JP2009046093A - Vehicular occupant detection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular occupant detection system capable of appropriately correcting a reference value for a load detection means by reference value correction performed once even if a difference from a value detected one cycle before becomes large. <P>SOLUTION: Immediately after a seating determination section (seating detection means) 5 inputs a detection result indicating the absence of any occupant on a seat 2 and an air bag ECU (air bag control section) 1 determines the deployment of an air bag 7, a reference correction section (reference correction means) 6 indefinitely or extremely increases a correction amount for the reference value correction of a plurality of load sensors (load detection means) 3a to 3d. <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.

  Conventionally, an occupant detection system that detects a load acting on a vehicle seat by a plurality of load detection means and determines whether an occupant is seated on the seat based on the detected value is known (for example, Patent Document 1).

  In this occupant detection system, after determining that the seat is vacant, if the difference between the detection value one cycle before and the current detection value is within a predetermined range, the reference value of each load detection means is corrected. .

  On the other hand, when the reference value correction is performed even if the difference from the detection value one cycle before exceeds the predetermined range, the correction amount that can be performed at one time is limited in order to prevent the reference value from deviating greatly. What to do is considered.

The “correction amount” is a difference between a newly set reference value and the current reference value.
Japanese Patent Laid-Open No. 2002-341052

  By the way, in the above-mentioned occupant detection system, since the reference value correction is performed when the difference from the detection value one cycle before is within a predetermined range, the reference value correction is performed when the difference between the detection values becomes large. There was a problem that could not be done.

  Also, when limiting the amount of correction at one time, if the detected value deviates significantly from the current reference value, it is not possible to correct the difference in consideration, and the reference value deviation can be corrected at one time. There wasn't. For this reason, there is a possibility that a passenger's seating judgment may be mistaken.

  Therefore, the present invention provides a vehicle occupant capable of appropriately correcting the reference value of the load detecting means by taking the difference into account even when the difference between the detected value and the current reference value becomes large. The problem is to provide a detection system.

  In order to solve the above problems, the present invention provides a plurality of load detection means for detecting a load acting on a seat provided in a vehicle, and an occupant seated on the seat based on the detection results of these load detection means. An airbag control unit provided in the vehicle, comprising: a seating detection unit that determines whether or not the vehicle is seated; and a reference correction unit that corrects a reference value of the plurality of load detection units. A detection result that the occupant is not seated on the seat is input from the seating detection means, and the airbag control unit determines whether the airbag is deployed. In this case, the reference correction unit sets the correction amount of the reference value correction of the plurality of load detection units to an unlimited or very large value.

  According to the present invention, the seat is distorted due to an impact to the extent that the airbag is deployed to the vehicle, and the detected value when the seat is determined to be vacant is greatly varied from the current reference value. However, in the reference value correction performed immediately after that, the correction amount is not limited or the correction amount is set to a very large value.

  Therefore, even if the difference between the detected value and the current reference value becomes large, a new reference value can be set in consideration of the difference, and it is possible to correct the value appropriately by performing a single reference value correction. .

  Further, the correction amount is set to an unlimited or very large value only when an airbag deployment determination is made. Therefore, when an impact is not input to the vehicle and seat distortion or the like is not considered, even if the difference between the detected value and the current reference value is large, the difference is not taken into account, and the reference value can be prevented from greatly deviating.

  A vehicle occupant detection system A according to the present invention is incorporated in an airbag system B mounted on a vehicle.

  As shown in FIG. 1, the airbag system B is mainly composed of an airbag ECU (airbag controller) 1, a vehicle occupant detection system A, an airbag 7, a warning lamp 8, and an occupant state display lamp 9. ing.

  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.

  Further, when the airbag 7 is subjected to the deployment control, the airbag ECU 1 inputs a deployment signal indicating that the airbag 7 has been deployed to an occupant detection ECU 4 described later of the vehicle occupant detection system A.

  The airbag 7 is deployed to protect the occupant during a vehicle collision and exhibits a buffering 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.

  Further, the occupant state display lamp 9 is an indicator lamp that displays occupant information such as no occupant, adult seating, and child seat installation.

  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 3a to 3d are so-called strain gauges, and detect the strain generated by the load acting on the seat 2 by converting it into electric resistance.

  Each of the load sensors 3a to 3d is attached to a different position of the seat 2, and detects loads at four different positions of the seat 2.

  Here, as shown in FIGS. 2A to 2C, the load sensors 3a to 3d are, for example, the right front leg portion and the left front side of the seat 2 of the passenger seat movably mounted on the seat rail 2a. It is provided on the leg, the right rear leg, and the 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 changed when the detection values of the load sensors 3a to 3d when the occupant is not seated on the seat 2 change due to the distortion of the vehicle body or the seat 2. Correction is made so that a predetermined 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.

  The reference correction unit 6 receives a correction result indicating that the airbag has been deployed from the airbag ECU 1 after the determination result that there is no occupant is input from the seating determination unit 5. Set to unlimited.

  Further, the reference correction unit 6 limits the correction amount of the reference value correction when the deployment signal is not input from the airbag ECU 1 after the determination result that there is no occupant is input from the seating determination unit 5. Set to a predetermined amount. In this case, the limited correction amount is a very small value.

  Here, the “correction amount” is a difference between a newly set reference value and the current reference value.

  The reference correction unit 6 corrects reference values of the plurality of load sensors 3a to 3d.

  That is, when the correction amount is set to be unlimited, the detection values of the load sensors 3a to 3d are corrected to become new reference values.

