JP2008252190A - Data processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data processor capable of preventing an erroneous operation when the level of a signal in a certain period of a steep rise temporarily drops. <P>SOLUTION: When deciding that period differences of a plurality of peaks of an input signal are nearly equal to one another and a rise time of the waveform is short, the constant-period noise recognizing unit 24 of a microcomputer 21 decides that the input is an external noise and inhibits a decision unit 23 from performing decision processing. When the rise time of the waveform is short and periods are different, it is decided that the input signal seems to be an external noise and data processing is postponed in the case that period differences after a peak having dropped in level is removed from the plurality of peaks are within a set value, so even when the level of the signal in the constant period of the steep rise temporarily drops, the data processing is not performed to prevent the erroneous operation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a data processing apparatus that performs data processing such as waveform feature detection by A / D conversion output of an input signal, and more particularly to a data processing apparatus that can prevent malfunction due to noise.

There are many devices that perform some control based on a signal obtained from a certain sensor. For example, in a vehicle security system, unauthorized opening of a door, entry into a vehicle interior, vehicle vibration, When an illegal intrusion such as a broken glass is detected, an alarm is generated, or an intrusion sensor at a predetermined location is notified by radio. The presence or absence of unauthorized intrusion into the vehicle is detected by extracting the fluctuation of the waveform (see, for example, Patent Document 1).
JP 2004-142660 A

FIG. 1 is a block diagram showing the configuration of a general security system. The security ECU 31 has a keyless entry function for performing lock control, and performs vehicle door lock / unlock control, door open / close control, An alarm is issued when the vehicle interior is intruded by unauthorized means, and arming / disarming control, vehicle door lock / unlock control, etc. are performed in response to a request signal from the transmitter 32.
The transmitter 32 has a lock button L and an unlock button U. When the lock button L is pressed, security setting (arming) is performed, and when the unlock button U is pressed, security reset (disarming) is performed.

  The security ECU 31 includes a courtesy SW 33 for detecting the open / closed state of the door, a hood SW 34 for detecting the open / closed state of the hood, and an intrusion for detecting that the door has been opened or the vehicle has been intruded by other than a proper method. SW and sensor outputs such as a sensor 35, a vibration sensor 36 for detecting vehicle vibration, an IGSW 37 for detecting an on / off switching state of an ignition switch, and a lock position SW 38 for detecting door locking and unlocking are input. In addition, a lock motor 39 that drives a door lock mechanism that locks and unlocks the door, a horn 40 that performs an alarm operation at the time of alarm, a hazard lamp 41, and the like are connected.

FIG. 2 shows an example of the intrusion sensor 35, which is a block diagram showing the configuration of an intrusion sensor using millimeter wave band high frequency signals. The output of the oscillation circuit 51 that generates a high frequency signal of 4 MHz is shown in FIG. The multiplication / amplification circuit 52 multiplies and amplifies the signal to a frequency signal of 24 GHz and transmits the signal from the transmission antenna 53. Then, the reflected wave that is reflected when the transmission radio wave from the transmission antenna 53 strikes a surrounding object is received by the reception antenna 54, and the reception signal from the reception antenna 54 and the transmission signal from the multiplication / amplification circuit 52 are combined by the mixing circuit 56. The signals are mixed and input to the detection circuit 57.
Then, the detection circuit 57 extracts the frequency component of the difference between the reception signal and the transmission signal as a beat signal, and the microcomputer 58 changes the waveform due to the movement of the object based on the data obtained by A / D converting the output of the detection circuit 57. The presence or absence of unauthorized intrusion into the vehicle is detected by extracting.

In the data processing apparatus using a microcomputer that processes the input signal like the above intrusion sensor, the signal from the sensor is sampled by the A / D converter and digitized, and the data processing circuit is based on the digital signal. Judgment processing is performed.
In this case, if the sampling period is short, the A / D converted waveform is close to the original signal, but if the sampling period is long, the A / D converted waveform is far from the original signal. Therefore, when the maximum frequency included in the original signal is fp, the sampling frequency is usually set to 2 fp or more.

