| In recent years, with the development of technology, electro-hydraulic servo controlled mechanical systems increasingly become complex, and there are non-linear, parameter uncertainty, mechanical resonance, unmodelled dynamic charcteristics, sensor dynamic charcteristics, load disturbance factors, etc.And the control system accuracy, responsiveness, stability and robustness requirements are higher and higher, so that a sharp contradiction appears between the system's complexity and demanding performance requirements of the control.Sliding mode variable structure control is a nonlinear controller.When the system state goes through the different areas of the state space, and the feedback controller structure changes according to certain rules,the control system has a certain ability to adapt the object system internal parameter variations and external disturbance,and ensure the system performance to achieve the desired quality. Sliding mode variable structure control system has better robustness than the conventional continuous control systems.But for a real sliding mode variable structure systems, it exists control limited, the system inertia switch in time and space lag, testing errors and the formation of discrete quasi-sliding mode and so on, which can cause buffeting. It made it difficult to the variable structure control in the application of the actual system, so the issue is to weaken the buffeting of variable structure for its control signal. During solving the problems, there are a number of ways, but the problem exists that either reduce the system robustness at the same time weaken the buffeting, or policy is too complex only for the computer simulation that can not be putted into practical engineering applications. Therefore, the design an advanced sliding mode variable structure strategy has very real significance that meets the real-time, robustness requirements, and effectively inhibits the buffeting.Sliding mode variable structure control and fuzzy control is developed independently of the two types of control methods, both are the effective methods for the uncertain control system, and their combination will further enhance the control effect. In this paper, according to the sliding mode variable structure control problems, fuzzy sliding mode controller was designed, by complementary controlling properties to obtain satisfactory control performance. In accordance with the real-time and robustness requirements, the fuzzy sliding mode algorithm was designed.By theoretical derivation, the hybrid simulation and test verification, it will lay the theoretical and methodological foundation for liable engineering applications.Influence factors of electro-hydraulic control system are very complex so accurate model is not described all features. In the analysis and design of system, simplified model is often used. Negligible factors may cause the quality deterioration and even instability of control system. On the basis of systematic analysis on electro-hydraulic servo valve control cylinder system, to improve modeling accuracy and consider the uncertainty of system parameters, system state-space model is established by using variables and deviation variables. For a more realistic system, using the actual hydraulic-mechanical system physical model and the digital controller model, the thesis achieves the hybrid simulation of electro-hydraulic valve-controlled cylinder position control system, so as establish a more realistic control state model.The thesis analyzes the basic problems and Lyapunov stability of sliding mode controller, describes the design and stability analysis of fuzzy controller, and investigates several programs of the fuzzy theory and sliding mode variable structure theory combination. For the deficiencies of fuzzy sliding mode variable structure control strategy, fuzzy sliding mode variable structure control for more in-depth study is proposed by the author in order to meet the practical engineering applications.The fuzzy controller is designed for adjusting the reaching law parameters, because the algorithm of reaching law sliding mode variable structure with fixed parameters can be not real-time adjusted with the system parameter and interfere changes. Switch sliding mode control of fuzzy adaptive reaching law index function has good robustness for non-linear, disturbance and parameter uncertainty, and overcomes the conventional sliding mode control big buffeting and frequent switch shortcomings. The system has stronger real-time and higher control accuracy. The control method is used in a large steel iron and steel group silicon electro-hydraulic single-roller CPC system, which the physical model and switch sliding mode controller model of fuzzy adaptive reaching law index function is for hybrid simulation. Studies show that the control system works stably and effectively suppresses chattering on the condition of the system comprehensive consideration nonlinearity, disturbance and parameters uncertainty.The proportion sliding mode strategy retains the linear control advantages, but the presence of buffeting will reduce the control precision, even stimulate the system unmodeled dynamics or cause mechanical resonance. These deficiencies seriously restricted the application of the proportion of sliding mode control in large-load high-precision electro-hydraulic position system. In order to avoid chattering influence on the system accuracy and stability, self-tuning sliding mode switching gain is designed to soften the control signal, according to the switch function and its derivative of the fuzzy model. As example of some iron and steel group EPC, which is a big load high precision hydraulic position servo system, is simulated hybrid. The results show that the system achieves the gains self-adjusting by fuzzy theory, effectively reduces the buffeting, implements high-precision control, and retains characteristics of the anti-parameter perturbations and anti-disturbance ability.Electro-hydraulic servo test system on Dspace is designed to achieve a fuzzy sliding mode control strategy based on rapid prototyping test. The electro-hydraulic servo test system hardware is designed, the system load policy on structural invariance principle was designed. For the electro-hydraulic position system of nonlinear, parameter uncertainty and external disturbances, by using proposed fuzzy adaptive reaching law and fuzzy self-tuning gain proportional sliding mode for real-time control, by comparison with the conventional control strategy to verify the validity of the proposed strategy.
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