Research On Dynamic Modeling And Simulation Of Dual Clutch Transmission

Dual Clutch Transmission(DCT) is developed base on the parallel shaft transmission , it is a kind of all-new automatic transmission. The principle of a DCT is depicted in chapter 2 and works as following: There are two set of gearboxes (gearbox 1 for the odd and gearbox 2 for the even gear numbers) that are both built up like conventional manual transmissions.Both gearboxes are connected to the output shaft via a gear stage and can be coupled to the main input shaft of the transmission and therefore to the engine by either of the two clutches. By changing from one gearbox to the other (i.e. by disengaging the offgoing clutch and engaging the oncoming clutch) a gearshift can be accomplished. This results in shift characteristics that are typical of clutch to clutch shifts.DCT is a new generation of automated mechanical transmission. it could change the ratio under the power on, so it reduces the shift time and improves the shift quality. It also inherits the advantage of conventional Manual transmission such as high efficiency, compact configuration,wide torque extension, So it has a bright market prospect. The DCT incorporates the merits of MT, AT and CVT, so the research and development about it has become the hot point in the world.The research of DCT is at the beginning stage in China. Further research and manufacture of it will definitely have positive significance to the improvement of ability to develop automatictransmission in China.This thesis analyzes the principle, the architecture, the shifting characters and the clutch pressure control system of the DCT,as well as the control strategy durning gearshift. Furthermore,it establish the dynamic model of a gearshift process based on the Matlab/Simulink software. Also, It analyze the shift process. There are six parts in the dissertation:The first part introduce the classification and status in quo of the automatic transmission market,it summarizes the birth and developing process of DCT, It analyzes the key technology of DCT and also proposes the object, significance and content of the paper.In the second chapter, the structure characteristic of single middle shaft DCT is analyzed discuss the shift process in the case of shift from first speed to second speed. It bring forward the improved layout of DCT according to it's dynamic traitIn addition, based on the characteristic analysis of the dry clutch and wet clutch, I decided to use wet clutch as the work component of this dissertation.It then introduced the system structure and the basis control method of DCT. and analyze the three components of DCT hydraulic system and the working principle of each partIn the third chapter,the system model of the whole powertrain system mounted with a DCT is built up. The engine is the source of the auto power, so it is the base of the powertrain simulation, Build the unloaded and loaded engine model for the simulationIt also analyzes the three methods to control the output torque of engine.It then analyzes the torque transferred durning the clutch engage and disengage process. put forward the transform condition between different situation.Analyze the gearshift process of DCT based on the dynamic analysis.Then it builds up the dynamic model of DCT gearshift process.In the end it analyzes the shift quality and propose that shift timeand jerk are the two appraisal criteria of shift quality.The gearshift process is analyzed in the fourth chapter.the control strategy of clutch engagement and disengagement is studied from analyzing the gearshift principle of DCT.The control logic of DCT gearshift process is designed based on the 2 parameters gearshift regulation.The dynamic model of gearshift process is established using Matlab/Simulink according to powertrain parameters of Santana 2000 and the gearshift process is simulated.The simulation results show that DCT is capable of accomplishing the requirment of powershift. the DCT model can reflect the system character.In the fifth chapter,The definition and characteristic of CAN(Controller Area Network) is introduced.analyze it's application during DCT gearshift process. Bring forward the point of sharing the information between engine ECU and DCT TCU,so as to relaize the integration of powertrain control system. By analyzing the sharing information between ECU and TCU,the communication between DCT and engine is defined.In the end the communication process and control arithmetic for harmonious control between DCT and Engine is introduced.The last chapter summarizes the whole paper. Introduce the main work and research resultAccording to the research work, we believe that DCT is of higher transmission efficiency, lower weight, smaller in sized and cheaper in price than the otherautomatic transmission. Besides, the power shifting is realized with simple parallel shaft transmission structure. This method will not only enhance the vehicle performances but also decreases the productive cost. Therefore, the DCT is specially suitable to be used in our country, and will take a important position inthe automatic transmission field.