Method/system for determining clutch touch point

A method for operating a control system for controlling a vehicular master friction clutch (14) as a function of a current clutch actuator (61) condition corresponding to clutch incipient engagement, said control system including sensors for providing input signals indicative of the condition of the actuator (61) and of the clutch (14), and means (30) for processing the signals according to predetermined logic rules and for issuing command output signals to at least said actuator, said actuator having a monitored variable parameter associated therewith which is determinative of the condition of said clutch, said method comprising;

• at each occurrence of a predetermined event, performing a clutch calibration operation for determining on the basis of sensed inputs, initial values of said parameter indicative of actuator condition (i) at initial clutch fully engaged condition (124) and (ii) at initial clutch incipient engaged condition (134);
• determining the value (132) of the difference between said initial values;
• thereafter, (i) determining on the basis of currently sensed inputs the current value (124') of said parameter indicative of current clutch fully engaged condition, (ii) determining an updated value of said parameter (134') indicative of current clutch incipient engagement conditions as a function of said value (124') indicative of current clutch fully engaged condition and said difference (132) between initial values, and
• utilizing said updated value of said parameter indicative of current incipient engaged conditions to issue command outputs to said actuators.

A control system for controlling a vehicular master friction clutch (14) as a function of a current clutch actuator (61) condition corresponding to clutch incipient engagement, said control system including sensors for providing input signals indicative of the condition of the actuator (61) and of the clutch (14), and means (30) for processing the signals according to predetermined logic rules and for issuing command output signals to at least said actuator, said actuator having a monitored variable parameter associated therewith which is determinative of the condition of said clutch, said system characterized by;

• means for, at each occurrence of a predetermined event, performing a clutch calibration operation for determining on the basis of sensed inputs, initial values of said parameter indicative of actuator condition (i) at initial clutch fully engaged condition (124) and (ii) at initial clutch incipient engaged condition (134);
• means for determining and memorizing the value (132) of the difference between said initial values;
• and for thereafter, (i) determining on the basis of currently sensed inputs the current value (124') of said parameter indicative of current clutch fully engaged condition, (ii) determining an updated value of said parameter (134') indicative of current clutch incipient engagement conditions as a function of said value (124') indicative of current clutch fully engaged condition and said difference (132) between initial values, and (iii) utilizing said updated value of said parameter indicative of current incipient engaged conditions to issue command outputs to said actuators.