Forward/Reverse Velocity and Acceleration Analysis for a Class of Lower-Mobility Parallel Mechanisms

This paper proposes a novel kinematic analysis method for a class of lower-mobility mechanisms whose degree-of-freedom (DoF) equal the number of single-DoF kinematic pairs in each kinematic limb if all multi-DoF kinematic pairs are substituted by the single one. For such an N-DoF ?N?6? mechanism, this method can build a square Jacobian matrix and cubic ?N?N?N? Hessian matrix. The formulas in this method for
different parallel mechanisms have unified forms and consequently the method is conve-nient for programming. The more complicated the mechanism is (for instance, the mecha-nism has more kinematic limbs or pairs), the more effective the method is.