JP2007203894A - Invasion detecting device for vehicle, computer program used for the device, and recording medium recording the program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an invasion detecting device for a vehicle, capable of preventing malfunction caused by wrongly recognizing swing of an ornament in a vehicular cabin as an invader. <P>SOLUTION: The invasion detecting device A for the vehicle comprises an ultrasonic wave transmitting portion 20 transmitting ultrasonic waves, an ultrasonic wave receiving portion 30 receiving reflecting waves against an article of the ultrasonic waves from the ultrasonic wave transmitting portion 20, an alarm sounding portion 40 sounding a predetermined alarm, a moving distance calculating portion 11 calculating a moving distance of the article from the reflecting waves received by the ultrasonic wave receiving portion 30 during a fixed sampling period, and an alarm sounding control portion 11 making the alarm sounding portion 40 sound the alarm when an accumulated moving distances accumulating the moving distances of the article calculated by the moving distance calculating portion 11 is not less than a predetermined value or longer than the predetermined value. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle intrusion detection device, a computer program used therefor, and a recording medium on which the computer program is recorded.

  As a security device for an automatic vehicle, one having a moving object detection device that monitors a vehicle interior of an automatic vehicle and detects an object moving in the vehicle interior in a non-contact manner has been proposed (for example, Patent Documents 1 and 2).

  In Patent Document 3, as a technique for preventing malfunction of a vehicle intrusion detection device that detects a moving object with ultrasonic waves, ultrasonic Doppler shift is an amount equivalent to human intrusion, and the reception level is due to disturbance. Only when it is higher than the level, it is disclosed that a person is detected as an illegal intrusion and erroneous detection is reliably prevented.

  Patent Document 4 discloses that by preventing the occurrence of a saturation phenomenon of an operational amplifier included in an amplifier circuit for an ultrasonic reception signal, erroneous detection due to the occurrence of a Doppler shift that is not a human intrusion is reliably prevented. ing.

In Patent Document 5, the standard deviation of the pulse period is calculated from the number of pulses counted during a predetermined detection period and each pulse period, and when both the number of pulses and the standard deviation exceed the set threshold values, It is disclosed that an erroneous detection due to a disturbance wave other than a signal indicating a person's intrusion into the vehicle interior or a noise component is determined by determining that there is an intrusion and outputting an alarm.
JP-A-63-251354 Japanese Patent Application Laid-Open No. 64-78951 Japanese Patent Laid-Open No. 9-274080 JP 2000-142324 A JP 2004-181982 A

  By the way, in the vehicle intrusion detection apparatus using ultrasonic waves, a malfunction may occur in which a shake of a decoration or the like in the passenger compartment is mistaken as an intruder and an alarm is issued.

  The present application has been made in view of the above points, and the purpose of the present application is to provide a vehicle intrusion detection device capable of preventing malfunction caused by misidentifying a shake or the like of a decoration in a vehicle interior as an intruder, The present invention also provides a computer program used therefor and a recording medium on which the computer program is recorded.

The present invention for achieving the above object
An ultrasonic transmitter for transmitting ultrasonic waves;
An ultrasonic receiver that receives a reflected wave of the ultrasonic wave from the ultrasonic transmitter to the object;
An alarm transmitter for issuing a predetermined alarm;
A moving distance calculating unit that calculates a moving distance of an object from a reflected wave received in a predetermined sampling period by the ultrasonic receiving unit;
An alarm transmission control unit that issues an alarm to the alarm transmission unit when the cumulative movement distance obtained by accumulating the movement distance of the object calculated by the movement distance calculation unit is greater than or equal to a predetermined value, or longer than a predetermined value;
An intrusion detection device for a vehicle characterized by comprising:

  According to the present invention, an alarm is issued when the cumulative moving distance of an object is greater than or equal to a predetermined value, or longer than a predetermined value. Therefore, an alarm is issued for a small movement of an object such as a shake of a decoration in a vehicle interior. Therefore, it is possible to prevent malfunction caused by misidentifying it as an intruder.

