Seat-occupancy state detection device

Patent metadata

Field	Value
Publication number	US-2016368398-A1
Application number	US-201615183925-A
Country	US
Kind code	A1
Filing date	Jun 16, 2016
Priority date	Jun 19, 2015
Publication date	Dec 22, 2016
Grant date	—

Abstract

A seat-occupancy state detection device includes: a seat occupancy sensor forming a pressure sensitive portion on a seat occupancy surface of a seat; a load sensor detecting a load applied to the seat occupancy surface; and a seat-occupancy state determination unit determining a seat occupancy state based on an ON/OFF state of the seat occupancy sensor and the load, wherein the seat-occupancy state determination unit includes a seat non-occupancy state determination section determining a seat non-occupancy state in a case where the seat occupancy sensor enters an OFF state and the load is equal to or lower than a first threshold value, and a threshold-value setting section setting a threshold value of the load, which is used in determination of the seat non-occupancy state, to a higher value, as duration increases after the seat occupancy sensor enters the OFF state.

First claim

What is claimed is:

1 . A seat-occupancy state detection device comprising:
a seat occupancy sensor that forms a pressure sensitive portion on a seat occupancy surface of a seat; a load sensor that detects a load applied to the seat occupancy surface; and a seat-occupancy state determination unit that determines a seat occupancy state of an occupant on the seat, based on an ON/OFF state of the seat occupancy sensor and the load which is detected by the load sensor, wherein the seat-occupancy state determination unit includes
a seat non-occupancy state determination section that determines a seat non-occupancy state in which no occupant sits on the seat in a case where the seat occupancy sensor enters an OFF state and the load is equal to or lower than a first threshold value, and
a threshold-value setting section that sets a threshold value of the load, which is used in determination of the seat non-occupancy state, to a higher value, as duration increases after the seat occupancy sensor enters the OFF state.

2 . The seat-occupancy state detection device according to claim 1 , further comprising:
a plurality of groups of the seat occupancy sensors that form the pressure sensitive portions at different positions from each other on the seat occupancy surface, wherein the threshold-value setting section sets the first threshold value, based on the duration after all of the groups of the seat occupancy sensors enter the OFF state, and wherein, in a case where the number of the seat occupancy sensors, which simultaneously enter the OFF state from the ON state, exceeds a predetermined threshold value, the threshold-value setting section sets the first threshold value to a constant value, regardless of the duration after the seat occupancy sensors enter the OFF states.

3 . The seat-occupancy state detection device according to claim 1 , further comprising:
a plurality of groups of the seat occupancy sensors that form the pressure sensitive portions at different positions from each other on the seat occupancy surface, wherein the threshold-value setting section sets the first threshold value, based on the duration after all of the groups of the seat occupancy sensors enter the OFF state, and wherein the threshold-value setting section sets the first threshold value, to a higher value in the shorter duration, as the number of the seat occupancy sensors, which simultaneously enter the OFF state from the ON state, is increased.

4 . The seat-occupancy state detection device according to claim 1 , further comprising:
the load senor provided on a lower side of the seat at an end portion on one side in a width direction of the seat; and a plurality of groups of the seat occupancy sensors arranged side by side in the width direction of the seat, wherein the seat-occupancy state determination unit includes
an occupant-detection determination section that determines a physique of the occupant who sits on the seat, based on a comparison between the load detected by the load sensor and a threshold value, and
a second threshold-value setting section that sets a second threshold value of the load, which is used in determination of the occupant's physique, to a higher value, as a load-applied position, which is assumed by an ON/OFF combination of the plurality of seat occupancy sensors, is closer to a position at which the load sensor is disposed.

5 . The seat-occupancy state detection device according to claim 1 , further comprising:
a zero-point correction unit that sets the load to a zero point of the load, in a case where the seat occupancy sensor is in the OFF state and the load, which is detected by the load senor, is equal to or lower than a third threshold value indicating an unloaded state.

6 . The seat-occupancy state detection device according to claim 5 , further comprising:
an abnormality determination unit that determines an occurrence of an abnormality in which the ON state of the seat occupancy sensor is maintained, in a case where the seat occupancy sensor is in the ON state, and the load is equal to or lower than the third threshold value.

Assignees

• Aisin Seiki

Inventors

• Fujii Hiroyuki
• Honda Isao
• Izuno Takahiro

Classifications

• B60R2021/01286

  Electronic control units · CPC title

• B60N2/002 Primary

  Seats provided with an occupancy detection means mounted therein or thereon (detection means responsive to presence or absence of children B60N2/266) · CPC title

• B60R21/01516 Primary

  using force or pressure sensing means · CPC title

• B60N2210/40

  Force or pressure sensors · CPC title

• B60N2/272

  Buckle lock sensors for child seat safety belts · CPC title