  In such a data processing apparatus, when a signal having a frequency higher than the frequency component necessary for the system is input to the sensor as external noise, the signal having a frequency component higher than the sampling frequency of the A / D converter has a waveform. Since it is not possible to recognize whether the noise is external noise or not, there is a possibility of malfunction, and therefore, when high-frequency noise enters, it is necessary to stop data processing.

  In addition, some data processing devices detect a signal with a substantially constant time interval even though the cycle is indefinite. When a power-on / off signal of a mobile phone as shown in FIG. 3 is input, since such a signal cannot be recognized well unless the sampling frequency of the A / D converter is increased, the data processing apparatus May malfunction.

  For this reason, conventionally, as shown in FIG. 4, (1) 450 ms has not elapsed since the output voltage of the sensor became 0.45 V or higher, (2) the maximum value of the period difference of each peak of the input waveform is 10 ms. (3) The number of peaks of the input waveform is 7 or more, (4) The sensor signal is being generated, that is, the sensor output voltage is less than 0.45 V for 100 ms, (5) When the five conditions that the peak generation time, that is, the sum of the seven peaks of the time from when the sensor output exceeds the reference voltage until the peak voltage occurs is 25 ms or less are satisfied, By prohibiting the data processing based on this, malfunction is prevented when a signal having a constant period with a sharp rise is input.

  As described above, conventionally, the determination time range is limited, that is, the determination is made with data within 450 ms from the signal generation, so the level of the external noise falls within that time, and the condition for determining the external noise When the periodicity is not correctly acquired, for example, when the level of the external noise temporarily decreases and the period becomes large as in periods T4 and T10 in FIG. 5, the maximum value of the period difference is 10 ms. Since the following conditions are not satisfied, the above-mentioned logic does not operate, detection is not prohibited, and an intruder is erroneously detected.

  Also, the waveform when the intruder enters the vehicle, that is, the pick-up waveform happens to be a waveform that satisfies the above five conditions as shown in FIG. However, when a waveform with a constant and a peak time that does not change so much is detected, there is a problem that data processing, that is, intruder detection processing is prohibited.

  The present invention has been made in view of the above problems, and can prevent malfunction even when the level of a signal having a constant period with a steep rise is temporarily reduced, and can prevent an input that is not external noise. It is an object of the present invention to provide a data processing apparatus capable of executing data processing even when a waveform temporarily satisfies an external noise determination condition.

  In order to achieve the above-described object, the data processing apparatus according to the present invention, when determining that the period difference between the plurality of peaks of the input signal is substantially the same and the rise time of the waveform is within a predetermined time, When the waveform rise time is within the predetermined time and the period is different, the period difference after removing the peaks whose level is below the predetermined level among the plurality of peaks is within the set value. Data processing was postponed because it seemed to be noise, and when it was determined that the rise time of the waveform exceeded a predetermined time in this postponed state, the postponement was terminated and data processing was carried out.

  Even when the data processing is prohibited, when it is determined that the rise time of the waveform has exceeded the predetermined time, the data processing prohibition is canceled and the subsequent data processing is not prohibited.

According to the data processing apparatus of the present invention, when the rise time of the waveform is within a predetermined time and the period is different, the period difference after removing a peak whose level is equal to or lower than the predetermined level among a plurality of peaks is set. If the value is within the range, data processing is postponed because it seems to be external noise, so even if the signal level of a constant cycle with a sharp rise rises temporarily, data processing is not performed and malfunctions are prevented. Can do.
Further, when it is determined that the rise time of the waveform exceeds the predetermined time in the data processing postponed state and the input signal is not external noise, the data processing postponement ends and data processing can be performed.

  Furthermore, even if it happens that an external noise determination condition is met with a pick-up waveform, that is, even if a waveform with a constant period difference and no change in time to peak is detected and data processing is prohibited, As shown in FIG. 6B, when a rise time up to a peak not seen in the external noise occurs, the data processing prohibition can be canceled and the subsequent data processing prohibition is not performed. It is possible to prevent erroneous prohibition of data processing.

