JP2009046114A - Occupant detection system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an occupant detection system for a vehicle, increasing the number of executions of correcting reference values of load detection means to improve detection accuracy of the load detection means. <P>SOLUTION: The occupant detection system for a vehicle comprises: a plurality of load sensors (load detection means) 3a-3d detecting loads acting on a seat 2 disposed to the vehicle; a seating determination means (seating detection means) 5 determining whether an occupant is seated on the seat 2 based on the detection results of these load sensors 3a-3d; and a reference correction part (reference correction means) 6 correcting reference values of the plurality of load sensors 3a-3d, based on the detection result of the seating determination part 5. If the sum of absolute values of fluctuation amounts of the detection results of the plurality of load sensors 3a-3d is smaller than a predetermined threshold value after the detection result of no occupant 2 on the seat is inputted from the seating determination part 5, the reference correction part 6 corrects the reference values by using the detection results of the plurality of load sensors 3a-3d as of then, as reference values. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle occupant detection system that determines whether or not an occupant is seated on a vehicle seat, and more particularly to correction of a reference value of a load detection means that detects a load acting on the seat.

  2. Description of the Related Art Conventionally, an occupant detection system that determines whether an occupant is seated on a seat based on a load acting on a vehicle seat is known (see, for example, Patent Document 1).

In this occupant detection system, the reference value of the load detection means is corrected after detecting whether or not the door has changed from the closed state to the open state.
Japanese Patent Laid-Open No. 2002-341052

  By the way, in the above-mentioned occupant detection system, the reference value correction of the load detection means is not performed unless a change in the state of the door is detected.

  For this reason, the number of corrections is limited, and even when the reference value is deviated due to, for example, vibration during traveling, it cannot be corrected during traveling of the vehicle, and the detection accuracy of the load detecting means may be reduced. was there.

  In addition, there is a problem that the reference value correction of the load detecting means cannot be performed accurately when the vehicle is in an unstable state.

  Therefore, an object of the present invention is to provide a vehicle occupant detection system that can increase the number of times of accurate reference value correction of the load detection means and improve the detection accuracy of the load detection means.

  In order to solve the above problems, a vehicle occupant detection system according to the present invention is based on a plurality of load detection means for detecting a load acting on a seat provided in a vehicle, and detection results of these load detection means. A seating detection means for determining whether an occupant is seated on the seat; and a reference correction means for correcting a reference value of the plurality of load detection means based on a detection result of the seating detection means. After the detection result that the occupant is not seated on the seat is input from the seating detection unit, the correction unit calculates the sum of the absolute values of the variation amounts of the detection results of the plurality of load detection units in advance. If it is smaller than the predetermined threshold value, the reference value correction is performed using the detection results of the plurality of load detection means at that time as reference values.

  The vehicle occupant detection system according to the present invention includes a plurality of load detection means for detecting a load acting on a seat provided in the vehicle, and an occupant seated on the seat based on detection results of the load detection means. A seating detecting means for determining whether or not the seating detecting means and a reference correcting means for correcting a reference value of the plurality of load detecting means based on a detection result of the seating detecting means. A vehicle state determination unit that determines the state of the vehicle based on the detection result of the load detection unit, and after the detection result that the occupant is not seated on the seat is input from the seating detection unit, When the vehicle state determination unit determines that the vehicle is stable, reference value correction is performed using detection results of the plurality of load detection means at that time as reference values.

  The vehicle state determination unit determines that the vehicle is stable if the absolute value of the total variation amount of the detection results of the plurality of load detection means is smaller than a predetermined threshold value. May be.

  Further, the reference correction means stores a storage means for storing a predetermined number of detection results of each of the plurality of load detection means, and an average value for calculating an average value of the plurality of detection results stored in the storage means A calculation unit, and the reference value correction may be performed using the value calculated by the average value calculation unit as a reference value.

