| Nowadays, the technology of auto shift is progressing rapidly. Accordingly, Vehicular Automatic Transmission has many types. It can be divided into three main types: Automatic Transmission (AT), Automated Mechanical Transmission (AMT) and Continuously Variable Transmission (CVT). They have their different characteristics.In order to guarantee the dynamical performance and the tractive characteristics, it is necessary for the driver not only to control the clutch pedal, accelerating pedal, braking pedal and joy stick exactly and appropriately but also to shift gears accurately and in time, because the working condition of heavy vehicle is bad, the load is large, gears are lot, the control is heavy and the driver must shift gears of the manual transmission at any moment according to the road surface and the working condition of vehicle. Wherefore using the manual transmission not only need shift gears frequently and rapidly but also can increase the labor intensity, disperse the driver's attention and make driving insecure. Compared with the manual transmission, the control of automatic transmission is easy. It can alleviate the driver's labor intensity, enhance the driving security, absorb vibration and impact, make starting and accelerating more calm, make driving more comfortable. It also can improve the dynamical performance, the tractive characteristics and average velocity, prolong the longevity of the driving unit parts, enhance emission level and decrease atmospheric pollution.Along with the development of the engine control technology and the automatic transmission technology ,the continuous enhancement of the ECU controlling function, as well as the development of the related control theory ,the engine control and the automatic control of transmission will be a whole body of dynamic system control. It has inevitably become one kind of development tendency. Depending on the rapid development of the micro-electronics technology and the control theory, both can achieve the best match and conformity. Through the accurate control of the engine and the transmission, transmission shifting can be performed without clutch operating.AMT without clutch operating inherit virtues of the traditional AMT. Its transmission efficiency is high, dynamical performance and the tractive characteristics are better than AT and CVT. It overcomes the problem of the clutch control and the shortcoming of clutch slip and improve the shift quality. Through shift without clutch operating, the command of AMT technology is reduced, the synchronizer is abolished and the cost and repairing rate is reduced. So AMT without clutch operating has good future. Combined with the important product project of commercial vehicle ,which is consigned by R&D FAW, this paper mainly research the control of engine rotate speed base on communication technology and design the control unit of engine rotate speed. This paper is divided in five chapters. The research contents are as follows:1. In chapter one, the meaning, types and development tendency of the heavy commercial vehicle transmission is introduced. The basic idea of AMT without clutch operating is introduced. The types and operating mode of heavy commercial vehicle AMT control system also is introduced.2. In chapter four a mechanical control unit of engine rotate speed is designed for AMT without clutch operating. The shortcoming and virtue of some kinds of detents is analyzed. The designing command is researched according to practical condition and based on analyses of foreign sample. The performance of friction materials is analyzed. Major factors impacting the working reliability and durability of detent is calculated. 3. In chapter two the shift process is analyzed and the powertrain is modeled and simulated. The control of shift process is the core for AMT without clutch operating. The automatic shifting system work condition of AMT without clutch operating. Based on these, the control strategy is introduced. Because the clutch is not engaged in the shift process and the control unit of engine rotate speed is added, the shift process of AMT without clutch operating is not same as the traditional AMT. The shift process is researched. Based on it, the simulation mode of powertrain is made, using SimulaitonX and according to parameters of vehicle, engine and transmission designed by R&D FAW.4. In chapter three the engine rotate speed control based on communication technology is researched. It is necessary for accurate control to make engine control and transmission control one body based on communication technology. CAN(Controller Area Net), the most used automobile communication technology and SAE J1939, a communication protocol for commercial vehicle. The design of communication system is also introduced. The PID control of engine rotate speed is researched and the shift process is analyzed based on tests.5. In last chapter the whole dissertation is summarized, elaborating its main research achievements, and make a hope in the future.
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