Method for operating a pre-crash sensing system to deploy airbags using confidence factors prior to collision

1. A method comprising:

scanning a frontal zone with a pre-crash sensing system and generating a pre-crash signal;

classifying a potential collision in response to the pre-crash signal;

using the collision classification, the pre-crash signal, and sensor-based predictions that provide data about the potential collision to set a pre-crash collision confidence level; and

when the confidence level is greater than or equal to a confidence factor threshold, deploying a restraint system in pre-collision mode, the pre-collision mode deploying the restraint system at a rate that is slower than deployment of the restraint system for a collision mode; and

when the confidence level is less than the confidence factor threshold, yet the potential collision is confirmed with vehicle collision sensors to be a collision, deploying the restraint system in collision mode.

2. A method as recited in claim 1 wherein classifying a potential collision comprises determining a collision classification as a collision overlap.

3. A method as recited in claim 1 wherein classifying a potential collision comprises determining a collision type.

4. A method as recited in claim 3 wherein the collision type comprises a front or rear collision.

5. A method as recited in claim 1 further comprising determining a time to collision and wherein deploying comprises deploying in response to the time to collision.

6. A method as recited in claim 1 further comprising determining occupant information and wherein deploying comprises deploying in response to the occupant information.

7. A method as recited in claim 1 further comprising determining a relative velocity and wherein deploying a restraint system comprises deploying a restraint system in response to the relative velocity.

8. A method of operating a restraint system having a reversible restraint and a non-reversible restraint comprising:

using a collision classification, a pre-crash signal, and sensor-based predictions that provide data about a potential collision to set a pre-crash collision confidence level;

estimating a time to collision;

deploying the reversible restraint in response to the confidence level and the time to collision as compared to a first threshold value for the confidence level and the estimated time to collision;

deploying the non-reversible restraint in response to the confidence level and the time to collision as compared to a second threshold value for the confidence level and the estimated time to collision; and

deploying the reversible restraint before deploying the non-reversible restraint as compared to a third threshold value for the confidence level and the estimated time to collision.

9. A method as recited in claim 8 further comprising monitoring a seatbelt status and wherein deploying the non-reversible restraint comprises deploying the non-reversible restraint in response to the seatbelt status.

10. A method as recited in claim 8 further comprising monitoring a seatbelt status and wherein deploying the reversible restraint comprises deploying the reversible restraint in response to the seatbelt status.

11. A method as recited in claim 8 further comprising determining a collision classification and monitoring a seatbelt status and wherein deploying the non-reversible restraint comprises deploying the non-reversible restraint in response to the collision classification and the seatbelt status.

12. A method as recited in claim 8 further comprising determining a collision classification and monitoring a seatbelt status and wherein deploying the reversible restraint comprises deploying the reversible restraint in response to the collision classification and the seatbelt status.

13. A method as recited in claim 12 wherein determining a collision classification comprises determining the collision classification as a front or rear collision.

14. A method as recited in claim 12 wherein determining a collision classification comprises determining the collision classification as a collision overlap.

15. A method as recited in claim 8 further comprising determining occupant information and wherein deploying the non-reversible restraint comprises deploying the non-reversible restraint in response to the occupant information.

16. A method as recited in claim 15 wherein determining occupant information comprises determining belted or unbelted status.

17. A method as recited in claim 15 wherein determining occupant information comprises determining a weight range.

18. A method as recited in claim 15 wherein determining occupant information comprises determining a seat position.

19. A method as recited in claim 8 further comprising determining an occupant information and wherein deploying the reversible restraint comprises deploying the reversible restraint in response to the occupant information.