JP4450129B2 - 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 and detects the presence or absence of an occupant on the seat and the presence or absence of a child-specific seat from the sensor output.
[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 larger than a predetermined value, it can be determined that the patient is an adult, and if the load is smaller than the predetermined value, the child can be determined.
[0004]
However, when determining whether an adult or a child 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.
In this occupant discrimination system, a sensor mat in which a plurality of sensor cells are arranged on a plane is incorporated in the lower part of the seating surface of the seat, the load distribution on the seat is detected from the output value of each sensor cell, and is estimated from the load distribution. The presence / absence of a child-specific sheet is detected based on the shape 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]
By the way, in the occupant discrimination system described above, when the sensitivity of individual sensor cells arranged on the sensor mat varies, when the load distribution is detected from the output of each sensor cell, the actual load distribution may not necessarily coincide. . In particular, since the sensor mat is incorporated in the lower part of the seat surface of the seat skin, in addition to the case where the sensitivity of each sensor cell itself varies, the output of each sensor cell may vary depending on the assembled state of the seat skin. is there.
The present invention has been made based on the above circumstances, and an object thereof is to provide a sensor that is stable with respect to a load applied via a seat skin in an occupant discrimination system in which a sensor mat is incorporated in a lower portion of a seat surface of a seat. It is to be able to obtain output.
[0007]
[Means for Solving the Problems]
(Means of Claim 1)
The sheet is composed of a foam and a sheet skin covering the surface of the foam. The foam has a hanging groove for narrowing the sheet skin, and the sheet skin has an earlobe for narrowing the sheet skin into the hanging groove. The foam is composed of a central part surrounded by a hanging groove and a side part outside the hanging groove, and the sensor mat is provided between the foam and the sheet skin in each of the central part and the side part. Yes.
A plurality of sensor cells are arranged on a plane, and each sensor cell has a sensor mat that can detect pressure independently. The sensor mat is incorporated between the foam and the sheet skin, and the sheet is output from the output of each sensor cell. an occupant classification system for occupant to determine whether a child or an adult above, in the manufacturing process of the sheet, the sensor mat when assembling between the foam and the seat skin, in a state where tension is applied to the sheet over preparative epidermis Installing set, then comprises carrying out the calibration process for adjusting the sensitivity of the individual sensor cells against a load applied through the seat upholstery. According to the present invention, by performing the calibration process, it is possible to prevent variations in the output of individual sensor cells with respect to the load applied via the sheet skin, and to obtain a stable sensor output .
[0008]
Further, the calibration step includes a step of applying an external force to the seat surface of the sheet cover to uniformly pressurize each sensor cell, and then removing the applied external force. In this case, since the output corresponding to the sensitivity of each sensor cell is obtained by uniformly pressurizing each sensor cell via the sheet skin, the sensitivity of each sensor cell can be adjusted according to the output. .
[0009]
The calibration step is characterized in that a fluid is sealed in a bag-like bag provided so as to be deformable, and the fluid is uniformly pressurized against the seating surface of the seat cover as a pressurizing medium. In this case, by using a bag-like bag, it is possible to easily and uniformly pressurize each sensor cell. In addition, gas, liquid, a gel-like body, etc. can be selected as the fluid enclosed with a bag.
[0010]
And the bag-shaped bag is provided in the magnitude | size which can pressurize the whole seat surface of a sheet | seat skin. In this case, the entire seating surface of the seat skin can be uniformly and uniformly pressurized by one bag.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of an occupant discrimination system for an automobile will be described with reference to the drawings.
FIG. 1 is an explanatory diagram of the calibration process.
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.
[0013]
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.
[0014]
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.
[0015]
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.
[0016]
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.
[0017]
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.
[0018]
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.
[0019]
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).
[0020]
Step40 ... Carry out the calibration process.
This calibration step adjusts the sensitivity of each sensor cell 9 with respect to the load applied via the trim 5 and is performed according to the following procedure.
First, a deformable big bag 15 (see FIG. 1) is prepared. The big bag 15 is provided in a sealed bag shape, and a fluid is sealed therein in advance. As the fluid, gas, liquid, gel-like body, or the like can be selected. The material of the big bag 15 is not easily broken even under a predetermined load. For example, rubber or thick vinyl may be used.
[0021]
Then, as shown in FIG. 1, the big bag 15 is arrange | positioned on the seat surface of the trim 5, and a load is applied with respect to the big bag 15 from the upper part. Thereby, the fluid sealed in the big bag 15 can be uniformly pressurized against the seating surface of the seat 1 using the pressurized medium. At this time, as shown in FIG. 2 (a), the pressure of the entire seating surface of the seat 1 at a time.
As a reference example, as shown in FIG. 2 (b), the seat 1 may be divided into a central portion and a side portion of the seat 1 and pressurized. In addition, when pressurizing separately in the seating surface center part and side part of the sheet | seat 1, you may pressurize each site | part with the single big bag 15, However, The big bag of the magnitude | size suitable for each site | part 15 may be used for pressurization. Further, the number of times external force is applied to the sheet 1 may be one, but an arbitrary number may be selected.
[0022]
Thereafter (after pressurization), the load applied to the big bag 15 is removed.
Subsequently, the sensitivity of each sensor cell 9 is adjusted by the ECU 11.
In this case, if the sensitivity of each sensor cell 9 varies, the output of each sensor cell 9 varies even though a load is uniformly applied to each sensor cell 9 via the trim 5. The sensitivity of each sensor cell 9 is adjusted according to the variation.
[0023]
(Effect of this embodiment)
The occupant discrimination system of the present embodiment performs a calibration process after the assembly of the seat 1 is completed. That is, by adjusting the sensitivity of each sensor cell 9 with respect to the load applied via the trim 5, a stable sensor output can be obtained in an actual use state.
In the calibration process described above, the big bag 15 in which a fluid has been sealed is used. However, for example, the big bag 15 is disposed on the seat surface of the seat 1 and the upper surface of the big bag 15 is positioned. In this state, a fluid may be injected into the big bag 15 to inflate the big bag 15 and pressurize the seat 1 by the inflating force.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a calibration process.
FIG. 2 is a plan view showing a place where a sheet is pressed in a calibration process.
FIG. 3 is a perspective view (a) and a sectional view (b) of a sheet.
FIG. 4 is an exploded perspective view of a seat cushion.
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 sheet manufacturing process.
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 Sensor built-in sheet (sheet)
5 Trim (sheet cover)
6 Sensor mat 9 Sensor cell 15 Big bag (bag-shaped bag)

