Gear shifting by engine control

By using engine control during the gear shift, a manual transmission can be automated without using the clutch during the shift event, it is then important to minimize the total time needed for a gear shift, but when doing so driveline resonances may be excited. This in turn may lead to problems with disengaging the old gear and synchronizing speeds for engaging the new gear. Internal driveline torque control is a novel idea for handling resonances and increasing shift quality. By estimating the transmitted torque and controlling it to zero by engine control, the gear can systematically be disengaged with minimized driver disturbances and faster speed synchronization. Field trials show fast shifts to neutral gear, despite disturbances and driveline oscillations at the start of the gear shift. The control scheme is simple and robust against variations among different gears. Furthermore, damping of driveline resonances can be obtained with an observer in combination with a proportional integral derivative feedback structure, despite the higher order driveline system.