Patent ID: 6155948
Filing Date: 2000-12-05
Classification: F16H,G01M,Y10T

Abstract:
A method for determining parameters of an electrohydraulically controlled automatic transmission (4) comprising the steps of:initiating successive transmission gearshifts on a final test bench;measuring, during the gear shifts, as a function of time, a value for a transmission input speed (nT), a transmission output speed (nAB), a transmission input moment (M.sub.-- in), and a transmission output moment (M.sub.-- out);determining from said measured values, parameters of the automatic transmission for controlling a clutch to be engaged during the gear change, the parameters consisting of, a filling time (tFull), a charge pressure (pFull), a reaction time (tRE), a friction value of the discs, and a pressurized fluid charge; andstoring the parameters in a memory (9) so that an electronic control unit corrects, in accordance with said parameters, a pressure level and time of a rapid filling pressure (pSF), the pressure level and the charge pressure (pFull), and the pressure level of a shift pressure (pSch), the shift pressure decisively determining the pressure level during upshift, downshift and overlapping shifts and gear introduction.