JP4273638B2 - Crew identification system for automobiles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an occupant discrimination system for an automobile that incorporates a sensor in the seat of an automobile, detects a load distribution on the seat from the sensor output, and discriminates whether the occupant is a child or an adult in consideration of the load distribution.
[0002]
[Prior art]
Conventionally, wearing a seat belt has been obligatory as a safety measure for protecting passengers from the impact of a vehicle accident. Therefore, when the seat belt is not worn, a warning light is turned on or a buzzer is sounded to warn the occupant of wearing the seat belt.
In recent years, the number of vehicles equipped with airbags has increased rapidly. For example, in the case of a vehicle with airbags attached to the passenger seat, the passenger seat can be used in the event of an accident even though no passenger is on the passenger seat. Will open the airbag. Thus, a technique has been put into practical use so that the passenger seat airbag is not opened when no passenger is seated in the passenger seat.
In order to warn the user of wearing the seat belt and prevent the passenger's airbag from being opened, the presence or absence of an occupant on the seat is detected in advance. There is a need. As a method for detecting the presence or absence of this occupant, an occupant detection system in which a pressure sensitive sensor is incorporated in the seat is known.
[0003]
[Problems to be solved by the invention]
However, since the airbag installed as a safety device has a large expansion force when opened, the following dangers have been pointed out.
For example, in a vehicle equipped with an airbag in the passenger seat, when a child rides in the passenger seat, the inflation force of the airbag becomes an impact force, which may have an unexpected adverse effect on the passenger (child). is there. For this reason, for example, when the passenger in the passenger seat is a child, it is better not to operate the airbag in the passenger seat.
Here, as a means for determining whether the passenger in the passenger seat is a child or an adult, it is conceivable to use the above-described passenger detection system. That is, if the load detected by the pressure sensor incorporated in the seat is greater than a predetermined value, it can be determined that the child is an adult, and if the load is smaller than the predetermined value, the child can be determined.
[0004]
However, when determining whether a child or an adult is only based on the magnitude of the load detected by the pressure sensor, there are the following problems.
First, even if the occupant is an adult, when the occupant rests his back on the seat back (backrest), the load detected by the pressure sensor becomes smaller as the seat back is tilted down. End up.
Secondly, when a child seat (baby seat, child seat, junior seat, etc.) is used in the passenger seat, the weight of the child seat is added to the weight of the child, and the load increases.
Third, when a child-specific seat is used, the child-specific seat is fixed to the passenger seat with a seat belt, so that the load detected by the pressure sensor changes depending on the tightening force of the seat belt.
As a result, with the conventional occupant detection system, it is extremely difficult to accurately determine whether a child or an adult.
[0005]
Therefore, the present applicant has developed an occupant discrimination system that can discriminate whether a child or an adult regardless of the presence or absence of a child-specific seat.
This occupant discrimination system incorporates a sensor mat with a plurality of sensor cells arranged on a flat surface, detects the load distribution on the seat from the output of each sensor cell, and estimates the shape from the load distribution. The presence / absence of a child-specific sheet is detected by a pattern. Even if a child-specific seat is not used, it is not possible to determine whether a child or an adult is based only on the sum of the loads detected by individual sensor cells. Or adult.
[0006]
However, in the above occupant discrimination system, the sensor mat is not mechanically positioned with respect to the seat, and therefore the position of the sensor mat may be shifted when the seat cover that covers the surface of the seat is assembled.
If it is actually used in this state (the sensor mat is shifted), the load distribution obtained from the output of each sensor cell will be biased. Get higher.
The present invention has been made based on the above circumstances, and an object of the present invention is to prevent misjudgment due to displacement of the sensor mat in an occupant discrimination system in which the sensor mat is incorporated in the lower part of the seat surface of the seat. .
[0007]
[Means for Solving the Problems]
(Means of Claim 1)
The occupant discrimination system of the present invention is a correction process for correcting a shift in load distribution due to a positional shift of the sensor mat after the sensor mat is assembled and a seat skin covering the seat surface of the seat is assembled in the seat manufacturing process. have.
As a result, even if the sensor mat is assembled with respect to the sheet in a state of being deviated from the normal position, it is possible to prevent misjudgment due to the positional deviation of the sensor mat by correcting the deviation of the load distribution according to the positional deviation amount. it can.
