The Design And Realization Of The Automatic Transmission Electronic Control Unit Based On Freescale MCU

Hydraulic automatic transmission is one kind of transmission; it is widely equippedin most domestic vehicles. In general, the hydraulic automatic gearbox transmits powerby torque converter and auxiliary gear mechanism. The auxiliary gears are used tochanging the transmission ratio by engaging different couple of gears. Torque converter,as one part of transmission, is directly bridged engine with auxiliary gears. Includingtorque and couplers in the automatic transmission, which are involved in this paper. Thetorque converter and couplers are parallel in physical, and they work in series.In this paper, the design and development of TCU (Transmission Control Unit) isdeveloped in order to match the MA4229hydraulic transmission. The automaticgearbox TCU is a joint development of smart electromechanical laboratory of UESTCand hydraulic transmission company--which name is KaiXing. At the same time, theproject is also the source of the topics. For MA4229automatic transmission’s TCU,following work is finished in this paper.Firstly, it introduces an overview of the domestic and international transmissionindustry, which contains the situation and application in this field, and vehicle ECU.There are different aspects in hydraulic automatic transmission, especially inmechanical structure. Due to the particularity of structure of MA4229AT, the data ofeach part should be collected and organized in order to understand the system ofMA4229AT. The mathematical model of electromagnetic valve unit, which is the mostimportant operating components in MA4229, is given. And do paving the way forfurther study of solenoid valve brake.Secondly, this thesis designs a set of embedded system based on microprocessorMC9S12XEP100for MA4229TCU. The embedded system contains two parts, whichconsists of hardware and software. Hardware circuit includes input module, executionmodule, communication module and power module. In the hardware circuit portion,problems of the existing circuit design are presented and the improved circuit is given.In software, UCOS-II is transplanted to MC9S12XEP100. Corresponding to thehardware modules, the drivers are designed. At last, combining drivers with strategy, MA4229transmission control function are realized.Finally, the related modules are tested and the results are given.All along, the foreign automatic transmission enterprises implement technologyblockade in order to realize the monopoly on domestic transmission industry and limitthe development of domestic gearbox industry both. At present, the domestic vehiclegearbox mainly depends on importing. Now many domestic vehicles, especially forhigh power transportation vehicles, are in urgent need of automatic transmissionassembly. MA4229is an automatic transmission with high power. The maximumtransmission power of MA4229is350kw. The development of the transmission systemis of great significance for the development of national independent brand and breakingthe foreign monopoly.