JP2002250653A - Method for detecting body weight on vehicle seat, and detector for body weight on the vehicle seat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for detecting body weight on a vehicle seat and a detector for body weight on a vehicle seat, capable of suitably detecting that a child restraint system(CRS) has been mounted. SOLUTION: When varying first and second detected values RR and RL within a prescribed period of time t, each including values which are not smaller than a threshold A and values smaller than a threshold B, a CPU 26 sets first and second load characteristic detection flags, respectively. The CPU 26 determines that the CRS has been mounted, when both the first and second flags are set, time lag between the setting of the first flag and the setting of the second flag is within a fixed period of time t3, and the sign of variation in the detected value RR and that of variation in the detected value RL are all identical.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle seat weight detecting method and a vehicle seat weight detecting apparatus capable of suitably detecting the mounting of a child restraint device.

[0002]

2. Description of the Related Art Conventionally, when an airbag is provided for protecting a occupant of a vehicle seat, in order to detect whether or not there is a occupant in the target seat, or to inflate the airbag. In order to properly adjust the amount of gas generated for exiting according to the occupant, the vehicle seat is provided with a weight detection device. A vehicle seat provided with this type of weight detection device is disclosed in, for example, Japanese Patent Application Laid-Open No. H11-304579.
Many publications are disclosed, for example, in Japanese Patent Publication No.

In this type of vehicle seat weight detection device, load sensors are installed at four corners below the seat to detect the load of a seated person, and the total value of the detected loads detected by the load sensors is used as the seating weight. The weight of the person is used to determine whether there is a seated person on the seat or whether the person sitting on the seat is an adult or a child.

[0004]

The vehicle seat has a child restraint device (hereinafter referred to as "CRS (Child Restoration)".
int System) "). When this CRS is mounted on a vehicle seat with a seat belt, an extremely large downward load is applied to the seat due to the tightening force. FIG.
5 shows load variation characteristics when S is mounted on a vehicle seat with a seat belt. Since the total load of each load sensor when the CRS is mounted includes the influence of the load of the tightening force, FIG.
As shown in (2), the total load value (characteristic curve T) of each load sensor exceeds the adult determination line L during the period in which the tightening force is applied, and returns to the adult determination line L or lower as the tightening force is released. Therefore, in the related art in which an adult determination is made based on the total load value (characteristic curve T) of each load sensor, CR
There is a possibility that the S mounting may be erroneously determined to be an adult occupant sitting on the target seat.

In view of this, an occupant determination logic including logic for determining whether to mount the CRS in consideration of an increase or decrease in the total load of each load sensor during CRS mounting is considered. The increase / decrease characteristics also appear when an adult occupant takes an action of stretching his / her waist while sitting (hereinafter referred to as waist-lift). FIG. 11 shows a load variation characteristic when an adult occupant floats while sitting down. Figure 1
As shown in FIG. 1, the total load value (characteristic curve T) of each load sensor is determined by the adult determination line L during the period in which the user is floating.
The load change tendency (the slope indicating the increase or decrease of the load of each load sensor or the total value thereof) is substantially the same as the load change tendency during the CRS mounting. Therefore, in the case where the determination is made by the occupant determination logic including the CRS mounting determination logic, there is a possibility that the sitting back of the adult may be erroneously determined to be the CRS mounting.

An object of the present invention is to provide a vehicle seat weight detecting method and a vehicle seat weight detecting device which can suitably detect the mounting of a child restraint device.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 is provided with a first load sensor and a second load sensor on both sides of a rear portion of a seat body of a vehicle seat. Third and fourth load sensors are provided on both sides of the front portion of the seat body, respectively, and vehicle seat weight detection for determining an occupant based on first to fourth detection values detected by the first to fourth load sensors. In the method, after the amount of change of the first and second detection values within a first set time is calculated, and after the amount of change of the first detection value within a second set time is equal to or greater than a first threshold value The first load characteristic detection flag is set when the difference is less than the second threshold value, and the second load characteristic detection flag is set after the variation amount of the second detection value within the second set time becomes equal to or greater than the first threshold value. When the load value falls below the threshold value, the second load characteristic detection flag is reset. The first and second load characteristic detection flags are set together, and the time between the setting of the first load characteristic detection flag and the setting of the second load characteristic detection flag is within the third set time. It is determined whether the sign of the change amount of the first detection value is the same as the sign of the change amount of the second detection value, and the sign of the change amount of the first detection value and the sign of the change amount of the second detection value are determined. The gist is that when they are the same, the attachment of the child restraint device is determined.

According to a second aspect of the present invention, a first load sensor and a second load sensor are provided on both sides of a rear portion of a seat body of a vehicle seat, and third and fourth load sensors are provided on both sides of a front portion of the seat body. Provided, these first to first
In a vehicle seat weight detection device that performs an occupant determination based on first to fourth detection values detected by a fourth load sensor, the amount of change in the first and second detection values within a first set time is determined. Calculating means for calculating, and confirming whether or not each variation amount of the first and second detection values within the second set time has become equal to or more than the first threshold value and then less than the second threshold value. Checking means; and a first based on a check result of the checking means.
Setting means for setting a second load characteristic detection flag and
Whether the first and second load characteristic detection flags are both set by the setting means, the time between the setting of the first load characteristic detection flag and the setting of the second load characteristic detection flag is within a third set time And a determination means for determining whether the sign of the variation of the first detection value and the variation amount of the second detection value are the same, and based on the determination result of the determination means. It is a gist of the present invention to provide a determination means for determining the mounting of the child restraint device.

