| The Automated Manual Transmission (AMT) retains the merits of the traditional manual gearboxes, such as high efficiency and good economy efficiency; it greatly meets the realistic demand of China's automobile development. By combining the research achievements on Torque Convertor and automatic gear shifting system development of parallel gearbox, Pro. Anlin Ge in Jilin University proposes a new type gear shifting system, which is hydro-dynamic mechanical gear shifting system, namely"TC+AMT", and our country is capable of designing and machining of the system. The system avoids the shortcomings of Automatic Transmission (AT) and AMT, that is to say, the high cost, manufacturing technology complexity of AT for using planetary transmission and the difficulty in starting process and poor shift quality of AMT.The dissertation is based on the research project"Traction Control system of Light Duty Tactical Vehicle", I have been done a series of research work. Firstly, I have done some work on designing the layout of the system according to the vehicle; Secondly, by combining the structure property of the system, I have designed and analyzed the hydraulic sub-system of the transmission; Finally I carried out a research work on the design and control of the wet shifting clutch, moreover, I do a further study on the hydraulic circuit for the clutch. The main purpose of the dissertation is to improve the shift quality of the automatic transmission by optimizing the engagement schedule of clutch.Because of the using of Torque Convertor, which has the ability of amplifying torque from the engine, the New-type Automatic Shifting System avoid the complex control of starting process in AMT, and all we need to do is the control of shifting process. According to difference power source of the automatic actuator for clutch, it mainly can be divided into three types: the electro-hydraulic, the fully electronic and the electro-pneumatic. Based on the property of the"TC+AMT"system, we selected the electro-hydraulic actuator, the power is provided by the hydraulic pump integrated to the automatic transmission system, and the cost has been pulled down immensely.Binding to the property, function and principle of the wet clutch, we developed its structure, analyzed its friction characteristics. There are three stages in the engagement of the wet clutch: squeeze, compact and rough, and the lubrication change from liquid lubricate to boundary lubricate. According to the sliding friction property of wet clutch, I have constructed the MATLAB/Simulink simulation model for the sliding stage and locked stage of the clutch.By analyzing the engagement of the wet clutch, we obtained the key points of the operation mechanism of the clutch. According to the design specification, it calculates the structure parameters and adjusted by the reference design manual. The fluid state is defined by the calculated Reynolds number, and the corresponding resistance and pressure drop is calculated in different situations. Because the clutch needs accurate control in the disengagement and engagement process, therefore, we selected the high speed on-off solenoid valve and the pressure sensor for the clutch according to our experimental and design experience, besides, I have prepared a hydraulic test bench for the solenoid valve, and obtained the flow-pressure property of the solenoid valve, furthermore, I have done an experiment calibration for the pressure sensor.Several important properties of clutch are analyzed before the electro-hydraulic system's simulation and analysis: the load and disengagement characteristic of disc spring which means the load-distortion relation of its big and small end during the process of clutch engagement and disengagement; the torque transmission property of three phases during the process of clutch engagement, analyzes those factors which influence the torque transmission; the wear abrasion property analyzes the relation between abrasion loss and friction work and how the application factors work on the relation between abrasion loss and friction work, and studies how the change of abrasion loss affects torque transmission. The viscosity of hydraulic oil is chosen by previous experimental experience and then sets the initial condition of the hydraulic valves and the properties of fluid. The simplified model of clutch disengagement and engagement process is built respectively; the simulation and analysis work is taken based on those calculated structure parameters. The pressure and flow change at the output port of on-off hydraulic valve, the volume and pressure change and the displacement of piston of hydraulic actuator cylinder.The control law during clutch engagement is gained through stressing the analysis of three phases of clutch engagement. The respective feature and range of application of PID control, fuzzy control, self-adapting control and intelligent control is introduced and then choose PID as the control algorithm. According to the feature of system structure and control, a clutch engagement model is established which takes the PWM signal of the hydraulic valve as the control output, and then simulate and analyze the engagement process, and it will give some help to the next experimental work.A information acquisition system is built based on the CAN bus technology aiming at the clutch automatic operating system. It takes PC as position machine and uses the software: CANoe to monitor the run state, and sets CAN database and CAPL and the variables according to the test requirement, such as the hydraulic pressure of the cylinder. Then we designed the panel which can appropriately control those variables. It uses the built MATLAB/Simulink model to produce program code and transfer to Cosmic to run, the control program and bottom API could be compiled in Cosmic. It debugs program by changing the control variables on panel while running CANoe to monitor the system state. It uses the panel to control the action of hydraulic valves, collect the data about the hydraulic pressure in the hydraulic cylinder of the wet clutch during disengagement and engagement process, and then convert these data to pass to position machine. It analyzes and adjusts the PID control algorithm by comparing the difference between the target and realistic pressure and the control purpose is gained properly.
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