Internal force coupling control for hyper-redundant multi-axis hydraulic shaking table

Traditional internal force coupling control for shaking table is complex and shows poor control performance because of the same control parameter numbers of the cylinders. In order to stabilize the internal force, a novel Internal Force Coupling (IFC) control strategy is proposed based on deformation displacement and force spaces. Nonlinear equations of electro-hydraulic servo system and single rigid body dynamic model of mechanical part of the hyper-redundant shaking table are established with hydraulic and parallel mechanism theory respectively. Under the analysis of internal force space, internal forces calculated by force synthesis matrix are compensated in closed loop and decomposed to the inputs of the servovalves through the redundant deformation matrix. Simulation results show that the IFC control strategy effectively reduces cylinder forces and internal coupling forces of the hyper-redundant multi-axis hydraulic shaking table.