JP2006182120A - Vehicular occupant detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular occupant detector capable of reliably detecting any abnormal load applied to a vehicle seat. <P>SOLUTION: The vehicular occupant detector comprises a measuring unit 3 to measure the load of a vehicle seat, and a signal processing unit 4 to perform the signal processing of the output of the measuring unit 3 to output the load detection signal S1. The signal processing unit 4 has an abnormal load detection unit 5 to output the abnormal load detection signal S2 discriminative from the load detection signal S1 if the measuring unit 3 measures the abnormal load outside the preset load detection range. The abnormal load detection unit 5 has a maintaining unit 47 for maintaining the abnormal load detection signal S2 for a predetermined period irrespective of the recovery of the abnormal load on the vehicle seat. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle occupant detection device that detects a load on a vehicle seat and discriminates an occupant on the vehicle seat based on detected load data.

  An example of such an apparatus is described in Patent Document 1 shown below. In this device, a load sensor is provided below the vehicle seat and a voltage signal corresponding to the load on the vehicle seat is output to the signal processing device. The signal processing device outputs a load detection signal clamped so as to correspond to a preset voltage range corresponding to an occupant weight load range from the output voltage from the load sensor. At this time, if the voltage signal measured by the load sensor is a voltage value set in a load region outside the occupant weight load range due to a collision or the like, an abnormal load detection signal is output. In other words, the device described in Patent Document 1 aims to more reliably detect that an abnormal load is applied to the load sensor by outputting an abnormal load detection signal.

JP 2002-286536 A (FIGS. 1, 5, and 5-8)

  By the way, generally in such an occupant detection device, the output that passed through the load sensor (gauge) and the signal processing device as described above is processed by an ECU (Electronic Control Unit) equipped with a microcomputer (hereinafter referred to as a microcomputer). . Therefore, the abnormal load detection signal is also input to such an ECU, and it is recognized that an abnormal load has been applied. In a normal state, when the weight of the occupant is detected as a load, the load detection signal input to the ECU is relatively static and stable. However, abnormal load detection signals due to abnormal loads that occur instantaneously, such as during a collision, change dynamically and drastically. In a circuit that performs digital signal processing, such as a microcomputer mounted on an ECU, data is generally captured and processed at regular intervals called a sampling period. For this reason, if the signal change time is faster than the sampling period, the ECU may miss this abnormal load detection signal, and as a result, the abnormal load may not be detected.

  In view of such problems, it is an object of the present invention to provide a vehicle occupant detection device that can more reliably detect an abnormal load applied to a vehicle seat.

In order to achieve the above object, the characteristic configuration of the vehicle occupant detection device according to the present invention is as follows:
A measurement unit that measures the load of the vehicle seat, and a signal processing unit that performs signal processing on the output of the measurement unit and outputs a load detection signal;
The signal processing unit outputs an abnormal load detection signal in a state distinguishable from the load detection signal when the measurement unit measures an abnormal load outside a preset load detection range. With
The abnormal load detection unit has a holding unit that holds the abnormal load detection signal for a predetermined period regardless of the recovery of the abnormal load applied to the vehicle seat.

  As described above, the abnormal load caused by a collision or the like changes dynamically and rapidly, and recovers from the abnormal load to the normal load in a short time. For this reason, the abnormality detection signal for detecting this abnormal load is not output in a short time, but if a holding part is provided as in this feature configuration, the abnormal load detection signal is maintained even after recovery to the normal load. . As a result, a subsequent device (for example, ECU or the like) that performs various determinations in response to the abnormal load detection signal can reliably detect the abnormal load without missing this signal.

  Here, the abnormal load is preferably a negative load.

  The load includes a positive load in the direction in which the load increases and a negative load in the direction in which the load decreases. For example, a negative abnormal load is generated when the load applied to the vehicle seat decreases due to the forward movement of the occupant on the vehicle seat by inertia force due to a forward collision or the like. Although a positive abnormal load is generated even in a rear-end collision or the like that is a collision in the reverse direction, it may be generated due to an impact of sitting on a vehicle seat. Therefore, if a positive abnormal load is targeted, the possibility of erroneous detection is increased. Therefore, if the detection target is a negative load as an abnormal load, the possibility of such erroneous detection can be reduced, and a vehicle occupant detection device that can detect an abnormal load reliably can be obtained.

