Optimal Design And Motion Control Of Magneto-rheological Electro Hy-Draulic System

Magnetorheological fluid(MRF)has attracted more and more attention due to its unique rheological effect and excellent properties.The MR electro hydraulic system which uses MRF as the energy transfer medium has emerged in various fields.This kind of electro-hydraulic systems is often seen in semi-active control applications,such as dampers,polisher,etc.Alternatively,the system can be used as an active actuator with the help of a pump to provide power.In the past,the application of the active MRF system was limited because the output speed can not be adjusted precisely in the single operating mode.This paper presents a MR electro hydraulic system with optimized mode and MR valves which are configured as an H-bridge.The output speed of the system can be adjusted by the combination currents of the valve group.Furthermore,an adaptive robust controller is designed to realize the position tracking of the system in this paper.The dissertation is organized in following chapters.In Chapter 1,the research background of MR fluid is described,as well as the research history and present status of MR electro hydraulic system and adaptive robust control.At last of this chapter,the main contents and objectives are summarized.In Chapter 2,the structure and working principle of the system are introduced in detail.The operating mode and the MR valves are optimized to realize the control of speed and improvement of performance.The mechanism and analytical models of the system are built and analyzed.In Chapter 3,the main properties of MRF and MR valves are presented at first.Then,the mo-tion characteristics are analyzed by simulation in different working mode.Finally,the comprehen-sive analysis of the performance and the work efficiency of the system under different parameters and incentive effects are described.In Chapter 4,the characteristics of the position control of the system are analyzed.Based on the adaptive robust control,the controller of the system is derived by using the backstepping method.Through simulation,the effect of the controller and the parameters on the control perfor-mance is shown and analyzed.In Chapter 5,the test scheme of MR electro hydraulic system is put forward,including the MR valve performance test and the position control experiment.The selection standards of important components are calculated,and the data acquisition program is designed.In Chapter 6,the main contents and results of research work are summarized,and the future research is presented.