JP2000331565A - Seating detecting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine a seating object and its seating state in detail. SOLUTION: A sheet like seating sensor 5 is embedded just under a cloth or leather upholstery of a seating part 2 of a seat 1. A weight sensor 6 for detecting a load of a seating object as a pressure is embedded under the seating sensor 5. The seating sensor 5 is a membrane switch structured by laminating a pair of flexible sheet through an insulating spacer, providing a position of a contact part turned on. A CPU 52 determines a seating object and its seating state based on output states of the seating sensor 5 and the weight sensor 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seating detection system which is installed in a seat of an automobile, an aircraft or the like, and determines a seating state and a seating target.

[0002]

2. Description of the Related Art Conventionally, this kind of seat detection system has been used to determine whether or not a passenger is in a passenger seat or its physique and to control the operation state of an airbag. I have. As this seating sensor, a sensor using a membrane switch capable of configuring a system at a relatively low cost is known.

FIG. 8 is a diagram showing a configuration of a seating sensor using a membrane switch. The membrane switch is configured by stacking a pair of flexible sheets 101 and 102 via an insulating spacer 103. Conductive patterns 104 and 105 are formed on the opposing surfaces of the flexible sheets 101 and 102, respectively. Insulation spacer 103
An opening 106 is formed at a predetermined position, and the conductive patterns 104 and 105 above and below the opening 106 are
07 is formed. The flexible sheet 101,
When a load in the thickness direction of 102 is applied, the conductive patterns 104 and 105 come into contact with each other through the opening 106, and the presence or absence of seating can be determined by detecting the current flowing due to this contact. In the case of a human body, since it has elasticity, a load is applied to the flexible sheet 101 in the portion of the opening 106 of any one of the contact portions 107 by dispersing and arranging the plurality of contact portions 107 on the seat. Is detected.

[0004]

However, in a seating sensor using a membrane switch, when a soft load is placed on a seat, it cannot be distinguished from a person. In recent years, there has been a movement to obligate the use of a child seat for a passenger seat. In the case of a child seat, there is a case that an infant rides on the vehicle, so that the operation control of the airbag cannot be the same as that of an adult.
Therefore, when a child seat is installed, it is necessary to detect the child seat. However, in a conventional seating sensor using a membrane switch, when the seat has a flat bottom surface such as a child seat, a load is uniformly applied on the flexible sheet 101, so that the contact portion 107 is unlikely to be turned on.

On the other hand, a seating detection system in which a plurality of electrodes are arranged on a seat to detect the presence or absence of a person by detecting a change in capacitance between the electrodes has also been proposed. Whether it is a child or a child, it is not possible to determine its weight, hardness, and the like.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a seating detection system capable of determining a seated object and its seating state in more detail.

[0007]

A seating detection system according to the present invention is formed by stacking a pair of flexible sheets via an insulating spacer, and a conductive sheet is provided on each of opposing surfaces of the pair of flexible sheets. As the pattern is formed,
An opening for forming a contact portion at a predetermined position of the insulating spacer is formed, and when a load in the thickness direction of the flexible sheet is applied to the contact portion, a conductive pattern facing the opening at the opening position contacts the membrane. A seating sensor comprising a switch, arranged at a seating portion of the seat, current detecting means for detecting a current flowing through a contact portion of the seating sensor to detect on / off of the contact portion, and provided at the seating portion. A weight sensor that detects a load applied to the seating portion by, for example, pressure, and a seating target determining unit that determines a seating state and a seating target based on a combination of detection outputs of the current detection unit and the weight sensor. Features.

That is, the seating sensor of the present invention is a membrane switch that is turned on when conductive patterns formed on the upper and lower flexible sheets are in contact with each other through openings formed in the insulating spacer. Therefore, when a soft object such as a human body is seated, one of the contact portions is turned on.However, when a rigid object such as a child seat having a flat bottom is placed, any of the contact portions is turned on. Also does not turn on. However, it is not possible to judge whether the seat is not seated or whether the child seat is placed by using only the seating sensor. Therefore, by combining a weight sensor, if an object or person is sitting,
The approximate weight can be known, and the seat sensor can determine whether the seat is a child seat or whether a person is actually sitting.

If the current detecting means is capable of independently detecting the on / off state of each of the contact portions of the seating sensor, the posture of the seating object, that is, the front and rear, depends on which of the contact portions is in the on state. It is possible to finely detect which of the left and right positions is seated.

