Dimensional synthesis of a robotized cell of support fixture

In this paper, an optimal designed 8-SPU parallel mechanism, acting as a cell of the self-configurable fixture which is used to support and clamp the thin-walled, large-scale plate and shell workpiece in automotive, aircraft and ship manufacturing industries, is proposed. In order to locate the maximum workspace with the global dexterity and conformity dexterity, single and multiple objective optimizations are performed under conditions of geometric constraints and kinematic performance indices by particle swarm optimization. The structural comprehensive parameters of parallel mechanism, such as the layout of joint points on the upper platform, the angle between two limbs of leg, and the ratio of radii of fixed to moving platforms, are optimized to obtain the optimal design dimensions. Furthermore, the effect of the optimized variables on kinematic performance indices is also intensively investigated. The compared results of the two optimization approaches indicate the feasibility of the proposed procedures.