  When the correction amount is set to a very small value, if the detected value of each of the load sensors 3a to 3d is smaller than this correction amount, the detected value is corrected to become a new reference value, and the detected value If this is larger than this correction amount, correction is performed so that a value obtained by changing the current reference value by the maximum correction amount becomes a new reference value regardless of the magnitude of the detected 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 present invention will be described with reference to the flowchart shown in FIG.

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

  Next, the seating determination unit 5 calls the detection values Fi, Fo, Ri, and Ro input to the memory unit 4a, and calculates the total sum W by the equation (1) (step 2).

W = Fi + Fo + Ri + Ro (1)
Then, based on the calculation result W, 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 is smaller than a predetermined threshold value TH / L (α), it is determined that the occupant is not seated on the seat 2 and it can be corrected, and the total sum W is the threshold value TH / L (α). If it is above, it is determined by determining that an occupant is seated on the seat 2 and that correction is impossible.

  If the total sum W is equal to or greater than the threshold value TH / L (α), that is, if NO in step 3, the reference value correction process is terminated without correcting the reference value.

  On the other hand, if the total sum W is smaller than the threshold value TH / L (α), that is, if YES in step 3, the seating determination unit 5 outputs a correctable signal to the reference correction unit 6 (step 4).

  The reference correction unit 6 to which the correction enable signal is input determines whether or not the airbag ECU 1 has controlled the deployment of the airbag 7 (step 5).

  This determination is made by determining that there is deployment control of the airbag 7 if a deployment signal is input from the airbag ECU 1, and determining that there is no deployment control of the airbag 7 if no deployment signal is input.

  Then, when the deployment control of the airbag 7 is not performed, that is, in the case of NO in step 5, the correction amount of the reference value correction of each of the load sensors 3a to 3d is limited, and here is set to 0.5 kg. (Step 6).

  On the other hand, when the deployment control of the airbag 7 is performed, that is, in the case of YES in step 5, it is assumed that the seat 2 or the like is distorted due to the large impact input to the vehicle and the load sensors 3a to 3d are The correction amount for the reference value correction is set to unlimited (step 7).

  When the correction amount is set, the reference values of the load sensors 3a to 3d are corrected (step 8).

  The correction of the reference value is performed when the correction amount is limited, and when the detection values Fi, Fo, Ri, Ro of the load sensors 3a to 3d are smaller than the correction amount of 0.5 kg. The values Fi, Fo, Ri, and Ro are corrected to become new reference values, and if the detected values Fi, Fo, Ri, and Ro are larger than the correction amount of 0.5 kg, the current reference value varies by 0.5 kg. The corrected value is corrected to become a new reference value.

  When the correction amount is set to unlimited, the detection values Fi, Fo, Ri, and Ro of the load sensors 3a to 3d are corrected to become new reference values.

  Thus, in the vehicle occupant detection system A according to the present invention, the detection result that the occupant is not seated on the seat 2 is input from the seating determination unit 5 and the airbag ECU 1 determines whether the airbag 7 is deployed. When a development signal indicating that has been performed is input, the reference correction unit 6 sets an unlimited correction amount for the reference value correction of the plurality of load sensors 3a to 3d.

  As a result, the seat 2 is distorted due to the impact of the airbag 7 being deployed to the vehicle, and the detected values Fi, Fo, Ri, Ro when the seat 2 is determined to be empty are Even if the value fluctuates greatly with respect to the reference value, the correction of the reference value performed immediately thereafter eliminates the limitation of the correction amount.

  For this reason, even if the difference between the detected values Fi, Fo, Ri, Ro and the current reference value becomes large, a new reference value can be set in consideration of the difference, and the reference value is corrected properly once. It becomes possible to correct to.

  Since the correction amount is set to unlimited only immediately after the airbag 7 is determined to be deployed, the detection values Fi and Fo are considered when an abnormality such as a large impact is input to the vehicle is not considered. Even if the difference between Ri, Ro and the current reference value is large, the difference is not considered.

  For this reason, the reference value is not greatly corrected, and it is possible to prevent the reference value from deviating greatly.

  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, the correction amount is unlimited in the reference value correction after the airbag 7 is deployed, but may be set to a very large value.

  That is, the correction amount is limited to 0.5 kg in the reference value correction when the airbag 7 is not deployed, whereas the correction amount is set to 15 kg, for example, in the reference value correction when the airbag 7 is deployed. And

  Even in this case, even if the detected value when the seat 2 is determined to be vacant is large and a large difference occurs with the current reference value, a new reference value is set in consideration of this difference. be able to. Thereby, it becomes possible to correct | amend appropriately by the reference value correction | amendment almost once.

  Note that the very large value set in this case only needs to be larger than the correction amount when the airbag 7 is not deployed, and can be set to any value.

1 is a block diagram showing an airbag system using a vehicle occupant detection system according to the present invention. It is explanatory drawing which shows the attachment structure of the load sensor in the passenger | crew detection system for vehicles which concerns on 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 this invention.

Explanation of symbols

A Vehicle occupant detection system 1 Airbag ECU (airbag controller)
2 Sheets 3a to 3d Load sensor (load detection means)
5 Seating determination unit (sitting detection means)
6 Reference correction unit (reference correction means)
7 Airbag

Claims (1)

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; Reference correction means for correcting a reference value of the plurality of load detection means,
A vehicle occupant detection system that outputs a detection result of the seating detection means to an airbag control unit provided in the vehicle,
When the detection result that the occupant is not seated on the seat is input from the seating detection means, and the airbag control unit performs the airbag deployment determination,
The vehicle occupant detection system, wherein the reference correction means sets the correction amount of the reference value correction of the plurality of load detection means to an unlimited or very large value.

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