MINIMIZATION OF JOINT REACTION FORCES OF THE 2-DOF PLANAR SERIAL MANIPULATORS

Abstract

This paper presents an approach for the minimization of joint reaction forces of a two degrees of freedom (2-DOF) planar serial manipulator. The joint reaction forces due to inertia forces in the manipulator (dynamic joint reaction forces) are minimized using the differential evolution algorithm (DE). The expressions for the dynamic joint reaction forces as well as driving torques in the joints are obtained in a symbolic form by means of the Lagrange equations of motion. The inertial properties of the manipulator links are represented by dynamical equivalent systems of two point masses. A single objective function in the form of the root mean square magnitude of the dynamic joint reactions is used. Three different ways of the minimizing of the dynamic joint reactions are presented. The first way is by attaching counterweights to the links, the second one is based on the lengths of the links as the design variables, and the third one represents the joint reaction forces minimization via the optimal selection of the angular rotations laws of the manipulator links. The effectiveness of the proposed ways of the joint reaction forces minimization is discussed.