Abstract:

During the operation of hyper- redundant shaking table under loads,the mass matrix in the dynamic modelbecomes non- diagonal due to the existence of eccentric load,which may result in the dynamic coupling among vari-ous 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 ofspace force systems,is constructed.Then,a coupling force observer based on the coupling model is introduced tothe DOF control structure.Moreover,the coupling force is regarded as a disturbance force loaded on the hydraulicsystem and is controlled by distributing it to each actuator through Jacobi matrix transformation.Finally,a feedfor-ward compensation control strategy of disturbance force is given based on the linear analysis of the hydraulic sys-tem.Simulated results indicate that the proposed decoupling control strategy for hyper- redundant shaking table iseffective in reducing the coupling among various degrees of freedom.

Key words: hyper- redundant shaking table, decoupling control, dynamic coupling, disturbance force compensa-tion, electro- hydraulic servo system