Multi-phase engine stop position control

摘要

A method is provided for controlling engine stop position in a vehicle having an engine with auto stop/auto start functionality. The method includes automatically ramping down engine speed upon initiation of an auto stop event, executing closed-loop speed control of the engine when the engine speed begins to ramp down, and for as long as the engine speed remains above a threshold engine speed while ramping down the engine speed; executing closed-loop position control of the engine while ramping down the engine speed once the engine speed is less than the threshold engine speed and greater than zero; and stopping the crankshaft to within a calibrated range of a targeted engine stop position. A controller is also provided that includes a hardware module and an algorithm adapted for executing the foregoing method, and a vehicle is provided having an engine with auto stop/start functionality and the controller noted above.

主权项

1. A vehicle comprising:
an engine with a crankshaft and auto start/auto stop functionality; a transmission having a transmission state; and a proportional-integral (PI) controller adapted for controlling a cranking position of the engine during an auto stop event, wherein the PI controller is in communication with the engine, and is configured for:
automatically ramping down engine speed upon initiation of an auto stop event;executing closed-loop speed control of the engine when the engine speed begins to ramp down, and for as long as the engine speed remains above a threshold engine speed while ramping down the engine speed;setting an I-term of the PI controller as a function of at least the transmission state and a speed of the vehicle;after setting the I-term, executing closed-loop position control of the engine while ramping down the engine speed when a predetermined condition is detected; andstopping the crankshaft to within a calibrated range of a targeted engine stop position.