[0008]
(Means of Claim 2)
In the passenger | crew discrimination | determination system for motor vehicles described in Claim 1,
In the correction process, pressure is applied on the seat surface of the seat skin with a certain area, the amount of displacement of the sensor mat is estimated from an output signal from a preselected sensor cell, and the displacement of the load distribution is estimated according to the amount of displacement. It is characterized by correcting. In this case, it is possible to estimate the amount of displacement of the sensor mat from a comparison between the magnitude of the load detected by the preselected sensor cell and the pressure area pressed on the sheet.
[0009]
(Means of claim 3)
In the vehicle occupant discrimination system according to claim 2,
In the correction step, at least two sensor cells arranged in a specific direction on the sensor mat are selected in advance, the amount of displacement of the sensor mat is estimated based on a signal output from the selected sensor cell, and the amount of displacement The deviation of the load distribution is corrected according to the above. In this case, since at least two sensor cells selected in advance are arranged in a specific direction on the sensor mat, the positional deviation amount of the sensor mat in the specific direction can be obtained by comparing the outputs of the at least two sensor cells. It can be easily estimated.
[0010]
(Means of claim 4)
In the passenger | crew discrimination | determination system for motor vehicles described in Claim 3,
The at least two sensor cells arranged in a specific direction on the sensor mat are at least two sensor cells at target positions in the front-rear direction or the left-right direction of the sensor mat. In this case, since at least two sensor cells selected in advance are disposed at target positions in the front-rear direction or the left-right direction of the sensor mat, by comparing the outputs of the at least two sensor cells, the front-rear direction or the left-right direction It is possible to easily estimate the amount of displacement of the sensor mat in the direction.
[0011]
(Means of claim 5)
In any one of the passenger | crew discrimination | determination systems for motor vehicles described in Claims 2-4,
In the correction process, when the sensor mat is in a normal position, a sensor cell arranged at a position deviating from a certain area pressed on the seating surface of the seat is selected in advance, and output from the selected sensor cell. A positional deviation amount of the sensor mat is estimated from the signal, and a deviation of the load distribution is corrected according to the positional deviation amount.
In this case, since the pressure is applied in a certain area where no load is directly applied directly above the selected sensor cell, the displacement amount of the sensor mat can be estimated based on the magnitude of the load detected by the selected sensor cell. .
[0012]
(Means of claim 6)
In any one of the passenger | crew discrimination | determination systems for motor vehicles described in Claims 2-4,
In the correction process, when the sensor mat is in the normal position, a sensor cell arranged in a certain area to be pressed on the seating surface of the seat is selected in advance, and the sensor is detected by a signal output from the selected sensor cell. A mat displacement amount is estimated, and a load distribution displacement is corrected according to the position displacement amount.
In this case, since pressure is applied in a certain area where a load is directly applied directly above the selected sensor cell, the amount of displacement of the sensor mat can be estimated based on the magnitude of the load detected by the selected sensor cell.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of an occupant discrimination system for an automobile will be described with reference to the drawings.
1 and 2 are explanatory diagrams of a process for correcting a shift in load distribution.
First, the structure and manufacturing process of the sensor built-in seat 1 used in the vehicle occupant discrimination system will be described.
The sensor built-in seat 1 according to the present embodiment is a seat cushion (see FIG. 3) that receives an occupant's buttocks. As shown in FIG. 4, the base 3 supported by the slide rail 2 and the base 3 are installed. It is composed of urethane foam (hereinafter abbreviated as foam 4) and a sheet skin (hereinafter referred to as trim 5) that covers the surface of the foam 4, and a sensor mat 6 is incorporated between the foam 4 and the trim 5.
[0014]
As shown in FIG. 5, the foam 4 forms the entire shape of the sheet 1, and a suspension groove 7 for narrowing (suspending) the trim 5 is provided on the upper surface thereof.
The trim 5 is squeezed into the foam 4 along the suspension groove 7, and the squeezed portion (trench portion) is formed as a design on the appearance. On the back surface of the trim 5, an ear hook part 8 (see FIG. 7) for narrowing the trim 5 into the hanging groove 7 of the foam 4 is provided in a bag shape.
In addition, regarding the foam 4, a portion surrounded by the two hanging grooves 7 is called a central portion, a portion outside the hanging grooves 7 is called a side portion, and for the trim 5, a portion surrounded by the earlobe portion 8 is called a portion. A portion outside the center portion and the earlobe portion 8 is referred to as a horizontal trim.