Hereinafter, an embodiment in which the data processing apparatus of the present invention is applied to an intrusion sensor of a security system will be described.
FIG. 7 is a block diagram showing the system configuration of the security system. This system is composed of an intrusion sensor 1, a security ECU 2, a horn 3, and the like. If a disturbance in the frequency of the radio wave is detected when a person moves in the passenger compartment, the security ECU 2 is notified, and the security ECU 2 performs an alarm operation by a horn 3 or a hazard lamp (not shown).

  The intrusion sensor 1 generates an oscillation circuit 11 that generates a high-frequency signal of 4 MHz, and multiplies and amplifies the output of the oscillation circuit 11 and outputs the output to the transmission antenna 13, and branches a part of the output signal to the mixing circuit 16. A multiplying / amplifying circuit 12, a receiving antenna 14 for receiving a reflected wave that is reflected when a transmission radio wave from the transmitting antenna 13 strikes a surrounding object, a receiving circuit 15 for receiving a signal from the receiving antenna 14, A mixing circuit 16 that mixes and outputs a reception signal from the reception circuit 15 and a transmission signal from the multiplication / amplification circuit 12, a detection circuit 17 that detects the mixed output from the mixing circuit 16, and an output of the detection circuit 17 is input. The sample hold circuit 18, the low frequency amplifier 19 to which the output of the sample hold circuit is input, the intermittent drive circuit 20, and the microcomputer 21 are included.

The microcomputer 21 extracts the frequency component of the difference between the reception signal and the transmission signal as a beat signal, and inputs an A / D converter 22 to which a signal from the low-frequency amplifier 19 that removes the offset voltage is input. The A / D conversion output of the D converter 22 is input, and a determination unit 23 that determines intrusion of a suspicious person, a periodic noise recognition unit 24, and an AND circuit 25 are included.
During the operation of the intrusion sensor 1, in order to reduce power consumption, the microcomputer 21 sends a signal to the intermittent drive circuit 20 at regular intervals, and when the intermittent drive circuit 20 receives a signal from the microcomputer 21, it oscillates for a certain period of time. The circuit 11 is driven.

  The output of the oscillation circuit 11 that generates a high frequency signal of 4 MHz is multiplied and amplified to a frequency signal of 24 GHz by the multiplication / amplification circuit 12 and transmitted from the transmission antenna 13. The reflected wave that is reflected when the transmission radio wave from the transmission antenna 13 strikes a surrounding object is received by the reception antenna 14 and input to the reception circuit 15, and the reception signal from the reception circuit 15 and the transmission from the multiplication / amplification circuit 12 are received. After the signal is mixed by the mixing circuit 16, it is detected by the detection circuit 17.

This detection signal is input to the low frequency amplifier 19 via the sample hold circuit 18, the frequency component of the difference between the reception signal and the transmission signal is input to the microcomputer 21 as a beat signal, and the microcomputer 21 outputs the output of the low frequency amplifier 19. Based on the A / D converted data, the presence or absence of unauthorized intrusion into the vehicle is detected by extracting the fluctuation of the waveform due to the movement of the object.
That is, the determination unit 23 performs a determination process based on the output of the A / D converter 22, for example, an intrusion determination process that detects the movement of a person and determines the presence of a person.

  On the other hand, the fixed-cycle noise recognizing unit 24 determines whether or not a signal with a sharp rising edge is input as a fixed-cycle signal based on the output of the A / D converter 22, and has a constant cycle with a sharp rising edge. When a signal is input, a high-level signal is output to the AND circuit 25, and output of the determination processing output of the determination unit 23 to the security ECU 2 is prohibited. The determination result is prevented from being input to the security ECU 2.

