| 1. The aim and significance of this paperAs the increasing need of vehicle automatic operations, now the automotive automatic transmission technologies develop fast. The automotive automatic transmissions fall in such three categories as AT (Automatic Transmissions), CVT (Continue Variable Transmissions) and AMT (Automated Manual Transmissions). Especially the AMT, now many important automotive companies have paid much attentions to it for its high fuel efficiency, lower exhaust and keeping almost all the manual transmission industry invest.But, in studying of AMT, we gradually found its disadvantage, the principle of AMT working decide that it must firstly separate the clutch in changing gear process, and then select gear,change gear, and engage the clutch. In this way, when the clutch is separated, the power of engine can't be transferred to the car till before the clutch is engaged again, So it produce the stoppage of transferring power in changing gear process, and the car must come into being speed-down, the longer changing gear time, and have the disadvantage to the car in the character of speed-up,comfort and so on.For making the best of AMT's advantage, in the same timeavoiding its disadvantage of power stoppage in the changing gear process, a kind of automatic transmission adoption Dual Clutch structure emerge as the times require, it rapidly becomes hotpot that many factory pay attention .In Automat Mechanical Transmission, the most important is control technology of clutch, and come down to clutch control technology in DCT is start and shift process, so start and shift is the most pivotal technology in process of empoldering DCT.Because the course of driving car is very complexity, and the driver subjective purpose is different from everyone, as well as the system exists non-linearity,time lag,disturbing,variational parameter, so conventional and ground on model control technology is very difficult to satisfy the requirement of clutch control; the technology of start is AMT's difficulty all along; and the start of DCT is similar to AMT, so the technology of start is one of pivotal things in DCT's system.In the shift process, the engine power is continuously transferred to the car all the time, this process is called the power shift process. But in process of two clutches switch, as the same as AT, inevitably exits overlap part, how to control C1,C2 cooperate time is one of the most important problems in DCT's control system. If two clutches cooperate time is too much, well then it will appear both lock up circs, will produce breakage action; if twoclutches cooperate time is small, well then will appear a little power interrupt, and will produce great influence to shift character. So it needs accurately regulate to clutches working pressure.The purpose of this paper is that provide control strategy plat for the two pivotal technologies—start and shift control of empolder DCT.2. The work of this paper⑴This paper upbuilds engine model,dynamics of DCT model,dynamic friction coefficient model,dynamic friction torque model,electromagnetic valve model.⑵This paper upbuilds the best power type shift rule,the best economy type shift rule; and control strategy and simulation model of start,control strategy and simulation model of shift.⑶Make the simulation for big,middle,small accelerograph of start process.⑷Make the simulation for big,middle,small accelerograph of add gear process.⑸Make the simulation for big,middle,small accelerograph of reduce gear process.⑹Make the simulation for speedup of 100 kilometre per hour.3. The harvest of this paperThe simulation results prove the rationality of this simulationplat, that provides the simulation plat for control strategy of start and shift process in 863 item, it may make debug strategy more convenient, quicken schedule of the 863 item, reduce emplodering cost. |
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