Study On The Launch Control Of Pneumatic Clutch In Heavy-duty Commercial Vehicle

Automated Mechanical Transmission (AMT) based on the Manual Transmission and dry clutch makes the vehicle start and shift automatically, which is done by the action of electrohydraulic servomechanism controlled by Transmission Control Unit(TCU). Because of the high transferring efficiency, low cost and easiness to manufacture, Automated Mechanical Transmission (AMT) plays an important role in the family of Automatic Transmission. With the increasing demands for improving oil efficiency and decreasing exhausted gas more and more people realize the importance and the necessity to develop the AMT system. Series of the products have been equipped in some types of vehicles by some well-known automobile corporations recently worldwide.As we all know, there are so many manual transmission plants in China , so AMT system is much more suitable to Chinese situation than any other kinds of automatic transmission (i.e. AT and CVT), the prospect of AMT market in China is great and prosperous. In August 1998, Santana 2000 equipped with AMT system which was developed by Hydraulic Mechanical Transmission Institute (HMTI) Jilin University (the former Jilin University of Technology)passed the national certification. The experts concluded that this research was advanced internationally.This means that AMT has been fully developed into the commercial stage. Now,some vehicle corporations are developing the AMT technology in China, but the technology is still not very mature and they aren't able to produce a real product.This paper is carried out combining the 863 project "heavy-duty automated mechanical transmission for commercial vehicles".Some analysises and researches are carried out to the automatic clutch pneumatic control system.The paper's main contents include several points followed:1.At first the development history and the present condition of AMT home and abroad are introduced briefly. Then put forward the development of key technologies for automatic transmission. The study points out that the clutch need to auto-control system and refers to the classification of automatic clutch control system.In the paper,we analyze advantages and disadvantages of several clutch control systems.We select the pneumatic clutch automatic control system in consideration of the need of this subject. The choice also identify the main contents of this article.2. This paper have a detailed description of the clutch for its load and disengagement preperties, torque transmission property and grinding property.It also introduce several control methods of a clutch and have a detailed analysis of the clutch's engagement process,which provides a theoretical basis for the choice of clutch control algorithm and control strategy and also provides a foundation for the following building up clutch model and simulation analysis.3.This paper has an analysis of the automatic clutch control system's principal.and describes in detail the structure of control system components. Several commonly used clutch lists in the paper.After comparing the advantages and disadvantages of various control algorithms,we choose the PID control algorithm. the establishment of the clutch model, and the process of clutch engagement simulation, through the analysis of simulation results to evaluate the control algorithm selected in this article.We have built up a clutch model and simulated the process of clutch engagement. Through the analysis of simulation results we can evaluate the control algorithm selected in this article.4.Control pincipias of a vehicle are described in this paper, including throttle opening, engine speed, input shaft speed, and the difference between inshaft speed and engine speed's impact on the amount and speed of clutch engagement. Evaluation indicators are showed in the paper,that is frictional work and the impact degree. Experimental analysis of clutch engagement process is carried out. We have introduced the test object and test equipment in the paper.Bench test and road test results are analyzed in the paper,from this analysis we can assess the clutch control strategy.5.The last chapter as the conclusion of the main ideas summarizes the whole paper.In a word, this paper studied the Automated mechanical transmission control technology systematically on the basis of former research. I only complete the above work because of limited time and the difficulty of AMT control system. Further research should be performed in order to improve the properties of the AMT system and vehicle later.