Occupant detection method and apparatus for air bag system
DCFirst Claim
1. In a vehicle restraint system having a controller for deploying air bags and means for selectively allowing deployment according to the outputs of seat sensors responding to the weight of an occupant, a method of allowing deployment according to sensor response including the steps of:
- determining measures represented by individual sensor outputs and calculating from the sensor outputs a relative weight parameter;
establishing a first threshold of the relative weight parameter;
allowing deployment when the relative weight parameter is above the first threshold;
establishing a lock threshold above the first threshold;
setting a lock flag when the relative weight parameter is above the lock threshold and deployment has been allowed for a given time;
establishing an unlock threshold at a level indicative of an empty seat;
clearing the flag when the relative weight parameter is below the unlock threshold for a time; and
allowing deployment while the lock flag is set.
9 Assignments
Litigations
6 Petitions
Accused Products
Abstract
Pressure sensors on the bottom surface of a seat cushion respond to occupant weight. A microprocessor evaluates the sensor outputs according to total force, load rating, long term average, sensor groups and a fuzzy measure to discriminate between large and small occupants and allow air bag deployment for large but not small occupants. Allow and inhibit decisions are filtered avoid sudden response to transient pressure changes on the seat. When a large occupant is positively detected, an allow decision is locked in place as long as total force exceeds a threshold.
128 Citations
27 Claims
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1. In a vehicle restraint system having a controller for deploying air bags and means for selectively allowing deployment according to the outputs of seat sensors responding to the weight of an occupant, a method of allowing deployment according to sensor response including the steps of:
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determining measures represented by individual sensor outputs and calculating from the sensor outputs a relative weight parameter; establishing a first threshold of the relative weight parameter; allowing deployment when the relative weight parameter is above the first threshold; establishing a lock threshold above the first threshold; setting a lock flag when the relative weight parameter is above the lock threshold and deployment has been allowed for a given time; establishing an unlock threshold at a level indicative of an empty seat; clearing the flag when the relative weight parameter is below the unlock threshold for a time; and allowing deployment while the lock flag is set. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. In a vehicle restraint system having a controller for deploying air bags and means for inhibiting deployment when a seat is not occupied by an adult including seat sensors responding to the weight of an occupant, a method of inhibiting and allowing deployment according to sensor response including the steps of:
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determining forces represented by individual sensor outputs and total force represented by all sensor outputs; establishing a first threshold of total force and a second threshold below the first threshold; inhibiting deployment when the total force is below a second threshold, and allowing deployment when the total force is above the first threshold; establishing a lock threshold above the first threshold; setting a lock flag when the total force is above the lock threshold and deployment has been allowed for a given time; establishing an unlock threshold at a level indicative of an empty seat; clearing the flag when the total force is below the unlock threshold for a time; and allowing deployment while the lock flag is set.
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17. In a vehicle restraint system having a controller for deploying air bags, means for inhibiting and allowing deployment according to whether a seat is occupied by a person of at least a minimum weight comprising:
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seat sensors responding to the weight of an occupant to produce sensor outputs; a microprocessor coupled to the sensor outputs and programmed to inhibit and allow deployment according to sensor response and particularly programmed to determine measures represented by individual sensor outputs and calculate from the sensor outputs a relative weight parameter, establish a first threshold of the relative weight parameter, allow deployment when the relative weight parameter is above the first threshold, establish a lock threshold above the first threshold, set a lock flag when the relative weight parameter is above the lock threshold and deployment has been allowed for a given time, establish an unlock threshold at a level indicative of an empty seat, clear the flag when the relative weight parameter is below the unlock threshold for a time, and allow deployment while the lock flag is set. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification