Belt load modulation for vehicle front oblique impacts
A system includes a sensor, a controller, and a seatbelt retractor. The controller is programmed to receive a signal from the sensor indicating detection of a vehicle front oblique impact. The seatbelt retractor includes a load limiting mechanism selectively releasable from a high load mode to a low load mode. The controller is programmed to release the load limiting mechanism from the high load mode to the low load mode at a predetermined time in response to a signal from the sensor indicating a vehicle front oblique impact.
1. A system comprising:
a sensor;
a controller programmed to receive a signal from the sensor indicating detection of a lateral acceleration of a vehicle impact; and
a seatbelt retractor including a load limiting mechanism selectively releasable from a high load mode to a low load mode;
the controller is programmed to release the load limiting mechanism from the high load mode to the low load mode at a predetermined time in response to a signal from the sensor indicating a lateral acceleration of the vehicle impact is above a threshold value; and
the controller is programmed to prevent switching of the load limiting mechanism from the high load mode to the low load mode in response to a signal from the sensor indicating a lateral acceleration of the vehicle impact is below the threshold value.
2. The system of claim 1 , further comprising a webbing retractable from the seatbelt retractor, the webbing engaged with the load limiting mechanism.
3. The system of claim 2 , wherein the seatbelt retractor exerts a force on the webbing that opposes webbing payout during a vehicle front oblique impact, and wherein the load limiting mechanism prevents the force of the seatbelt retractor on the webbing from exceeding a high load limit.
4. The system of claim 3 , wherein when the load limiting mechanism is released from the high load mode to the low load mode, the load limiting mechanism prevents the force of the seatbelt retractor on the webbing from exceeding a low load limit, the low load limit being less than the high load limit.
5. The system of claim 3 , wherein the predetermined time is based on the force of the seatbelt retractor reaching the high load limit.
6. The system of claim 3 , wherein the predetermined time occurs prior to the force of the seatbelt retractor reaching the high load limit.
7. The system of claim 1 , wherein the predetermined time is based on the sensor detecting a vehicle front oblique impact.
8. The system of claim 1 , further comprising an airbag inflatable to an inflated position, and wherein the predetermined time is based on an initiation of inflation of the airbag.
9. The system of claim 1 , further comprising an airbag inflatable to an inflated position, and wherein the predetermined time occurs when an occupant impacts the airbag in the inflated position.
10. The system of claim 1 , further comprising a component sensor, the controller is programmed to receive a signal from the component sensor indicating an impact condition.
11. The system of claim 10 , wherein the predetermined time is based on receipt of a signal from the component sensor.
12. The system of claim 11 , further comprising a seat moveable along a seat track to a plurality of positions, and wherein the component sensor is a seat position sensor, the signal is one position of the seat.
13. The system of claim 11 , further comprising a seat, and wherein the component sensor is an occupant classification sensor, the signal is a physical characteristic of an occupant in the seat.
14. The system of claim 11 , further comprising a webbing retractable from the seatbelt retractor and wherein the component sensor is a webbing payout sensor, the signal is an amount of payout of the webbing from the seatbelt retractor.
15. The system of claim 11 , wherein the component sensor is an accelerometer, the signal is an acceleration of the vehicle.
16. The system of claim 1 , wherein the load limiting mechanism releases from the high load mode to the low load mode during a step time, the step time includes a start time and a finish time.
17. The system of claim 16 , wherein the start time of the step time is at the predetermined time and the finish time of the step time is at the predetermined time.
18. The system of claim 16 , wherein the start time of the step time is at the predetermined time and the finish time of the step time is after the predetermined time.
19. The system of claim 1 , wherein the load limiting mechanism includes a pyrotechnic device, the pyrotechnic device releases the load limiting mechanism from the high load mode to the low load mode in response to a signal from the controller indicating a vehicle front oblique impact.
20. The system of claim 1 , further comprising a seat position sensor and a seat moveable along a seat track, the seat track having a mid-position, and wherein the controller is programmed to prevent switching of the load limiting mechanism from the high load mode to the low load mode in response to a signal from the seat position sensor indicating the seat is in front of the mid-position on the seat track.