  If the reference correction means corrects the reference value of the plurality of load detection means if the sum of the absolute values of the fluctuation amounts of the detection results of the plurality of load detection means is smaller than a predetermined threshold value, Since the stable state of the vehicle can be determined based on the sum of the absolute values of the fluctuation amounts of the detection results of the detection means, the reference value correction of the load detection means is performed by selecting when the vehicle is in the stable state. Can do. That is, even when the vehicle is running, the reference value can be corrected if the vehicle is stable and the input of noise is relatively small.

  Thereby, the frequency | count of execution of exact reference value correction can be increased, and the detection accuracy of a load detection means can be improved.

  In addition, the reference correction unit has a vehicle state determination unit that determines the state of the vehicle based on the detection results of the plurality of load detection units, and when the vehicle state determination unit determines that the vehicle is stable, In the case of correcting the reference value of the load detecting means, it is possible to correct the reference value of the load detecting means by accurately selecting when the vehicle is in a stable state. That is, even when the vehicle is running, it is possible to perform the reference value correction by selecting a state in which the vehicle is stable and relatively little noise is input.

  Thereby, the frequency | count of execution of exact reference value correction can be increased, and the detection accuracy of a load detection means can be improved.

  If the vehicle state determination unit determines that the vehicle is stable if the absolute value of the total variation amount of the detection results of the plurality of load detection means is smaller than a predetermined threshold, the vehicle state This determination process can be simplified, and the load on the calculation software can be reduced. Therefore, it can be controlled by a small CPU or the like, and an increase in manufacturing cost can be suppressed.

  Furthermore, if the reference correction unit stores the detection result of the load detection unit a plurality of times and performs the reference value correction using the calculated average value as the reference value, the accuracy of the reference value correction can be increased, and the load It becomes possible to improve the detection accuracy of the detection means.

  A vehicle occupant detection system according to an embodiment of the present invention will be described with reference to the drawings.

  The vehicle occupant detection system A according to the best embodiment is incorporated in an airbag system B mounted on a vehicle.

  As shown in FIG. 1, the airbag system B mainly includes an airbag ECU 1, a vehicle occupant detection system A, an occupant state display lamp 6, an airbag 7, and a warning lamp 8.

  The airbag ECU 1 incorporates a CPU 1a and controls the deployment of the airbag 7 based on occupant information obtained from the vehicle occupant detection system A. Here, deployment control is performed such as not deploying when there is no occupant, fully deploying when an adult is on board, and not deploying when a child is on board using a child seat. ing.

  The occupant state display lamp 6 is an indicator lamp that displays occupant information such as no occupant, adult seating, and child seat installation.

  The airbag 7 is deployed to protect the occupant during a vehicle collision and exhibits a buffer function. In addition, the magnitude | size of expansion | deployment can be changed according to passenger | crew information by control of airbag ECU1.

  The warning lamp 8 is an indicator lamp for displaying a warning when a failure in the airbag system is detected.

  The vehicle occupant detection device A includes a plurality of load sensors (load detection means) 3a to 3d attached to a seat 2 provided in the vehicle, and an occupant detection ECU 4.

  The plurality of load sensors 3 a to 3 d are respectively attached to different positions of the seat 2, and detect loads at four different positions of the seat 2.

  As shown in FIGS. 2A to 2C, the load sensors 3a to 3d are, for example, the right front leg and the left front leg of the passenger seat 2 movably mounted on the seat rail 2a. , Right rear leg and left rear leg respectively. Thereby, the load which acted on each leg part is detected separately.

  The occupant detection ECU 4 includes a memory unit 4a, a seating determination unit (sitting detection unit) 5, a reference correction unit (reference correction unit) 6, an occupant determination unit (not shown), and the like.

  The memory unit 4a is a storage device to which detection values detected by the load sensors 3a to 3d are input, and the input detection values can be appropriately called by the seating determination unit 5, the reference correction unit 6, and the like.

  The seating determination unit 5 determines the presence / absence of an occupant on the seat 2 based on detection values from the load sensors 3a to 3d. Here, the sum of the detected values is compared with a predetermined threshold value, and when the sum is smaller than this threshold value, it is determined that there is no passenger.

