Seat belt tension prediction
First Claim
1. A system for measuring seat belt tension in a vehicle having an airbag control system and a seat, comprising:
- a.)a. an accelerometer rigidly secured to said vehicle in proximity to the seat thereof, said accelerometer having an output signal responsive to the vertical acceleration of said vehicle;
b.)b. a seat weight sensor having an output signal responsive to the force exerted by a mass on said seat; and
c.)c. a computer processor having first and second inputs, the first input being operatively coupled to the output signal of said accelerometer and the second input being operatively coupled to the output signal of said seat weight sensor, wherein said processor calculates tension in said seat belt by comparing the output signal of said seat weight sensor at discrete time intervals with predicted fluctuations in the force exerted on the seat caused by vertical acceleration acting upon the mass, assuming no seatbelt tension.
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Accused Products
Abstract
A vehicle seat belt tension prediction restraint actuator control system and method comprises an accelerometer having an output that generates a signal responsive to vertical acceleration of the vehicle, a seat weight force responsive sensor having an output that generates a signal responsive to the force exerted by a mass resting on the seat, and a processor means operatively coupled to the accelerometer and the force responsive sensor for calculating seat belt tension controlling the actuation of a restraint actuator responsive thereto. The processor is provided with a plurality of inputs operatively coupled to the accelerometer output and seat weight sensor output. Suitable programming is provided to instruct In one embodiment, the processor to calculates the average mass resting on the vehicle seat and predictthe s a force that should be exerted on the seat for corresponding to a measured level of vertical acceleration assuming zero belt tension. The processor then compares the controls the actuation of the restraint actuator responsive to a comparison of an actual force measured by the seat weight force responsive sensor with the predicted force to determine seat belt tension thereby obviating the necessity of complex hardware in physical contact with the seat belt system . In another embodiment, the processor controls the actuation of the restraint actuator responsive to a ratio of a measure of seat weight divided by a measure of vertical acceleration and by the average mass.
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Citations
28 Claims
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1. A system for measuring seat belt tension in a vehicle having an airbag control system and a seat, comprising:
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a.)a. an accelerometer rigidly secured to said vehicle in proximity to the seat thereof, said accelerometer having an output signal responsive to the vertical acceleration of said vehicle;
b.)b. a seat weight sensor having an output signal responsive to the force exerted by a mass on said seat; and
c.)c. a computer processor having first and second inputs, the first input being operatively coupled to the output signal of said accelerometer and the second input being operatively coupled to the output signal of said seat weight sensor, wherein said processor calculates tension in said seat belt by comparing the output signal of said seat weight sensor at discrete time intervals with predicted fluctuations in the force exerted on the seat caused by vertical acceleration acting upon the mass, assuming no seatbelt tension. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for predicting seatbelt tension in a vehicle having a seat, an accelerometer rigidly secured to said vehicle in proximity to the seat, said accelerometer having an output signal responsive to a vertical acceleration of said vehicle, a seat weight sensor having an output signal responsive to a force exerted by a mass acting on the seat, and a processor having a first input operatively coupled to the output signal of said accelerometer and a second input operatively coupled to the output signal of said weight sensor comprising:
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a.)a. measuring an actual variation in force due to vertical acceleration exerted on the seat over a predetermined time period;
b.)b. calculating an average mass on the seat;
c.)c. calculating a predicted variation in force due to vertical acceleration exerted on the seat by multiplying the average mass on the seat by the variation in vertical acceleration over a predetermined time period; and
d.)d. dividing the actual variation in force by the predicted variation in force whereby a quotient represents normalized seatbelt tension.
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10. A method for predicting seatbelt tension in a vehicle having a seat, an accelerometer rigidly secured to said vehicle in proximity to the seat, said accelerometer having an output signal responsive to a vertical acceleration of said vehicle, a seat weight sensor having an output signal responsive to a force exerted by a mass on the seat, and a processor having a first input operatively coupled to the output signal of said accelerometer and a second input operatively coupled to the output signal of said weight sensor comprising:
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a.)a. measuring the force duct to vertical acceleration exerted on the seat at discrete time intervals;
b.)b. calculating an average mass on the seat;
c.)c. calculating at discrete time intervals a predicted force acting on the seat due to vertical acceleration, assuming the tension in said seat belt is zero; and
d.)d. calculating at discrete time intervals a difference between the measured force exerted on the seat and the predicted force whereby the difference is indicative of seats belt tension.
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11. A method for predicting seatbelt tension in a vehicle having a seat, an accelerometer rigidly secured to said vehicle in proximity to the seat, said accelerometer having an output signal responsive to a vertical acceleration of said vehicle, a seat weight sensor having an output signal responsive to a force exerted by a mass on the seat, and a processor having a first input operatively coupled to the output signal of said accelerometer and a second input operatively coupled to the output signal of said weight sensor comprising:
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a.)a. measuring the force due to vertical acceleration exerted on the seat at discrete time intervals;
b.)b. calculating an average mass on the seat;
c.)c. measuring the vertical acceleration acting on said vehicle at discrete time intervals;
d.)d. calculating at discrete time intervals a predicted force exerted on the seat by multiplying the vertical acceleration at each time interval by the average mass, assuming the tension in said seat belt is zero; and
e.)e. calculating at discrete time intervals a ratio between the measured force exerted on the seat and the predicted force exerted on the seat whereby the ratio is indicative of seat belt tension.
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12. A system for measuring seat belt tension in a vehicle having an airbag control system and a seat, comprising:
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a. an accelerometer rigidly secured to said vehicle in proximity to the seat thereof, said accelerometer having an output signal responsive to the vertical acceleration of said vehicle;
b. a seat weight sensor having an output signal responsive to the force exerted by a mass on said seat; and
c. a processor having first and second inputs, the first input being operatively coupled to the output signal of said accelerometer and the second input being operatively coupled to the output signal of said seat weight sensor, wherein said processor calculates tension in said seat belt responsive to said output signal of said accelerometer and responsive to said output signal of said seat weight sensor. - View Dependent Claims (13, 14, 15, 16)
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17. A system for controlling the actuation of an air bag in a vehicle, comprising:
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a. an accelerometer operatively coupled to the vehicle, wherein said accelerometer generates a first signal responsive to a vertical acceleration of the vehicle proximate to a seat thereof, wherein said seat is associated with the air bag;
b. a seat weight sensor, wherein said seat weight sensor generates a second signal responsive to a weight on said seat; and
c. a processor operatively coupled to said accelerometer and to said seat weight sensor, wherein said processor is adapted to generate a third signal for controlling the actuation of the air bag, and said third signal is responsive to both said first signal and said second signal. - View Dependent Claims (18, 19, 20, 21)
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22. A method of controlling the actuation of an air bag in a vehicle, comprising:
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a. measuring a vertical acceleration of the vehicle proximate to a location of a seat, wherein said seat is associated with the air bag;
b. measuring a weight upon said seat of the vehicle; and
c. controlling the actuation of the air bag responsive to said operations of measuring said vertical acceleration and measuring said weight. - View Dependent Claims (23, 24, 25, 26, 27, 28)
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Specification