System and method for controlling a vehicle power-shift transmission

摘要

A description is given of a control system (30) and a method for controlling the control elements (22) (clutches, brakes) of a vehicle power-shift transmission (20). The control system (30) contains a microprocessor which periodically executes an algorithm and which has a memory in which a sequential set of time reference values (TE(i)) and a sequential set of pressure guide values (PE(i)) are stored. During filling periods (Twake(el)), which are characteristic of the control elements (22), the control system (30) applies a filling-pressure pulse to each element (22) coming into operation. After the filling of the control elements (22), the control system (30) determines changeover time values (t(sft)), which are formed as a function of the filling period (Twake(el)). The control system (30) applies pressure signals to the control elements (22) at times which are represented by the changeover time values (t(sft)) and are characteristic of each element (22). Following a synchronis starting time (tr), the control system (30) determines synchronism changeover time values, which are equal for all the control elements (22). Following the synchronism starting time (tr), the control system (30) furthermore applies pressure signals to the control elements (22) at times which are determined as a function of the synchronism changeover time values.