CONTINUOUSLY VARIABLE TRANSMISSION CLUTCH CONTROL SYSTEM

摘要

A clutch control system provides and regulates pressure at a clutch (28) for a transmitting torque from an engine (12) to a drive train (30,32) through a continuously variable transmission (18). A positive torque value is determined for each throttle setting and provided as a pressure input signal (62). Engine speed is monitored through a closed loop feedback system (68) to provide an error signal (on 106) to the desired pressure setting. A pressure control loop (110) monitors pressure at the clutch through a closed loop feedback system to maintain the pressure at the clutch at a desired level. Filtering (74,92) is provided in the torque and engine speed loops to provide for a more realistic response to driver demand. Incorporation of belt ratio factor (82) in the engine speed control loop further provides for consistent and accurate response to driver demand variations at differing transmission drive levels. Overall line pressure within the associated hydraulic system further controls a proportional gain in the pressure control loop to provide appropriate response. Phase compensation and integral dynamic phase factors in the pressure control loop further guarantee a zero level steady state error signal and the generation of accurate control over the pressure control valve.