Decoupling control of hyper-redundant shaking table based on dynamic coupling model

During the operation of hyper-redundant shaking table under loads, the mass matrix in the dynamic model becomes non-diagonal due to the existence of eccentric load, which may result in the dynamic coupling among various degrees of freedom (DOF). In order to solve this problem, a dynamic model of hyper-redundant shaking table, which includes a nonlinear model of the hydraulic system and a mechanical coupling model based on the analysis of space force systems, is constructed. Then, a coupling force observer based on the coupling model is introduced to the DOF control structure. Moreover, the coupling force is regarded as a disturbance force loaded on the hydraulic system and is controlled by distributing it to each actuator through Jacobi matrix transformation. Finally, a feedforward compensation control strategy of disturbance force is given based on the linear analysis of the hydraulic system. Simulated results indicate that the proposed decoupling control strategy for hyper-redundant shaking table is effective in reducing the coupling among various degrees of freedom.