【作者】 郑宏宇；

【导师】 赵丁选；

【作者基本信息】 吉林大学 ， 机械电子工程， 2006， 硕士

【摘要】 论文介绍了液压机械无级变速器的分类、特点以及国内外发展现状,说明了在工程车辆上研究液压机械无级变速的目的和意义。对液压机械无级变速器进行了理论研究,分析了液压机械无级传动工作原理并在此基础上自行设计出等比三段式液压机械无级变速器,详细分析了其基本的工作原理和工作特性以及动力性和经济性。针对提高发动机功率的利用率,确定了控制目标,对传动系统进行自动控制,实现发动机与负载的合理匹配。在对发动机、液压系统的原理进行分析的基础上建立了发动机、伺服阀、液压缸和变量泵—定量马达的数学模型和传递函数,并在Matlab/Simulink环境支持下进行了计算机仿真,验证了此系统的可行性和实用性。其后根据此无级变速器开发了相应的液压机械无级变速系统的硬件和相配套的软件系统。更多还原

【Abstract】 Based on the introduction of such important moments as the as the function,types, characters, the current research and application situation ofhydro-mechanical transmission, this paper proves that it is necessary and feasibleto study the automatic control system of hydro-mechanical transmission forconstruction Vehicle. On the base of designing a new scheme, which was geometricproportion, three-range hydro-mechanical Transmission, and the characteristicswere analyzed. Have set up mathematics models of the engine, hydraulic systemand hydro-mechanical Transmission Control System. Finally supported byMatlab/Simulink figure modeling technology. We carried on the development andresearch of the automatic transmission on the construction machinery surroundingthe automatic transmission control technology and the design of the hardware andsoftware of the control system. Study an improve the performance of drive andeconomy of hydro-mechanical Transmission Control System of ConstructionVehicle.1.The sum of the Development of hydro-mechanical TransmissionOn the base of referring to a great deal of external and internal vehiclehydro-mechanical transmission information, the feature, development course,developmental status and trend, the state of applied in construction vehicle of allkinds of automatic transmission were introduced according to the different sorts athome and abroad and the state of applied in construction vehicle of thehydro-mechanical transmission were introduced, the view was pointed that themeaning, feasible analysis and key technology have been described. With theadvent of “IT Revolution”, the intellectualized and integrated control is the trend ofautomatic transmission. Hydro-mechanical transmission can avoid the difference ofthe drivers, alleviate the intension of work, improve productivity and cut down thepollution.2.The characteristic of hydro-mechanical Transmission Control SystemAiming at the problem that the transmission ratio for the construction vehiclehydrokinetic machine transmission is not continuous during the shift course, A newscheme was designed in this paper, which was geometric proportion three-rangehydro-mechanical Transmission, and the characteristics were analyzed, such as thevelocity characteristic, power characteristic and economy characteristic, etc..Through the contrast analysis of the characteristic between the hydrokineticmachine transmission and the hydro-mechanical complex transmission, the powerand economy characteristic of the hydro-mechanical complex transmission allgained the improving. According to the variety state of the load for vehicle, thetransmission system of hydro-mechanical complex transmission can realize thematching between the load and the engine, through automatically adjusting theobliquity of variable bump, and the curve of power characteristic becamesmoothing, the analysis results will have the important practical significance toimprove the transmission system of the construction vehicle.3. The study of strategy of systemThis paper proves that how to control the engine and hydraulic system andpoint out the aim and signification about control the engine and hydraulic systemand proposes that rotate speed of engine has great significance to control engine.According to the change of load about Construction Vehicle, through the use ofPID control method, the ideal control effect could be available.4.Computer simulation of control systemSystem simulation is an indispensable research tool and means whileprocessing systemic analysis and design, new product developed and new theoryvalidated. Explain purpose and meaning of applying the simulation of the computerto the hydro-mechanical transmission. The essentials of computer simulation weresummarized. The relationship between the simulation of the computer andexperiment was discussed. The task of computer simulation was brought forward.The modeling principle was explained. The structure dynamic model was built. Thecomposing of engineering vehicular hydro-mechanical transmission system isintroduced. Have set up mathematics models of the engine, hydraulic system andhydro-mechanical Transmission Control System. Finally supported byMatlab/Simulink figure modeling technology, the vehicle transmission dynamicsemulation software have developed, and the simulation experiment have carried onwith this software.5.The design and debug of hardware and software on the hydro-mechanicaltransmission electronics control systemThe automatically controlled unit of the gearbox has higher practical valuethrough MCS-51 one-chip computer. Have designed the one-chip computersystems including hardware part and software part and the main thought ofhardware circuit design on the construction vehicle was systematically explained inan all-round way, and the module method have been adopted in the course of thedesigning, including the inputting, outputting and ECU units, which simplified thedesign and debug course through separating the designing of the inputting, theoutputting, and ECU units, we briefly state the settlement of hardware and softwareanti-interference of the control system based on the microprocessor single chip.Combining the hardware circuit, we design the software of the control system, too.更多还原