  Hereinafter, embodiments will be described in detail with reference to the drawings.

  FIG. 1 shows a configuration of a vehicle intrusion detection device A of the present embodiment. This intrusion detection device A for vehicles is attached to the interior of a vehicle compartment for automobile crime prevention.

  The vehicle intrusion detection apparatus A includes an apparatus main body 10 and a transmission side ultrasonic sensor (ultrasonic transmission unit) 20, a reception side ultrasonic sensor (ultrasonic reception unit) 30, and an alarm device (alarm transmission unit) connected thereto. 40). The apparatus main body 10 and the alarm device 40 are installed on the back side of the instrument panel, for example, and the transmission-side ultrasonic sensor 20 and the reception-side ultrasonic sensor 30 face the vehicle interior side on both sides on the dashboard, for example. Installed.

  The apparatus body 10 includes a microcomputer (hereinafter abbreviated as “microcomputer”) 11. The transmission side ultrasonic sensor 20 is connected to the A terminal 11 a of the microcomputer 11 via the sensor drive circuit 12. The reception-side ultrasonic sensor 30 is connected to the B terminal 11b of the microcomputer 11 via a filter circuit. The filter circuit includes a first amplifier circuit 13, a half-wave rectifier circuit 14, a band-pass filter (hereinafter referred to as “BPF”) + second amplifier circuit 15 from the reception-side ultrasonic sensor 30 side toward the microcomputer 11 side. The waveform shaping circuit 16 is connected in series. The alarm device 40 is connected to the C terminal 11 c of the microcomputer 11 via the alarm sounding circuit 17. The alarm device 40 may sound or emit light, or may transmit a signal to the outside.

  Next, the operation of the vehicle intrusion detection device A will be described.

  When the door of the automobile is locked when the engine is off, the vehicle intrusion detection device A is turned on.

  When the vehicle intrusion detection device A is turned on, the microcomputer 11 outputs a square wave signal having a frequency of 40 kHz, for example, from the A terminal 11a. The transmission-side ultrasonic sensor 20 converts a square wave signal received from the microcomputer 11 via the sensor drive circuit 12 into an ultrasonic pulse and transmits it to the vehicle interior.

  The reception-side ultrasonic sensor 30 had a reflected wave of an ultrasonic pulse transmitted from the transmission-side ultrasonic sensor 20 reflected on a stationary object such as the inner wall of the vehicle interior, and a moving object such as an intruder in the vehicle interior. In such a case, a minute signal as shown in FIG. 2A in which the reflected waves reflected by the moving object are combined is received. Here, the reflected wave reflected by the stationary object is an ultrasonic pulse having the same frequency as the ultrasonic pulse transmitted from the transmission-side ultrasonic sensor 20. The reflected wave reflected by the moving object is an ultrasonic pulse having a Doppler frequency f expressed by the following formula (1).

  The first amplifying circuit 13 amplifies a minute signal received by the receiving-side ultrasonic sensor 30 as it is and outputs it as shown in FIG.

  The half-wave rectifier circuit 14 takes out only the signal below the reference value (or above) from the signal amplified by the first amplifier circuit 13 and outputs it as shown in FIG.

BPF + second amplifier circuit 15, requires the frequency output of the half-wave rectifier circuit 14 (e.g., 100 Hz) and then filtered to pass the peak, the signal of the Doppler shift frequency f _r represented by the following formula (2) Amplified and output as shown in FIG. Since a signal having the same frequency as the ultrasonic pulse transmitted from the transmission-side ultrasonic sensor 20 is filtered, when there is no moving object such as an intruder in the vehicle interior, as shown in FIG. No signal is output, and a constant value signal without change is output.

  The waveform shaping circuit 16 extracts only the necessary frequency component from the output of the BPF + second amplification circuit 15 and extracts only the frequency component exceeding the threshold voltage and outputs it as shown in FIG.

