Hybrid electric vehicle driveline active damping and transient smoothness control
A method and system for controlling a hybrid electric vehicle include controlling torque in a traction motor in response to a provisional motor torque that has been adjusted based on a difference between a measured traction motor speed and a calculated vehicle speed and filtered to attenuate a resonant driveline frequency.
1. A method of controlling a hybrid electric vehicle comprising:
commanding a traction motor to supply a traction motor torque in response to a provisional motor torque, the provisional motor torque being adjusted by a PD control based on a difference between a measured traction motor speed and a calculated vehicle speed and filtered by a filter to attenuate a driveline natural resonant frequency, the PD control being distinct from the filter.
2. The method of claim 1 , wherein the calculated vehicle speed is based on an average of wheel speed signals.
3. The method of claim 2 , wherein the wheel speed signals are received from an antilock brake system control module.
4. The method of claim 1 , wherein the calculated vehicle speed is based on a measured motor speed filtered through a low pass filter.
5. The method of claim 1 , wherein the provisional motor torque is generated in response to an engine start event.
6. The method of claim 1 , wherein the provisional motor torque is generated in response to a change in driver torque request.
7. A hybrid vehicle controller configured to receive a torque request and output a commanded motor torque, the controller comprising control logic that controls motor torque based on a target torque, the target torque being filtered by a filter to attenuate a driveline natural resonant frequency and adjusted by a PD control based on a difference of a measured motor speed and a calculated vehicle speed, the filter being distinct from the PD control.
8. The controller of claim 7 , wherein the control logic comprises a band stop filter that filters the target torque.
9. The controller of claim 7 , wherein the control logic comprises a band pass filter that filters the target torque.
10. The controller of claim 7 , wherein the calculated vehicle speed is based on an average of wheel speed signals.
11. The controller of claim 10 , wherein the wheel speed signals are received from an antilock brake system control module.
12. The controller of claim 7 , wherein the calculated vehicle speed is based on a measured motor speed filtered through a low pass filter.
13. The controller of claim 7 , wherein the control logic comprises a closed loop controller that adjusts the commanded torque based on a difference between a measured motor speed and a calculated vehicle speed in a feedback path.
14. The controller of claim 13 , wherein the closed loop controller includes a feedforward loop that filters the commanded motor torque to remove frequency components related to the driveline natural resonant frequency in the feedforward path.
15. The controller of claim 13 , wherein the closed loop controller filters the commanded motor torque to remove frequency components related to the driveline natural resonant frequency in the feedback path.
16. A hybrid vehicle comprising:
a motor drivably connected to traction wheels by a driveline having a natural resonant frequency; and
a motor controller configured to control motor torque in response to a provisional motor torque, the provisional motor torque being filtered by a filter to attenuate a driveline resonant frequency and damped by a PD control, distinct from the filter, based on a difference of a measured motor speed and a calculated vehicle speed.
17. The hybrid vehicle of claim 16 , wherein the motor controller filters the provisional motor torque using a band stop filter to remove poles of the driveline natural resonant frequency and introduce a pair of well-damped poles at another frequency.
18. The hybrid vehicle of claim 16 , wherein the calculated vehicle speed is based on an average of wheel speed signals.
19. The hybrid vehicle of claim 18 , wherein the wheel speed signals are received from an antilock brake system control module.
20. The hybrid vehicle of claim 16 , wherein the calculated vehicle speed is based on a measured motor speed filtered through a low pass filter.