According to a third aspect of the present invention, in the vehicle seat weight detecting apparatus according to the second aspect, the setting means sets the first detection value variation within the second set time to a first value. The first load characteristic detection flag is set when the threshold value becomes equal to or greater than the threshold value and becomes less than the second threshold value, and a variation amount of the second detection value within the second set time is equal to or greater than the first threshold value The point is that the second load characteristic detection flag is set when the value becomes less than the second threshold value after the condition (1).

The invention according to claim 4 is the invention according to claim 2 or 3.
3. The vehicle seat weight detecting device according to claim 2, wherein the determining unit sets the first and second load characteristic detection flags together, and sets the first load characteristic detection flag and the second load characteristic detection flag.
When the time between the setting of the load characteristic detection flag is within the third set time, it is determined whether or not the sign of the variation of the first detection value is the same as that of the variation of the second detection value. The gist is that they have done so.

[0011] The invention according to claim 5 is the invention according to claims 2 to 4.
In the vehicle seat weight detection device according to any one of the above, when the sign of the variation of the first detection value and the sign of the variation of the second detection value are all the same,
The gist of the present invention is to determine whether to attach the child restraint device.

According to a sixth aspect of the present invention, there is provided the vehicle seat weight detecting method according to the first aspect and the vehicle seat weight detecting apparatus according to any one of the second to fifth aspects. The gist of the 3 setting times is that the setting time is set to a value suitable for grasping the fluctuation tendency of the first and second detection values in response to the mounting of the child restraint device.

(Operation) According to the first and second aspects of the invention, the amount of change in each of the first and second detection values is monitored, and the load characteristics of the first and second detection values are detected. The presence or absence of the child restraint device can be detected extremely easily and preferably based on the load characteristics of the first and second detection values.

According to the configuration of the invention as set forth in claims 3 to 6, the characteristics of the load change of the target seat when the child restraint device is mounted can be distinguished from the other load change characteristics. The presence or absence of the attachment can be suitably detected.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a vehicle seat weight detecting apparatus embodying the present invention will be described below with reference to FIGS.

FIG. 1 shows a seat body 1 provided in a vehicle seat.
FIG. The seat body 1 is arranged on the passenger seat side of the vehicle, and a pair of left and right support frames 2 in FIG. 1 are fixed side by side on a vehicle floor (not shown). A pair of front and rear brackets 3 are fixed to the upper surface of each support frame 2, and a lower rail 4 is supported and fixed to the pair of front and rear brackets 3 along the support frame 2. The pair of left and right lower rails 4 is formed in a U-shaped cross section, and the upper part thereof is open and the opening forms a slide groove 5 extending in the front-rear direction.

A slide groove 5 formed in each lower rail 4
, A pair of left and right upper rails 6 are provided so as to be slidable in the front-rear direction along the slide grooves 5. FIG.
As shown in FIG. 2, a lower arm 11 that supports the seat cushion 9 and the seat back 10 of the seat body 1 at a predetermined interval via a pair of left and right front sensor brackets 7 and a rear sensor bracket 8 is provided on each upper rail 6. Are linked.

As shown in FIG. 3A, the upper and lower ends of the front sensor bracket 7 are formed into an upper fastening portion 7a and a lower fastening portion 7b, and the upper and lower fastening portions 7a and 7b are curved. A bending portion 7c is formed. The front sensor bracket 7 includes the upper and lower fastening portions 7a and 7b.
Are connected to the front side of the lower arm 11 and the upper rail 6, respectively. The front right load sensor 21 as a third load sensor and the front left load sensor 22 as a fourth load sensor are provided on the bending portions 7c of the right and left front sensor brackets 7, respectively.
Is affixed. These front right load sensors 21
The front left load sensor 22 includes a strain detecting element such as a strain gauge, and electrically detects the amount of bending of the bending portion 7c relative to the load applied to the seat cushion 9. I have.

As shown in FIG. 3B, the upper and lower ends of the rear sensor bracket 8 are formed as an upper fastening portion 8a and a lower fastening portion 8b, and the upper and lower fastening portions 8a and 8b are curved. The bent portion 8c is formed. The rear sensor bracket 8 includes the upper and lower fastening portions 8a and 8b.
Are connected to the lower arm 11 and the rear side of the upper rail 6, respectively. A right rear load sensor 23 as a first load sensor and a rear left load sensor 24 as a second load sensor are adhered to the bent portions 8c of the right and left rear sensor brackets 8, respectively. Like the front right load sensor 21 and the front left load sensor 22, the rear right load sensor 23 and the rear left load sensor 24 include a strain detecting element such as a strain gauge, for example. The amount of flexure of the flexure 8c relative to the flexure 8c is electrically detected.

An anchor bracket 14 of a belt anchor 13 for connecting the seat belt 12 is connected to the upper rail 6 on one side (the left side in FIG. 1). A belt attachment detection sensor (not shown) is provided in the belt anchor 13.

FIG. 4 is a block diagram showing an electrical configuration of the weight detection device 20 provided in the vehicle seat. The weight detection device 20 includes the load sensors 21 to 24 and an electronic control device (hereinafter, referred to as “ECU”) 25.

The ECU 25 includes a central processing unit (hereinafter, referred to as a central processing unit).
A “CPU”) 26 and a sensor signal input circuit 27
And a determination output circuit 28. The sensor signal input circuit 27 includes active filters 27a, 27b, 27c, and 27d provided corresponding to the front right load sensor 21, the front left load sensor 22, the rear right load sensor 23, and the rear left load sensor 24, respectively.
The load signals from the load sensors 21 to 24 are input to the CPU 26 via the active filters 27a to 27d. The active filters 27a to 27d are well-known low-pass filters in which a passive element including, for example, a capacitor and a resistor is combined with an active element such as an amplifier.

