Adaptive control of a linear actuator

A vehicle comprising:

• an engine;
• a transmission;
• an input clutch that selectively connects the engine to the transmission;
• hydraulic fluid;
• a clutch that includes a clutch apply piston, wherein the clutch is an actuatable device that is actuated by the clutch apply piston via the hydraulic fluid;
• a position sensor operable to measure a position of the clutch piston and output the measured position as a position signal;
• and
• a controller in electrical communication with the actuatable device and the position sensor, wherein the controller is programmed to:
• transmit a series of respectively increasing and decreasing pressure step commands to the clutch apply piston;
• generate respective increasing and decreasing position-to-pressure (PTP) curves at a predetermined time using the measured position in response to transmitting the series of respectively increasing and decreasing pressure step commands;
• adjust the increasing and decreasing PTP curves using a calibrated set of offsets;
• locate a PTP point in a hysteresis range between the adjusted increasing and a decreasing PTP curves;
• and
• control the actuatable device using the located PTP point.

A method for use in a system having hydraulic fluid, an actuatable device that includes a linear actuator moveable via the hydraulic fluid, a position sensor operable to measure a position of the linear actuator and output the measured position as a position signal, and a controller in electrical communication with the actuatable device and the position sensor, the method comprising:

• transmitting a series of respectively increasing and decreasing pressure step commands to the linear actuator;
• generating respective increasing and decreasing position-to-pressure (PTP) curves at a predetermined time using the measured position in response to transmitting the series of respectively increasing and decreasing pressure step commands;
• adjusting the increasing and decreasing PTP curves using a calibrated set of offsets;
• locating a PTP point in a hysteresis range between the adjusted increasing and decreasing PTP curves;
• and
• controlling the actuatable device using the located PTP point.