FIG. 8 is a diagram showing a hardware configuration for realizing the functions of the determination unit 23, the fixed-cycle noise recognition unit 24, and the AND circuit 25 of the microcomputer 21, and includes an A / D converter 22, a CPU 26, a ROM (Read Only Memory). ) 27 and RAM 28 (Random Access Memory).
The CPU 26 controls each part of the hardware of the microcomputer 21 and executes various programs such as a suspicious person intrusion determination program based on a program stored in the ROM 27. The RAM 28 is composed of SRAM or the like, and stores temporary data generated when the program is executed, for example, the sampling value from the A / D converter 22, the number of peaks in the input waveform, the period difference, the time to peak, and the like. In addition to storing, a flag storage area for storing a detection prohibition flag, a detection prohibition release flag, and a detection determination postponement flag is provided.
As described above, the determination unit 23, the fixed-cycle noise recognition unit 24, and the AND circuit 25 are configured by the CPU 26, the ROM 27, and the RAM 28, and their functions are executed by software.

Next, the operation of the intrusion determination process and the determination prohibition process performed by the CPU 26 will be described with reference to the flowcharts of FIGS.
The CPU 26 always determines whether or not the level of the input signal exceeds 0.45 V based on the A / D conversion output input every 0.5 ms from the A / D converter 22, as shown in FIG. When the level of the input signal exceeds 0.45 V, the intrusion determination processing program shown in the flowcharts of FIGS. 9A, 9B, and 10 is started, and the sampling value from the A / D converter 22 is transferred to the RAM 28. Is stored (step 101).

Next, the CPU 26 determines based on the sampling value stored in the RAM 28 whether or not the sensor signal is being generated, that is, whether or not the state where the sampling value is less than 0.45 V continues for 100 ms (step 102). If it is determined that the sensor signal is being generated, the number of peaks in the input waveform and the signal generation time based on the sampling value stored in the RAM 28, that is, the elapsed time since the input signal level exceeded 0.45V for the first time. And updating the peak voltage (step 103).
As shown in FIG. 11, the CPU 26 counts up the number of peaks when the current sampling value exceeds 0.45V from less than 0.45V, but counts if it is not lower than 0V from the previous count-up. Do not up.

When the number of peaks in the input waveform, the signal generation time, and the peak voltage are updated, the CPU 26 determines whether or not it is the determination timing, that is, whether or not the current sampling value exceeds 0.45 V from less than 0.45 V. (Step 104), and if it is determined that it is not the determination timing, the subsequent detection prohibition and prohibition release steps are not executed.
If the current sampling value is less than 0.45 V and exceeds 0.45 V and it is determined that the determination timing is reached, the CPU 26 determines whether or not the current number of peaks is 7 or more (step 105). If it is determined that the number is not 7 or more, subsequent detection prohibition and prohibition release steps are not executed.

  On the other hand, if it is determined in step 105 that the number of peaks is 7 or more, the CPU 26, as shown in FIG. 5, determines the absolute period difference between the peaks T1, T2,. The values | T2-T1 |, | T3-T2 |,... Are calculated, and the maximum value Max of the period differences for the past seven peaks is stored in the RAM 28 (step 106). If the maximum value Max of the period difference for the past seven peaks is already stored in the RAM 28, the value is updated.

Next, the CPU 26 calculates a time integration value Tp up to the peak for the past seven peaks, and stores or updates it in the RAM 28 (step 107).
That is, as shown in FIG. 12, the CPU 26 calculates the time tp1, tp2, tp3,... From the rising edge to the peak of the waveform, and the integrated value Tp of the time tp from the rising edge to the peak of the past seven peaks. Ask for.

  When the above calculation is completed, the CPU 26 determines whether or not the time integrated value Tp until the peak of the past seven peaks is smaller than 25 ms (step 108), and if it is determined that the time integrated value Tp is smaller than 25 ms, It is determined that there is a possibility of external noise in the input waveform, and it is determined whether or not the detection prohibition release flag stored in the RAM 28 is on (step 109).