Accordingly, the active filters 27a to 27a
27d allows only low frequency signals among the load signals from the load sensors 21 to 24 to pass, and causes other signals to be lost.

Incidentally, the active filters 27a, 27
7b, load signals from the front right load sensor 21 and the front left load sensor 22, respectively, and the rear right load sensor 23 that has passed the active filter 27c.
, The third detection value FR, the fourth detection value FL, and the first detection value RR based on the load signal from the rear left load sensor 24 that has passed through the active filter 27d.
And the second detection value RL are calculated.

The CPU 26 executes various arithmetic processes according to a control program and initial data stored in advance, and outputs the arithmetic results to the judgment output circuit 28.
The calculation result is output to, for example, an electronic control unit (hereinafter, referred to as an “airbag ECU”) 30 of the airbag device via the determination output circuit 28, whereby the operation of the airbag device is controlled. I have.

A detection signal from a belt attachment detection sensor provided on the belt anchor 13 is transmitted to the CPU 2.
6 is input. Here, as shown in FIG. 1, a child restraint device (hereinafter, referred to as “CRS”) 31 may be attached to the seat body 1.
The CRS 31 is fixed to the seat body 1 by fastening with the seat belt 12. Accordingly, it has been confirmed by the applicants that the first to fourth detection values RR, RL, FR, FL have load variation characteristics as shown in FIG. 10 due to the effect of the tightening force when the CRS 31 is mounted. ing. In addition, the first to fourth detection values RR, RL, FR, and FL are obtained by the adult occupant floating while sitting down.
Has also been confirmed by the applicants to have a load variation characteristic as shown in FIG.

More specifically, the CRS 31 is connected to the seat belt 1.
2 and attached to the seat body 1 (CRS
At the time of wearing), in order to increase the tightening of the seat belt 12, the wearer takes an action such as riding on the CRS 31 to perform the CRS 3
1 and tighten the seat belt 12. Therefore, when the CRS is mounted, the rear sensors 23 and 24 are pressed. When the mounting is completed in the above state, the pressing of the wearer on the CRS 31 is released, and the load generated by the pressing is reduced. CRS
Looking at the overall load variation of the seat body 1 during mounting, as shown in FIG. 10, the first to fourth detection values RR, R
It is confirmed that the fluctuations of L, FR, and FL are intense and large. In particular, the decrease and variation of the first and second detection values RR and RL from the release of the CRS hold down to the stabilization of the load variation are short (from time tk to time ta shown in FIG. 10).
It can be seen that it has become larger inside. That is, the slope of the characteristic curve of the first and second detection values RR and RL at that time is large. In addition, the first time immediately before the stability of the load fluctuation
It is also confirmed that the fluctuation directions (increase / decrease directions) of the second detection values RR and RL match.

On the other hand, when the adult occupant lifts his / her waist while sitting (while lifting his / her waist), the seat belt 12 is not tightened, so that the first to fourth detection values RR,
It is confirmed that the fluctuations of RL, FR, and FL are gentle and small. Particularly, the first and second detection values R immediately before the stability of the load fluctuation (from time tm to time ta shown in FIG. 11).
It can be seen that the decrease fluctuation of R and RL is small.
That is, the slopes of the characteristic curves of the first and second detection values RR and RL at that time are small.

Therefore, it can be seen that by monitoring the decreasing fluctuation of the first and second detection values RR and RL immediately before the stability of the load fluctuation, the mounting of the CRS 31 can be confirmed separately from the adult occupant's waving.

The first and second detection values RR, RL
In consideration of the characteristics described above, processing such as determination of CRS mounting in the present embodiment will be described based on the flowcharts of FIGS. This process is performed by a periodic interruption every predetermined time (for example, 0.1 seconds (100 ms)).

When the process proceeds to this routine, first, in step 101, the CPU 26 determines whether or not the seat belt 12 is worn based on the detection signal of the belt wearing detection sensor. When the CPU 26 determines that the seat belt 12 is not fastened, there is no prerequisite for wearing the CRS. Therefore, the CPU 26 clears all the flags in step 122, ends the CRS wearing determination processing, and returns to the original processing. Return to routine. That is, in the present embodiment, the CPU 26 performs the CRS only when the seat belt 12 is fastened by the process of step 101.
A mounting determination process is performed. On the other hand, CPU
26 determines that the seat belt 12 has been worn,
Move to step 102.

In step 102, the CPU 26 reads the first and second detection values RR and RL and stores them in the memory, and at this time the first and second detection values RR and RL,
RL and the first and second detection values RR, R before a predetermined time t0 as a first set time already stored in the CPU 26.
L and the amount of change of the first detection value RR and the second detection value RL
Are calculated respectively. After that, the CPU 26
The calculated variation of the first detection value RR and the second detection value RL
Is stored in the memory. In the present embodiment, the CPU 26 always updates the memory so as to store only the fluctuation amount of the first detection value RR and the fluctuation amount of the second detection value RL within a certain time t as the second set time. It has become. When the calculation and storage of the variation of the first detection value RR and the variation of the second detection value RL are completed, in the present embodiment, the process first proceeds to step 103 so as to monitor the variation characteristics of the second detection value RL. I do. Note that the predetermined time t0 and the fixed time t are set to values suitable for grasping the fluctuation tendency of the first and second detection values RR and RL in response to the mounting of the CRS 31. . In the present embodiment, t0 is set to 0.5 seconds (500 ms), and t is set to 3 seconds (3000 ms).

