Seated-state detection sensor and passenger seat air bag device control system employing the seated-state detection sensor

• US 6,367,837 B1
• Filed: 03/17/2000
• Issued: 04/09/2002
• Est. Priority Date: 03/18/1999
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Uenaka, Hiroshi, Fujimoto, Osamu, Hamada, Makoto, Yamashita, Seiji
• Primary Examiner(s): Mai, Lanna
• Assistant Examiner(s): BUCHANAN, CHRISTOPHER R
• Application Number:
  US09/528,193
• Time in Patent Office: 753 Days
• Field of Search: 280/735, 280/734, 280/730.1, 280/732, 280/728.1, 180/273
• US Class Current: 280/735
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means
• CPC Class Codes: B60R 21/01542 detecting passenger motion

Abstract

A seated-state detection sensor is disposed in a seat portion of a seat cushion of a passenger seat. The seated-state detection sensor is divided into three parts, that is, a first seated-state detection sensor, a second seated-state detection sensor and a third seated-state detection sensor, which are arranged in this order from the rear side of the vehicle. The first seated-state detection sensor and the second seated-state detection sensor are designed to determine whether or not there is a passenger seated. The second seated-state detection sensor and the third seated-state detection sensor are designed to detect forward displacement of the passenger.

Claims

1. A passenger seat air bag device control system comprising:

a seated-state detection sensor, disposed in a seat cushion and divided into a plurality of parts in a longitudinal direction of a vehicle, including a seated-state detecting portion for detecting whether or not there is a passenger seated and a displacement detecting portion for detecting forward displacement of the passenger; and

a control unit that receives signals from the sensor, calculates the displacement speed of the passenger, and controls the passenger seat air bag device based on the seated-state of the passenger and the speed of forward displacement of the passenger.

2. The passenger seat air bag device control system according to claim 1, wherein:

an interval between on-to-off transition timings of a front and a rear displacement detecting portions of the seated-state detection sensor is measured; and

if the measured interval is in a predetermined time range, it is judged that the passenger has been displaced forwardly, and activation or deactivation of the air bag device or an output level of an inflator is controlled.

3. The passenger seat air bag device control system according to claim 2, wherein:

the predetermined time range is a range of time required for the passenger to be displaced forwardly at the time of braking as a precaution against collision.

4. The passenger seat air bag device control system according to claim 3, wherein:

the predetermined time range ranges from 20 ms to 250 ms.

5. The passenger seat air bag device control system according to claim 1, wherein:

the seated-state detecting portion is a rear portion of a plurality of divided parts of the seated-state detection sensor; and

the displacement detecting portion is a front portion of a plurality of divided parts of the seated-state detection sensor.

6. The passenger seat air bag device control system according to claim 1, wherein:

the displacement detecting portion is composed of front and rear portions of the divided parts of the seated-state detection sensor.

7. The passenger seat air bag device control system according to claim 6, wherein:

on-to-off transition timings of the rear and front portions of the seated-state detection sensor are measured; and

if an interval between the measured timings is in a predetermined time range, it is judged that the passenger has been displaced forwardly, and activation or deactivation of the air bag device or an output level of an inflator is controlled.

8. The passenger seat air bag device control system according to claim 7, wherein:

the predetermined time range ranges from 20 ms to 250 ms.

9. The passenger seat air bag device control system according to claim 1, wherein:

an interval between on-to-off transition timings of a first seated-state detection sensor constituting a rear portion of the seated-state detection sensor and a second seated-state detection sensor constituting an intermediate portion of the seated-state detection sensor and an interval between on-to-off transition timings of the second seated-state detection sensor and a third seated-state detection sensor constituting a front portion of the seated-state detection sensor are measured; and

only if both the intervals are in a predetermined time range, the air bag device is controlled to be deactivated.

10. The passenger seat air bag device control system according to claim 9, wherein:

the predetermined time range ranges from 20 ms to 250 ms.

11. The passenger seat air bag device control system according to claim 1, wherein:

when a first seated-state detection sensor constituting a rear portion of the seated-state detection sensor is off and a second seated-state detection sensor constituting an intermediate portion of the seated-state detection sensor is on, it is predicated that the passenger has been seated in a front side of a vehicle seat from the very outset, and an interval between on-to-off transition timings of the second seated-state detection sensor and a third seated-state detection sensor constituting a front portion of the seated-state detection sensor is measured, and it is determined whether or not the measured period is within a predetermined length of time, and then the air bag device is controlled to be deactivated.

12. The passenger seat air bag device control system according to claim 11, wherein:

a detecting position of the second seated-state detection sensor corresponds to a position of a rump of a child passenger who is seated in a front portion of the seat cushion with his or her knees flexed.

13. The passenger seat air bag device control system according to claim 12, wherein:

a detecting position of the second seated-state detection sensor is set to a position at a distance of 150 mm to 300 mm from a front end of the seat cushion.

14. The passenger seat air bag device control system according to claim 1, wherein:

a rear portion of the seated-state detection sensor sets an on-signal duration period which is at least more than twice as long as an off-to-on time lag; and

if at least one on-signal is detected within the on-signal duration period, it is determined that there is a passenger seated.

15. The passenger seat air bag device control system according to claim 1, further comprising:

a seat back sensor which is disposed in a seat back and detects whether or not an upper part of a passenger is located in a rear portion of the seat, wherein;

if the seat back sensor detects that the upper part of the passenger is located in the rear portion of the seat, the air bag device is controlled to be ready for activation.

16. A passenger seat air bag device control system comprising:

a seated-state detection sensor, disposed in a seat cushion, for detecting whether or not there is a passenger seated, the seated-state sensor having a displacement detecting portion, divided into a plurality of parts in a longitudinal direction of a vehicle, for detecting forward displacement of the passenger; and

a control unit that receives signals from the sensor, calculates the displacement speed of the passenger, and controls the passenger seat air bag device based on the seated-state of the passenger and the speed of forward displacement of the passenger.