Switch control method for automatic gear involves determining whether signal to change from reverse to forwards driving has been input and whether engine was running idle at the time

摘要

The method involves determining whether a signal to change from reverse to forwards driving has been input and whether the engine was running idle at the time. The pulse repetition rate of a control signal is adjusted to match the engine running state, the turbine rpm, slipping engagement state and the switch synchronisation. An original switch signal is output with a first pulse repetition rate for a first period, if the engine is running idle. The pulse repetition rate is reduced to a second rate, and a signal is output with the second rate for a control for switching engagement at a drive unit (30). If the turbine rpm is smaller than a first threshold, which is determined from a second desired turbine rpm, a reaction control signal is delivered to the drive unit. If the turbine rpm variation is between a third and a fourth threshold, the reaction control signal is ended, if the coupling is in a slipping engagement state, and the first pulse repetition rate is corrected to deliver an open slip control signal to the drive unit. If the engine is not running idle, it determined whether a switch synchronisation has ended, and if so, the throttle flap opening is corrected and the pulse repetition rate is increased to a fifth threshold for a given time period.