A part of the plurality of contact portions of the seating sensor has a pair of flexible sheets provided with a convex portion on a surface opposite to a surface on which at least one conductive pattern is formed. If there is, even if the bottom surface is flat, such as a child seat, the bottom surface pushes the convex portion provided on the contact portion, so that the child seat detection and the detection output of the weight sensor can be further combined with the detection output of the weight sensor. Child seats and luggage can be distinguished. Here, the convex portion refers to various types such as a protrusion formed on the surface of the flexible sheet of the membrane switch, a ridge, a raised portion covering the entire contact portion, a plurality of small protrusions formed on the entire contact portion, and the like. Can be adopted.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a seat detection system according to the present invention and an automobile seat to which the system is applied. The seat 1 includes a seating portion 2, a backrest portion 3, and a headrest 4. A seat-shaped seating sensor 5 is embedded immediately below the cloth or leather upholstery of the seating portion 2, and a weight sensor is provided inside the seating portion 2. 6 is embedded. The embedding position of the weight sensor 6 may be in the middle of the urethane cushion.

The seating sensor 5 is composed of a membrane switch. As shown in an exploded perspective view of FIG. 2, a pair of flexible sheets 11 made of an insulating resin film such as a polyester film. 12 is formed by superimposing them via an insulating spacer 13. Conductive patterns 14 and 15 made of silver paste or the like are formed on the facing surfaces of the flexible sheets 11 and 12 by a method such as screen printing. In this example, the conductive pattern 14 on the upper side of the figure includes lands 14 a formed at portions corresponding to the contact portions 16, respectively.
4a and a lead portion 14b commonly connected to the + side power supply terminal. In this example, the lower conductive pattern 15 includes lands 15a formed at portions corresponding to the contact portions 16, and leads 15b that individually guide current flowing through each of the lands 15a to the detection system. I have. An opening 17 is formed at a position corresponding to the contact portion 16 of the insulating spacer 13, and the upper and lower lands 14a and 15a come into contact with each other through the opening 17 when a load is applied.

On the other hand, as shown in FIG. 3, the weight sensor 6 includes a cushion 21 forming the seating portion 2, a pressure detection bag 31 disposed between the resin sheets 22, and an air of the pressure detection bag 31. And a semiconductor pressure sensor 33 for detecting a pressure of air transmitted through the pipe 32. The semiconductor pressure sensor 33 detects, for example, a pressure applied to a diaphragm formed by etching a silicon substrate as a change in capacitance between electrodes formed on the diaphragm and the base, or detects a strain of the diaphragm as a resistance change. Etc. can be used.

As shown in FIG. 1 and FIG.
The current flowing through each of the contact portions 16 is introduced into a current detection circuit 51, where ON / OFF of each contact portion 16 is detected and converted into digital data indicating ON / OFF. Also,
The output of the semiconductor pressure sensor 33 is converted by the detection circuit 53 into digital data corresponding to the pressure. The digital data output from the detection circuits 51 and 53 is taken into a CPU 52 as a seating object determination unit. CPU
52 determines the presence / absence of a seat and its target based on the on / off state of the seat sensor 5 and the weight value detected by the weight sensor 6 as follows. Further, when the seating sensor 5 is in the ON state, the seating position is determined based on any one of the positions where the ON contact portions are concentrated, that is, the front side, the rear side, the right side, and the left side of the seating section 2. Further, the physique of the seated person is also determined based on the number of the contact portions 16 that are turned on. When the seating sensor 5 is off, it is considered that the baggage is large. As a result, the presence or absence of a person, its weight and posture,
The child seat can be distinguished from other objects.

[0015]

[Table 1]

The present invention is not limited to the above embodiment. FIG. 5 is a view showing another embodiment of the present invention, and is a view showing a configuration of a seating detection system in which the above-described seating sensors 5 are dispersedly arranged in a detection area. For example, left and right and center detection areas AL, AC, and AR are set in the seat 1, and the seating sensors 5 are arranged in the respective areas AL, AC, and AR.
The current introduced from one or a plurality of leads from the seating sensor 5 is switched, for example, in a time-division manner via the switching circuit 54 and is guided to the current detection circuit 51. By doing so, the circuit scale of the current detection circuit 51 can be reduced.

As shown in FIG. 6, the seating sensor 5 includes a land 14a of the flexible sheet 11 in addition to the contact portion 16.
A contact portion 18 having a projection 40 formed on the surface opposite to the formation surface may be further provided. The protrusions 40 are formed by placing a dome-shaped resin on the flexible sheet 11, by screen printing, or by bonding a dome-shaped rubber with a double-sided tape or an adhesive. And the like. The contact portions 16 without projections and the contact portions 18 with projections are arranged so as to be uniformly distributed as shown in the figure. In this embodiment, the projections 40 are provided on the flexible sheet 11,
It may be provided on the lower side of the flexible sheet 12 or on both the flexible sheets 11 and 12.

