Smooth Gear Shift Control System of Automatic Transmission Using Estimated Output Shaft Torque

As for an automotive automatic transmission, a total control system using estimated output shat torque has been investigated in order to enhance drivability and improve fuel economy. The system provides efficient control for both engine and transmission, which leads to an enhancement of drivability by reducing shock during gear shifting. This paper describes a new smooth gear shift control method especially for 2-3 upshift using the total control system based on torque. A test vehicle equipped with an electronically controlled throttle valve has been developed and the effectiveness of the proposed control method has been verified.