Unified analysis of statics of some limited-DOF parallel manipulators

SUMMARY An observation approach is proposed for determining the poses of the active/constrained wrench and the unified statics of some limited-DOF parallel manipulators (PMs) are studied systematically. First, a general PM model is constructed, and the unified inverse displacement is analyzed. Second, various types of acceptable legs are synthesized; the poses of the active/constrained wrench exerted on the various acceptable legs are determined by the observation approach. Third, a unified 6 × 6 Jacobina matrix and a unified statics equation are derived for solving active/constrained wrench of many limited-DOF PMs. Finally, two PMs are presented to illustrate this approach.