[0015]
As shown in FIG. 5A, the sensor mat 6 has a first sensor portion 6A disposed at the center portion of the foam 4 and a second sensor portion 6B disposed at the side portion of the foam 4. A plurality of sensor cells 9 are arranged on the sheet surface.
The sensor cell 9 is a pressure conversion element whose resistance value changes according to pressure, for example, and a plurality of sensor cells 9 arranged on the sensor mat 6 can detect pressure independently.
[0016]
In the first sensor portion 6A, a plurality of sensor cells 9 are arranged at equal intervals in the front-rear direction and the left-right direction on a rectangular sheet surface.
In the second sensor portion 6B, a plurality of sensor cells 9 are arranged at equal intervals on a sheet surface that is elongated in the front-rear direction along the side portion of the foam 4.
The first sensor unit 6A and the second sensor unit 6B are integrally provided with their sheet surfaces connected to each other.
The sensor mat 6 is connected to the ECU 11 via the printed circuit board 10, converts a change in pressure detected by each sensor cell 9 into an electrical signal, and outputs the electrical signal to the ECU 11.
[0017]
The ECU 11 is an electronic control unit that incorporates a microcomputer, and is incorporated in the rear end of the foam 4 as shown in FIG. 5B, for example.
The ECU 11 detects the sum of the loads applied to the seat and the load distribution from the output signals of the individual sensor cells 9, and based on the detection results, the presence / absence of a passenger and the presence / absence of a child-specific seat described below. And discrimination between children and adults.
[0018]
a) The presence / absence of an occupant is obtained by calculating the sum of the loads detected by the individual sensor cells 9, and if the value is equal to or greater than a predetermined value, it is determined that the occupant is seated on the seat 1, and if smaller than the predetermined value, the seat 1 It is determined that no occupant is sitting.
b) The presence / absence of a child-specific seat is determined by detecting the load distribution on the seat from the output signals of the individual sensor cells 9 and determining whether the child-specific seat is used according to the shape pattern estimated from the load distribution.
c) In order to discriminate between children and adults, a decision criterion based on the load distribution is added to a decision criterion based on the sum of loads, and a decision is finally made as to whether the child is an adult.
[0019]
Next, the manufacturing process of the sensor built-in sheet 1 will be described.
FIG. 6 is a flowchart showing the manufacturing process.
Step10 ... Install Form 4 on stand 3.
Step 20 ... The sensor mat 6 is arranged at a predetermined position on the upper surface of the form 4.
Step30 ... Assemble the trim 5.
The assembly work of the trim 5 is generally performed according to the following procedure.
First step: First, as shown in FIG. 7, the center portion of the trim 5 is arranged so as to match the center portion of the foam 4, and the wire 12 passed through the earlobe portion 8 and the foam 4 are provided. By simultaneously hooking the wire 13 with the C-shaped hog ring 14 and closing and tightening the hog ring 14, the center portion of the trim 5 covers the center portion of the foam 4.
[0020]
Second step: Subsequently, the lateral trim is turned to the side surface of the foam 4 so as to wrap the outside of the side portion of the foam 4, and the hook portion 5a provided at the end of the lateral trim is hooked on the outer edge portion of the base 3 or the like. Do work. At this time, in order to prevent looseness (wrinkle) from occurring in the lateral trim, tension is applied to the lateral trim in the assembled state. That is, as shown in FIG. 8, the assembly work of the horizontal trim is performed in a state where the foam 4 is pressed and crushed in the vertical direction, and the hook portion 5a of the horizontal trim is hooked on the outer edge portion of the base 3 or the like. , The pressure from above and below is removed. As a result, the lateral trim is attached so as to cover from the side portion of the foam 4 to the side surface of the foam 4 in a state where tension is applied (a state where there is no slack).
[0021]
Step40 ... A correction process is performed.
In this correction process, if the sensor mat 6 incorporated in the lower part of the seating surface of the seat 1 is not disposed at a normal position, the load distribution detected by the ECU 11 during actual use deviates from the normal load distribution. The deviation of the load distribution is corrected.
Hereinafter, the procedure of the correction process will be described with reference to FIGS.
First, at least two sensor cells 9 are selected in advance. In this case, it is desirable to select at least two sensor cells 9 arranged at target positions with a certain interval in a specific direction (for example, front-rear direction, left-right direction) of the sensor mat 6.
[0022]
Subsequently, as shown in FIG. 1, a load is applied to the center portion of the seat surface of the trim 5 using an indenter 15. At this time, the pressure is applied in an area where a load is not directly applied to the selected at least two sensor cells 9. Alternatively, the pressure is applied in an area where a load is directly applied directly above at least two selected sensor cells 9.