  The reference correction unit 6 corrects the reference values of the load sensors 3a to 3d based on the detection values from the load sensors 3a to 3d.

  The reference value correction means that the detection value is a predetermined value when the detection values of the load sensors 3a to 3d when the occupant is not seated on the seat 2 change due to distortion of the vehicle body or the seat 2. The correction is performed so that the reference value or zero is obtained.

  If this reference value correction is not properly performed, the detection accuracy of the load sensors 3a to 3d will decrease.

  Then, after the determination result that there is no occupant is input from the seating determination unit 5, the reference correction unit 6 calculates the absolute value of the change amount of the detection value of each of the load sensors 3 a to 3 d. Then, the sum of these changes is compared with a predetermined threshold, and it is determined that the reference value can be corrected when the sum of the changes is smaller than this threshold.

  The reference correction unit 6 includes a buffer memory (storage unit) 6a and an average calculation unit (average calculation unit) 6b.

  The buffer memory 6a is a storage device that temporarily stores the detection values detected by the load sensors 3a to 3d when the reference correction unit 6 determines that the reference value can be corrected. The stored detection value is called from the memory unit 4a and input.

  When the detection value (hereinafter referred to as buffer data) input and stored in the buffer memory 6a reaches a predetermined number, that is, when the data write to the buffer memory 6a is performed a predetermined number of times, the average calculation unit 6b An average value is calculated.

  The calculated average value is input from the reference correction unit 6 to each of the load sensors 3a to 3d as a new reference value.

  Note that an occupant determination unit (not shown) determines the occupant state on the seat 2 based on detection values from the load sensors 3a to 3d when the seating determination unit 5 determines that there is an occupant.

  Next, reference value correction processing of the vehicle occupant detection system A according to the best embodiment will be described with reference to the flowchart shown in FIG.

  First, when a driver occupant sits on the driver's seat and turns on an ignition key (not shown), for example, the load sensors 3a to 3d of the passenger seat seat 2 detect the load acting on the seat 2, respectively. Then, the occupant detection ECU 4 inputs the detected value to the memory unit 4a (step 1).

  Here, the detection value of the load sensor 3a is Fi, the detection value of the load sensor 3b is Fo, the detection value of the load sensor 3c is Ri, the detection value of the load sensor 3d is Ro, and the detection values Fi, Fo, Ri in FIG. , Ro is shown in a graph.

  The detection values at a certain predetermined time Tn are indicated as Fi (n), Fo (n), Ri (n), and Ro (n).

  Next, the seating determination unit 5 detects the detection values Fi (n), Fo (n), Ri (n), and the detection values Fi, Fo, Ri, Ro from the detection values Fi, Fo, Ri, Ro inputted to the memory unit 4a. Ro (n) is called, and the total sum W (n) at the predetermined time Tn is calculated by the equation (1) (step 2).

W (n) = Fi (n) + Fo (n) + Ri (n) + Ro (n) (1)
Then, based on this calculation result W (n), it is determined whether or not the reference values of the load sensors 3a to 3d can be corrected (step 3).

  In this determination, if the total sum W (n) is smaller than a predetermined threshold value TH / L (β), it is determined that the occupant is not seated on the seat 2 and can be corrected, and the total sum W (n) is the threshold value. If TH / L (β) or more, it is determined that correction is not possible because an occupant is seated on the seat 2.

  If the total sum W (n) is equal to or greater than the threshold value TH / L (β), that is, if NO in step 3, the process returns to step 1.

  On the other hand, when the total sum W (n) is smaller than the threshold value TH / L (β), that is, in the case of YES in step 3, it is detected by the reference correction unit 6 a predetermined time before each of the load sensors 3a to 3d. The absolute values ΔFi, ΔFo, ΔRi, ΔRo of the fluctuation amount between the detected value and the currently detected value are calculated (step 4).

