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Control Study For Electro-hydraulic Servo Shaking Table Based On Minimal Control Synthesis Algorithm

Posted on:2017-03-26Degree:MasterType:Thesis
Country:ChinaCandidate:R XiaoFull Text:PDF
GTID:2348330518972383Subject:Mechanical engineering
Abstract/Summary:PDF Full Text Request
Electro-hydraulic servo shaking table is a kind of main device of vibration test, which has been widely applied to many fields, such as seismic simulation, aerospace and construction engineering and other engineering fields. Therefore, research on electro-hydraulic servo shaking table has great research significance. In fact, the electro-hydraulic servo system of the shaking table is a nonlinear system,the influence of factors such as the internal parameters change and the external interference causes acceleration tracking precision of the system lower. Because the shaking table has been limited by the effectiveness of conventional fixed-gain algorithms used in their control, these algorithms are normally based on linear models of the shaking table and specimen, whose parameters are assumed to be fixed. The parameters of the controller of conventional fixed-gain algorithm should be redesigned, and sometimes even the structure of the controller needs to adjust when the internal parameters of the system change, affecting the stability of the system. So this paper applies the Minimal Control Synthesis algorithm to improve the acceleration tracking accuracy of the electro-hydraulic servo shaking table system.In this paper, the development status of electro-hydraulic servo shaking table at home and abroad, and the control strategies are introduced firstly. The dynamic mechanism model of the electro-hydraulic servo shaking table is established and the frequency characteristic analysis is carried out, the analysis results show that the bandwidth of the system cannot meet the requirement of the expectations. Therefore, and the three-variable controller for shaking table is designed and simulated, the results show that meeting the bandwidth of the expectations, but the acceleration tracking accuracy is not well.According to the system acceleration tracking accuracy, the minimal control synthesis(MCS) algorithm is applied to shaking table system. With respect to other control algorithms,MCS algorithm has much advantage. When the non-linear system has internal parameter of variations, external disturbances and inner motion couples, MCS algorithm has excellent closed-loop characteristics. MCS algorithm also does not need to identify the mathematical model of the controlled plant. The derivation of the control law and the solving of the Lyapunov equation are not essential. The control principle and control schemes of the MCS algorithm are introduced, and the stability of the MCS algorithm applied to the shaking table system is proved.Finally, MATLAB software is used to simulate the shaking table system. The control performance of the MCS algorithm is compared with the TVC controller, the results show that the input signal is a sine wave with different frequencies,the acceleration tracking accuracy of the applied by MCS algorithm is significantly higher than that of TVC controller;When the input signal is a random wave,MCS algorithm can effectively improve the acceleration tracking accuracy of the system; If system parameter changes, MCS algorithm can well control shaking table system by automatically adjusting the gain parameters, which adequately demonstrate the effectiveness of the MCS algorithm is applied to the electro-hydraulic servo shaking table system.
Keywords/Search Tags:electro-hydraulic servo shaking tables, three-variable control, minimal control synthesis algorithm
PDF Full Text Request
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