Test Study on Cryogenic Property of Automatic Mechanical Transmission

A control variable method was used to experimentally study the properties of automatic mechanical transmission (AMT) actuators under cryogenic running conditions. Through a lot of cryogenic tests and subsequent data analysis, the cryogenic characteristic curves of actuators were drawn out. In addition, in allusion to the phenomenon that the clutch and shift gear in AMT were stuck at -40 degrees C, a cryogenic thawing program was added into the control system of AMT. The testing results show that this cryogenic thawing strategy can effectively reduce the starting and running resistance of AMT at low temperature, so that the vehicles equipped with AMT can normally operate at low temperature of -40 degrees C, thus enhancing the reliability of vehicles with AMT under low temperature operation. The present temperature compensation control and thawing strategy have the great significance for improving AMT control reliability and security at low temperature.