KR20120061436A - Improved apparatus for sensing seat occupancy - Google Patents

Improved apparatus for sensing seat occupancy Download PDF

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Publication number
KR20120061436A
KR20120061436A KR1020100122757A KR20100122757A KR20120061436A KR 20120061436 A KR20120061436 A KR 20120061436A KR 1020100122757 A KR1020100122757 A KR 1020100122757A KR 20100122757 A KR20100122757 A KR 20100122757A KR 20120061436 A KR20120061436 A KR 20120061436A
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KR
South Korea
Prior art keywords
seat
sensing
impedance
detecting unit
reactor
Prior art date
Application number
KR1020100122757A
Other languages
Korean (ko)
Inventor
금명훈
Original Assignee
현대모비스 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by 현대모비스 주식회사 filed Critical 현대모비스 주식회사
Priority to KR1020100122757A priority Critical patent/KR20120061436A/en
Publication of KR20120061436A publication Critical patent/KR20120061436A/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
    • B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
    • B60N2/002—Seats provided with an occupancy detection means mounted therein or thereon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/01—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents
    • B60R21/015—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents including means for detecting the presence or position of passengers, passenger seats or child seats, and the related safety parameters therefor, e.g. speed or timing of airbag inflation in relation to occupant position or seat belt use
    • B60R21/01512—Passenger detection systems
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/01—Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Transportation (AREA)
  • Geophysics And Detection Of Objects (AREA)
  • Seats For Vehicles (AREA)
  • Air Bags (AREA)

Abstract

PURPOSE: A capacitance-type seat sensing system strongly against noise is provided to reduce wrong recognition by guaranteeing robust property against external noise because an LC circuit has a NBPF(Narrow Band Pass Filter) property. CONSTITUTION: A capacitance-type seat sensing system strongly against noise(100) comprises sensing mats(110), a reactor(140), an impedance detecting unit(120), and a seat ECU(Electronic Control Unit)(130). The sensing mats are installed inside a seat cushion of a vehicle seat. The sensing mats sense body pressure of occupants and are composed of a dielectric substance and an insulator. The reactor is directly connected with the sensing mats. The impedance detecting unit is directly connected to the reactor and measures impedance. The seat ECU is directly connected to the sensing mats and the impedance detecting unit to constitute a closed circuit. The seat ECU applies output frequency to the impedance detecting unit to receive phase difference signals.

Description

Capacity-sensitive sheet detection device resisting noise {IMPROVED APPARATUS FOR SENSING SEAT OCCUPANCY}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a sheet capacitive sensor that is resistant to noise, and more particularly, to a sheet capacitive sensor that is robust to noise that is robust against external noise during capacitive capacity recognition using an LC series circuit structure.

In general, the occupant classification system of a vehicle can determine the number of passengers and the gender and age of the passengers. Among them, there is a passenger detection device that distinguishes passengers by detecting storage capacity.

As shown in FIG. 1, the passenger detecting apparatus for classifying passengers by detecting the storage capacity determines whether the vehicle is an adult or a child by using a difference in the storage capacity formed between the power storage plate provided under the seat and the ground of the vehicle body. Device.

As shown in the figure, the air permittivity and the permittivity of the human (moisture 60%) are different from each other, so that the presence of a person between the capacitor plates changes the storage capacity.

However, in the mass-capacity passenger recognition device currently in mass production, the equivalent circuit of the sensing stage is composed of an RC series circuit or an RC parallel circuit. That is, circuits in which resistors and capacitors are connected in series or in parallel, and these circuits have characteristics of a low pass filter (LPF) or a high pass filter (HPF), so they receive a lot of noise from the outside and are very vulnerable to noise. There was.

On the other hand, Figure 2a, 2b shows a passenger sensing device composed of a plurality of modes, one mode is the loading mode, the other mode is the coupling mode.

1.Loading Mode

-Electrode: 1

-Operating frequency and AC power: AC_V (f2) _4

(Step1) Power on AC_V (f2) _4

(Step2) Capacitive coupling between object on seat and electrode 1

(Step3) Capacitive Coupling measurement uses current flowing using I (f2) _6.

