Reaserch On Transmission Control Unit Testing And Diagnosis For AMT Of Heavy-Duty Commercial Vehicle

With the development of automotive industry, the automation level of power train system become higher, it is a good plan that the heavy duty commercial vehicle with the automated mechanical transmission. It has lots of advantages, such as: the transmission efficiency is high, the production line don't need too much change, the manufacturing cost is low, the investment is less, the performance-price ratio is higher, it also can adapt the automotive industry of our country quickly, and has broad prospects. The research on AMT is wide at home and abroad, the research direction of AMT change from automation to intelligent, the AMT product of foreign is mature,the AMT product of the enterprise of our country become better and better.The intelligent level of Modern Automobile become higher than ever before, one of the important symbol is that more electronic control unit (ECU) been used, so the automobile are achieving intelligence control. The complex degree of the software and the hardware of ECU become higher, the transmission control unit (TCU) is the most important part of automated mechanical transmission (AMT). During the development process of TCU, the testing is a key step, it has the relationship with the safety of automobile. There is a lot of testing work during TCU development period. The hardware testing is relatively simple and regulate, as the complex and particularity of the automobile, the software testing is complex and difficult. The testing and diagnosis supplement each other, the monitoring process of the testing provide necessary information for diagnosis, the result of diagnosis provide the basis for the design of the test case. The main purpose of this paper is that, make the TCU testing conveniently and effectively, make the diagnosis fault of TCU accurately.In this paper, hardware in the loop simulation is modeling, based on heavy-duty commercial vehicle AMT. Testing the bottom layer and Application layer, by use of HIL model and load box and other equipments. Deeply study the AMT system, Analysis the causes of TCU fault and study the diagnostic methods, designed a whole test diagnostic process for TCU. Main contents of the study include:1. Discussed the current development of AMT for heavy-duty commercial vehicles, testing and diagnostic methods of TCU, defined the purpose and significance of this study.2. Introduced the vehicle type which assembled the AMT system this paper studied, studied the basic structure of AMT for heavy-duty commercial vehicles, especially the pneumatic clutch actuator and shift actuator and selector actuator, and the control principle, the key sensor in the system and its working principle.3. Based on In-depth study of the AMT system, established MATLAB/Simulink hardware-in-the-loop simulation model for hardware platform of dSPACE, the emphasis of the model is the drive train system and the pneumatic actuator. Provide a platform for the subsequent tests.4. Studied the characteristics of the basic hardware of TCU, bring up test methods of basic functions for TCU,and the testing methods by using hardware-in-the-loop simulation of dSPACE.5. Analysis the hardware and software fault of TCU, study on the specific failure characteristics, and proposed appropriate diagnostic methods.Automated mechanical transmission of heavy duty commercial vehicle is analyzed in this paper, hardware-in-the-loop simulation model is built, the drive train system is key point, the testing methods is brought up both bottom layer and Application layer, and we can add new test case according to actual demand, this is a timely and effective way to test or diagnostic the modify the control strategy for TCU programmers.