JP2000301980A - Occupant detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an occupant detecting device for precisely classifying the weights of occupants on seats, and particularly for surely detecting that infants or children are seated via child seats. SOLUTION: In this device, a determining means 13 classifies occupants seated on seats, based on the results of detection by a first detecting means 11 for detecting the distribution of load applied to the seating part of a vehicle seat and a second detecting means 12 for detecting the seat weight of the vehicle and the load applied to the entire seats. In particular, the device surely detects that infants or children are seated via child seats.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an occupant detection device capable of reliably detecting the presence or absence of a child seat on a vehicle seat and classifying occupants seated on the seat.

[0002]

2. Description of the Related Art For example, airbags are one of the safety equipments of automobiles, and as automobiles equipped with the airbag apparatus are rapidly spreading, injuries and deaths caused by the airbag apparatus increase. I have. These accidents are caused by the fact that the airbag device is designed to operate for adult men, and these accidents tend to occur more often for children and small women.

[0003] Therefore, the occupant's physique information is accurately obtained,
A so-called smart airbag system that controls an airbag in accordance with the occupant's physique has been studied. here,
As a threshold value to match the occupant's physique, there are various methods that use the occupant's position on the seat in addition to the physique information such as weight and height as a threshold value. Promising. Specifically, this is a system in which the weight of an occupant is determined and classified, and the deployment speed and deployment intensity of the airbag are controlled.

[0004]

In order to measure the load value on the seat and control the deployment speed and deployment strength of the airbag in accordance with the weight of the occupant, it is necessary to accurately obtain the weight information of the occupant. is there. However, even if a plurality of sensors, measuring devices, and the like are combined, it is difficult to accurately measure the posture of the occupant, changes in ambient temperature and humidity, vibrations of the vehicle, and the like. As a result, it is considered appropriate to classify the occupant weight into ranges having a certain width in consideration of the dispersion of the respective measurement values.

On the other hand, when an infant or a child is seated through a child seat (a child auxiliary seat including an infant seat or a booster seat), the height of the infant or the child, the distance to the dashboard, and Is significantly different from that of a small adult woman sitting on a seat. For this reason, it is required not to unnecessarily operate auxiliary devices around the seat such as an airbag. However, when a child sits on a seat using a child seat and when a small adult woman sits on the seat, the load value applied to the seat is approximated, and accurate occupant information cannot be obtained. There is a risk that the peripheral parts of the seat may be operated unnecessarily. Therefore, while accurately classifying the weight of the occupant,
In particular, it is necessary to reliably detect a case where an infant or child is sitting through a child seat.

Incidentally, Japanese Patent Application Laid-Open No. 9-150662 discloses that
Although a configuration in which a strain gauge is arranged between a seat cushion and a plurality of brackets for fixing the same to a vehicle floor is disclosed, this is ensured without being influenced by a seated position of a seated person on a seat. It merely detects the presence or absence of a seated occupant, does not accurately classify the weight of the occupant on the seat, and particularly cannot reliably detect the case where an infant or child is seated through the child seat.

An object of the present invention is to provide an occupant detection device that accurately classifies the weight of an occupant on a seat and, particularly, reliably detects a case where an infant or child is seated through a child seat. is there.

[0008]

In order to achieve the above object, an occupant detection device according to the present invention comprises: first detection means for detecting a load distribution applied to a seat portion of a vehicle; and a seat weight of the vehicle. Further, the determination means classifies the occupant seated on the seat based on the detection result of the second detection means for detecting the load applied to the entire seat.

[0009] Whether a person is seated on the seat, whether a child seat or luggage is on the seat is detected from the load distribution applied to the seating portion of the vehicle obtained by the first detecting means, and the seat is detected by the second detecting means. The load applied to the whole is detected for each weight of the seat, the weight of the occupant on the seat is accurately classified, and the case where an infant or child is seated through the child seat is detected.

