Optimal Design of Generalized Stewart Parallel Manipulator Based Precise Tracking-Pointing Platform with Dynamic Isotropy

A precise tracking-pointing platform should meet such requirements as highly pointing,vibration isolation and vibration suppression.A Stewart parallel manipulator with dynamic isotropy is applicable to satisfy precise tracking and pointing performances,while it is still difficult to realize an optimal design for the desired specification.A traditional Stewart parallel manipulator is impossible to achieve complete isotropy because the payload is restricted rigorously.To solve the problem,a kind of generalized Stewart parallel manipulator with fault tolerance is defined and the concept of dynamic isotropy is presented.Considering the mass geometry characteristics of the payload,analytical formulations of dynamic isotropy are derived without complex computations.Based on the deduced formulations,a particle swarm optimization method is proposed to develop a high accuracy tracking-pointing platform using generalized Stewart parallel manipulators with better dexterity,motion ability and no element interactions.The evaluation shows that the generalized Stewart parallel manipulator can reach isotropy for a real payload and the design scheme is optimal and mechanically feasible.