  The absolute values ΔFi, ΔFo, ΔRi, and ΔRo of the fluctuation amounts are calculated by first detecting the detected values Fi (n−1) and Fo (n−1) at time Tn−1 (predetermined time) input to the memory unit 4a. ), Ri (n−1), and Ro (n−1) are called.

  Next, the detection values Fi (n-1), Fo (n-1) at the time Tn-1 from the detection values Fi (n), Fo (n), Ri (n), Ro (n) at the time Tn (current). ), Ri (n-1), Ro (n-1) are subtracted and the absolute value of the obtained result is taken (see equations (2) to (5)).

ΔFi = ABS {Fi (n) −Fi (n−1)} (2)
ΔFo = ABS {Fo (n) −Fo (n−1)} (3)
ΔRi = ABS {Ri (n) −Ri (n−1)} (4)
ΔRo = ABS {Ro (n) −Ro (n−1)} (5)
Note that the absolute values ΔFi, ΔFo, ΔRi, and ΔRo of the fluctuation amounts are shown in a graph as enlarged in FIG.

  Thereafter, the sum ΔW of the absolute values ΔFi, ΔFo, ΔRi, and ΔRo of the fluctuation amounts is calculated by the equation (6) (step 5).

ΔW = ΔFi + ΔFo + ΔRi + ΔRo (6)
Then, based on the calculation result ΔW, it is determined whether or not the vehicle is in a stable state (step 6).

  In this determination, if the total sum ΔW is smaller than a predetermined threshold TH / L (α), it is determined that the vehicle is in a stable state, and if the total ΔW is equal to or greater than the threshold TH / L (α), the vehicle is determined. This is performed by determining that is not stable. Thereby, even when the vehicle is traveling, the stable state of the vehicle can be determined.

  Here, the “stable state” may be a case where the vehicle is running flat or stopped, and the “variable state” may be that the vehicle is turning, accelerating / decelerating, or the like.

  If the total sum ΔW is equal to or greater than the threshold value TH / L (α), that is, if NO in step 6, all the buffer data input to the buffer memory 6a is cleared (erased) (step 7). Return to.

  On the other hand, if the total sum ΔW is smaller than the threshold value TH / L (α), that is, if YES in step 6, the detected values Fi (n), Fo (n), Ri (n), called from the memory unit 4a, Ro (n) is input to the buffer memory 6a (step 8).

  Next, it is determined whether or not the detection values Fi, Fo, Ri, and Ro for each of the load sensors 3a to 3d input and stored in the buffer memory 6a are a predetermined number n determined arbitrarily in advance ( Step 9).

  That is, it is determined whether or not the buffer data has been written to the buffer memory 6a n times.

  If the number of buffer data is not n, that is, if NO in step 9, the process returns to step 1.

  On the other hand, if the number of buffer data is n, that is, if YES in step 9, all the buffer data input to the buffer memory 6a is input to the average calculation unit 6b, and the average of the buffer data is input by the average calculation unit 6b. A value is calculated (step 10).

  Then, the calculated average value is used as a reference value in each of the load sensors 3a to 3d, and is input to each of the load sensors 3a to 3d to correct these reference values (step 11).

  This reference value correction is performed by replacing the current detection value of each of the load sensors 3a to 3d with an average value that is a reference value.

  Also, this reference value correction process is periodically performed, for example, every 100 msec from when the ignition key is turned on until it is turned off. Therefore, it is possible to immediately correct the reference values of the load sensors 3a to 3d.

  Thus, in the vehicle occupant detection system A according to the present invention, the stable state of the vehicle can be determined based on the sum ΔW of the absolute values of the fluctuation amounts of the detection values of the load sensors 3a to 3d. Therefore, even when the vehicle is traveling, the reference value correction can be performed by selecting when the vehicle is in a stable state, such as when the vehicle is traveling flat.

  Then, the number of times of performing the accurate reference value correction can be increased, and even when the reference values of the load sensors 3a to 3d are shifted due to vibration during traveling, the reference value is immediately corrected. be able to. And it becomes possible to improve the detection accuracy of the load sensors 3a to 3d.