In step 103, the CPU 26 determines whether or not the second load characteristic detection flag has been set in step 109 described later in the previous processing cycle. Then, when the second load characteristic detection flag is set, the CPU 26 subsequently determines in step 104 whether or not a predetermined time t1 has elapsed since the second load characteristic detection flag was set. still,
The predetermined time t1 is set to a value suitable for grasping the fluctuation tendency of the first and second detection values RR and RL in response to the mounting of the CRS 31. In the present embodiment, t1 is set to 0.5 seconds (500 ms).

Then, in step 104, the CPU 2
6, when it is determined that the predetermined time t1 has elapsed since the setting of the second load characteristic detection flag, the second load characteristic detection flag is cleared (step 105), and a new second load characteristic detection flag is set. The process proceeds to a setting process (steps 106 to 109).

On the other hand, in step 103, the CPU 26
When the second load characteristic detection flag is not set, the process skips steps 104 and 105 and shifts to a process for setting a new second load characteristic detection flag (steps 106 to 109).

In step 106, the CPU 26 determines whether the predetermined time t stored in the memory in step 102 has reached t.
It is checked whether or not there is a variation of the second detection value RL within the threshold value A or more as the first threshold value. Then, when the CPU 26 confirms that there is a variation of the second detection value RL within the predetermined time t that is equal to or larger than the threshold value A, the process proceeds to step 107. The threshold value A is set to a value suitable for grasping the tendency of the first and second detection values RR and RL to fluctuate in response to the mounting of the CRS 31. In the present embodiment, the threshold value A is set to, for example, 3 kg.

In step 107, the CPU 26 determines whether the predetermined time t stored in the memory in step 102 has reached t.
It is confirmed whether or not there is a variation of the second detection value RL within the threshold value B which is less than the threshold value B as the second threshold value. Then, when the CPU 26 confirms that the variation amount of the second detection value RL within the predetermined time t is less than the threshold value B, the process proceeds to step 108. The threshold value B is set to a value suitable for grasping the tendency of the first and second detection values RR and RL to change in response to the mounting of the CRS 31. In the present embodiment, the threshold value B is set to, for example, 1 kg.

In step 108, the CPU 26 determines whether or not the time interval between the value equal to or more than the threshold value A confirmed in step 106 and the value less than the threshold value B confirmed in step 107 is within a predetermined time t2. Judge about. In other words, in step 108, the CPU 26
Is that the time delay between the occurrence time of the variation of the second detection value RL equal to or greater than the threshold value A and the occurrence time of the variation amount of the second detection value RL less than the threshold value B is within a predetermined time t2. It is determined whether or not. In addition, the predetermined time t2 is set to a value suitable for grasping the fluctuation tendency of the first and second detection values RR and RL in response to the mounting of the CRS 31. In the present embodiment, t2 is set to 0.5 seconds (500 ms). Further, the threshold A
When there are a plurality of fluctuation amounts of the second detection value RL and a plurality of fluctuation amounts of the second detection value RL less than the threshold value B, the judgment is made by using those which are temporally closest to each other.

Then, in step 108, the CPU 2
6 indicates that the time delay between the occurrence time of the variation of the second detection value RL equal to or greater than the threshold value A and the occurrence time of the variation amount of the second detection value RL less than the threshold value B is within a predetermined time t2. If it is determined that there is, the process proceeds to step 109.

In step 109, the CPU 26 sets the second load characteristic detection flag and sets a holding timer for the flag set. That is, in step 104, the CPU 26 determines whether the predetermined time t1 has elapsed since the second load characteristic detection flag was set based on the holding timer.

When the processing of step 109 is completed, the CPU
Step 26 proceeds to step 110 so as to monitor the load fluctuation of the first detection value RR. On the other hand, in step 104, when the CPU 26 determines that the predetermined time t1 has not elapsed since the second load characteristic detection flag was set in step 109, the CPU 26 skips steps 105 to 108 and directly determines the first detection value RR. The process proceeds to step 110 so as to start monitoring the load variation.

Note that the CPU 26 determines in step 106
When any one of the conditions from Step 108 to Step 108 is not satisfied, the process proceeds to Step 110. That is, step 10
In step 6, when the CPU 26 confirms in step 102 that there is no fluctuation amount of the second detection value RL within the predetermined time t stored in the memory that is equal to or larger than the threshold value A, the process proceeds to step 110. . Or step 10
In step 7, when the CPU 26 confirms in step 102 that there is no variation in the second detection value RL stored in the memory within the predetermined time t that is smaller than the threshold value B, the CPU 26 proceeds to step 110. . Or step 10
In step 8, when the CPU 26 determines that the time interval between the value equal to or more than the threshold value A confirmed in step 106 and the value less than the threshold value B confirmed in step 107 is not within the predetermined time t2, the process proceeds to step 110. Move to

As shown in FIG. 6, in step 110, the CPU 26 determines whether or not the first load characteristic detection flag has been set in step 116 described later in the previous processing cycle. When the first load characteristic detection flag is set, the CPU 26 subsequently determines in step 111 whether or not a predetermined time t1 (for example, 500 ms) has elapsed since the first load characteristic detection flag was set. I do.

Then, in step 111, the CPU 2
6, when it is determined that the predetermined time t1 has elapsed since the first load characteristic detection flag was set, the first load characteristic detection flag is cleared (step 112), and a new first load characteristic detection flag is set. The process proceeds to the setting process (steps 113 to 116).

