Drive system and method of control
View Patent ↗A drive system and method of control. The method includes reducing damping of a damped torque command signal when an error between a torque command signal and the damped torque command signal exceeds a threshold amount. Torque is provided with a torque source of the drive system based on the damped torque command signal.
1. A method of controlling a drive system of a vehicle, the method comprising:
determining, with a controller of the drive system, an error between a torque command signal and a damped torque command signal by comparing the torque command signal to the damped torque command signal;
determining, with the controller, whether the error exceeds a threshold amount;
reducing, with the controller, damping of the damped torque command signal when the error exceeds the threshold amount; and
providing torque with a torque source of the drive system based on the damped torque command signal.
2. The method of claim 1 wherein the torque command signal is based on a position of an accelerator pedal.
3. The method of claim 1 wherein comparing the torque command signal to the damped torque command signal includes subtracting the damped torque command signal from the torque command signal.
4. The method of claim 1 wherein the threshold amount is based on a resonant frequency of the vehicle.
5. The method of claim 1 wherein the damped torque command signal is based on the torque command signal.
6. The method of claim 1 wherein the damped torque command signal is determined by filtering the torque command signal using data from a torque request up lookup table and data from a torque request down lookup table.
7. The method of claim 6 wherein the torque request up lookup table controls a rate at which damping of the torque command signal increases.
8. The method of claim 6 wherein the torque request down lookup table controls a rate at which damping of the torque command signal decreases.
9. The method of claim 6 wherein filtering the torque command signal with the torque request up lookup table and the torque request down lookup table includes selecting a value from the torque request up lookup table based on the error and selecting a value from the torque request down lookup table based on the error.
10. The method of claim 1 wherein the threshold amount is a constant.
11. The method of claim 1 wherein reducing damping of the damped torque command signal when the error exceeds the threshold amount includes reducing damping of the damped torque command signal in proportion to the error.
12. The method of claim 1 wherein reducing damping of the damped torque command signal when the error exceeds the threshold amount includes progressively decreasing the damping when the torque command signal is indicative of a request for acceleration.
13. The method of claim 12 wherein providing torque with the torque source based on the damped torque command signal includes increasing torque provided with the torque source along a continuous curve.
14. The method of claim 1 wherein reducing damping of the damped torque command signal when the error exceeds the threshold amount includes progressively increasing the damping when the torque command signal is indicative of a request for deceleration.
15. The method of claim 14 wherein providing torque with the torque source based on the damped torque command signal includes decreasing torque provided with the torque source along a continuous curve.
16. The method of claim 1 further comprising not reducing damping of the damped torque command signal when the error does not exceed the threshold amount.
17. A drive system comprising:
a torque source that is configured to provide torque to a vehicle wheel;
an accelerator pedal;
an accelerator pedal position sensor that provides a torque command signal based on a position of the accelerator pedal; and
a controller that controls torque provided with the torque source based on a damped torque command signal, wherein the controller is configured to reduce damping of the damped torque command signal when an error between the torque command signal and the damped torque command signal exceeds a threshold amount.
18. The drive system of claim 17 wherein the controller does not reduce damping of the damped torque command signal when the error does not exceed the threshold amount.
19. The drive system of claim 18 wherein the accelerator pedal is actuated by a foot of a driver and not reducing damping of the damped torque command signal filters vibration of the foot.
20. The drive system of claim 17 wherein the torque source includes an electric motor and torque is provided by the electric motor.