Occupant classification apparatus for vehicle

Patent metadata

Field	Value
Publication number	US-2017166153-A1
Application number	US-201615226173-A
Country	US
Kind code	A1
Filing date	Aug 2, 2016
Priority date	Dec 9, 2015
Publication date	Jun 15, 2017
Grant date	—

Abstract

The present invention provides an occupant classification apparatus for a vehicle. The occupant classification apparatus for a vehicle includes a sensor mat that is mounted on each seat in the vehicle to sense objects disposed on the seats. An impedance measurer is configured to measure a current based on impedance of the object using the sensor mat A controller is configured to analyze the current measured by the impedance measurer and estimate the object that corresponds to the analyzed result.

First claim

What is claimed is:

1 . An occupant classification apparatus for a vehicle, comprising:
a sensor mat mounted at each seat in the vehicle to sense objects disposed on the seats; an impedance measurer configured to measure a current based on impedance of the object using the sensor mat; and a controller configured to analyze the current measured by the impedance measurer and estimate the object that corresponds to the analyzed result.

2 . The occupant classification apparatus according to claim 1 , wherein the sensor mat includes a first electrode and a second electrode disposed to overlap with each other in a vertical direction to generate an electric field via alternating current (AC) power.

3 . The occupant classification apparatus according to claim 2 , wherein the first electrode and the second electrode are formed of the same shape and material.

4 . The occupant classification apparatus according to claim 2 , wherein the first electrode and the second electrode are formed of different shapes and materials.

5 . The occupant classification apparatus according to claim 1 , wherein the impedance measurer includes:
a power supplier configured to generate AC power; a measurer configured to be applied with the AC power to measure the current based on the impedance of the object; and an operator configured to convert a signal measured by the measurer into a frequency domain by Fourier transform to operate a first value and a second value of the measured signal.

6 . The occupant classification apparatus according to claim 5 , wherein the power supplier includes:
a clock generator configured to generate a clock signal; a direct digital synthesizer configured to generate a digital waveform signal based on the clock signal; a digital-to analog converter configured to convert the digital waveform signal into an analog waveform signal; a gain changer configured to adjust a gain of the analog waveform signal; and a first voltage biasing unit configured to apply a bias voltage to an analog waveform signal output from the gain changer.

7 . The occupant classification apparatus according to claim 5 , wherein the measurer includes:
an impedance unit configured to measure the current based on the impedance of the object; a differential amplifier configured to amplify a voltage applied to a plurality of terminals of the impedance unit; and a comparator configured to form the first electrode and the second electrode of the sensor mat at the same potential.

8 . The occupant classification apparatus according to claim 7 , wherein the comparator includes a voltage follower.

9 . The occupant classification apparatus according to claim 5 , wherein the operator includes:
a second voltage biasing unit configured to re-bias a signal biased by a first voltage biasing unit to extract an AC component; an analog to digital converter configured to convert the analog signal re-biased by the second voltage biasing into the digital waveform signal; a Fourier transformer configured to transform the digital waveform signal into a frequency domain; a first register configured to store a first output from the Fourier transformer; a second register configured to store a second output from the Fourier transformer; and an interface configured to transmit the first value and the second value stored in the first register and the second register to the controller.

10 . The occupant classification apparatus according to claim 9 , wherein the operator further includes:
a temperature sensor measuring current peripheral temperature, the Fourier transformer is configured to adjust a distortion of the first value and the second value based on the peripheral temperature.

11 . The occupant classification apparatus according to claim 9 , wherein the Fourier transformer is implemented as fast Fourier transform.

12 . The occupant classification apparatus according to claim 9 , wherein the Fourier transformer is implemented as discrete Fourier transform.

13 . The occupant classification apparatus according to claim 5 , wherein the controller is configured to periodically adjust a frequency and a gain of the AC power to monitor occurrence of abnormality due to electromagnetic wave interference and noise to adjust an operation state.

14 . The occupant classification apparatus according to claim 13 , wherein the operation state at least one selected from the group consisting of: a normal operation state, a temporary interference and noise state, and an abnormal operation state.

15 . The occupant classification apparatus according to claim 14 , wherein the controller is configured to output a default value or a preliminary classification value as a classification value for the object, when the operation state is in the temporary interference and noise state.

Assignees

• Hyundai Motor Co Ltd
• Tyco Electronics Amp Korea Co Ltd

Inventors

• Kim Nam Gyun
• Park Chun Seok
• Song Kwang Ho

Classifications

• B60R21/01524 Primary

  using electric switches · CPC title

• G01G19/4142

  for controlling activation of safety devices, e.g. airbag systems (electrical circuits for triggering safety arrangements in case of vehicle accidents B60R21/015) · CPC title

• G01R31/001

  Measuring interference from external sources to, or emission from, the device under test, e.g. EMC, EMI, EMP or ESD testing (measuring electromagnetic fields G01R29/08; circuits for generating HV pulses in dielectric strength testing G01R31/14) · CPC title

• G01R19/0007

  Frequency selective voltage or current level measuring (measuring frequency G01R23/00; testing attenuation in line transmission systems H04B3/48; monitoring testing in transmission systems H04B17/00) · CPC title

• B60R2021/01286

  Electronic control units · CPC title