(Step4) Classification

-Adult: High Signal-Child: Low Signal-CRS: Very Low Signal

That is, by measuring the capacitive coupling between the human body on the sheet and the electrode # 1, and measuring the current flow on the f2 (6) by using the capacitive coupling, it can be determined that the adult at the high signal and the child at the low signal. It is a system.

Looking at the principle more schematically, as shown in Figure 2b.

That is, the insulating layer 40 is provided between the sensing electrode 30 and the shield electrode 50, and the current protection device 60 is provided, thereby providing the capacitance between the sensing electrode 30 and the shield electrode 50. You can measure it.

The capacitance-aware passenger identification device having the general RC series circuit structure shown in FIGS. 3b, 3c, 3d, and 3e has the characteristics of a primary system consisting of only a capacitor and a resistor. Looking at the frequency response of this circuit, the absolute value of the admittance drops gently as the frequency increases, and the phase difference is fixed at 90 degrees. Therefore, the capacitance due to the dynamic frequency fluctuations is gentle and continuous, which is suitable for measuring quantitative values.

The technical structure described above is a background technique for assisting the understanding of the present invention, and does not mean the prior art widely known in the technical field to which the present invention belongs.

However, the conventional passenger sensing device has a characteristic of a low pass filter (LPF) or a high pass filter (HPF), and thus has a problem of receiving a lot of noise applied from the outside and being very vulnerable to noise.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a storage capacity sheet sensing device that is strong against noise that is robust against external noise when the storage capacity recognition using the LC series circuit structure is applied.

According to the present invention, there is provided a seat-capacitance detecting device having a strong resistance against noise, which is installed in a seat cushion of a vehicle seat and senses a body pressure of a passenger in the vehicle seat, and includes a sensing sheet made of a dielectric and an insulator; A reactor directly connected to the sensing sheet; An impedance detector connected directly to the reactor and measuring impedance; Each of the sensing seat and the impedance detection unit is directly connected to form a closed circuit, and the output frequency is applied to the impedance detection unit to configure the seat ECU receiving the phase difference signal, it characterized in that the equivalent circuit of the LC series resonance.

The impedance detection unit of the present invention is characterized in that for detecting the phase change value and the size change value of the dielectric.

The seat-capacity detection device of a high capacity against noise according to the present invention can detect boarding information of a passenger more accurately, and has a merit of significantly lowering the possibility of misrecognition because it is robust to external noise.

1 is a view showing a capacitive passenger detection device according to a conventional embodiment.
2A and 2B illustrate a sheet occupancy detecting apparatus according to a conventional embodiment.
3A, 3B, 3C, 3D, and 3E are diagrams for explaining the capacity detecting sheet sensing device and its principle according to a conventional embodiment.
4A, 4B, and 4C are diagrams showing equivalent circuits and frequency characteristics of a sheet capacitance device having a strong capacitance against noise according to an embodiment of the present invention.
5A, 5B, and 5C are diagrams illustrating a sensing mat and a device configuration of a sheet capacitance device having a strong capacity against noise according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, a storage capacity-type sheet detecting apparatus resistant to noise according to an embodiment of the present invention will be described in detail. In this process, the thickness of the lines or the size of the components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to a user's or operator's intention or custom. Therefore, the definitions of these terms should be made based on the contents throughout the specification.

4A, 4B, and 4C are diagrams showing equivalent circuits and frequency characteristics of a sheet capacitance device having a strong capacitance against noise according to an embodiment of the present invention.

The seat capacity detecting device 100 having a strong resistance against noise according to an embodiment of the present invention is a device that is robust against external noise when the capacitance is recognized using an LC series circuit structure, and according to an embodiment of the present invention. The structure of the sensor constituting the sheet sensing device 100 of the strong capacitance type has a LC series circuit structure.

