Closed loop control of shifting clutch actuators in an automatic speed change transmission

A method of controlling shifting of an automatic multiple gear change transmission comprising:

• (a) providing a power input and power output member in said transmission for each gear change in the transmission and disposing a clutch for transmitting torque between the input and output member;
• (b) disposing an hydraulically operated actuator for individually activating and deactivating each clutch;
• (c) disposing a pump in said transmission and connecting the outlet of the pump to the inlet of a plurality of electrically operated pressure control valves;
• (d) connecting one of said valves to each of said actuators and controlling pressure thereto for effecting a gear change;
• (e) disposing a plurality of pressure sensors with one of said sensors sensing the pressure supplied to each of said actuators and generating an electrical signal indicative of the sensed pressure;
• (f) providing an electronic controller for said valves and connecting each of said pressure sensors thereto and providing said electrical pressure signal to said controller for each valve;
• and,
• (g) generating a control signal to each of said valves based on one of said electrical pressure signals.

A method of controlling shifting in an automatic multiple gear change power transmission comprising:

• (a) providing a power input and power output member in said transmission for each gear change and disposing a clutch for transmitting torque between the input and output member;
• (b) disposing a fluid pressure operated actuator for individually actuating and deactivating each clutch;
• (c) disposing a fluid pump and providing pressurized fluid to a plurality of electrically operated valves;
• (d) connecting one of the valves to each actuator and controlling fluid pressure thereto;
• (e) disposing a pressure sensor with each actuator and sensing the pressure supplied to said actuator and generating an electrical clutch pressure signal indicative of the sensed pressure;
• (f) providing a shift program and generating an electrical shift pressure command signal for each gear change;
• (g) comparing said clutch pressure signal (PS) with said shift pressure command signal (PC) and calculating the error (ΔP) for each command signal;
• (h) assigning an initial value of valve energization (IE) from a known relationship of valve energization with actuator pressure and known maximum valve energization;
• and,
• (i) repeating steps (f) through (h) until the computed error is within a predetermined deviation from zero (ΔPMAX) for each command signal.

A method of controlling shifting in an automatic multiple gear change power transmission comprising:

• (a) providing a clutch and transmitting torque between an input and output member for each gear change;
• (b) disposing a plurality of fluid pressure operated actuators and actuating and de-actuating one of said actuators for each clutch;
• (c) disposing a pump and supplying pressurized fluid to each of said actuators;
• (d) disposing a plurality of electrically operated valves with each of said valves controlling fluid pressure from the pump to one of the actuators;
• (e) sensing the pressure supplied to the actuator and generating an electrical signal indicative of the sensed pressure;
• (f) providing a shift program and generating an electrical shift pressure command signal for each gear change;
• (g) comparing each clutch pressure signal and respectively each corresponding shift pressure command signal and computing the difference;
• (h) varying the energization of each respective valve until said difference is negligible.