Research On Motion Control Strategy Of Dual Electrohydraulic Shaking Tables System

Electro-hydraulic shaking table is an important equipment for vibration environment simulation and widely used in many industrial fields.With the development of science and technology,the structure of the test piece is more and more complicated,the quality and volume are getting larger,and the single shaking table vibration simulation test is difficult to achieve the specified movement pose to simulate the real vibration environment.The emergence of the array system has created the necessary conditions for the vibration simulation test of large-span structural specimens.The array vibration simulation system is a new direction of the vibration simulation system.The motion control system is the core technology of the array simulation system,and its performance directly determines the test effect of the vibration simulation test.The motion control technology of the array simulation system has important theoretical significance and engineering practical value.In this paper,the array vibration simulation acceleration control system is designed first.Based on kinematic analysis,the conversion between the single cylinder signal and the degree of freedom signal is performed.Combined with the classic three-variable controller,the acceleration control loop of the array system is constructed.The simulation is carried out in Matlab/Simulink,and the simulation results show that the acceleration control system is effective.Secondly,aiming at the redundancy drive problem of the array system,the workspace force matrix method is used to calculate the redundancy force,and it is converted into the servo valve adjustment signal by the redundant force decomposition matrix,which effectively weakens the internal force coupling between the cylinders.The simulation is carried out in Matlab/Simulink.The simulation results show that compared with the traditional pressure stabilization control method,the force matrix method is adopted,and the control effect is better.Thirdly,in order to reduce the influence of interference force on the system,a interference compensation method for array vibration simulation system is proposed.The interference force observer is constructed by using the platform and the load mass array,the hydraulic cylinder acceleration and the two-chamber differential pressure signal,and the interference force compensator is constructed based on the inverse model of the hydraulic power mechanism.The simulation was carried out in Matlab/Simulink,and the effect of the interference compensation method was analyzed by the frequency characteristics of the array system.Finally,the effectiveness of the above control strategy is tested by the test of step response,acceleration frequency characteristic analysis and interference force frequency characteristic analysis.The test results show that the redundant force coordination and interference force compensation method can significantly improve the control precision of the system.