  In the above-described embodiment, the reference values of the load sensors 3a to 3d are corrected using an average value of a predetermined number (n) of detected values as a reference value. Thereby, the accuracy of the reference value correction can be increased, and the detection accuracy of the load sensors 3a to 3d can be further improved.

  Next, a vehicle occupant detection system according to a first embodiment of the present invention will be described with reference to the drawings.

  The vehicle occupant detection system A1 according to the first embodiment is incorporated in an airbag system B mounted on a vehicle. Here, since this airbag system B is equivalent to the airbag system B in the above-mentioned best embodiment, detailed description will be omitted.

  The vehicle occupant detection system A1 includes a plurality of load sensors (load detection means) 3a to 3d attached to a seat 2 provided in the vehicle, and an occupant detection ECU 10. Here, since each load sensor 3a-3d is equivalent to the load sensors 3a-3d in the above-mentioned best embodiment, detailed description is abbreviate | omitted.

  The occupant detection ECU 10 includes a memory unit 10a, a seating determination unit (sitting detection unit) 11, a reference correction unit (reference correction unit) 12, an occupant determination unit (not shown), and the like.

  The memory unit 10a is a storage device to which detection values detected by the load sensors 3a to 3d are input, and the input detection values can be appropriately called by the seating determination unit 11, the reference correction unit 12, and the like.

  The seating determination unit 11 determines the presence / absence of an occupant on the seat 2 based on detection values from the load sensors 3a to 3d. Here, the sum of the detected values is compared with a predetermined threshold value, and when the sum is smaller than this threshold value, it is determined that there is no passenger.

  The reference correction unit 12 includes a vehicle state determination unit 13, a buffer memory (storage unit) 14, and an average calculation unit (average calculation unit) 15. Based on detection values from the load sensors 3a to 3d. When it is determined that the vehicle is stable, the reference values of the load sensors 3a to 3d are corrected.

  The vehicle state determination unit 13 determines the vehicle state based on the detection values of the load sensors 3a to 3d after the determination result that there is no passenger is input from the seating determination unit 11. Here, the absolute value of the change amount of the sum of the detection values of the load sensors 3a to 3d is obtained, the change amount of the sum is compared with a predetermined threshold value, and the change amount of the sum is smaller than this threshold value. It is determined that the vehicle is stable.

  The buffer memory 14 is a storage device that temporarily stores detection values detected by the load sensors 3a to 3d when the vehicle state determination unit 13 determines that the vehicle is stable. The stored detection value is called from the memory unit 10a and input.

  When the detection value (hereinafter referred to as buffer data) input and stored in the buffer memory 14 reaches a predetermined number, that is, when the data write to the buffer memory 14 is performed a predetermined number of times, the average calculating unit 15 An average value is calculated.

  The calculated average value is input as a new reference value from the reference correction unit 12 to each of the load sensors 3a to 3d.

  Note that an occupant determination unit (not shown) determines the occupant state on the seat 2 based on detection values from the load sensors 3a to 3d when the seating determination unit 11 determines that there is an occupant.

  Next, reference value correction processing of the vehicle occupant detection system A1 according to the first embodiment will be described with reference to the flowchart shown in FIG.

  First, when a driver occupant sits on the driver's seat and turns on an ignition key (not shown), for example, the load sensors 3a to 3d of the passenger seat seat 2 detect the load acting on the seat 2, respectively. Then, the occupant detection ECU 10 inputs the detected value to the memory unit 10a (step 20).

  Here, the detection value of the load sensor 3a is Fi, the detection value of the load sensor 3b is Fo, the detection value of the load sensor 3c is Ri, the detection value of the load sensor 3d is Ro, and the detection value at a predetermined time Tn is Fi ( n), Fo (n), Ri (n), and Ro (n).

  Next, the seating determination unit 11 detects the detection values Fi (n), Fo (n), Ri (n), and the detection values Fi, Fo, Ri, and Ro that are input to the memory unit 10a at a predetermined time Tn. Ro (n) is called, and the total sum W (n) at the predetermined time Tn is calculated by the equation (1) (step 21). The calculated total sum W (n) is input to the memory unit 10a.

