Design Of Electronic Control System Of Automobile Automatic Transmission Based On Vehicle Network

The automation of automobile transmission is one of the cores of automobile electronic technology. with the number of unskilled drivers is increasing, automatic transmission becomes an important direction of improving automobile structure. AMT(Automatic Mechanical Transmission) is a high-tech product with mechanical and electrical Integration, merged with electronics, microcomputer control technology, and modern transmission theory, based on traditional shaft manual gearbox transmission. It is the hot research and development trend of automatic transmission.AMT is composed of three parts, the first is TCU(Transmission Control Unit)-electronic control system, the second is the executing agency for electrical, the third is automotive transmission device. Electronic control system is its key component of control and development, whose good or bad design is a decision to the merit of the transmission performance. It is also the difficulty in the design of AMT. This paper mainly design the electronic control system of AMT, including its hardware circuit design , the research of transmission rule, summary of the overall software design and module design.In the hardware design of electronic control system, for the electronic control system has to capture a large number of shift sensor signals, in the design of this paper, first of all, classify the type of the sensor signals :such as switch signal , pulse signal and analog signal. for different types of sensor signals, design an independent data acquisition circuit in order to reduce the mutual interference between sensors and improve the accuracy of acquisitions of sensor signals acquisitions; In the design of drive circuit of the clutch servo motor and gear selection stepper motor, using the integrated motor drive chip MC33486 and SAA1042 ,directly control by PWM control function of TCU chip to make circuit simple and precision high; in the electronic control system design CAN controller and transceiver so that the transmission become a node of the vehicle network so that it can access to the CAN network and communicate with automobile status information display node on vehicle network. In the design of software ,in the process of signal acquisition ,design a digital filter software program in order to reduce error of the signal acquisition ; Software system is designed by the vehicle shifting process as module, module program can be shared to shorten the software development cycle and reduce code redundancy.AMT has the advantage of low-cost development, high efficiency of energy conversion and simple control. There are extremely important academic and practical value for the research on and application in its electronic control system, which will lay the foundation for the AMT promotion and application.