On the other hand, in step 110, the CPU 26
When the first load characteristic detection flag is not set, the process skips steps 111 and 112 and shifts to a process for setting a new first load characteristic detection flag (step 113 to step 116).

At step 113, the CPU 26 determines whether the predetermined time t stored in the memory at step 102 has reached t.
It is confirmed whether or not there is a variation of the first detection value RR within the threshold value A or more. And CPU2
6 is a variation amount of the first detection value RR within the predetermined time t.
If it is confirmed that there is one having the threshold A or more, step 1
Go to 14.

In step 114, the CPU 26 determines whether the predetermined time t stored in the memory in step 102 has reached t.
Of the first detection value RR is less than the threshold value B. And CPU2
6 is a variation amount of the first detection value RR within the predetermined time t.
If it is confirmed that there is one less than the threshold B, step 1
Move to 15.

In step 115, the CPU 26 determines whether or not the time interval between the value equal to or more than the threshold value A confirmed in step 113 and the value less than the threshold value B confirmed in step 114 is within a predetermined time t2. Judge about. In other words, in step 115, the CPU 26
Is that the time delay between the occurrence time of the variation of the first detection value RR equal to or greater than the threshold value A and the occurrence time of the variation amount of the first detection value RR less than the threshold value B is within a predetermined time t2. It is determined whether or not. In the present embodiment, the variation of the first detection value RR equal to or greater than the threshold value A and the threshold value B
If there are a plurality of items each of which is less than one, the judgment is made using the items that are temporally closest to each other.

Then, in step 115, the CPU 2
6 indicates that the time delay between the occurrence time of the variation of the first detection value RR equal to or greater than the threshold value A and the occurrence time of the variation amount of the first detection value RR less than the threshold value B is within a predetermined time t2. If it is determined that there is, the process proceeds to step 116.

In step 116, the CPU 26 sets the first load characteristic detection flag and sets a holding timer for the flag set. That is, in step 111, the CPU 26 determines whether or not the predetermined time t1 has elapsed since the first load characteristic detection flag was set based on the holding timer.

When the processing of step 116 is completed, the CPU
26 proceeds to step 117. Step 1
In step 11, when the CPU 26 determines that the predetermined time t1 has not elapsed since the first load characteristic detection flag was set in step 116, the CPU 26 executes steps 112 to 1
Step 15 is skipped and the process proceeds directly to step 117.

If any of the conditions in steps 113 to 115 is not satisfied, the CPU 26 proceeds to step 117. That is, in step 113, the CPU 26 determines that, among the fluctuation amounts of the first detection value RR within the fixed time t stored in the memory in step 102, there is no fluctuation amount equal to or larger than the threshold value A.
Move to step 117. Alternatively, in step 114, when the CPU 26 confirms that there is no variation of the first detection value RR within the fixed time t stored in the memory in the step 102 that is less than the threshold value B,
Move to step 117. Alternatively, when the CPU 26 determines in the step 115 that the time interval between the value equal to or more than the threshold value A confirmed in the step 113 and the value less than the threshold value B confirmed in the step 114 is not within the predetermined time t2. , To step 117.

As shown in FIG. 7, in step 117, the CPU 26 determines whether or not both the second load characteristic detection flag and the first load characteristic detection flag are set. When both the second load characteristic detection flag and the first load characteristic detection flag are not set, the CPU 2
Step 6 ends the CRS mounting determination process and returns to the original processing routine. Eventually, when both the second load characteristic detection flag and the first load characteristic detection flag are set,
The CPU 26 proceeds to step 118.

In step 118, the CPU 26 sets the second load characteristic detection flag set in step 109 and the first load characteristic detection flag set in step 116 within a fixed time t3 as a third set time. It is determined whether or not it is the one that is. That is,
It is determined whether the delay between the detection of the load characteristic of the second detection value RL and the detection of the load characteristic of the first detection value RR is within a predetermined time t3. When the CPU 26 determines that the delay between the detection of the load characteristic of the second detection value RL and the detection of the load characteristic of the first detection value RR is within the predetermined time t3, the CPU 26 proceeds to step 11.
Move to 9. The predetermined time t3 is equal to the CRS3.
1 is set to a value suitable for grasping the fluctuation tendency of the first and second detection values RR and RL in response to mounting. In the present embodiment, t3 is set to 0.5 seconds (500 m
s) (for example, 450 ms).

In step 119, the CPU 26 determines the amount of change in all the second detection values RL and all the first detection values R
It is determined whether or not the sign of the variation amount of R is the same (that is, whether or not the variation direction (increase / decrease direction) of the second detection value RL and the first detection value RR is the same). And CPU2
In step 6, when the fluctuation direction (increase / decrease direction) of the second detection value RL and the first detection value RR is the same, it is determined that the CRS is mounted (step 120). After that, the CRS mounting determination process ends, and the process returns to the original processing routine.

On the other hand, steps 118 and 119
When any of the conditions is not satisfied, the CPU 26
After clearing all the flags (that is, the second load characteristic detection flag and the first load characteristic detection flag) stored in the memory in step 121, the CRS mounting determination process is terminated, and the process returns to the original processing routine. . That is,
If the delay between the detection of the load characteristic of the second detection value RL and the detection of the load characteristic of the first detection value RR is not within the predetermined time t3, the CPU
26 clears all the flags stored in the memory and then ends the CRS mounting determination process and returns to the original processing routine. Alternatively, the second detection value RL and the first detection value
When the fluctuation direction (increase / decrease direction) of the detection value RR is not the same, the CPU 26 clears all the flags stored in the memory, and then ends the CRS mounting determination process.
Return to the original processing routine.

