Vehicle response during vehicle acceleration conditions
A vehicle control method for transitioning through transmission lash regions is described using a variety of information, such as, for example, gear ratio, clutch slippage, etc. Further, different adjustment of spark and throttle angle is used to provide a rapid torque response while still reducing effects of the lash. Finally, transitions taking into account both slipping and non-slipping transmissions are described.
1. A vehicle control method for a vehicle having an internal combustion engine coupled to a torque converter, the torque converter having an input speed and an output speed, the torque converter coupled to a transmission, the transmission coupled to wheels on a road, the method comprising:
in response to a driver tip-out, decreasing powertrain output so that positive torque is not transmitted to the wheels;
and after said tip-out and in response to a driver tip-in, and at least during transitioning to transmission of positive powertrain torque to the wheels, retarding ignition timing while continually increasing engine airflow until torque converter input speed is greater than torque converter output speed, and then advancing spark angle to rapidly provide output torque, where said ignition timing and airflow are further adjusted based on a transmission gear change.
2. The method of claim 1 wherein the transmission includes a clutch, wherein said clutch is a torque converter lock-up clutch and wherein said clutch is un-locked during said transitioning.
3. The method of claim 1 wherein said transmission gear change is a commanded gear change of the transmission.
4. The method of claim 1 wherein said transmission gear change is an actual gear change of the transmission.
5. A vehicle control method for a vehicle having powertrain with an internal combustion engine, a torque converter having an input speed and an output speed, a transmission, and a clutch, the method comprising:
in response to a driver tip-out, decreasing powertrain output so that positive torque is not transmitted to the wheels;
when said clutch is not transmitting torque and after said tip-out and in response to a driver tip-in, and at least during transitioning to transmission of positive powertrain torque to the wheels, retarding ignition timing while increasing engine airflow until torque converter input speed is greater than torque converter output speed, and then advancing spark angle to rapidly provide output torque; and
when transmitting at least some torque across the clutch and after said tip-out and in response to a driver tip-in, and at least during transitioning to transmission of positive powertrain torque to the wheels, retarding ignition timing while increasing engine airflow, where said retarding and adjustment is different from that when said clutch is not transmitting torque, and then advancing spark angle to rapidly provide output torque.
6. The method of claim 5 wherein spark angle is further adjusted during at least one of said transitions based on a gear ratio of the transmission.
7. The method of claim 6 wherein said difference is a different ramping of spark timing.
8. The method of claim 6 wherein said difference is a different ramping of throttle position.
9. The method of claim 5 wherein said clutch is a torque converter lock-up clutch.