Air bag control system for passenger seats

• US 6,186,538 B1
• Filed: 03/30/1998
• Issued: 02/13/2001
• Est. Priority Date: 04/01/1997
• Status: Expired due to Fees

• Current Assignee: Toyoda Jidosha Kabushiki Kaisha
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Inoue, Yoshiaki, Osanai, Akihiro, Hamada, Makoto, Izawa, Minoru
• Primary Examiner(s): Mai, Lanna
• Assistant Examiner(s): TO, TOAN C
• Application Number:
  US09/049,984
• Time in Patent Office: 1,051 Days
• Field of Search: 280/728.2, 280/728.3, 280/732, 280/735, 280/730.2, 280/730.1, 280/752, 280/753
• US Class Current: 280/735
• CPC Class Codes: B60N 2/002 Seats provided with an occupancy detection means mounted therein or thereon detection means responsive to presence or absence of children B60N2/266
• CPC Class Codes: B60R 21/01512 Passenger detection systems

Abstract

An air bag control system for passenger seat has a seated-state detection sensor provided in a seat, a proximity sensor that detects an object near an air bag apparatus, and an impact sensor that detects a deceleration at the time of an impact. If there is no detection made by the proximity sensor for a predetermined length of time after the seated-state detection sensor detects the seating of an occupant, a control device keeps the air bag apparatus in an operable state after elapse of the predetermined length of time. If there is no detection made by the proximity sensor for the predetermined length of time after the seated-state detection sensor makes detection, the control device ignores an on-state of the proximity sensor or a signal from the proximity sensor, and keeps the air bag apparatus in the operable state. With this control, even if a sitting adult extends his/her arm to an instrument panel after elapse of the predetermined length of time, the air bag apparatus is operated when the impact sensor detects a deceleration equal to or greater than a predetermined value.

Claims

1. An air big system comprising:

a seated-state detection sensor provided in a seat and configured to detect whether a passenger is seated;

a proximity sensor that detects an object near an air bag apparatus;

an impact sensor that detects a deceleration at the time of an impact; and

control means coupled to the detection sensor, the proximity sensor, and the impact sensor, the control means controlling the air bag apparatus to be in an operable state, in which the air bag apparatus can be operated in response to the detection of deceleration by the impact sensor when a predetermined length of time after the seated-state detection sensor detects the seating of an occupant has passed without an object being detected by the proximity sensor.

2. An air bag system according to claim 1, further comprising:

an auxiliary proximity sensor disposed at a forward position in an upper surface of an instrument panel, the forward position being near a windshield pane, the auxiliary proximity sensor having a detection area that extends rearwardly,

wherein the control means sets the air bag apparatus to be in an operation prevented state based on inputs from the proximity sensor and the auxiliary proximity sensor, the control means giving a higher priority to the auxiliary proximity sensor than the proximity sensor.

3. An air bag system according to claim 1, further comprising:

a belt-set sensor that detects a set state of a seat belt and outputs a signal indicating whether the seat belt is set; and

an inflator controllable to a plurality of pressures including a high pressure and a low pressure,

wherein if the control means determines that the seat belt is set on the basis of the signal from the belt-set sensor, the control means controlling the inflator to operate at a pressure higher than a pressure used if the control means determines that the seat belt is not set.

4. An air bag system according to claim 1, further comprising:

an auxiliary seated-state detection sensor provided in a forward portion of a seat cushion; and

an inflator controllable to a plurality of pressures including a high pressure and a low pressure,

wherein the seated-state detection sensor is provided in a rearward portion of the seat cushion, and

wherein if each of the seated-state detection sensor and the auxiliary seated-state detection sensor detects a seated state, the control means determines that an adult is seated on the seat cushion in a normal sitting posture, and operates the inflator at a relatively high pressure, and

wherein if the seated-state detection sensor detects a seated-state and the auxiliary seated-state detection sensor does not detect a seated state, the control means determines that a child is seated on the seat cushion in a normal sitting posture, and does one of the following;

(A) operates the inflator at a relatively low pressure, (B) prevents operation of the inflator.

5. An air bag system according to claim 4, wherein a set detection pressure of the auxiliary seated-state detection sensor is higher than a set detection pressure of the seated-state detection sensor.

6. An air bag system according to claim 4, wherein the auxiliary seated-state detection sensor is disposed at a position between 150 mm and 250 mm from a forward end of the seat cushion, and a detection pressure of the auxiliary seated-state detection sensor is set to 120 g/cm²-180 g/cm².

7. An air bag system according to claim 4, further comprising:

an alarm device that is operated by the control means if the control means determines that a child is seated in the normal sitting posture on the seat cushion.