W (n) = Fi (n) + Fo (n) + Ri (n) + Ro (n) (1)
Then, based on this calculation result W (n), it is determined whether or not the reference values of the load sensors 3a to 3d can be corrected (step 22).

  In this determination, if the total sum W (n) is smaller than a predetermined threshold value TH / L (β), it is determined that the occupant is not seated on the seat 2 and can be corrected, and the total sum W (n) is the threshold value. If TH / L (β) or more, it is determined that correction is not possible because an occupant is seated on the seat 2.

  If the total sum W (n) is equal to or greater than the threshold value TH / L (β), that is, if NO in step 22, the process returns to step 20.

  On the other hand, when the total sum W (n) is smaller than the threshold value TH / L (β), that is, in the case of YES at step 22, the vehicle state determination unit 13 detects the load sensors 3a to 3d before the predetermined time. The absolute value ΔW1 of the fluctuation amount between the sum of the detected values and the sum of the currently detected detection values is calculated (step 23).

  The absolute value ΔW1 of the total fluctuation amount is calculated by first detecting the detected values Fi (n−1), Fo (n−1), Ri () at the time Tn−1 (predetermined time) input to the memory unit 10a. n-1), the sum of Ro (n-1) W (n-1) and the sum of the detected values Fi (n), Fo (n), Ri (n), Ro (n) at time Tn (current). Call W (n) respectively.

  Note that the total sum W (n-1) and the total sum W (n) are input to the memory unit 10a, and need not be calculated again.

  Next, the sum W (n-1) at time Tn-1 is subtracted from the sum W (n) at time Tn, and the absolute value of the obtained result is taken (see equation (2)).

ΔW1 = ABS {W (n) −W (n−1)} (2)
Then, based on the calculation result ΔW1, it is determined whether or not the vehicle is in a stable state (step 24).

  In this determination, if the total fluctuation amount ΔW1 is smaller than a predetermined threshold TH / L (α), it is determined that the vehicle is in a stable state, and the total fluctuation amount ΔW1 is equal to the threshold TH / L (α ) If it is above, it is determined by determining that the vehicle has fluctuated and is not in a stable state. Thereby, even when the vehicle is traveling, the stable state of the vehicle can be determined.

  If the total fluctuation amount ΔW1 is equal to or greater than the threshold value TH / L (α), that is, if NO in step 24, the vehicle is not stable and all the buffer data input to the buffer memory 14 is cleared ( Delete) (step 25) and return to step 20.

  On the other hand, if the total variation ΔW1 is smaller than the threshold value TH / L (α), that is, if YES in step 24, the detected values Fi (n), Fo (n), Ri () called from the memory unit 10a. n) and Ro (n) are input to the buffer memory 14 (step 26).

  Next, it is determined whether or not the detection values Fi, Fo, Ri, and Ro for each of the load sensors 3a to 3d input and stored in the buffer memory 14 are a predetermined number n arbitrarily determined in advance ( Step 27). That is, it is determined whether or not the buffer data has been written to the buffer memory 14 n times.

  If the number of buffer data is not n, that is, if NO in step 27, the process returns to step 20.

  On the other hand, if the number of buffer data is n, that is, if YES in step 27, all the buffer data input to the buffer memory 14 are input to the average calculator 15, and the average calculator 15 averages the buffer data. A value is calculated. The average value is calculated for each of the load sensors 3a to 3d (step 28).

  The calculated average value is used as a reference value for each of the load sensors 3a to 3d, and this average value is input to each of the load sensors 3a to 3d to correct these reference values (step 29).

  This reference value correction is performed by replacing the current detection value of each of the load sensors 3a to 3d with an average value that is a reference value.

