| The conventional manual transmission has high efficiency, simple structure and low cost. They are also used extensively. Automatic mechanical transmission (AMT) holds the merits of the conventional manual transmission, and can be manipulated simpler and easier by the driver. The driveline life is extended by the electronic control. Therefore the AMT plays an important role in automated transmissions. Having high ratio of the performance to cost, it is suitable for the situation of our country. But owing to the difficulty of the control of the clutch, it is difficult to make it industrialization. So our work team puts forward a no clutch manipulation AMT gear shift system. In the process of vehicle starting, the driver controls the clutch .In the process of gear shifting,TCU cancels the control of the clutch, depending on adjusting the speed and toque of the engine to finish gear shifting automatically and exactly. Eliminating the concussion and the time of the clutch attrition to improve the quality of gear shift and shorten the course of industrialization in our country.The AMT can be actuated by electrical-hydraulic, electrical-pneumatic or electrical way. With the rapid development of electronics technology and automatic control technology, electric-powered drag in the control system of transmission become a trend, furthermore the control character ,precision and celerity of motor have got great improvement recently. Even more it adapts the digitized development direction, tends to the combination miniaturization, practical application and multi-purpose. Thus it makes the control method of the system simpler and the control precision also further enhancement, responded movement more accurate. Completely satisfies the requirement of AMT gear shift automatically, thus this system has selected the electrically controlled electrically operated operation method. In order to choose appropriate electromotor which is the power source of the E-E shift system, analyzing the merits and demerits of stepping motor, direct current motor and brushless current motor. Then combine to the characteristic of gear shift system. Finally chose the brushless direct current motor as its power souse. And analyzed the mathematical model and the movement model of the brushless direct current motor, and then analyzed the error of the model. built the foundation for the simulation analysis behind. The direct current motor has two drive types: the pulse width modulation (PWM) and the linear amplifier modulation. The linear amplifier modulation is a high power consumption modulation type, however pulse width modulation control motor by changing the duty cycle of the voltage of motor. The transistor is either saturated or closed, thus transistor power consumption will reduce remarkably. So PWM is elected for its drive type.In the process of gear shifting, the motor control needs to adapt different condition of ground and engine, need to adapt different shift choice, need to adapt the resistance changed . Even each product of the identical batch of product, each time, period of the length of the box and so on, has the influence to the state of transmission, presents the complex changeable characteristic. this complex changeable characteristic is difficult to be described by some mathematic models, only has to recur to the adaptive control strategy .So control strategy in the process of gear shift in the control system play a very important role. So this paper adopts classical three closed loop control system of position, speed, current control. The function of the position regulator is to achieve the position modulation exactly, without concussion. The function of the speed regulator is to achieve the adjustment of the disturbance of the speed and its output limits the maximal current value. The function of the current regulator is to achieve current follow, automatic protection when current flowed and the prompt suppression of the voltage fluctuation. Then design the loop of the position, speed and current.With the increasing expansion of the domain of BLDC, the requirement of the design of the motor control system become more and more rigorously. This paper based on the mathematical model of the Brushless DC motor (BLDC), a model for modeling and simulation of BLDC system in MATLAB has been built. In MATLAB/SIMULINK, the isolated functional blocks, such as BLDC block, hysteresis current controller block, Speed controller block, position controller ect, have been modeled. By the organic combination of these blocks, the model of BLDC can be established easily. To guarantee the validity and speediness in simulation, the back EMF is generated using piecewise linear curves. The reasonability and validity of the strategy have been testified by the simulation results.The driver circuit affect the control precision and the speed of response, so it is a key circuit of the gear shift control system. This digital servor system ,designed with DSP, provides a good solution for PWM signal generation, motor peed feedback and electromotor circuit ,driver circuit and safeguard current feedback in servo system. And rotor position measure circuit, phase current circuit are given more description ,and the corresponding hardware circuit is described.In conclusion, this paper makes some basic works on the development of E-E shift system. The content of this paper is mainly concerned with the analysis of brushless direct current motor system, the analysis of three closed loop control system of position, speed, current control, the analysis of simulink, the hardware design of E-E shift system. This paper has some actual meaning when E-E AMT is put into production.
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