waveform diagram for explaining the operation of another embodiment of the present invention.

6 is a flowchart for explaining the operation of the embodiment of FIG.

FIG. 7 is a signal waveform diagram for explaining the operation of still another embodiment of the present invention.

8 is a flowchart for explaining the operation of the embodiment in FIG.

FIG. 9 is a flowchart for explaining the operation of another embodiment of the present invention.

FIG. 10 is a schematic configuration diagram of another embodiment of the present invention.

11 is a flowchart for explaining the operation of the embodiment in FIG.

FIG. 12 is a waveform diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anti-theft device 2 Transmitting means 3 Receiving means 4 Microcomputer (judging means) 5,7 Ultrasonic transducer 9 Detection circuit 10 A / D converter 12 RAM (storage section)

Claims (6)

[Claims] 1. An intruding object detecting device for detecting an object invading a detection space, comprising: a transmitting means for intermittently transmitting an ultrasonic wave to the detection space; and a fixed period after the transmission by the transmitting means. Receiving means for receiving the reflected wave and outputting the received data corresponding to the reflected wave, and a judging means for judging the presence or absence of an intruding object based on the received data output from the receiving means. Intruding object detection device. 2. The determining means determines the presence or absence of an intruding object by comparing the previous data and the current data of the received data output from the receiving means each time the data is received over the certain period. The intruding object detection device according to claim 1. 3. A discriminating means for discriminating whether or not the reflected wave is stable based on the received data outputted from the receiving means and for outputting a start signal when it is judged that the reflected wave is stable. The intruding object detecting apparatus according to claim 1 or 2, wherein the determining means starts an operation of determining the presence or absence of an intruding object in response to the start signal. 4. The receiving means includes an ultrasonic transducer for receiving a reflected wave, a detection circuit for detecting the output of the ultrasonic transducer, and A / D conversion of the output of the detection circuit for reception data. And an A / D converter for outputting as the storage unit, the determination unit storing the reception data from the A / D converter, and the previous reception data and the current reception stored in the storage unit. The intruding object detecting apparatus according to claim 2 or 3, further comprising: a determination unit that determines the presence or absence of an intruding object by comparing the areas of respective figures based on the data. 5. The receiving means includes an ultrasonic transducer for receiving a reflected wave, a detection circuit for detecting the output of the ultrasonic transducer, and A / D conversion of the output of the detection circuit for reception data. And an A / D converter for outputting as the storage unit, the determination unit storing the reception data from the A / D converter, and the previous reception data and the current reception stored in the storage unit. The intruding object detecting apparatus according to claim 2 or 3, further comprising: a determination unit that determines the presence or absence of an intruding object by comparing barycentric positions of respective figures based on respective data. 6. The judging means includes a correcting section for weighting received data from the receiving means and outputting the weighted data to the storage section based on an elapsed time from the start of reception by the receiving means. The intruding object detection device according to claim 4 or 5.