  If it is determined that the detection prohibition release flag is turned on, the CPU 26 does not execute the subsequent detection prohibition determination step because the detection prohibition has been released in the past, and the detection prohibition release flag is turned off. If it is determined that the detection prohibition has not been released in the past, it is determined whether or not the maximum value Max of the period difference for the past seven peaks is smaller than 10 ms (step 110).

  If it is determined that the maximum value Max of the period difference for the past seven peaks is smaller than 10 ms, the CPU 26 determines that a fixed period noise is generated with a signal having a fixed period and the rise of the signal is steep, and stores the flag in the RAM 28. When the region detection prohibition flag is turned on (step 111), and it is determined that the maximum value Max of the period difference for the past seven peaks is greater than 10 ms, it is determined that it is not periodic noise, and the detection prohibition flag is not turned on.

  On the other hand, if it is determined in step 108 that the time integration value Tp is greater than 25 ms, it is determined that the input signal is not fixed period noise, and the detection prohibition release flag stored in the RAM 28 is turned on (step 112), and then detection prohibition is performed. If the flag is on, the detection prohibition flag is turned off (step 113).

  As a result, even if the waveform that satisfies the fixed-cycle noise determination condition is detected in the pick-up waveform and the detection prohibition flag is turned on, the rise time to the peak that is not seen in the fixed-cycle noise occurs. Since the detection prohibition flag is turned off and the detection prohibition release flag is turned on, the detection prohibition flag is not turned on again in the subsequent processing.

  If it is determined in step 104, step 105, step 109, or step 110 that the subsequent steps are not executed, or after the flag on / off processing is performed in steps 111 and 113, the CPU 26 The detection determination postponement step shown in the flowchart is executed, and it is determined from the determination timing, that is, from the sampling value at that time, whether or not the time is the end of the period determination range of one mountain (step 114).

  If it is determined that it is not the end of the period determination range for one mountain, the CPU 26 does not execute the subsequent detection determination postponement step, but at the end of the period determination range for one mountain as shown in FIG. If it is determined that the number of peaks is 7 or more (step 115), and if it is determined that the number of peaks is not 7 or more, the subsequent detection determination postponing step is executed. do not do.

On the other hand, if it is determined that the number of peaks is 7 or more, the CPU 26 calculates a cycle from the current peak peak time and the previous peak peak time (step 116), and then calculates the cycle. It is determined whether or not the level of the input signal has fallen temporarily within the range, that is, whether or not a small mountain has occurred as in periods T4 and T10 in FIG. 5 (step 117).
When it is determined that the level of the input signal is temporarily lowered, the CPU 26 deletes the previous cycle storage by adopting the calculated cycle (step 118), and does not execute the subsequent detection determination postponement step.

When it is determined in step 117 that the level of the input signal has not decreased, the CPU 26 refers to the previous cycle stored in the RAM 28 to determine whether the previous cycle is stored (step 117). 119) When it is determined that the previous cycle is not stored, the current cycle is stored in the RAM 28 as the previous cycle (step 120), and the subsequent detection determination postponing step is not executed.
If it is determined that the previous cycle is stored, the CPU 26 calculates a cycle difference between the previous cycle and the current cycle and stores it in the RAM 28 (step 121), and then sets the current cycle to the previous cycle. Is stored in the RAM 28 (step 122).

  Next, the CPU 26 determines whether or not the period difference calculated in step 121 is within a set value, for example, 5 ms (step 123). If it is determined that the period difference exceeds the set value, the fixed period If it is determined that the possibility of non-noise is high and the subsequent detection determination postponement step is not executed, and it is determined that the period difference is within the set value, it is determined that the possibility of periodic noise is high, and detection prohibition is canceled. It is determined whether or not the flag is on (step 124).

If it is determined in step 124 that the detection prohibition release flag is off, the CPU 26 determines that it is likely to be periodic noise, and turns on the detection determination postponement flag (step 125).
In this way, when the period difference after removing the peaks whose levels have temporarily decreased among the plurality of peaks is within the set value, the detection condition determination is postponed because it seems to be periodic noise, so the rise is steep. Even when the signal level of a certain period temporarily decreases, intrusion is not detected, and malfunction can be prevented.