  The abnormal load detection signal held by the holding unit is preferably released from the holding state by stopping power supply to the signal processing unit.

  When the vehicle engine is stopped and the ignition key is removed, the power supply from the battery is generally stopped. When the holding state is canceled by stopping the power supply in this way, it is possible to prevent the abnormality detection signal detected during the previous operation from being held during the next operation and causing erroneous detection. In addition, when it can be clearly determined that there is a false detection, the power supply can be stopped and returned to the initial state by control from an ECU or the like that supplies power to the signal processing unit. Therefore, if it is configured as described above and it is possible to cancel the holding of the abnormality detection signal by the holding unit, it is effective in preventing erroneous detection and promptly returning at the time of erroneous detection.

  In addition, it is preferable that the abnormal load detection unit includes a filter unit for removing the abnormal load as noise when the time measured as the abnormal load is a predetermined time or less.

  Since many electric products such as audio products and car navigation systems and electric devices such as motors are driven in the vehicle, electromagnetic noise is generated. Therefore, such electromagnetic noise is superimposed on the output of the measurement unit, and the level may be the same as when an abnormal load is applied. Further, there is a case where a load equivalent to an abnormal load is instantaneously generated due to a change in posture of an occupant seated on the vehicle seat. In such a case, it is not preferable to output an abnormality detection signal. The fluctuations (noise component signals) based on electromagnetic noise, posture change, and the like as described above occur in a very short time and are so-called high-frequency ones. In the above configuration, a filter for removing these noise component signals is provided to remove detection of abnormal loads that are observed only for a predetermined time or less. As a result, false detection can be reduced.

  An initialization unit that controls the abnormality detection unit not to output and hold the abnormality detection signal until a predetermined time elapses after the power supply to the signal processing unit is started. It is preferable to have

  Immediately after the power supply is started, the operation of the circuit is generally not completely stable. Therefore, even if it is not an abnormal load, there is a possibility that a signal similar to that when an abnormal load is detected appears. Therefore, an initialization unit is provided that performs control so that the abnormality detection signal is not output and held for a certain time (predetermined time) after the start of power supply. This is preferable because erroneous detection can be prevented.

  Further, the load detection signal is output as a voltage value, the abnormality detection signal is output as a voltage value that can be distinguished from the load detection signal, and the signal processing unit is configured to output the load detection signal and the abnormality detection. The signal may be output using the same terminal.

  If the load detection signal is output as a voltage value, the load can be known in a simple manner according to the voltage, which is preferable because the processing load of various circuits in the subsequent stage can be reduced. Further, the abnormality detection signal can be distinguished from the load detection signal as a voltage value outside the range (load detection range) of the load detection signal. Therefore, it is possible to simply know that an abnormal load is applied according to this voltage. Further, since the load detection signal and the abnormality detection signal can be distinguished by the voltage value, both signals can be output using the same terminal. As a result, a subsequent processing device, such as an ECU, can obtain whether or not an abnormal load has been applied and the value of the load depending on the voltage level of one signal. This is useful for increasing the processing speed and reducing the size of the apparatus.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram of a vehicle occupant detection device according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing an example in which the vehicle occupant detection device of FIG. 1 is installed in a vehicle seat.

  As shown in FIG. 2, a plurality of sensors 2 as load detection devices are assembled to the lower part of the vehicle seat 20, and configured to measure the load caused by the occupant seated on the vehicle seat 20. The sensors 2 are provided on the seat rail 26 of the vehicle seat 20 as sensors 21 to 24 at four locations, a right front portion, a right rear portion, a left front portion, and a left rear portion, respectively. The sensors 21 to 24 are connected to an ECU (Electronic Control Unit) 1 as a control device via a transmission line 25.

  In the present embodiment, the sensor 2 is configured by using a gauge (resistor strain gauge) 3 including four resistors 3a, 3b, 3c, and 3d that are bridge-connected as shown in FIG. Resistors 3a and 3b and resistors 3c and 3d are connected in series, and are connected in parallel, and a power supply voltage is applied to both ends of the parallel connection via the signal processing unit 4. . A voltage V1 corresponding to the strain, that is, corresponding to the load, appears between the midpoint of the resistors 3a and 3b and the midpoint of the resistors 3c and 3d. This voltage V1 follows substantially linearly with respect to the applied load. The gauge 3 corresponds to the measurement unit of the present invention, and the voltage V1 corresponds to the output of the measurement unit of the present invention.

