On Forward Kinematics of a 3SPR Parallel Manipulator

This letter presents a new numerical method to solve the forward kinematics (FK) of parallel manipulator with three-limb spherical-prismatic-revolute (3SPR) structure. Unlike existing approaches that require manipulator’s Jacobian matrix and its inverse at each iteration, proposed algorithm requires much less complex computations estimate FK parameters. A cost function is introduced measures difference between actual values estimates. At problem handled in two steps. First, estimates platform orientation from heave are obtained. Then, updated along gradient direction function. To evaluate performance algorithm, we compare results those Jacobian-based (JB) approach for 3SPR manipulator.