Since the first steam engine powered vehicle was invented in 1769, the automobile manufacturing industry has prospered rapidly. In addition, regulations on the fuel economy and gas emission standards have been getting stronger as the expectations from the consumers are getting higher. The transmissions, one of the major components of the vehicle powertrain are closely related to these social needs on GHG/FE standards.
The automatic transmission with a torque converter has structural limitations that the fuel economy is lowered compared to the manual transmission, while it provides better shift quality. An automated manual transmission(AMT), designed to work without equipping a torque converter, can increase fuel economy as it keeps the driving conveniences to the same level. However, because of the structural problem of AMT thermal managements should be considered and further researches are needed on low-gear shift qualities. In terms of electric vehicles, it requires lower capacity of motor-generator, inverter and batteries to produce equivalent level of power performance when 2~4 speed transmission is applied with the reduction gear than the reduction gear is equipped only. In this case it leads to reduce the total weight and cost, however, the linearity of the shift quality can be lowered.
In this study, an analysis proceeded on the shift characteristics, the critical point of the operating element and the shift quality related to the change of the accelerator pedal opening during the up-shift, which has the most weight on the shift quality in general. especially this paper suggests a systematic reviews on the vehicle test results of control force to the operating element, engine RPM, output shaft torque and speed.