| 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. |