  The output (voltage V1) of the gauge 3 is input to the signal processing unit 4, and is input to the primary amplification unit 41 through the noise filter 40a. The primary amplifying unit 41 amplifies the voltage V1, amplifies it together with various adjustments such as zero adjustment and sensitivity adjustment for adjusting the voltage at zero load, and outputs it as a signal of voltage level V2.

  In the secondary amplifying unit 42, the output of the primary amplifying unit 41 is amplified so as to have a voltage suitable for processing by the ECU 1, which is a subsequent processing unit. The clamp unit 43 determines and outputs a signal range corresponding to the load detection range from the output of the secondary amplification unit 42 (load detection signal S1 in FIG. 1). The output signal is output to the ECU 1 via the filter (noise filter) 40c of the output unit (see the load detection signal S3 in FIG. 1).

  The power is controlled by the ECU 1 and supplied to the sensor 2 (signal processing unit 4 and gauge 3). For this reason, a noise filter is also inserted in the power supply line in order to remove the influence of noise received between the ECU 1 and the signal processing unit 4 having a relatively long wiring as shown in FIG. In FIG. 1, reference numeral 40b denotes a power supply voltage Vcc filter, and reference numeral 40d denotes a GND filter.

  FIG. 3 is a graph showing the voltage level of the load detection signal S3 output to the ECU 1 from the sensor 2 (signal processing unit 4) of FIG. As shown in FIG. 3, when the load detection signal S3 is output from the clamp unit 43, the voltage level is limited between the upper limit voltage CL2 and the lower limit voltage CL1. In FIG. 3, the range indicated by the symbol L0 on the horizontal axis (the range indicated by the symbol V0 on the vertical axis) is an occupant detection range for detecting the occupant's load. Since the occupant detection range may be displaced due to a deviation of the zero point of the sensor 2 (gauge 3), a wider load detection range L3 is set. The voltage range corresponding to this is the voltage range between the upper limit voltage CL2 and the lower limit voltage CL1 described above.

  On the other hand, when a voltage value outside this voltage range (load detection range) is detected, for example, when an abnormal load is applied due to a collision or the like, the following occurs. For example, when the gauge 3 is greatly distorted with respect to the passenger's load, the output (voltage V1) of the gauge 3 shown in FIG. This signal is amplified by the primary amplifier 41 and then applied to the abnormality detector 5 as the voltage V2. When the voltage V2 exceeds TH1 ', which is a voltage level exceeding the upper limit voltage CL2, the abnormality detection unit 5 detects it as an abnormal load. Then, a voltage value higher than the upper limit voltage CL2 is output as an abnormality detection signal. In the present embodiment, Vcc, which is substantially the power supply voltage, is the voltage value of the abnormality detection signal. FIG. 3 shows an example in which an abnormal load in the negative direction is detected in the range of the symbol L4 and an abnormal detection voltage higher than the upper limit voltage CL2 of the load detection signal is output. Here, the load range indicated by the symbols L1 and L2 is not an occupant detection range but an abnormal load has been reached. In the above description, the case where the voltage V1 of the output of the gauge 3 is large has been described. However, an abnormal load that is positive or negative in vibration is often observed with respect to one impact, and it is sufficient to target one of them. is there. The abnormal load detection is performed by setting a threshold value TH1 corresponding to the above TH1 'for the output voltage V2 of the primary amplifying unit 41. That is, a determination is made to output an abnormality detection signal when the output voltage V2 of the primary amplifying unit 41 exceeds the threshold value TH1. Details will be described later.

  Since the abnormality detection signal detects an abnormal load that dynamically changes such as a collision, the output time is short. Therefore, the ECU 1 may miss this abnormality detection signal. Therefore, as shown in FIG. 1, the abnormal load detection unit 5 includes a comparison unit 44, an initialization unit 45, a filter 46, and a holding unit 47 to solve this problem.

[First embodiment]
A detailed circuit diagram of the abnormal load detector 5 is shown in FIG. As shown in FIGS. 1 and 4, the output voltage V <b> 1 of the gauge 3 is input as a voltage V <b> 2 to the secondary amplification unit 42 and the abnormal load detection unit 5 through the noise filter 40 a and the primary amplification unit 41. Is done. The signal processing on the side input to the secondary amplifier 42 is as described above. Hereinafter, the signal processing on the side input to the abnormal load detection unit 5 will be described.