When the seating sensor 5 is configured in this manner, as shown in FIG. 7A, when a load is applied to the seating sensor 5 by an elastic body, such as when a person is riding on the seating portion 2. , Both of the contact portions 16 and 18 are turned on. On the other hand, when the load is uniformly applied to the flat surface as in a child seat having a flat bottom surface as shown in FIG. 3B, the contact portion 16 is not turned on, but the projection of the contact portion 18 is pressed. Is turned on. Therefore, by monitoring the on / off states of the contact portions 16 and 18, respectively, it is possible to finely determine whether the seated object has a flat bottom surface, its area, pattern (shape), and the like.

Although the weight sensor is provided between the cushion 21 and the resin sheet 22 in the above embodiment, the weight sensor may be provided between the seating sensor 5 and the cushion, or the cushion may be divided into two parts and disposed between them. good. Further, as the weight sensor, in addition to the above-described pressure sensor, a sensor using a strain gauge or a sensor using a piezoelectric element may be used.

[0020]

As described above, according to the present invention, a seating sensor comprising a membrane switch for detecting a load in the thickness direction is provided at the seating portion of the seat, and a weight sensor for detecting the weight of the seating object is provided. Since the seating target determining means determines the presence or absence of the seating and the seating target based on the detection outputs of these sensors, the presence / absence of the seating, the state of the seating target, the posture thereof, and the like can be determined in detail, and the deployment control of the airbag can be performed. Etc., detailed control becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram showing a seating detection system according to an embodiment of the present invention and an automobile seat into which the system is incorporated.

FIG. 2 is an exploded perspective view of the seating sensor used in the system, partially cut away.

FIG. 3 is a diagram showing a configuration of a weight sensor in the system.

FIG. 4 is a circuit diagram showing a detection system of a seating sensor of the system.

FIG. 5 is a diagram showing a configuration of a seating detection system according to another embodiment of the present invention.

FIG. 6 is an exploded perspective view showing a configuration of a seating sensor according to still another embodiment of the present invention, with a portion cut away.

FIG. 7 is a diagram for explaining the operation of the seating sensor.

FIG. 8 is a partially cutaway perspective view showing a conventional seat sensor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Seat, 2 ... Seating part, 5 ... Seating sensor, 6 ... Weight sensor, 51 ... Current detection circuit, 52 ... CPU, 53 ... Detection circuit, 54 ... Switching circuit.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiyoshi Oba 1440 Mutsuzaki Sakura City Chiba Prefecture Fujikura Sakura Works Co., Ltd. 72) Inventor Takaaki Katsumata 1440, Murosaki, Sakura-shi, Chiba F-term in Fujikura Sakura Plant (reference) 3D054 EE09 EE10 EE11 EE31 5G006 AA01 AB02 AZ01 BA01 BA02 BB07 FB29 FB31 FB35 FD02

Claims (4)

[Claims] 1. A pair of flexible sheets are formed by superimposing them via an insulating spacer, a conductive pattern is formed on each of the opposing surfaces of the pair of flexible sheets, and a predetermined position of the insulating spacer is provided. An opening for forming a contact portion is formed, and when a load in the thickness direction of the flexible sheet is applied at the contact portion, a membrane switch that contacts a conductive pattern facing the opening portion position,
A seating sensor arranged at a seating portion of a seat; current detecting means for detecting a current flowing through a contact portion of the seating sensor to detect on / off of the contact portion; and a seating portion provided at the seating portion, 1. A seating detection system comprising: a weight sensor that detects a load applied to a vehicle; and a seating target determination unit that determines a seating state and a seating target based on a combination of detection outputs of the current detection unit and the weight sensor. 2. The pressure sensor according to claim 1, wherein the weight sensor is a pressure sensor that detects a pressure applied to a seat.
A seating detection system as described. 3. The seating detection system according to claim 1, wherein said current detecting means independently detects on / off of each contact portion of said seating sensor. 4. A part of the plurality of contact portions of the seating sensor is located on a side of at least one of the pair of flexible sheets opposite to a surface on which the conductive pattern is formed. The seating detection system according to any one of claims 1 to 3, wherein the surface is a contact portion with a convex portion having a convex portion provided on a surface thereof.