Patent ID: 7344474

Claim:
A method for controlling automatic upshifting in a vehicular automated mechanical transmission system comprising a fuel-controlled engine, an input shaft deceleration device, multiple-speed mechanical transmission, a master clutch and a controller for receiving input signals including one or more of signals indicative of engine speed, engine torque, transmission engaged gear ratio, operator throttle setting and vehicle speed, and to process said input signals in accordance with logic rules to issue command output signals to transmission system actuators including a transmission actuator effective to shift said transmission, an input shaft deceleration device actuator effective to operate said input shaft deceleration device, and a clutch actuator effective to engage and disengage said master clutch, the method comprising the steps of: establishing an upshift feasibility criteria for determining feasibility of upshifts into a target gear ratio (GR T ); and performing at least one of the following steps upon sensing a requirement for an upshift from an engaged gear ratio (GR): (a) determining if a single upshift without use of said input shaft decelerating device and without disengaging the master friction clutch is feasible and, if feasible, commanding a single upshift from the currently engaged ratio without using said input shaft decelerating device and without disengaging the master friction clutch; (b) determining if a single upshift using said input shaft decelerating device and without disengaging the master friction clutch is feasible and, if feasible, commanding a single upshift from the currently engaged ratio using said input shaft decelerating device and without disengaging the master friction clutch; (c) determining if a single upshift with disengaging the master friction clutch is feasible and, if so, commanding a single upshift from the currently engaged ratio with disengaging the master friction clutch; and (d) retaining the transmission engaged in the currently engaged ratio.