  First, the comparison unit 44 determines whether or not the load is out of the load detection range. More specifically, the comparator CO1 is used to determine which of the threshold value TH1 and the output voltage V2 from the gauge 3 (primary amplifier 41) is greater. The threshold value TH1 is set by dividing the voltage between the power supply voltage Vcc and GND (ground) by resistors R1 and R2. When the comparator CO1 detects an abnormal load in the negative direction, the output voltage V3 changes from near 0V which is the GND level to near the power supply voltage Vcc which is the high level.

  The output of the comparator CO1 is input to the filter 46 through the initialization unit 45. The filter 46 constitutes an integration circuit (low-pass filter) by the resistor R7 and the capacitor C2. Therefore, the output voltage V5 of the filter 46 rises gently. In the present embodiment, a configuration using a low-pass filter using a CR circuit is shown. However, the configuration is not limited to this, and other configurations such as a low-pass filter using an LC circuit may be used.

  The output of the filter 46 is input to the transistor TR2 of the holding unit 47. In this embodiment, the transistor TR2 is an NPN transistor. The transistor TR2 switches according to the base voltage (the holding unit drive voltage V5 that is the output of the filter 46). When the voltage of the holding unit drive voltage V5 rises and a current of a predetermined level or more flows through the base of the transistor TR2, the transistor TR2 is driven. If the holding unit drive voltage V5 is equal to or lower than the base voltage of the transistor TR2, the transistor TR2 is not driven. The output voltage V3 of the comparator CO1 has a square wave shape. A signal that should not be detected as an abnormal load, such as noise, is also a square wave with a short pulse width. Since the filter 46 constitutes an integrating circuit, the holding unit drive voltage V5 does not reach the base voltage of the transistor TR2 in the case of a signal waveform with a short pulse width originating from noise or the like. That is, the noise signal waveform is removed by the filter 46. Note that the same applies when an FET (field effect transistor) or a comparator is used instead of the transistor TR2.

  The collector of the transistor TR2 is connected to the base of the transistor TR4 through the resistor R8 and to the base of the transistor TR3 through the resistor 9. As described above, when the transistor TR2 of the holding unit 47 is driven, the collector becomes almost conductive with the emitter having the GND potential. As a result, the voltage between the emitter and the base of the transistor TR4 of PNP type rises, a base current flows, and the transistor TR4 is driven. The emitter of the transistor TR4 is connected to the power supply voltage Vcc, and the power supply voltage Vcc appears at the collector when the collector and the emitter become substantially conductive. When the power supply voltage Vcc is 5V, a voltage of approximately 4.8V or higher is output to the collector. The output of the transistor TR4 becomes an abnormal load detection signal S2.

  On the other hand, by driving the transistor TR2, the voltage between the emitter and base of the transistor TR3 of the holding unit 47 rises, a base current flows, and the transistor TR3 is driven. By driving the transistor TR3, the holding unit drive voltage V5 becomes substantially the power supply voltage Vcc. As a result, the holding unit drive voltage V5 substantially maintains the power supply voltage Vcc regardless of a decrease in the potential of the abnormal load detection voltage V3. Therefore, the transistor TR2 continues to be driven and the transistor TR4 also continues to be driven. As a result, the abnormal load detection signal S2 holds an output of 4.8 V or more which is substantially the power supply voltage Vcc.

  The abnormal load detection signal S2 is connected to the same signal line as the load detection signal S1 as shown in FIGS. 1 and 4 (see point B), and passes through an output filter (noise filter) 40c to the ECU 1. Is output. As already described with reference to FIG. 3, the abnormal load detection signal S2 and the load detection signal S1 have different voltages and can be distinguished from each other. Thus, the abnormal load detection signal S2 and the load detection signal S1 are output from the same terminal via the same signal line. ing. That is, when the abnormal load detection signal S2 is generated, the voltage of the abnormal load detection signal S2, which is a higher voltage, is output to the ECU 1 as an output voltage value.

