Research On Electro-hydraulic Hybrid Drive System And Its Control Ctrategy

There are contradictions which is difficult to coordinate among the high-power,high-precision, fast-response in the modern drive. This paper puts forward a new way ofelectrical and hydraulic hybrid drive system, then studies the dynamic design theory andthe hybrid control strategy in order to improve the precision and response speed of thesystem.Firstly, this paper has made a preliminary description of the research background,the development and problems of hybrid drive system. And then, this paper made adetailed analysis of the hybrid drive system and analyzed the role of each part accordingto working principle.Secondly, this paper studied design theory of hybrid drive system, includingmathematical modeling and dynamic simulation research of large stroke hydraulic drivesystem and electric servo drive system. The mathematical model describing the dynamicperformance of hydraulic proportional valve and the flow equation of hydraulic cylinderwere established. The friction characteristic of the piston rod of hydraulic cylinder wasstudied. The dynamic response characteristics under typical load conditions of hydraulicsystem has been researched. The dynamic response model of the servo motor was set up.The simulation model was established based on Matlab/Simulink.Afterward, in order to achieve the aim of the system quickly and accuratelypositioning, comprehensiving the above research foundation, this paper studed thecontrol strategy of hybrid drive system, discussed the basis of the hybrid driveclassification and the threshold of switching control strategy, set up the joint dynamicsimulation model.Finally, this paper has developed the hybrid experiment device, complete thehardware design, accomplished the selection of various components, protocoled theprinciple diagram of the hydraulic system and electrical wiring diagram, set up hybriddrive system experiment device. The controller of experiment device was designed andimplemented by programming. This paper Conducted some preliminary debuggingexperiments, lay the foundation for experiments verificating theory model.In conclusion, this paper provides theoretical basis and design method of high precision drive for metallurgical equipment, forging equipment, CNC machine andother high-end equipment.