Ford Motor Company Limited

Steven M Lepi

Michael John Cullen

Bruce J Palansky

Thomas L Greene

An electronic control system for scheduling gearshifts in an automatic transmission includes storing in electronic memory accessible to a microprocessor, functions relating vehicle speed to throttle position, one function being related to each upshift and downshift. Gearshifts are made by probing computer memory with current values for throttle position and vehicle speed, and determining on the basis of the stored shift schedule whether an upshift or downshift is required. Upshift points are determined also on the basis of an empirically determined function relating throttle position and vehicle acceleration immediately before an upshift. Shift control logic commands an upshift on the basis of a predetermined shift schedule, provided minimum vehicle acceleration-engine throttle position criteria are satisfied. Vehicle acceleration and speed from stored schedules of gearshift functions are corrected automatically and continually by a calculated ratio to account for changes in the driveline components from the components originally installed in the powertrain of which the transmission is a member and differences these component changes produce from a calculated base NOV value.

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Livonia, MI, United States of America

Steven M Lepi