An occupant detection device according to a second aspect of the present invention comprises a first detection means for detecting the presence or absence of a child seat on a vehicle seat, and a second detection means for detecting a seat weight of the vehicle and a load applied to the entire seat. The determination means classifies the occupant seated on the seat based on the detection result of the second detection means. The first detecting means detects the presence or absence of the child seat on the seat, and the second detecting means detects the load applied to the entire seat for each seat weight, so that the weight of the occupant on the seat can be accurately classified. In this case, it is possible to reliably detect a case where an infant or child is sitting through the child seat.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an occupant detection device according to a first embodiment of the present invention will be described with reference to the drawings. The occupant detection device 10 according to the first embodiment of the present invention is shown in FIG.
As shown in FIG. 1, a seat pressure sensor (first detecting means) 11 for detecting a distribution of a load applied to a seat seat 1 of a vehicle.
Load sensors (second detection means) 12a and 12b for detecting the weight of the vehicle seat and the load applied to the entire seat;
A processing unit 13 for classifying the occupant seated on the seat based on the detection results of the seat pressure sensor 11 and the load sensor 12
And so on.

As the seat pressure sensor 11, a film pressure sensor is used. As shown in FIG. 2, the film-shaped pressure sensor has a plurality of pressure-sensitive sensor elements 11a arranged in a sheet shape, and is disposed near the skin of the seat seating portion 1 so as to easily receive a load from an occupant. I have. The pressure-sensitive sensor element 11a is, as shown in FIG.
An insulating layer 11d made of an adhesive layer having a predetermined thickness is sandwiched between insulating plastic films 11b and 11c such as T, and a metal foil having a predetermined shape is stuck on the insulating plastic film or a conductive paint is printed in a predetermined shape. The conductive layers 11e and 11f, which have been formed into circuit patterns, are adhered so as to face each other at regular intervals. When pressure is applied to the pressure-sensitive sensor element 11a in the directions of arrows P and Q,
The conductive layers 11e and 11f come into contact with each other, and by detecting this electrically, the pressure applied to the pressure-sensitive sensor element 11a is detected.

Such a pressure-sensitive sensor element 11a
Are arranged in a matrix, as partially shown in FIG. 2, the area of the buttocks of the occupant seated on the seat seating section 1 from the output from each pressure-sensitive sensor element 11 a of the seating section pressure-sensitive sensor 11. In addition, an area of the child seat that is in contact with the seat or the seat seating section 1 or an area of a load that is in contact with the seat seating section 1 can be detected.

As the load sensors 12a and 12b, capacitance type pressure sensors are used, and as shown in FIG. Each of the load sensors 12a and 12b measures the weight of the seat acting on the seat and the weight of the occupant on the entire seat, and transmits the output signal to the processing unit 13. The load may be measured using a strain gauge instead of the capacitance type pressure sensor.

The processing unit 13 includes a CPU 13c and a memory 13m. The CPU 13c determines whether an occupant is seated on the seat occupant 1 based on the detection result of the seat pressure sensor 11 based on a judgment flow described in detail below. It is determined whether a child seat or a load is loaded, whether the detection area of the seat pressure sensor 11 has changed, that is, whether the center of gravity of the occupant has moved on the seat, the weight of the occupant on the seat, Classification etc. are performed for each. The memory 13m stores a threshold value necessary for the CPU 13m to determine whether an occupant is seated on the seat, whether a child seat is mounted, whether a load is mounted, and the like, based on the detection result of the seat pressure sensor 11. A pattern, a threshold value required for the CPU 13m to perform classification by weight of the occupant on the seat, and the like are stored.

Hereinafter, the occupant detection routine will be described in detail with reference to flowcharts shown in FIGS.
First, the load applied to the seat seat 1 is measured by the seat pressure sensor 11 (step S101), and the presence or absence of the load applied to the seat seat 1 is checked (step S1).
02). If the load is not applied to the seat sitting portion 1, it is determined that the seat is empty (step S103). This determination result is transmitted to the control device of the seat peripheral device so that, for example, the airbag or the like does not needlessly operate. If there is an output of the seating pressure sensor 11, the presence or absence of a shift in the center of gravity is detected from the output of the seating pressure sensor 11 (step S104). If there is no movement of the center of gravity, it is determined that a load is on the seat. (Step S105). If there is a shift in the center of gravity, this load distribution pattern
RS) whether the load distribution pattern is approximated or not.
U13c compares the threshold pattern with the threshold pattern in the memory 13m (step S106), and when they are similar, determines that there is a child seat on the sheet (step S10).
7). In this case, since it has already been detected in step S104 that the center of gravity has moved on the seat, it is determined at the same time that a child or child is riding on the child seat.

