Interference Force Compensation Method Study For Electro-hydralic Shaking Table

Electro hydraulic shaking table is the key equipment of vibration environment test.The shaking table is widely applied in the national defense industry and civil industry departments,such as aviation,aerospace,ordnance and nuclear industry,automobile,architecture.The vibration test provides important experimental evidence for performance testing and technical improvement.The interference caused by the foundation elasticity,load elasticity and flexible connection affects the control accuracy in the movement of the shaking table and leads the failure of evaluation of the reliability of the product based on the vibration simulation test data.The mechanism of the disturbing force of the shaking table in various working conditions were analyzed and the compensation method of the interference force of the shaking table were studied in this project.First,2-DOF compensation control method was developed to eliminate the influence of interference force on the shaking table system.The valve controlled cylinder model under the ideal condition was established by Matlab/Simulink and used totest the effectiveness of the method.Secondly,the foundation elasticity system,elastic load system,flexible connection system and complicated working condition system were analyzed and modeled in detail based on the actual working condition of electro-hydraulic shaking table.The 2-DOF compensation control method was used to compensate the interference and the three state controller was used to design the acceleration tracking loop.The simulation model was established in Matlab/Simulink,and used to test the effectiveness of the interference compensation and acceleration tracking controller under various working conditions.Then,the complex function curve fitting method was used to identify the transmission function of the compensation controller based on the experimental data.Finally,the 2-DOF compensation control method was applied in the shaking table.The step response,the sinusoidal tracking and the frequency characteristic analysis results show that the 2-DOF compensation control method could significantly weaken the influence of interference force and improve the acceleration tracking accuracy of the electro-hydraulic shaking table system.