STUDY OF OPTIMAL DESIGN AND LEG INERTIA EFFECT IN LARGE HYDRAULIC STEWART PLATFORM

抄録

The optimum design of parallel manipulators is an important and challenging problem. Currently, much of optimization work has been done over several criteria related to workspace, stiffness, dexterity and conditioning index. Relatively few papers have taken the control problem into consideration. In this paper, an optimal design method based on generalized natural frequency is proposed, which aims to expand the bandwidth for the control of large hydraulic Stewart platform. A Lagrangian formulation which considers the whole leg inertia is presented to obtain accurate equivalent inertia matrix, based on which, the influence of design parameters on generalized natural frequency is studied. Conclusion drawn from numerical examples, based on more accurate model, demonstrates that the leg inertia especially the piston part plays an important role on the dynamics, and five design parameters (diameters of the moving platform and the base, piston mass, effective driving area and fully retracted leg length) influence the frequency most.