If the load distribution pattern does not approximate the load distribution pattern of the child seat, it is determined that the occupant is sitting directly on the seat (step S108).
Next, the load applied to the entire sheet is measured by the load sensor 12 (Step S109). Load sensor 12
Is interposed in the supporting portions 3 and 4 for supporting the seat frame (not shown) on the floor 2, so that the load applied to the entire seat can be measured according to the weight of the seat. Measurement can be performed with high accuracy.

When a capacitance type sensor is used as the load sensor 12, the initial value of the load sensor is liable to drift due to the influence of temperature or the like, but when the output of the pressure sensor 11 is zero, That is, by performing the initial value calibration periodically using the time when the occupant is not seated on the seat, the drift of the output value can be prevented. Subsequently, classification is performed for each seated person's weight (step S110). This can be easily performed by the CPU 13c comparing the load value applied to the sheet obtained from the load sensor 12 with a threshold value stored in the memory 13m.

As an example, when the occupant on the seat is classified into a standard adult weight class, a small female weight class, and a child weight class based on the load value applied to the seat, and is determined to be a child weight class. Even if step S
If it is determined in 107 that there is a child seat on the seat, it is determined that the child is not directly seated on the seat, but a child is sitting on the seat via the child seat.

According to the occupant detection device according to the first embodiment of the present invention, the occupants on the seat can be accurately classified as described above. Activate the airbag normally when belonging to the adult weight class, activate the airbag slower than normal deployment speed when belonging to the small female weight class, and activate the airbag when belonging to the child weight class. It can be prevented from expanding. Also, even if the weight of the occupant on the seat belongs to the weight class of the child, if it is determined that the infant is seated on the seat via the child seat, the seat such as a door lock is automatically set. By operating the peripheral device, it is possible to prevent the infant from inadvertently opening the door.

Next, an occupant detection device according to a second embodiment of the present invention will be described. In addition, about the structure equivalent to the structure concerning the above-mentioned embodiment, the corresponding code | symbol is attached | subjected and detailed description is abbreviate | omitted. As shown in FIG. 6, an occupant detection device 20 according to a second embodiment of the present invention includes a child seat detection antenna (first detection means) 21 arranged on a seat seating portion 1 of a vehicle, and a seat weight of the vehicle. And a load sensor (second detection means) 22a, 22b for detecting a load applied to the entire seat, and a processing unit (classification means) for classifying an occupant seated on the seat based on detection results of the detection antenna 21 and the load sensor 22. ) 23 and the like.

The child seat detection antenna 21 detects the tag 6 attached to the child seat 5 in a non-contact manner, and is attached under the sheet surface so that the tag 6 can be easily detected. As the load sensor 22, a capacitance type pressure sensor similar to the load sensor 12 used in the occupant detection device 10 according to the first embodiment is used, and a support for supporting a seat frame (not shown) on the floor 2 is used. The load applied to the entire sheet is measured with respect to the weight of the sheet.

The processing unit 23 includes a CPU 23c and a memory 23m. The CPU 23c determines whether or not the child seat 5 is placed on the sheet based on the detection result of the child seat detection antenna 21 based on a determination flow described in detail below. At the same time, the weight of the occupant on the seat is classified. The memory 23m stores a threshold pattern required for the CPU 23c to classify the occupants on the seat based on the detection result of the load sensor 22.

Hereinafter, the occupant detection routine will be described in detail with reference to the flowchart shown in FIG. First, the presence / absence of a child seat (CRS) on the seat is determined by detecting the tag 6 of the child seat by the child seat detection antenna 21 (step S20).
1) If there is no output from the detection antenna 21, it is determined that there is no child seat (step S202). On the other hand, if there is an output from the detection antenna 21, it is determined that there is a child seat (step S203). After making these determinations, the load applied to the entire sheet is measured by the load sensor 22 (step S204).

When a capacitive sensor is used as the load sensor 22, when the occupant is not seated, for example, when the occupant goes out of the vehicle by opening the door, the CPU 23c detects the The drift of the output value can be prevented by performing the initial value calibration. Subsequently, classification is performed for each weight of the seated person (step S205). This is because the load value applied to the entire sheet obtained from the load sensor 22 is calculated by the CPU 2.
By comparing 3c with the threshold value stored in the memory 23m, the operation can be performed in the same manner as the occupant detection device 10 of the first embodiment.

