Method for controlling automatic transmission of e.g. hybrid car, involves comparing car speed with setpoint speed when descent situation is detected, and triggering downshift of transmission ratio when car speed exceeds setpoint speed

摘要

The method involves comparing the speed (V) of a car with a setpoint speed (Cons V) when a descent situation of the car is detected. A downshift of the transmission ratio is triggered when the speed of the car exceeds the setpoint speed by a deviation value (Vs), where the descent situation is detected when a measured value of a road slope (P) is greater than a threshold slope value (Ps). The downshift of the transmission ratio is triggered based on status of a speed regulation system (S-RV), an automatic transmission mode (M-TA) and the position of the accelerator pedal (Ppedale). An independent claim is also included for a control system for controlling an automatic transmission of a thermal or hybrid car.