Improved inverse kinematics and dynamics model research of general parallel mechanisms

Since the classical kinematics model of parallel manipulators cannot accurately reflect the angular velocity and angular acceleration of the limbs, an improved kinematics model is proposed and an inverse dynamic model of the general parallel manipulator is derived based on the improved kinematics model. This paper proves that the shortcoming of the classical kinematics model is that a single model cannot accurately describe the movement of several types of branches in a parallel manipulator. Combined with the principle of angular velocity superposition and vector chain method, the improved kinematic models of the general parallel manipulator's several typical limbs are derived. Then, an explicit inverse dynamic model of a general parallel robot is established based on the principle of virtual work. Finally, to describe the effectiveness of the improved model, we analyzed a new type of UP+SPR+SPU parallel manipulator. The improved models had higher accuracy than the classical models through the comparison.