Subsequently, the outputs of at least two sensor cells 9 selected in advance and the sensor cells 9 in the vicinity thereof are compared with the outputs when the sensor mat 6 is disposed at a normal position (FIG. 1). Estimate the amount of deviation. For example, in the case shown in FIG. 2, it can be estimated that the sensor mat 6 is shifted in the right direction in the figure by one cell compared to the case where the sensor mat 6 is disposed at a normal position.
Finally, the ECU 11 corrects the deviation of the load distribution obtained from the output of each sensor cell 9 according to the estimated amount of deviation of the sensor mat 6.
[0023]
(Effect of this embodiment)
In the vehicle occupant discrimination system of the present embodiment, after the seat 1 is assembled, the positional deviation amount of the sensor mat 6 incorporated in the seat 1 is estimated, and detected from the output of each sensor cell 9 according to the deviation amount. A correction process for correcting the deviation of the load distribution is provided. As a result, even if the sensor mat 6 is assembled with respect to the sheet 1 in a state of being deviated from the normal position, the deviation of the load distribution is corrected according to the amount of deviation. It is possible to prevent erroneous determination.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a process for correcting a shift in load distribution.
FIG. 2 is an explanatory diagram of a process of correcting a shift in load distribution.
FIG. 3 is a perspective view (a) and a sectional view (b) of a seat cushion.
FIG. 4 is an exploded perspective view of a sensor mat.
FIG. 5 is a plan view (a) and a side sectional view (b) of a foam having a sensor mat.
FIG. 6 is a flowchart showing a manufacturing process of the sensor built-in sheet.
FIG. 7 is a cross-sectional view showing a first step for assembling a trim.
FIG. 8 is a cross-sectional view showing a second step for assembling the trim.
[Explanation of symbols]
1 Seat 5 Trim (Seat skin)
6 Sensor mat 9 Sensor cell

Claims (6)

A plurality of sensor cells are arranged on a plane, and each sensor cell has a sensor mat that can detect pressure independently.
This sensor mat is incorporated in the lower part of the seat surface of the automobile seat, detects the load distribution applied on the seat surface of the seat from the output of the individual sensor cells, and based on the load distribution, whether the passenger on the seat is a child An occupant discrimination system that discriminates between adults,
In the manufacturing process of the sheet,
After the sensor mat is assembled and a seat skin covering the seat surface of the seat is assembled, the sensor mat includes a correction step of correcting a shift of the load distribution due to a positional shift of the sensor mat. Crew identification system. In the passenger | crew discrimination | determination system for motor vehicles described in Claim 1,
In the correction step, pressure is applied to the seating surface of the seat skin with a certain area, and the amount of displacement of the sensor mat is estimated from an output signal from the sensor cell selected in advance, and the amount of displacement is determined according to the amount of displacement. An occupant discrimination system for an automobile, wherein the deviation of the load distribution is corrected. In the vehicle occupant discrimination system according to claim 2,
In the correction step, at least two sensor cells arranged in a specific direction on the sensor mat are selected in advance, and a positional deviation amount of the sensor mat is estimated by a signal output from the selected sensor cell, An occupant discrimination system for an automobile, wherein the deviation of the load distribution is corrected according to the positional deviation amount. In the passenger | crew discrimination | determination system for motor vehicles described in Claim 3,
The at least two sensor cells arranged in a specific direction on the sensor mat are at least two sensor cells at target positions in the front-rear direction or the left-right direction of the sensor mat. Occupant identification system. In any one of the passenger | crew discrimination | determination systems for motor vehicles described in Claims 2-4,
In the correction step, when the sensor mat is in a normal position, the sensor cell arranged in a position deviating from a certain area pressed on the seating surface of the sheet is selected in advance, and the selected sensor cell An occupant discrimination system for an automobile, wherein a displacement amount of the sensor mat is estimated from a signal output from the vehicle, and a displacement of the load distribution is corrected according to the displacement amount. In any one of the passenger | crew discrimination | determination systems for motor vehicles described in Claims 2-4,
In the correction step, when the sensor mat is in a normal position, the sensor cell arranged in a certain area to be pressed on the seating surface of the seat is selected in advance and output from the selected sensor cell. An automobile occupant discrimination system characterized in that a position shift amount of the sensor mat is estimated from a signal to correct the load distribution shift according to the position shift amount.

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