  In this way, the abnormal load detection signal S2 is generated based on the holding unit drive voltage V5. If the abnormal load detection signal S2 is generated in an unstable state such as immediately after the power supply, an erroneous detection may be caused. Therefore, the initialization unit 45 that controls the abnormal load detection voltage V3 is provided. As shown in FIG. 4, a divided voltage V4 obtained by dividing the power supply voltage Vcc and GND by resistors R3 and R4 is input to the plus side terminal of the comparator CO2. On the other hand, a divided voltage obtained by dividing the power supply voltage Vcc and GND by resistors R5 and R6 is input to the minus side terminal of the comparator CO2 so as to be equal to or higher than the voltage dividing resistor V4. Further, a capacitor C1 is connected in parallel to the voltage dividing resistor R6 on the GND side of the negative terminal, and a predetermined time T1 is required until the divided voltage by the resistors R5 and R6 is reached.

  When power is supplied, the divided voltage generated by the resistors R5 and R6 requires a predetermined time T1 to rise, so that the divided voltage V4 at the positive terminal of the comparator CO2 is higher. Accordingly, the output of the comparator CO2 becomes high level (Vcc), and this output drives the NPN transistor TR1. By driving the transistor TR1, the holding unit driving voltage V5 is substantially fixed to the GND potential, and the holding unit 47 cannot be driven. When the predetermined time T1 elapses and the divided voltage by the resistors R5 and R6 exceeds the divided voltage V4 by the resistors R3 and R4, the output of the comparator CO2 becomes low level (GND). As a result, the transistor TR1 enters a non-driving state, and the holding unit driving voltage V5 is determined by the abnormal load detection voltage V3.

  Thus, by providing the initialization unit 45, it is possible to control so as not to output and hold the abnormal load detection signal S2 for a predetermined time T1 after the start of power supply. Note that a function of releasing the holding of the abnormal load detection signal S2 can be added by using the function of the initialization unit 45. By stopping the supply of power to the abnormal load detection unit 5 while the abnormal load detection signal S2 is held, or by supplying the power after the stop, the holding of the abnormal load detection signal S2 can be released. Further, it can be canceled by providing a switch or a signal input for discharging the charged capacitor C1 or setting the base voltage of the transistor TR1 to a high level.

[Second Embodiment]
Next, as shown in FIG. 5, an embodiment in which the voltage level of the abnormal load detection signal S2 (hereinafter referred to as S12 in the second embodiment) is set to approximately GND will be described. This is a case where, on the graph of FIG. 5, the voltage level further falls below TH2 ′, which is a voltage level lower than the lower limit voltage CL1 after passing through the secondary amplifying unit 42. At this time, the abnormal load detection unit 5 of the signal processing unit 4 outputs a GND level abnormality detection signal using this as an abnormal load. FIG. 6 is a detailed circuit diagram of the abnormal load detection unit 5 suitable for this embodiment.

  Also in the second embodiment, the input to the abnormal load detection unit 5 is not the output side of the secondary amplification unit 42. Similar to the previous embodiment, it is the output side of the primary amplifying unit 41 or the input side of the upstream primary amplifying unit 41 (the output of the gauge 3). As will be described later, in this embodiment, since the small side (negative abnormal load) is detected, the signal before amplification by the primary amplification unit 41 may be easier to handle. The circuit diagram shown in FIG. 6 shows an example in which the output of the primary amplifying unit 41 is input to the abnormal load detecting unit 5 as in the previous embodiment for ease of explanation. The TH2 'is actually a threshold value TH2 corresponding to the voltage on the input side or output side of the primary amplifying unit 41.

  First, the comparison unit 44 determines whether or not the load is out of the load detection range. Specifically, the comparator CO11 is used to determine which of the threshold value TH2 and the output voltage V2 from the primary amplifier 41 is greater. The threshold value TH2 is set by dividing the voltage between the power supply voltage Vcc and GND (ground) by resistors R11 and R12. When the comparator CO11 detects an abnormal load, its output changes from a high level (60% or more of the power supply voltage Vcc) to a GND level (0.8 V or less).

  The abnormal load detection signal V13, which is the output of the comparator CO11, is input to the holding unit 47 through the filter 46. The filter 46 constitutes an integration circuit (low-pass filter) by the resistor R13 and the capacitor C11. Therefore, the output voltage (holding unit drive voltage) V15 of the filter 46 changes gently. In the present embodiment, a configuration using a low-pass filter using a CR circuit is shown. However, the configuration is not limited to this, and other configurations such as a low-pass filter using an LC circuit may be used.

