Microcomputer Controlled Automatic Transmission

This paper will discuss the concept, design and development progress of Borg-Warner’s microcomputer controlled automatic transmission. It was ascertained that an electronic transmission control system capable of high performance and cost effectiveness must combine both shift point and shift quality as an integrated control. Flexible shift point schedules were programmed as any given function of throttle position and transmission output shaft speed. Shift quality control includes both upshift and downshift ratio changes. This is achieved using a unique torque transducer positioned on the output shaft of the transmission. The shift quality strategies utilize this transducer in open loop algorithms and a high response closed loop torque control system.