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The shift quality is one of the most important factors that affect the vehicle performances of comfort, ride and drivability for vehicles equipped with dual clutch transmission (DCT). Assessing the shift quality first and then optimizing shift control strategy and algorithm by the guidance of assessment results to improve the vehicle performance is a useful idea for the development of DCT and other types of automatic transmissions. This paper defines the shift quality assessment criteria in detail for DCT from the control point of view. A shift quality assessment system and a DCT vehicle model used for validation of assessment system are built with MATLAB/Simulink tools. Through the co-simulation of DCT vehicle model and assessment system, the shift quality control objectives, namely the expected control range of each assessment criterion, are determined, which provide reference and guidance for the optimization of DCT shift control.

A good starting quality for AMT (Automated Manual Transmission) vehicles means that the vehicle is started quickly and smoothly on the premise of protecting powertrain system. The starting quality is closely related to the vehicle ride comfort and the service life of powertrain system. In order to improve the starting quality, a good idea is evaluating the starting process firstly and then optimizing the control strategy. However this method has two problems to be solved. The first one is how to define a series of objective criterions to judge the starting quality, and the other is how to select a suitable algorithm to optimize the starting control. This paper focuses on the starting quality assessment and optimization of AMT vehicles. First, the assessment criterions for starting quality are defined in detail from the control point of view and a corresponding assessment system is created.

With the work medium of automatic transmission fluid (ATF), torque converter (TC) functions perfect performances such as smooth start, torque amplification, and the peak load restraint, and these properties makes the TC most suitable for off-road vehicles. An idea on the integration of TC and synchromesh gear box with their respective advantages is explored and introduced in this paper; here the system is named as Hydrodynamic Synchromesh Automated Transmission (HSAT). An automated control system makes the gear box as an automated manual transmission (AMT). HSAT takes TC as the starting device and accomplish shift process through AMT. The flow field optimized TC structure and the match calculation among the three parts of engine, TC and synchromesh gearbox; made this powertrain system has a good performance and the ability to reduce the fuel consumption.