  On the other hand, if it is determined in step 124 that the detection prohibition release flag is turned on, it is already determined that the input signal is not fixed period noise, so the CPU 26 determines that the detection determination postponement flag is turned on. Then, the detection determination postponement flag is turned off (step 126).

  If the subsequent detection determination postponement step is not executed in step 114, step 115, or step 123, the cycle is not adopted in step 118, the cycle is stored in step 120, or the detection determination is made in step 126. After turning off the postponement flag, the CPU 26 executes a detection condition determination subroutine program (step 127). The operation of the detection condition determination subroutine program will be described below with reference to the flowchart of FIG.

  When the detection condition determination subroutine program shown in FIG. 10 is started, the CPU 26 determines whether the signal generation time stored in the RAM 28 is 450 ms or more (step 201), and the input signal level exceeds 0.45 V for the first time. If the elapsed time has not reached 450 ms, the intrusion is not detected, the detection condition determination subroutine program is terminated, and the process returns to the main program.

  On the other hand, if it is determined in step 201 that the elapsed time since the level of the input signal exceeds 0.45 V for the first time exceeds 450 ms, the CPU 26 determines that the peak voltage stored in the RAM 28 is the detected threshold voltage, for example, 1 V. When it is determined whether or not the peak voltage is equal to or lower than the detection threshold voltage (step 202), the CPU 26 determines that no intrusion is detected, ends the detection condition determination subroutine program, and returns to the main program.

  When it is determined in step 202 that the peak voltage exceeds the detection threshold voltage, the CPU 26 determines whether or not the detection determination postponement flag stored in the RAM 28 is turned on (step 203). If it is determined that the postponement flag is turned on, the CPU 26 determines that no intrusion has been detected, ends the subroutine program for determining the detection condition, and returns to the main program.

  Further, when it is determined in step 203 that the detection determination postponement flag is not turned on, the CPU 26 determines whether or not the detection prohibition flag stored in the RAM 28 is turned on (step 204). If it is determined that it is turned on, the CPU 26 determines that no intrusion has been detected, ends the detection condition determination subroutine program, and returns to the main program.

  On the other hand, if it is determined in step 204 that the detection prohibition flag is not turned on, the CPU 26 determines that it is not a periodic noise and determines that a suspicious person has entered, and stores each flag and a stored value such as a time integration value up to a peak. After clearing, the intrusion determination processing and determination prohibition processing programs are terminated.

  After detecting no intrusion in the detection condition determination in step 127 or turning on the detection determination postponement flag in step 125, the CPU 26 determines whether or not the next sampling value has occurred (step 128). When the sampling value output every 0.5 ms by the / D converter 22 is input, the process returns to step 102 to determine whether or not the signal generation is continuing. If it is determined that the signal generation is continuing, the detection is prohibited again. Start the prohibition release step.

  If it is determined in step 102 that the state where the sampling value is less than 0.45 V continues for 100 ms, the CPU 26 determines that the signal has been completed, and integrates the time until the peak of each flag and the past seven peaks. The stored values such as the value Tp, the maximum value Max of the period difference for the past seven peaks, the number of peaks, the signal generation time, the peak voltage, and the current cycle are cleared (step 129), and then the program is terminated.

As described above, since the detection determination process and the detection prohibition process are executed, when a waveform as shown in FIG. 13 is input, after transition to a signal state, a small mountain in the mountain 2 due to a temporary decrease in level. Is not recognized, the detection prohibition flag is not turned on because the period difference is generated. However, the number of peaks is 7 or more, and the level is temporarily lowered, that is, the peaks 2 and 4 are excluded continuously. Since the detection determination postponement flag is turned on at the time when the difference between the peak peak periods is 5 ms or less, for example, at the time P8 in FIG. 13, the detection determination is postponed.
This detection determination postponed state ends when the time integrated value Tp up to the peak of the past seven peaks reaches 25 ms or more, and is determined to be a suspicious person intrusion detection. Further, when the signal is terminated in the detection determination postponed state, it is determined that the noise is a fixed period and is not determined as intrusion detection.