  Thus, in the vehicle occupant detection system A1 according to the first embodiment, the reference correction unit 12 includes the vehicle state determination unit 13, and the vehicle state determination unit 13 determines whether or not the vehicle is stable. Thus, it is possible to accurately select the stable state of the vehicle and correct the reference values of the load sensors 3a to 3d. Thereby, the frequency | count of execution of the exact reference value correction | amendment of each load sensor 3a-3d can be increased, and the detection accuracy of a load detection means can be improved.

  In particular, in the first embodiment described above, if the vehicle state determination unit 13 determines that the absolute value of the total variation amount ΔW1 of the detection results of the load sensors 3a to 3d is smaller than a predetermined threshold value TH / L (α), the vehicle is It is judged to be stable.

  Therefore, the vehicle state determination process can be simplified, and the load on the calculation software can be reduced. Therefore, it can be controlled by a small CPU or the like, and an increase in manufacturing cost can be suppressed.

  As mentioned above, although embodiment concerning this invention has been explained in full detail with drawing, a concrete structure is not restricted to the above-mentioned embodiment. Design changes and the like within the scope not departing from the gist of the present invention are included in the present invention.

  For example, in the above-described embodiment, an average value of a predetermined number (n) of predetermined detection values is used as the reference value, but the detection value when it is determined that the vehicle is in a stable state may be used as the reference value as it is. Good. In this case, the reference value can be set in a short time, and the reference value can be corrected in a short time.

1 is a block diagram showing an airbag system using a vehicle occupant detection system according to a preferred embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the attachment structure of the load sensor in the vehicle occupant detection system which concerns on the best embodiment of this invention, (a) is a top view, (b) is a side view, (c) is a front view. . It is the flowchart which showed the reference value correction process in the vehicle occupant detection system which concerns on the best embodiment of this invention. It is the graph which showed the detection result of a load sensor, and the sum total of the absolute value of the fluctuation amount. 1 is a block diagram showing an airbag system using a vehicle occupant detection system according to Embodiment 1 of the present invention. It is the flowchart which showed the reference value correction process in the vehicle occupant detection system which concerns on Example 1 of this invention.

Explanation of symbols

A Vehicle occupant detection system 2 Seats 3a to 3d Load sensor (load detection means)
5 Seating determination unit (sitting detection means)
6 Reference correction unit (reference correction means)

Claims (4)

A plurality of load detection means for detecting a load acting on a seat provided in the vehicle; a seating detection means for determining whether or not an occupant is seated on the seat based on a detection result of the load detection means; A reference correction means for correcting a reference value of the plurality of load detection means based on a detection result of the seating detection means;
After the detection result that the occupant is not seated on the seat is input from the seating detection unit, the reference correction unit calculates a sum of absolute values of fluctuation amounts of detection results of the plurality of load detection units. If the vehicle is smaller than a predetermined threshold, the vehicle occupant detection system performs reference value correction using the detection results of the plurality of load detection means at that time as reference values. A plurality of load detection means for detecting a load acting on a seat provided in the vehicle; a seating detection means for determining whether or not an occupant is seated on the seat based on a detection result of the load detection means; A reference correction means for correcting a reference value of the plurality of load detection means based on a detection result of the seating detection means;
The reference correction unit includes a vehicle state determination unit that determines the state of the vehicle based on detection results of the plurality of load detection units.
After the detection result that the occupant is not seated on the seat is input from the seating detection means, when the vehicle state determination unit determines that the vehicle is stable, the plurality of loads at that time A vehicle occupant detection system that performs reference value correction using a detection result of a detection means as a reference value.   The vehicle state determination unit determines that the vehicle is stable if an absolute value of a variation amount of a sum of detection results of the plurality of load detection means is smaller than a predetermined threshold value. The vehicle occupant detection system according to claim 2. The reference correction means includes a storage means for storing a predetermined number of detection results of each of the plurality of load detection means, and an average value calculation means for calculating an average value of the plurality of detection results stored in the storage means. The vehicle occupant detection system according to any one of claims 1 to 3, wherein reference value correction is performed using the value calculated by the average value calculation means as a reference value.

Images