On the Synthesis of Spatial RRSS Motion Generators with Prescribed Coupler Loads

This work extends the concepts and methodologies of Shen et al(1) and Al-Smadi et al(2) to synthesis of spatial RRSS motion generators with applied coupler loads. A general four-bar mechanism constraint that includes a coupler static load and a driver static torques is formulated using the principal of virtual work. This constraint is combined with the conventional RRSS motion generation model by Suh and Radcliffe(13) to form a nonlinear optimization problem from which RRSS mechanism solutions are calculated that approximate prescribed coupler poses and satisfy prescribed driver static torques for given coupler loads.