Specifically, the occupants on the seat are classified into a standard adult weight class, a small female weight class, and a child weight class based on the load value applied to the seat, and are determined to be the child weight class. Step S
If it is determined in 203 that there is a child seat on the seat, it is determined that the child is not sitting directly on the seat but a child is sitting on the seat via the child seat 5.

According to the occupant detection device 20 according to the second embodiment of the present invention, the presence / absence of a child seat can be detected and the occupants on the seat can be classified by a simpler judgment flow. As a result, similarly to the occupant detection device 10 according to the first embodiment, it is possible to operate the airbag properly according to the weight of the occupant on the seat, to operate the airbag at a low deployment speed, or not to deploy the airbag. it can.
In addition, since it is reliably detected that an infant is sitting on the seat via a child seat, door peripherals such as door locks are automatically activated to prevent the infant from inadvertently opening the door. It is possible to do.

Note that, apart from the occupant detection device according to the above-described embodiment, a sensor combining a dielectric sensor and a pressure sensor may be used as the first detection means. For example, by attaching the dielectric sensor to the backrest of the seat, it is possible to distinguish between the child seat on the seat and the booster seat. As the second detecting means, any sensor can be used in place of the capacitance type sensor as long as it can accurately measure the weight of a piezoelectric element type sensor, pressure sensitive rubber, pressure sensitive ink, or the like. May be.

Further, it goes without saying that various types of judgment flows can be applied instead of the judgment flow of the occupant detection device according to the above-described embodiment without departing from the object of the present invention.

[0030]

As described above, the occupant detection device according to the present invention determines whether a person is seated on the seat or whether the child seat or luggage is on the basis of the load distribution applied to the seat seat portion of the vehicle by the first detection means. In addition to detecting whether the vehicle is on the vehicle and detecting the load applied to the entire seat for each seat weight by the second detecting means, it is possible to accurately classify the weight of the occupant on the seat and, in particular, through the child seat. Thus, it is possible to reliably detect the case where the infant is seated.

According to a second aspect of the present invention, in the occupant detection device, the first detection means detects the presence or absence of the child seat on the seat, and the second detection means determines the load applied to the entire seat by the weight of the seat. Because it detects
In addition to accurately classifying the weight of the occupants on the seat,
Through the child seat, it is possible to reliably detect a case where an infant or child is sitting.

[Brief description of the drawings]

FIG. 1 is an occupant detection device 1 according to a first embodiment of the present invention.
FIG.

FIG. 2 is a view partially showing a seat pressure sensor 11 used in the occupant detection device 10 of FIG. 1;

FIG. 3 is a cross-sectional view of a sensor element 11a constituting the seat pressure sensor of FIG. 2;

FIG. 4 is an occupant detection device 1 according to the first embodiment of the present invention.
It is a figure showing the judgment flow of 0.

FIG. 5 is a diagram illustrating a determination flow following FIG. 4;

FIG. 6 shows an occupant detection device 2 according to a second embodiment of the present invention.
FIG.

FIG. 7 is an occupant detection device 2 according to a second embodiment of the present invention.
It is a figure showing the judgment flow of 0.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Seat seating part 2 Floor 3, 4 Support part 5 Child seat 6 Tag 10 Occupant detection device 11 Seating part pressure sensor 11a Pressure sensor element 12 Load sensor 13 Processing part 20 Occupant detection device 21 Detection antenna 22 Load sensor 23 Processing part

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takayuki Enomoto 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. F-term (reference) 2F051 AA01 AB07 AC01 AC07 3B084 JA06 JC01 3B088 QA05

Claims (2)

[Claims] 1. A first detecting means for detecting a distribution of a load applied to a seating portion of a vehicle, a second detecting means for detecting a weight of a vehicle seat and a load applied to the entire seat, and the first detecting means. An occupant detection device comprising: a determination unit configured to classify an occupant seated on a seat based on a detection result of the second detection unit. 2. A first detecting means for detecting the presence or absence of a child seat on a vehicle seat, a second detecting means for detecting a weight of the vehicle seat and a load applied to the entire seat,
An occupant detection device, comprising: a determination unit that classifies an occupant seated on a seat based on detection results of the first detection unit and the second detection unit.