Control system for automatic transmission

摘要

A control system for an automatic transmission comprises running status detecting means 3, 6 for sensing the engine speed and throttle opening of a vehicle; running resistance estimating means 13 for estimating a running resistance on the basis of the running status of the vehicle; and shift characteristic changing means 15 for changing shift characteristics in accordance with the running resistance of the vehicle. The control system further comprises a traction control system to reduce the engine output the engine by means of a sub throttle valve on the occurence of wheel slip. The operation of the sub throttle valve is detetected by a sensor 7. The running resistance estimating means 13 estimates the running resistance of the vehicle on the basis of the running status detecting means 3, 6 and the sensor 7 of the sub throttle valve.