Robust Active Disturbances Rejection Control Strategy Of Electro-hydraulic Shaking Table

The shaking table is the key test equipment for the vibration simulation test of the test piece.Because of the characteristics of strong load capacity and excellent frequency characteristics,the redundant drive electro-hydraulic shaking table equipment has been widely used in the vibration simulation test of large-scale structural industrial equipment and buildings and bridges,and plays an irreplaceable role in the field of vibration simulation test.However,in the current servo control system of the shaking table,the traditional three state controller is difficult to effectively suppress the disturbance caused by the unknown interference force during the operation of the shaking table,so the motion accuracy of the shaking table is difficult to be guaranteed.Based on the above reasons,this paper is devoted to design the disturbance rejection controller in the servo control system of the electro-hydraulic shaking table,with the purpose of suppressing the disturbance in the electro-hydraulic shaking table.Firstly,the robust pole assignment control strategy is applied to the motion control of the valve control cylinder system,which is the driving mechanism of the electro-hydraulic shaking table.This paper will introduce the design process of the robust pole assignment control strategy,and establish the valve control cylinder system model on the premise of considering the dynamic characteristics of the valve core in the electro-hydraulic servo valve.In order to test the disturbance immunity of the robust pole assignment control strategy,the control model of valve control cylinder system based on the robust pole assignment control strategy is established in Matlab/Simulink.Secondly,the active disturbances rejection control Strategy(ADRC)is applied to the motion control system of valve control cylinder system.On the premise of neglecting the dynamic characteristics of the valve core in the electro-hydraulic servo valve,the third-order linear active disturbances rejection control is established between the command signal of the valve control cylinder system and the speed signal of the piston rod.By establishing the control model of the valve control cylinder system based on ADRC,the suppressing disturbance ability of ADRC is tested.After the simulation,the reason why the linear ADRC is difficult to be applied to the position closed-loop control system of the valve control cylinder system is explained.Based on the above simulation analysis,in view of the limitations of ADRC and robust pole assignment control strategies,this paper simplifies the valve control cylinder system model which considering the dynamic characteristics of the valve core in the electro-hydraulic servo valve,and proposes the robust liner active disturbances rejection control strategies(RLADRC)for the model.To test disturbance rejection effect of RLADRC in valve control cylinder system.the paper will establish this simulation model in Matlab/Simulink.Finally,the proposed RLADRC is applied to the servo control system of the two degree of freedom redundant electro-hydraulic shaking table.To test the control effect of RLADRC in the electro-hydraulic shaking table,the two degree of freedom redundant electro-hydraulic shaking table control simulation model based on RLADRC is established in Matlab/Simulink.After analyzing the results of simulation and test,The conclusion is that RLADRC has obvious effect on suppressing the constant,sinusoidal and random disturbance signals in the electro-hydraulic shaking table.