  The output (V15) of the filter 46 is input to the transistor TR11 of the holding unit 47. In this embodiment, the transistor TR11 is a PNP type transistor. When the transistor TR11 of the holding unit 47 is driven, the transistors TR12 and TR13 are also driven. As a result, the emitter-collector of the transistor TR13 becomes substantially conductive, and an abnormal load detection signal S12 having a potential lower than the lower limit voltage CL1 and approximately GND level (0.2 V or less) is obtained. Even if the abnormal load detection voltage V13 returns to the high level, the transistor TR12 remains in the driving state, so that the transistors TR11 and TR13 continue to be in the driving state, and the abnormal load detection signal S12 is held.

  Since the initialization unit 45 has the same configuration as that of the previous embodiment, the illustration in FIG. 6 and the description in the second embodiment are omitted. Similar to the previous embodiment, it functions to ensure stability at a predetermined time T1 immediately after power supply. The same is true in that the function of the initialization unit 45 can be used to add a function of releasing the holding of the abnormal load detection signal S12. By stopping the supply of power to the abnormal load detection unit 5 while the abnormal load detection signal S12 is held, or by supplying the power after the stop, the holding of the abnormal load detection signal S12 can be released. Further, it can be canceled by providing a switch or a signal input for discharging the charged capacitor C1 or setting the base voltage of the transistor TR1 to a high level.

  As described above, according to the present invention, it is possible to provide a vehicle occupant detection device that can more reliably detect an abnormal load applied to a vehicle seat.

  INDUSTRIAL APPLICABILITY The present invention can be used to ensure detection of an abnormality in a sensor with an abnormality detection function that uses a signal that changes statically during normal times and dynamically changes abruptly when abnormal. . For example, detection of an abnormal load such as at the time of a collision in a vehicle occupant detection device that detects the load on the vehicle seat and determines the occupant on the vehicle seat based on the detected load data.

1 is a schematic block diagram of a vehicle occupant detection device according to an embodiment of the present invention. The schematic diagram which shows an example in which the passenger | crew detection apparatus of the vehicle of FIG. 1 was installed in the vehicle seat. The graph which shows the voltage level of the load detection signal output to ECU from the sensor of FIG. Detailed circuit diagram of the abnormal load detector in FIG. The graph which shows the other example of the voltage level of the load detection signal output to ECU from the sensor of FIG. Detailed circuit diagram of abnormal load detector corresponding to another example of voltage level of load detection signal shown in FIG.

Explanation of symbols

1 ECU
2 Sensor 3 gauge (resistor strain gauge, measuring part)
4 Signal processing unit 5 Abnormal load detection unit 47 Holding unit S1 Load detection signal S2 Abnormal load detection signal

Claims (6)

A vehicle occupant detection device including a measurement unit that measures a load on a vehicle seat and a signal processing unit that performs signal processing on an output of the measurement unit and outputs a load detection signal,
The signal processing unit outputs an abnormal load detection signal in a state distinguishable from the load detection signal when the measurement unit measures an abnormal load outside a preset load detection range. With
The abnormal load detection unit is a vehicle occupant detection device having a holding unit that holds the abnormal load detection signal for a predetermined period regardless of recovery of the abnormal load applied to the vehicle seat.   The vehicle occupant detection device according to claim 1, wherein the abnormal load is a negative load.   The vehicle occupant detection device according to claim 1 or 2, wherein the abnormal load detection signal held by the holding unit is released from the holding state by stopping power supply to the signal processing unit.   The said abnormal load detection part is provided with the filter part for removing this as noise, when the time measured as the said abnormal load is less than predetermined time. Vehicle occupant detection device.   The abnormality detection unit includes an initialization unit that controls to not output and hold the abnormality detection signal until a predetermined time elapses after power supply to the signal processing unit is started. The vehicle occupant detection device according to any one of claims 1 to 4.   The load detection signal is output as a voltage value, the abnormality detection signal is output as a voltage value distinguishable from the load detection signal, and the signal processing unit includes the load detection signal and the abnormality detection signal. The vehicle occupant detection device according to any one of claims 1 to 5, wherein the vehicle is output using the same terminal.

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