Claims (1)

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 a car seat, and is an occupant discrimination system that discriminates whether the occupant on the seat is a child or an adult from the output of the individual sensor cells,
The sheet is composed of a foam and a sheet skin covering the surface of the foam, and the foam is provided with a hanging groove for narrowing the sheet skin, and the sheet skin is inserted into the hanging groove in the sheet skin. An earlobe part for narrowing down is provided, and the foam consists of a central part surrounded by the hanging groove, and a side part outside the hanging groove,
The sensor mat is provided between the foam and the sheet skin in each of the central portion and the side portion,
Applied in the manufacturing process of the sheet, when assembling the sensor mat between the seat skin and the foam, only assembling under tension to said sheet over preparative epidermis, then through the seat skin Performing a calibration step to adjust the sensitivity of the individual sensor cells to the applied load,
The calibration step includes the step of applying an external force to the seating surface of the sheet skin, uniformly pressing the individual sensor cells, and then removing the applied external force,
Uniform pressurization to the individual sensor cells is performed by enclosing a fluid in a bag-like bag provided so as to be deformable, and uniformly pressurizing the seat skin of the seat skin as a pressurizing medium. I,
The occupant discrimination system for an automobile, wherein the bag-like bag is provided with a size capable of pressurizing the entire seating surface of the seat skin.

Images