INFLUENCE OF KINEMATIC REDUNDANCY ON TYPE-II SINGULARITY LOCI OF PARALLEL KINEMATIC MACHINES

摘要

In this paper the effect of kinematic redundancy in order to reduce the type-II singularity loci and to increase the operational, i.e. singularity-free, workspace is demonstrated. The proposed approach consists of one additional prismatic actuator allowing one base joint to move linearly. As a result, a selective reconfiguration can be performed which can be used to avoid singular configurations. Exemplarily, kinematically redundant schemes for the planar 3RRR and the spherical 6UPS are considered. The relationship between the redundancy and the operational workspace is studied and several analysis examples demonstrate the effectiveness of the proposed concept.