Research On The Control Strategies Of AMT’s Clutch Engagement At Vehicle Start

Automated Mechanical Transmission is suitable for China national conditions. Moreand more vehicles equipped with AMT transmission. However, there are many keytechnologies need to be resolved in domestic AMT industry. The control strategies ofAMT’s clutch engagement at vehicle start is one of problems that need to solve urgently.Research in this filed has important significance of independent innovation of theAutomobile Industry in China.The paper researched mainly includes:Firstly, analysis of the structure and working principle of the diaphragm spring clutch.Clarify leaf spring, axial deformation of the diaphragm spring and its influence on the loaddeformation characteristic curve. The mathematical model of relationship between pressforce and release stroke is set up, also the model of clutch torque delivery.Secondly, for vehicle starting conditions, analysis of the relationship between thedriver, the vehicle and the traveling environment and its influence on the clutch andtransmission. Two indices, jeck and friction work, are confirmed to be most important inevaluation of the clutch control at vehicle starting through the analysis of clutchengagement.Thirdly, a double layers fuzzy controller is designed for the clutch engagementprocess. The first layer of controller is to inference intention of the driver. The second layerof controller is to determine engaging speed. The clutch engagement at vehicle start issimulated to verify the effectiveness and validity of proposed control strategy. Thesimulation results show that the controller accurately reflected the initial intention of thedriver, significantly reducing the clutch friction power and limiting the impact to thereasonable scope.Fourthly, in this thesis, the hardware/software, of an electronic control is alsopreliminary designed around the Freescale microcontroller MC9S12DG128.