Rear steering control for vehicles with front and rear steering
First Claim
1. A method for steering a vehicle having driver-controlled front wheel steering and active rear wheel steering, comprising:
- determining a rear wheel steering angle static portion based on a control gain and a front wheel steering angle;
determining a slew-limited magnitude of desired lateral acceleration based on a desired lateral acceleration;
determining a multiplying factor based on the slew-limited magnitude of desired lateral acceleration; and
determining a feed-forward rear steering angle based on the multiplying factor, the rear wheel steering angle static portion, and a rear wheel steering angle dynamic portion.
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Abstract
The invention provides a method and computer usable medium, including a program, for steering a vehicle having driver-controlled front wheel steering and active rear wheel steering. A rear wheel steering angle static portion is determined based on a control gain and a front wheel steering angle. A slew-limited magnitude of desired lateral acceleration is determined based on a desired lateral acceleration. A multiplying factor is determined based on the slew-limited magnitude of desired lateral acceleration. A feed-forward rear steering angle is determined based on the multiplying factor, the rear wheel steering angle static portion, and a rear wheel steering angle dynamic portion.
47 Citations
18 Claims
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1. A method for steering a vehicle having driver-controlled front wheel steering and active rear wheel steering, comprising:
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determining a rear wheel steering angle static portion based on a control gain and a front wheel steering angle;
determining a slew-limited magnitude of desired lateral acceleration based on a desired lateral acceleration;
determining a multiplying factor based on the slew-limited magnitude of desired lateral acceleration; and
determining a feed-forward rear steering angle based on the multiplying factor, the rear wheel steering angle static portion, and a rear wheel steering angle dynamic portion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 18)
where δ
r is the feed-forward steering angle, Kff is a rear wheel static feed-forward gain, f is the multiplying factor, K1 is a lead gain, T is a time constant, and δ
f is the front wheel steering angle.
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8. The method of claim 7 wherein at least one of the rear wheel static feed-forward gain, Kff, the lead gain, K1, and the time constant, T, are functions of vehicle speed.
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9. The method of claim 1 wherein the feed-forward rear steering angle is determined based on at least one value table.
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18. The computer usable medium of claim 1 wherein the feed-forward rear steering angle is determined based on at least one value table.
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10. A computer usable medium including a program for steering a vehicle having driver-controlled front wheel steering and active rear wheel steering, comprising:
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computer readable program code for determining a rear wheel steering angle static portion based on a control gain and a front wheel steering angle;
computer readable program code for determining a slew-limited magnitude of desired lateral acceleration based on a desired lateral acceleration;
computer readable program code for determining a multiplying factor based on the slew-limited magnitude of desired lateral acceleration; and
computer readable program code for determining a feed-forward rear steering angle based on the multiplying factor, the rear wheel steering angle static portion, and a rear wheel steering angle dynamic portion. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
where δ
r is the feed-forward steering angle, Kff is a rear wheel static feed-forward gain, f is the multiplying factor, K1 is a lead gain, T is a time constant, and δ
f is the front wheel steering angle.
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17. The computer usable medium of claim 16 wherein at least one of the rear wheel static feed-forward gain, Kff, the lead gain, K1, and the time constant, T, are functions of vehicle speed.
Specification