Abstract: An apparatus and method for performing a kiss point determining algorithm which is responsive to the approach rate of the release bearing of a clutch for performing the algorithm only under reliable operating conditions. The apparatus includes an electronic controller which sets an approach rate for engaging the clutch in response to the amount of depression of the accelerator pedal of the vehicle by the operator. The amount of engine torque or other engine operating condition is measured and compared against a predetermined magnitude which is indicative of the onset of engagement of the clutch. When an increase of a predetermined magnitude is detected, the accelerator pedal position is compared against a predetermined value. If the accelerator pedal is depressed more than the predetermined value, the kiss point is re-defined as the current location of the release bearing. If the accelerator pedal is not depressed more than the predetermined value, the kiss point is not re-defined.

Abstract: An apparatus and method for controlling the engagement rate of a clutch in a partially or fully automated mechanical transmission is responsive to certain calculations derived from the rotational speeds of the input member and the output member of the clutch. The apparatus includes an electronic controller which initially sets a desired speed for the vehicle engine during the shifting process, determines a rate of engagement movement of a release bearing of the clutch, and actuates appropriate valves to initiate the gradual engagement of the clutch. In a first embodiment, the electronic controller compares the rotational speeds of the input and output shafts of the clutch in order to determine if the difference therebetween is less than a first constant value. If so, it can be inferred that the clutch is sufficiently close to full engagement as to warrant the interruption the gradual engagement process and immediately move the release bearing from its current position to the fully engaged position.