  As described above, the microcomputer 11 receives the pulse signal based on the movement of the moving object in the vehicle interior.

The microcomputer 11 stores a control program in a built-in ROM, and executes processing of the control program based on a pulse signal from the waveform shaping circuit 16. The control program calculates the moving distance calculation procedure for calculating the moving distance L of the object from the reflected wave received by the receiving-side ultrasonic sensor 30 at a certain sampling period (for example, 100 ms) and the moving distance calculating procedure. An alarm sending procedure for causing the alarm device 40 to issue an alarm when the accumulated moving distance Lt obtained by accumulating the moving distance L of the object is greater than or _equal to a predetermined _Lmin (or longer than the predetermined _Lmin ). It is something to be made. Therefore, the microcomputer 11 constitutes a movement distance calculation unit and an alarm transmission control unit.

  The detailed control contents will be described below based on the flowchart of FIG.

  First, in step S1 after the start, it is determined whether or not a certain sampling period has elapsed. If YES, the process proceeds to the following step S2, and if NO, the process returns to step S1.

  In step S2, the number of pulses P in the sampling period is counted, and the process proceeds to subsequent step S3.

In step S3, it is determined whether or not the number of pulses P is greater than or equal to a predetermined P _min (for example, P _min = 4) (or whether it is greater than the predetermined P _min ). If NO, the process proceeds to step S10.

In step S4, it is determined whether or not the number of pulses P is less than or equal to a predetermined P _max (eg, P _max = 25) (or less than a predetermined P _max ). If NO, the process proceeds to step S11.

Here, assuming that the moving object in the passenger compartment is an intruder, the following equation (3) is experimentally obtained for the moving speed V. In other words, it is a normal human movable speed. In this formula (3), for example, V _min = 0.17 m / s and V _max = 1.08 m / s.

  On the other hand, when the above equation (2) is modified, the following equation (4) is obtained for the moving speed V of the moving object.

If equation (4) is deformed into Equation (3), the following equation for the Doppler shift frequency f _r (5) is obtained. In this equation (5), for example, f _min = 40 Hz and f _max = 250 Hz.

Then, f _min to P _min and f _max to P _max are obtained, respectively.

  Accordingly, in step S2 and step S3, it is determined whether or not the moving object is moving at a normal human movable speed. That is, if YES is determined in both step S2 and step S3, it can be determined that the moving object is likely to be a human.

  In step S5, the timer count is reset, and the process proceeds to subsequent step S6.

  In step S6, the number of pulses P is converted into a movement distance L, and the process proceeds to the subsequent step S7.

  Here, the following equation (6) is experimentally obtained for the moving distance L of the moving object in the unit sampling period. In this formula (6), for example, a = 0.43 mm / piece.

In step S7, by adding the travel distance L to the accumulated travel distance L _t, the process proceeds to the next step S8.

In step S8, it is determined whether or not the cumulative movement distance Lt is greater than or _equal to a predetermined L _min (for example, L _min = 15 to 30 cm) (or whether it is longer than the predetermined L _min ). In step S9, an alarm is given to the alarm device 40. If NO, the process returns to step S1.

When the cumulative travel distance L _t is equal to or greater than a predetermined L _min, the moving object is not a vehicle interior decorations such as a human, can be the words intruder is determined to very high.

  In step S10, the number of pulses P is converted into a movement distance L, and the process proceeds to step S12.

  If NO is determined in step S3, the process proceeds to step S10. This is because the moving speed of the moving object is slow and it is determined that the moving object is unlikely to be a human, but it depends on the detection circuit and the sampling period. In consideration of the possibility of missing pulses, the number of pulses P is converted into the movement distance L.

  In step S11, the moving distance L = 0 is set, and the process proceeds to step S12.

