Control of active vehicle devices during cornering
A method of triggering an active device of a vehicle at a pre-determined threshold comprises generating a steering wheel signal from steering angle rate of change of steering angle of the vehicle, the signal representing an advance in time in comparison to the steering wheel position and/or speed, and determining a conditioned vehicle lateral acceleration in dependence on the steering wheel signal and a measured vehicle lateral acceleration, the conditioned vehicle lateral acceleration being advanced in time in comparison with the measured vehicle lateral acceleration. An active device of the vehicle is triggered if the conditioned vehicle lateral acceleration exceeds a threshold lateral acceleration.
1. A method of triggering an active device of a vehicle comprising:
generating a steering signal from a steering angle and a rate of change of steering angle of the vehicle, said signal representing an advance in time in comparison to said steering angle;
determining a conditioned vehicle lateral acceleration in dependence on said steering signal and a measured vehicle lateral acceleration, said conditioned vehicle lateral acceleration being advanced in time in comparison with said measured vehicle lateral acceleration; and
triggering an active device of the vehicle if said conditioned vehicle lateral acceleration exceeds a threshold lateral acceleration.
2. The method of claim 1 , wherein steering angle is represented by an angular departure from a reference position.
3. The method of claim 2 , wherein the reference position is straight ahead.
4. The method of claim 2 , further comprising the step of applying a minimum level to one or more of the steering angle, the rate of change of steering angle, vehicle speed, or lateral acceleration, below which an instance of the method is terminated.
5. The method of claim 1 , wherein said steering signal is determined from a look-up table.
6. The method of claim 1 , wherein said steering signal is determined from an algorithm linking steering angle and rate of change of steering angle.
7. The method of claim 1 , and including the steps of:
determining a modified vehicle lateral acceleration by reference to vehicle speed, and
determining said conditioned vehicle lateral acceleration by reference to said modified vehicle lateral acceleration.
8. The method of claim 1 , wherein the method is implemented by using an electronic control module of a vehicle.
9. The method of claim 1 , wherein the active device comprises one or more of:
a seat belt tensioner,
an active seat bolster, and
a deployable aerodynamic device.
10. The method of claim 1 , comprising determining steering angle from an electronic signal of steering wheel angle.
11. The method of claim 10 , comprising determining rate of change of steering angle from an electronic signal of steering wheel angle and an electronic clock signal.
12. A system for a vehicle comprising an electronic control unit (ECU) and one or more sensors in communication with the ECU, wherein the ECU and the one or more sensors generate a steering signal from a steering angle and a rate change of steering angle of the vehicle, said signal representing an advance in time in comparison to said steering angle; determine a conditioned vehicle lateral acceleration in dependence on said steering signal and a measured vehicle lateral acceleration, said conditioned vehicle lateral acceleration being advanced in time in comparison with said measured vehicle lateral acceleration ;and trigger an active device of the vehicle if said conditiond vehicle lateral acceleration exceeds a threshold lateral acceleration.
13. A vehicle having a system as claimed in claim 12 .