As shown in FIGS. 4A and 4B, when a reactor (also referred to as a coil) is added to the primary circuit, resonance characteristics are generated due to generation of electrical inertia. The occurrence of resonance is accompanied by a dramatic increase in the absolute value of the admittance and a phase change from 0 to 180 degrees, which allows the resonance frequency between the resonance frequency in the vacancy state and the additional capacitor component formed when a person is seated. Applying the measurement frequency as a value gives a qualitative big difference that the phase difference has a big change from 0 degree to 180 degree.

This is more robust to disturbances compared to the conventional method of measuring RC series circuits.

LC series resonance has Narrow Band Pass Filter which passes the signal stage well and has excellent noise removal performance in the band-pass type resonance, which is robust to external noise.

5A, 5B, and 5C are diagrams illustrating a sensing mat and an apparatus configuration of a sheet capacitance device having a strong capacitance against noise according to an embodiment of the present invention.

Referring to this, the sensing mat 110 is configured in the seat-sensing device 100 of the capacitance-resistant method according to an embodiment of the present invention is provided on the inner side of the sheet as shown in Figure 5a, 5b.

More specifically, the seat-capacity detection device 100 of the noise resistant type according to an embodiment of the present invention is installed in the seat cushion of the vehicle seat to detect the body pressure of the passenger in the vehicle seat and is made of a dielectric and an insulator. Sensing sheet 110; A reactor 140 directly connected to the sensing sheet 110; An impedance detection unit 120 is directly connected to the reactor to measure the impedance.

In addition, the seat-sensing device 100 of the capacitance-resistant method according to an embodiment of the present invention is directly connected to the sensing sheet 110 and the impedance detection unit 120 to form a closed circuit and the impedance detection unit 120 The sheet ECU 130 receives the phase difference signal by applying the output frequency to the circuit, thereby forming an equivalent circuit of LC series resonance.

In this case, the impedance detector 120 detects the phase change value and the magnitude change value of the dielectric.

Therefore, the seat-sensing device 100 of noise storage type strong against noise according to an exemplary embodiment of the present invention changes the C value of the sensing mat when the occupant rides, which is a phase change of the measured impedance. And Magnitude.

The LC series circuit is more accurate than the RC structure because the conventional RC system uses only the size change. In addition, since the LC circuit has a NBPF (Narrow Band Pass Filter) characteristic, it has a robust characteristic against external noise.

Therefore, the seat-capacity detection device 100 of the strong capacity against noise according to an embodiment of the present invention can detect the boarding information of the crew more accurately, and it is robust to external noise, thereby greatly reducing the possibility of misrecognition.

Although the present invention has been described with reference to the embodiments shown in the drawings, it is merely exemplary and various modifications and equivalent other embodiments are possible to those skilled in the art. Will understand. Therefore, the true technical protection scope of the present invention will be defined by the claims below.

100: storage capacity sheet sensing device resistant to noise
110: sensing mat 120: impedance detector
130: seat ECU 140: reactor

Claims (2)

A sensing seat installed in the seat cushion of the vehicle seat to sense the body pressure of the passenger in the vehicle seat and comprising a dielectric and an insulator;
A reactor directly connected to the sensing sheet;
An impedance detector connected directly to the reactor and measuring impedance;
A power storage unit that is directly connected to the sensing sheet and the impedance detecting unit, respectively, constitutes a closed circuit, and is configured as a seat ECU receiving a phase difference signal by applying an output frequency to the impedance detecting unit to form an equivalent circuit of LC series resonance. Capacitive seat detection device. The sheet sensing device according to claim 1, wherein the impedance detector detects a phase change value and a magnitude change value of the dielectric.
KR1020100122757A 2010-12-03 2010-12-03 Improved apparatus for sensing seat occupancy KR20120061436A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020100122757A KR20120061436A (en) 2010-12-03 2010-12-03 Improved apparatus for sensing seat occupancy

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020100122757A KR20120061436A (en) 2010-12-03 2010-12-03 Improved apparatus for sensing seat occupancy

Publications (1)

Publication Number Publication Date
KR20120061436A true KR20120061436A (en) 2012-06-13

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020100122757A KR20120061436A (en) 2010-12-03 2010-12-03 Improved apparatus for sensing seat occupancy

Country Status (1)

Country Link
KR (1) KR20120061436A (en)

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