If NO is determined in step S3, the process proceeds to step S11. This is because it is determined that the moving speed of the moving object is high and the moving object is unlikely to be a human, so the number of pulses P is set as the moving distance. It is intended to avoid adding to the cumulative movement distance L _t in terms of L.

  In step S12, it is determined whether the elapsed time since the previous timer was reset has not passed a fixed time T (for example, 500 ms). If YES, the process proceeds to step S7. If NO, the process proceeds to step S7. Proceed to S13.

  In step S13, the timer count is reset, and the process proceeds to subsequent step S14.

In step S14, the cumulative movement distance _Lt is reset and the process returns to step S1.

If NO is determined in step S12, the process proceeds to step S13 and step S14 and returns to step S1. This is because the detection of a moving object that seems to be a human is not continued for a certain period of time T, the timer and the accumulation. The movement distance _Lt is reset so that the movement distances up to that point are not accumulated.

According to such a vehicle intrusion detection system A, if the cumulative travel distance L _t of the moving object is equal to or larger than the predetermined L _min (or if longer than a predetermined L _min) an alarm, moreover, moving Since the moving distance L is accumulated when the object is moving at a normal moving speed of a human, when an alarm is issued, the possibility that the moving object is a human intruder is extremely high. A small movement of an object, such as a swinging ornament in the passenger compartment, does not issue an alarm, thus preventing a malfunction caused by misidentifying it as an intruder.

  In addition, the switch of the vehicle intrusion detection device A is turned off by releasing the door lock.

  INDUSTRIAL APPLICABILITY The present invention is useful for a vehicle intrusion detection device, a computer program used for the vehicle intrusion detection device, and a recording medium on which the computer program is recorded.

It is a block diagram which shows the intrusion detection apparatus for vehicles. It is a figure which shows a signal waveform. It is a flowchart which shows control of a microcomputer.

Explanation of symbols

A vehicle intrusion detection device 10 device body 11 microcomputer (movement distance calculation unit, alarm transmission control unit)
11a A terminal 11b B terminal 11c C terminal 12 Sensor drive circuit 13 First amplifier circuit 14 Half-wave rectifier circuit 15 BPF + second amplifier circuit 16 Waveform shaping circuit 17 Alarm sounding circuit 20 Transmission-side ultrasonic sensor (ultrasonic transmitter)
30 Receiving side ultrasonic sensor (ultrasonic receiving part)
40 Alarm (alarm transmitter)

Claims (4)

An ultrasonic transmitter for transmitting ultrasonic waves;
An ultrasonic receiving unit that receives a reflected wave from the ultrasonic transmitting unit to an ultrasonic object;
An alarm transmitter for issuing a predetermined alarm;
A moving distance calculating unit that calculates a moving distance of an object from a reflected wave received in a predetermined sampling period by the ultrasonic receiving unit;
An alarm transmission control unit that issues an alarm to the alarm transmission unit when the accumulated movement distance obtained by accumulating the movement distance of the object calculated by the movement distance calculation unit is greater than or equal to a predetermined value, or longer than a predetermined value;
A vehicle intrusion detection device comprising: In the vehicle intrusion detection device according to claim 1,
The intrusion detection device for a vehicle, wherein the moving distance calculation unit is configured to calculate a moving distance of the object from the reflected wave when the moving speed of the object calculated from the reflected wave is within a predetermined range. . To the computer to which the ultrasonic wave receiving unit for receiving the reflected wave from the ultrasonic wave transmitting unit to the object and the alarm transmitting unit for emitting a predetermined alarm are respectively connected,
A moving distance calculation procedure for calculating a moving distance of an object from a reflected wave received in a certain sampling period by the ultrasonic receiving unit;
An alarm transmission procedure for issuing an alarm to the alarm transmission unit when the accumulated movement distance obtained by accumulating the movement distance of the object calculated in the movement distance calculation procedure is greater than or equal to a predetermined value, or longer than a predetermined value;
A computer program used to execute   A computer-readable recording medium on which the computer program according to claim 3 is recorded.

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