8. An air bag system according to claim 4, further comprising:

a belt-set sensor that detects a fastened state of a seat belt and outputs to the control means a signal indicating whether the seat belt is fastened,

wherein if the control means determines that a child is seated in the normal sitting posture on the seat cushion and that the seat belt is fastened, the control means operates the inflator at a relatively low pressure, and

wherein the control means prevents operation of the inflator if the control means determines that a child is seated in the normal sitting posture on the seat cushion and that the seat belt is not fastened.

9. An air bag system according to claim 4, further comprising:

a belt-set sensor that detects a fastened state of a seat belt and outputs to the control means a signal indicating whether the seat belt is fastened,

wherein if the control means determines that an adult is seated in the normal sitting posture on the seat cushion and that the seat belt is fastened, the control means operates the inflator at a relatively high pressure, and

wherein if the control means determines that an adult is seated in the normal sitting posture on the seat cushion and that the seat belt is not fastened, the control means operates the inflator at a relatively low pressure.

10. An air bag system according to claim 4, further comprising a belt-set sensor that detects a fastened state of a seat belt and outputs to the control means a signal indicating whether the seat belt is fastened,

wherein the control means controls the inflator such that the inflator is operated at a relatively high pressure only when it is determined by the control means that an adult is seated in the normal sitting posture on the seat cushion and that the seat belt is fastened and, on the basis of a signal from the impact sensor, and that a strong impact has occurred.

11. An air bag system according to claim 1, further comprising:

at least one of a shoulder posture detection sensor provided in an upper portion of a seat back for detecting a shoulder portion of the occupant, and a head posture detection sensor provided in a head rest for detecting a head portion of the occupant,

wherein the seated-state detection sensor is formed of at least one of a hip-waist posture detection sensor provided in a lower portion of the seat back for detecting a hip-waist portion of the occupant, and a buttock sensor provided in a rear portion of a seat cushion, for detecting a buttock portion of the occupant, and

wherein if any of the shoulder posture detection sensor, the head posture detection sensor, the hip-waist posture detection sensor and the buttock sensor detects the occupant, the control means gives priority to a detection signal from any of the shoulder posture detection sensor, the head posture detection sensor, the hip-waist posture detection sensor and the buttock sensor, over a detection signal from the proximity sensor, and sets the air bag apparatus in the operable state.

12. An air bag system according to claim 11,

wherein each of the shoulder posture detection sensor, head posture detection sensor and hip-waist posture detection sensor is one of an electric capacity type sensor and an electrostatic capacity type sensor.

13. An air bag system according to claim 11,

wherein under a situation that neither the shoulder posture detection sensor nor the head posture detection sensor makes detection, if the proximity sensor does not make detection for a predetermined length of time after at least one of the hip-waist posture detection sensor and the buttock sensor make detection, the control means determines that the occupant is seated in the normal sitting posture on the seat cushion and performs control such that the air bag apparatus is maintained in the operable state.

14. An air bag system comprising:

a proximity sensor that detects an occupant near an air bag apparatus;

at least one of a shoulder posture detection sensor provided in an upper portion of a seat back for detecting a shoulder portion of the occupant, and a head posture detection sensor provided in a head rest for detecting a head portion of the occupant;

at least one of a hip-waist posture detection sensor provided in a lower portion of the seat back for detecting a hip-waist portion of the occupant, and a buttock sensor provided in a rear portion of a seat cushion for detecting a buttock portion of the occupant; and

control means for determining whether the occupant is seated and correspondingly controlling operation of the air bag, on the basis of a combination of a signal from the at least one of the shoulder posture detection sensor and the head posture detection sensor and a signal from the at least one of the hip-waist posture detection sensor and the buttock sensor;

wherein if any of the shoulder posture detection sensor, the head posture detection sensor, the hip-waist posture detection sensor and the buttock sensor detects the occupant, the control means gives priority to the detection signals from the shoulder posture detection sensor, the head posture detection sensor, the hip-waist posture detection sensor and the buttock sensor, over a detection signal from the proximity sensor, and sets the air bag apparatus in an operable state.

15. An air bag system according to claim 14,

wherein each of the shoulder posture detection sensor, the head posture detection sensor and the hip-waist posture detection sensor is one of an electric capacity type sensor and an electrostatic capacity type sensor.

16. An air bag system according to claim 14,

wherein under a situation that neither the shoulder posture detection sensor nor the head posture detection sensor detects the occupant, if the proximity sensor does not detect the occupant for a predetermined length of time after at least one of the hip-waist posture detection sensor and the buttock sensor detect the occupant, the control means determines that the occupant is seated in the normal sitting posture on the seat cushion and performs control such that the air bag apparatus is maintained in the operable state.