Further, the CP that has proceeded to step 120
U26 transmits the judgment result of CRS mounting to the judgment output circuit 2
For example, the output is sent to the airbag ECU 30 via the ECU 8.
Then, the airbag ECU 30 suitably controls the operation of the airbag device based on the determination result.

As described in detail above, according to the present embodiment, the following effects can be obtained. (1) In the present embodiment, the amount of change in the first detection value RR and the amount of change in the second detection value RL at which a remarkable difference can be confirmed in response to the mounting of the CRS 31 are checked.
In order to detect the presence or absence of the CRS 31 on the basis of the result of the confirmation, the adult's waist lifted while sitting is compared to that of the prior art.
This prevents erroneous determination of RS attachment. As a result, C
The presence / absence of the attachment of the RS 31 can be detected extremely easily and suitably.

(2) In the present embodiment, when the CRS 31 is mounted, the first and second detection values RR and RL correspond to large fluctuations of the first and second detection values RR and RL, respectively. By confirming whether or not each of the fluctuation amounts of the detection values RR and RL exceeds the threshold value A, C
The presence / absence of the attachment of the RS 31 can be detected more strictly.

(3) In the present embodiment, when the CRS is mounted, C
The first and second detection values RR, RL within a predetermined time t correspond to the respective amounts of change of the first and second detection values RR, RL promptly recovering to a stable state after the release of the pressing on the RS 31. It is determined whether or not each of the fluctuation amounts is smaller than the threshold value B, thereby obtaining the CRS3.
1 can be detected more strictly.

(4) In the present embodiment, when the CRS is mounted, C
In response to the quick recovery of the amount of change of each of the first and second detection values RR and RL to the stable state after the release of the hold on RS31, the occurrence time of the threshold value A or more and the threshold value By confirming whether or not the time delay from the occurrence time of the thing less than B is within the predetermined time t2, the presence or absence of the mounting of the CRS 31 can be more strictly detected.

(5) In this embodiment, whether the delay between the detection of the load characteristic of the second detection value RL and the detection of the load characteristic of the first detection value RR is within a certain time t3 in response to the mounting of the CRS 31 By confirming whether or not the CRS 31 is attached, the presence or absence of the CRS 31 can be more strictly detected.

(6) In the present embodiment, it is determined whether or not the fluctuation direction of the first detection value RR and the fluctuation direction of the second detection value RL are the same in response to the mounting of the CRS 31. By confirming, the presence or absence of the mounting of the CRS 31 can be more strictly detected.

The embodiment of the present invention is not limited to the above embodiment, but may be modified as follows. The shapes of the front and rear sensor brackets 7 and 8 adopted in the above embodiment are merely examples, and any shape may be used as long as bending occurs according to the seat weight (load of the occupant).

The mounting positions (front and rear sensor brackets 7, 8) of the load sensors 21 to 24 adopted in the above embodiment are merely examples, and the seat weight (the load of the occupant) is detected in the same arrangement. If so, the mounting position is arbitrary.

In the determination of CRS wearing in the above embodiment,
First, the load fluctuation of the second detection value RL is monitored (step 10).
3 to 109), the load variation of the first detection value RR was monitored (step 110 to step 116). However, the load variation of the first detection value RR was monitored first, and then the second detection value RR was monitored. It may be performed to monitor the load fluctuation of the RL.

Step 118 may be omitted. In this case, the delay between the detection of the load characteristic of the second detection value RL and the detection of the load characteristic of the first detection value RR in steps 104 and 110 is within a predetermined time t1 (that is, 0.5 seconds).

The first to third set times t0, t, t3 are:
The value may be set to any other suitable value for grasping the fluctuation tendency of the first and second detection values RR and RL in response to the mounting of the CRS 31.

The determination of CRS wearing is shown in FIGS. 8 and 9.
May be performed according to the flowchart shown in FIG. More specifically, as shown in FIG. 8, when the process proceeds to this routine, first, in step 201, the CPU 26 determines whether or not the seat belt 12 is worn based on the detection signal of the belt wearing detection sensor. And the CPU 26
When there is no precondition for wearing the CRS when it is determined that the seat belt 12 is not worn,
After clearing all the flags at 13, the CRS mounting determination process ends, and the process returns to the original processing routine.
On the other hand, when the CPU 26 determines that the seat belt 12 is fastened, the process proceeds to step 202.

In step 202, the CPU 26 reads the first and second detection values RR and RL and stores them in the memory, and at this time, the first and second detection values RR and RL.
RL and a predetermined time t0 already stored in the CPU 26.
The variation of the first detection value RR and the variation of the second detection value RL are calculated using the previous first and second detection values RR and RL, respectively. After that, the CPU 26 calculates the calculated first detection value R
The amount of change in R and the amount of change in the second detection value RL are stored in a memory. Note that, in this case, the CPU 26 sets the time t
The memory is constantly updated so that only the variation of the first detection value RR and the variation of the second detection value RL within (for example, 3 seconds) are stored. Then, when the calculation and storage of the variation of the first detection value RR and the variation of the second detection value RL are completed, the process proceeds to step 203.

In step 203, the CPU 26 determines that the predetermined time t stored in the memory in step 202 has been reached.
It is confirmed whether or not there is a variation of the second detection value RL within the threshold value A or more. And CPU2
6 is a variation amount of the second detection value RL within the predetermined time t.
If it is confirmed that there is one having the threshold A or more, step 2
Move to 04.

