| With the development of modern industry, electro-hydraulic servo technology has been widely used in both military and civil industry such as aeronautics and astronautics, nonferrous metal smelting, water resources and hydropower, petroleum and chemical industry, and machinery manufacturing, for its quick response, high precision, small volume and large output force. Electro-hydraulic servo position control system is one of the most basic and typical electro-hydraulic servo control systems, and has been widely used, which makes a difference in both engineering practice and theory research.For asymmetric cylinder controlled by electro-hydraulic servo four way valve and unsymmetric cylinder controlled by electro-hydraulic servo three way valve, both nonlinear model and linear model are established, the simulation of which are done and the differences of the two theory are analysed. Based on the four way electro-hydraulic servo valve, the control system of a butterfly valve is developed, and the theory analysis and static and dynamic test of which proved that the control precision and automation degree have been improved. At present, the system has been applied in hot rolling production line of steel industry. The control system of fan anti-surge valve based on three way electro-hydraulic servo valve is developed, the thery analysis and static and dynamic test are done, and the influence of various structural parameters are analysed.Contents of each chapter list as follows:In chapter 1, on the basis of the analysis of materials from home and abroad, the development of electro-hydraulic technology and position control system are introduced. And the typical electro-hydraulic valves and electro-hydraulic position control systems are introduced. Based on the electro-hydraulic servo butterfly valve control system, the basic overview and drive equipment of the butterfly valve are introduced. Based on the electro-hydraulic servo fan anti-surge valve control system, the basic overview of turbo blower and the fan surge phenomenon are introduced. At last, the significance and contents are mentioned. In chapter 2, for asymmetric cylinder controlled by electro-hydraulic servo four way valve and unsymmetric cylinder controlled by electro-hydraulic servo three way valve, both nonlinear model and linear model are established, the simulation of which are done and the differences of the two theory are analysed, and the scope of application of linear model and nonlinear model is analysed.In chapter 3, the drive system of a butterfly valve based on four way electro-hydraulic servo valve is designed, the structure and work principle of which are introduced. The nonlinear model of the system is established, and the the simulation is done based on the nonlinear model by AMESim, and the influence of various structural parameters is discussed. At last, the static and dynamic test of the systm is done.In chapter 4, the control system of fan anti-surge valve based on three way electro-hydraulic servo valve is analysed, and the structure and work principle of three way electro-hydraulic servo valve and position control system are introduced. The nonlinear model of the system is established, and the the simulation is done based on the nonlinear model by AMESim, and the influence of various structural parameters is discussed. At last, the static and dynamic test of the systm is done.All achievements of the thesis are summarized and the further research work is put forward in chapter 5. |
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