Selectable enhanced creep control mode for automated clutch and vehicular automated mechanical transmission system utilizing same

A computer-based controller (20) for clutch control in a vehicle having a fuel-controlled internal combustion engine (12), a fuel controller (34) for controlling fueling of the engine, a manually controlled throttle (32) displaceable between 0% and 100% displaced positions, a multiple-speed mechanical transmission (16) having an input shaft (44), a master friction clutch (14) drivingly interposed between the engine and the transmission input shaft, a clutch actuator (36) for causing the clutch to be fully engaged, fully disengaged or partially engaged, and a manual selector (40) for selecting operation in a creep mode, said controller comprising:

• input signal receiving means for receiving input signals (22) including signals indicative of engaged transmission ratio (GR), engine rotational speed (ES), input shaft rotational speed (IS), throttle displacement (THL) and selector operation (ECCM=0 or 1);
• and
• processing means for processing said input signals in accordance with logic rules to issue command output signals (24) to system actuators including said fuel controller and said clutch actuator, said controller characterized by logic rules:
• causing operation in an enhanced creep control mode upon sensing (i) operation in a low transmission ratio, (ii) manual selection of operation in a creep mode (ECCM=1) and (iii) throttle displacement less than an enhanced creep control mode throttle reference value (T.sub.ECCM) equal to at least 50% displacement.

A vehicular automated mechanical transmission system (10) including a fuel-controlled internal combustion engine (12), a fuel controller (34) for controlling fueling of the engine a manually controlled throttle (32) displaceable between 0% and 100% displaced positions, a multiple-speed mechanical transmission (16) having an input shaft, said transmission having a lowest ratio in the forward direction of rotation, a transmission operator (38) for controlling shifting of the transmission, a master friction clutch (14) drivingly interposed between the engine and the transmission input shaft, a clutch actuator (36) for causing the clutch to be fully engaged, fully disengaged or partially engaged, a manual selector (40) for selecting operation in a creep mode, and a controller (20) for receiving input signals including signals indicative of engaged gear ratio (GR), engine rotational speed (ES), input shaft rotational speed (IS), throttle displacement (THL) and selector operation (ECCM=0 or 1) and for processing same in accordance with programmed logic rules to issue command output signals to system actuators including said fuel controller, said transmission operator and said clutch actuator, said system characterized by said logic rules including rules:

• causing operation in an enhanced creep control mode upon sensing (i) manual selection of operation in a creep mode (ECCM=1), (ii) operation in a low transmission ratio, and (iii) throttle displacement less than an enhanced creep control mode throttle reference value (T.sub.ECCM) equal to about 50% displacement.