The number of peaks for determining the peak occurrence time, the voltage value for determining the presence / absence of a signal, the maximum value of the period difference / the determination value for the peak occurrence time, etc., described in the above embodiment are examples, and may be changed as appropriate. Is possible.
Further, in the above embodiment, the intrusion detection processing program is executed when the amplitude of the input signal becomes a certain value or more. However, if the period or time of the first one waveform or several waveforms is not used, Noise detection can be performed only after the waveform is stabilized.

Furthermore, in the above embodiment, to calculate the period difference of the past seven peaks, the difference between the periods of the previous and subsequent peaks was obtained. The first one waveform was used as a reference value, and the period and reference value of the subsequent waveforms were It is also possible to obtain the period difference by calculating the difference between
In the above embodiment, an example in which the data processing apparatus of the present invention is applied to a security system has been described. However, the data processing apparatus of the present invention is applied to a data processing apparatus that performs various waveform recognition other than the above. Is possible.

The block diagram which shows the structure of a general security system. The block diagram which shows the structure of an intrusion sensor. An example of a signal with a constant period and a sharp rising edge. A condition for determining a conventional signal having a constant period and a signal whose rising edge is steep. An example of the waveform in which the condition of FIG. 4 is not satisfied. An example of a pick-up waveform that is erroneously determined as noise. The block diagram which shows the structure of the security system which implemented this invention. The figure which shows the hardware constitutions of a microcomputer. The flowchart which shows the effect | action of an intrusion determination process and a determination prohibition process. The flowchart which shows the effect | action of an intrusion determination process and a determination prohibition process. The flowchart which shows the effect | action of the subroutine program of detection condition determination. Explanatory drawing of count-up of the number of the peaks of a waveform. Explanatory drawing for calculating | requiring the integrated value of the time from a rise to a peak. An example of the waveform in which a detection determination postponement process is performed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Intrusion sensor 11 Oscillation circuit 12 Multiplication / amplification circuit 13 Transmission antenna 14 Reception antenna 15 Reception circuit 16 Mixing circuit 17 Detection circuit 18 Sample hold circuit 19 Low frequency amplifier 20 Intermittent drive circuit 21 Microcomputer 22 A / D converter 23 Determination part 24 Periodic noise recognition unit 25 AND circuit 2 Security ECU
3 Horn

Claims (7)

Data processing means for processing the A / D conversion output of the input signal;
When the waveform having the same period is continuously input and the rise time of the waveform is determined to be within the predetermined time, the external noise determination means for determining the external noise is provided,
When it is determined that the input signal is external noise, the external noise determination means prohibits the data processing of the data processing means, and the data processing means when the waveform rise time is within a predetermined time and the period is different. A data processing apparatus characterized by postponing the data processing. The data processing apparatus according to claim 1, wherein
The period after the external noise determination means determines whether or not the external noise is based on the period difference and rise time of a plurality of peaks of the input signal, and removes the peaks whose level is equal to or lower than a predetermined level in the period A data processing apparatus characterized in that if the difference is within a set value, the data processing of the data processing means is postponed. In the data processing device according to claim 1 or 2,
In the data processing postponed state, the data processing device is characterized in that the external noise determination means terminates the data processing postponement when it is determined that the rising time of the waveform is a predetermined time or more. In the data processing device according to any one of claims 1 to 3,
A data processing apparatus characterized in that, when it is determined that the input signal is not external noise, data processing by the data processing means is started after a predetermined time has elapsed since the input signal was generated. In the data processing device according to any one of claims 1 to 4,
In the data processing prohibited state, when it is determined that the rising time of the waveform has reached a predetermined time or more, the external noise determination means cancels the data processing prohibition and does not prohibit the subsequent data processing. Data processing device.   A security device comprising the data processing device according to claim 1.   An intrusion sensor comprising the data processing device according to any one of claims 1 to 5.

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