Development Of AMT Control Software Based On Embedded RTOS

Electronics and automation have become the tendency ofautomobile development. Vehicular automatic transmission is animportant section of automobile electronic control technology.Vehicular Automatic Transmission can be divided into three types:one kind is Automatic Transmission (AT), the second kind isAutomated Manual Transmission (AMT), the other kind isContinuously Variable Transmission (CVT).1. The conception and the function of AMTAMT (Automated Manual Transmission) is developed fromtraditional shaft manual gearbox and dry clutch, it appliedelectronic technology and the theory of automatic transmission,and it control the system through the TCU(Transmission ControlUnit).TCU control the detachment and conjunction of the clutch,the action of shifting and the engine so that the AMT can achievethe start, shift and automatic transmission of the vehicle. Thebasic principle of AMT: in terms of the intension of the driver(acceleration pedal, stopping pedal, switching) and the currentstatus of the vehicle( speed of engine, speed of input shaft,vehicle speed and gear position),rest on suitable controlrules(the rule of shift, detach rule of clutch etc.),through themechanism of fuel supply, clutch and shifting, AMT control the thesystem of the power train together(engine, gearbox clutch).2. The disadvantage of traditional control software and solutionIt is founded that the traditional method of AMT developmenthas some disadvantage by long-term development of AMT controlsoftware:1. The program language is assemble language, the assemblelanguage can deal with the hardware directly and find the problemof circuit, but it is unfit for the renewal of the software in thephase of product because of bad readability and modularity. Withthe expansion of application software, the structure oftraditional software is difficult to manage and upgrade.2. The traditional software is foreground/background system,the capability of real time is not good. The traditional softwarehas only the application software without backup of operatingsystem. The application program is foreground/background system,background is endless program which deal with command input andaction of throttle and shifting etc. foreground take charge thecritical operation such as stopping. This kind of system isdifficult undertake the capability of real time, and it isdifficult to make clutch and throttle work together in the actionof shifting, this difficulty in traditional software is solvedthrough some sleight or double CPU, the system program changed tobe disordered. Based on these problems above, the paper discuss the AMTcontrol software based on RTOS, the system manage the hardware byOS, it reduced the difficulty of application software andenhanced the usage of CPU with the backup of operating system.3. AMT control software system design The paper completed these researches according thearchitecture of hardware/software: 1. Construct the hardware platform. It must reserve a timerfor clock tick when designing the hardware. 2. Transplantation of the operating system. Aim for theP80c592 single chip which conclude the core of 8051, the paperconfigure the OS and save the resources of CPU at most so that OScan run on the single chip. 3. Develop driver. According the need of peripheral equipment,the paper has developed A/D drivers, PWM drivers, CAN drivers, etc. 4. Develop application software. After analyze the principleof AMT and need of the whole system, the paper carried out themodularization development aim for application software, it canmake the software high cohesion and low coupling, and it make thesoftware easy to upgrade or improve.4. Main content of the paper 1. The First Chapter: Introduction, the chapter introducebasic knowledge related to the paper, It includes the history ofautomatic transmission, the principle of AMT, basic concept anddevelopment tendency of embedded system, and basic conceptembedded RTOS and OSEK RTOS. At last it analyzed the disadvantageof traditional and solution. 2. The Second Chapter: Hardware platform design, the chaptermainly introduce hardware design of AMT control system, itconcludes peripheral equipment such as sensor, interface of motorand interface of CAN bus etc. 3. The Third Chapter: AMT control software system design, thechapter expounded AMT control software design based on embeddedRTOS, and it design the transplantation of μC/OS, divers ,andapplication software. 4. The forth chapter: Embedded RTOS μC/OS and itstransplantation, the chapter first introduce embedded RTOS μC/OS,then tell about the transplantation of it and its test programdetailed. 5. The fifth chapter: AMT drivers development, the chapterfirst designed A/D drivers, PWM drivers, Compare drivers, Serialdrivers, and CAN drivers, based on them the paper discussed thedrivers development of engine, clutch, and gearbox. 6. The sixth chapter: The application program design, thechapter split the task into several tasks, then designed every taskdetailed. The system has ten tasks, it has three modules whichconcludes control module, calibration module, and diagnosismodule. Calibration module and diagnosis module are separatemodule, they all implement through CAN interface. The controlmodule is the most important section in application program, itcontrol the actuators to shift, stopping, and start etc. 7. The seventh chapter: Experiments and conclusions, thechapter firstly analyze the result of experiment, then analyze theadvantage and disadvantage of the paper, finally, it expound theprospective research direction.5. Summarize The AMT control system discussed in the paper is completedwith FAW research center. 1. The power of AMT control system come from batteries ofvehicle, it does not contaminate circumstances and the price ofit is lower. 2. AMT control software development based on embedded realtime operating system.