In step 204, the CPU 26 determines whether the predetermined time t stored in the memory in step 202 has been reached.
It is checked whether or not there is a variation of the second detection value RL within the threshold value B among the variations. And CPU2
6 is a variation amount of the second detection value RL within the predetermined time t.
If it is confirmed that there is one that is less than the threshold B, step 2
Move to 05.

In step 205, the CPU 26 sets the time interval between the value equal to or more than the threshold value A confirmed in step 203 and the value less than the threshold value B confirmed in step 204 to a predetermined time t 2 (for example, 0.5 seconds). ) Is determined. That is, it is determined whether or not the time delay between the occurrence times of the ones greater than or equal to the threshold value A and the occurrence times of the ones less than the threshold value B is within a predetermined time t2. Then, when the CPU 26 determines that the time delay between the occurrence time of the threshold value A or more and the occurrence time of the threshold value B or less is within the predetermined time t2,
Move to step 206. If any one of the conditions in steps 203 to 205 is not satisfied, C
The PU 26 ends the CRS mounting determination processing, and returns to the original processing routine.

In step 206, the CPU 26 sets a second load characteristic detection flag and stores it in the memory. When the second load characteristic detection flag stored in the memory in the previous processing cycle is set, the subsequent second load characteristic detection flag always overwrites the previous second load characteristic detection flag. Thereafter, the process proceeds to step 207.

As shown in FIG. 9, in step 207, the CPU 26 determines, among the fluctuation amounts of the first detection value RR stored in the memory in step 202 within the predetermined time t, those having a threshold value A or more. Check if there is. Then, when the CPU 26 confirms that there is a variation of the first detection value RR within the predetermined time t that is equal to or larger than the threshold value A, the process proceeds to step 208.

In step 208, the CPU 26 sets the predetermined time t stored in the memory in step 202.
Of the first detection value RR is less than the threshold value B. And CPU2
6 is a variation amount of the first detection value RR within the predetermined time t.
If it is confirmed that there is one that is less than the threshold B, step 2
Move to 09.

In step 209, the CPU 26 determines whether the time interval between the threshold value A equal to or more than the threshold value A confirmed in step 207 and the value less than the threshold value B confirmed in step 208 is within a predetermined time t2. Judge about. That is, it is determined whether or not the time delay between the occurrence times of the ones greater than or equal to the threshold value A and the occurrence times of the ones less than the threshold value B is within a predetermined time t2. And
When the CPU 26 determines that the time delay between the occurrence time of the threshold value A or more and the occurrence time of the threshold value B or less is within the predetermined time t2, the process proceeds to step 210.

At step 210, the CPU 26 sets the first load characteristic detection flag and stores it in the memory. If the first load characteristic detection flag stored in the memory in the previous processing cycle is set, the subsequent first load characteristic detection flag overwrites the previous first load characteristic detection flag. Thereafter, the process proceeds to step 211. If any of the conditions of Steps 207 to 209 is not satisfied, the CPU 26 terminates the CRS mounting determination process and returns to the original processing routine.

In step 211, the CPU 26 determines whether or not both the second load characteristic detection flag and the first load characteristic detection flag are set. When neither the second load characteristic detection flag nor the first load characteristic detection flag is set, the CPU 26 terminates the CRS mounting determination processing and returns to the original processing routine.
Eventually, when both the second load characteristic detection flag and the first load characteristic detection flag are set, the CPU 26 proceeds to step 212.

In step 212, the CPU 26 sets the second load characteristic detection flag set in step 206 and the first load characteristic detection flag set in step 210 in a fixed time t4 (for example, 1 (5 seconds). That is, the delay between the detection of the load characteristic of the second detection value RL and the detection of the load characteristic of the first detection value RR is delayed for the fixed time t4.
It is determined whether it is within. And CPU2
6 is the load characteristic detection of the second detection value RL and the first detection value RR
When it is determined that the delay of the load characteristic detection is within the predetermined time t4, the process proceeds to step 213.

In step 213, the CPU 26 determines the amount of change in all the second detection values RL and all the first detection values R
It is determined whether or not the sign of the variation amount of R is the same (that is, whether or not the variation direction (increase / decrease direction) of the second detection value RL and the first detection value RR is the same). And CPU2
In step 6, when the fluctuation direction (increase / decrease direction) of the second detection value RL and the first detection value RR is the same, it is determined that the CRS is mounted (step 214). After that, the CRS mounting determination process ends, and the process returns to the original processing routine.

On the other hand, steps 212 and 213
When any of the conditions is not satisfied, the CPU 26
After clearing all the flags (that is, the second load characteristic detection flag and the first load characteristic detection flag) stored in the memory in step 215, the CRS mounting determination process is terminated, and the process returns to the original processing routine. . That is,
If the delay between the detection of the load characteristic of the second detection value RL and the detection of the load characteristic of the first detection value RR is not within the fixed time t4, the CPU
26 clears all the flags stored in the memory and then ends the CRS mounting determination process and returns to the original processing routine. Alternatively, the second detection value RL and the first detection value
When the fluctuation direction (increase / decrease direction) of the detection value RR is not the same, the CPU 26 clears all the flags stored in the memory, and then ends the CRS mounting determination process.
Return to the original processing routine. Step 2
The CPU 26, which has proceeded to S14, outputs the determination result of the CRS wearing via the determination output circuit 28, for example, to the airbag EC.
Output to U30. And the airbag ECU 30
The operation of the airbag device is suitably controlled based on the determination result.

