Idle drive torque control for automated vehicle master clutch

A vehicular drive line system including a fuel-controlled engine having an output member, a multiple-speed, change-gear transmission having an input shaft drivingly coupled to said output member by a master friction clutch, a clutch operator for selectively engaging and disengaging said clutch to provide a selected torque transfer capacity from said output member to said input shaft, an operator-set throttle device for manual requesting of fuel supply to said engine, an engine controller for controlling fueling of said engine, said controller effective to fuel said engine to cause said engine to rotate at a selected engine speed and to develop a selected torque, a system controller for receiving input signals including signals indicative of (i) displacement of said throttle device and (ii) speed of said vehicle, and for processing same according to logic rules to issue command output signals to system actuators including said clutch operator and said engine controller, said system characterized by said logic rules including rules for:

• (1) storing a preselected an idle drive torque value;
• (2) comparing throttle device displacement to a first reference value and vehicle speed to a second reference value;
• and
• (3) if throttle device displacement is no greater than said first reference value and vehicle speed is less than said second reference value, (i) causing said engine to rotate at a selected speed and to develop said idle drive torque at the output member thereof and (ii) causing said clutch to be engaged to have a torque transfer capacity equal to said idle drive torque.