In the above embodiment, the passenger seat is arranged on the left side of the vehicle. However, for example, the passenger seat may be arranged on the right side of the vehicle. In short, CRS
It is sufficient if the present invention is applied to a structure in which characteristics specific to the seat weight appear by mounting the seat 31.

[0084]

As described in detail above, according to the first to sixth aspects of the present invention, the mounting of the child restraint apparatus can be suitably detected.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a vehicle seat according to the present invention.

FIG. 2 is a side view showing the same embodiment.

FIG. 3 is a front view showing front and rear sensor brackets.

FIG. 4 is an exemplary block diagram showing an electrical configuration of the vehicle seat weight detection device according to the embodiment;

FIG. 5 is a flowchart showing a detection mode according to the embodiment;

FIG. 6 is a flowchart showing a detection mode according to the embodiment;

FIG. 7 is a flowchart showing a detection mode according to the embodiment;

FIG. 8 is a flowchart showing another example of a detection mode.

FIG. 9 is a flowchart illustrating another example of a detection mode.

FIG. 10 is a graph showing characteristics of detection values from load sensors when the CRS is mounted.

FIG. 11 is a graph showing characteristics of detection values from load sensors when a seated person is lifted up.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Seat main body, 20 ... Vehicle seat weight detection apparatus, 2
1. Front right load sensor as third load sensor
22: a front left load sensor as a fourth load sensor; 23, a rear right load sensor as a first load sensor; 24, a rear left load sensor as a second load sensor; 31: a child restraint system (CRS).

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Kouji Aoki 2-1-1 Asahi-cho, Kariya-shi, Aichi Prefecture Aisin Seiki Co., Ltd. (72) Inventor Satoshi Fujimoto 1-Toyota-cho, Toyota-shi, Aichi Prefecture Toyota Motor Corporation F term in the company (reference) 3B087 DE08 3D054 AA03 AA04 EE09 EE10 EE36

Claims (6)

[Claims] A first load sensor and a second load sensor are respectively provided on both sides of a rear portion of a seat body of a vehicle seat, and third and fourth load sensors are provided on both sides of a front portion of the seat body, respectively. In a vehicle seat weight detection method for performing an occupant determination based on first to fourth detection values detected by a fourth load sensor, an amount of change in the first and second detection values within a first set time is respectively determined. When the amount of change of the first detection value within the second set time becomes equal to or more than the first threshold value and then becomes less than the second threshold value, the first
A load characteristic detection flag is set, and the second load characteristic detection is performed when the amount of change of the second detection value within the second set time becomes equal to or more than the first threshold and then becomes less than the second threshold. Setting a flag, the first and second load characteristic detection flags are both set, and the time between the setting of the first load characteristic detection flag and the setting of the second load characteristic detection flag is within a third set time It is determined whether the sign of the variation of the first detection value is the same as the sign of the variation of the second detection value, and the difference between the variation of the first detection value and the variation of the second detection value A method for detecting the weight of a vehicle seat, wherein the determination is made as to whether the child restraint device is mounted when the signs are the same. 2. A first load sensor and a second load sensor are provided on both sides of a rear portion of a seat body of a vehicle seat, and third and fourth load sensors are provided on both sides of a front portion of the seat body, respectively. In a vehicle seat weight detection device that performs occupant determination based on first to fourth detection values detected by a fourth load sensor, the amount of change in the first and second detection values within a first set time is determined by: Calculating means for calculating, and confirming whether or not each variation amount of the first and second detection values within the second set time has become equal to or more than the first threshold value and then less than the second threshold value. Confirmation means; setting means for setting first and second load characteristic detection flags based on the confirmation result of the confirmation means; and whether or not both the first and second load characteristic detection flags are set by the setting means Or the first load characteristic Whether the time between the setting of the output flag and the setting of the second load characteristic detection flag is within the third set time, and the sign of the fluctuation amount of the first detection value and the fluctuation amount of the second detection value is A vehicle seat weight detecting device, comprising: determining means for determining whether each is the same; and determining means for determining whether to attach the child restraint device based on a result of the determination by the determining means. 3. The vehicle seat weight detecting device according to claim 2, wherein the setting unit is configured to perform a process after the variation of the first detection value within the second setting time becomes equal to or greater than a first threshold value. Setting the first load characteristic detection flag when it becomes less than the second threshold,
The second load characteristic detection flag is set when a variation amount of the second detection value within the second set time becomes equal to or more than a first threshold value and becomes less than a second threshold value. A vehicle seat weight detecting device characterized by the above-mentioned. 4. The vehicle seat weight detecting device according to claim 2, wherein said determining means sets both said first and second load characteristic detection flags and sets said first load characteristic detection flag. When the time between the setting of the second load characteristic detection flag and the second load characteristic detection flag is within the third set time, it is determined whether or not the sign of the change amount of the first detection value and the change amount of the second detection value are the same. A vehicle seat weight detecting device, characterized in that the determination is made as follows. 5. The vehicle seat weight detecting device according to claim 2, wherein the determination unit determines a sign of a variation of the first detection value and a variation of the second detection value. The vehicle seat weight detecting device is characterized in that the mounting of the child restraint device is determined when all are the same. 6. The first to third set times are set to values suitable for grasping a change tendency of the first and second detection values in response to mounting of the child restraint device. The vehicle seat weight detecting method according to claim 1, wherein the vehicle seat weight detecting device according to any one of claims 2 to 5.