Dynamic balancing methodology of planar parallel manipulator using a constrained optimisation procedure

Abstract

This paper presents the design and analysis of reactionless planar parallel mechanism with kinematic constraints such as dexterity, workspace, mass and stiffness. The dynamic balancing procedure of the manipulator is formulated as an optimisation problem and it is achieved by adding counterweights to driving and distal links of the mechanism. While the mechanism is following a trajectory, various joints are subjected to instantaneous reaction forces and couples. The expressions for a set of such transmitted forces and shaking moments acting on the base active joints are explicitly obtained from dynamic equations and are minimised by selecting optimised link geometric parameters including positions of mass centres. The required dexterity, stiffness and workspace are considered as constraints along with variable limits. This nonlinear formulation is solved using binary coded genetic algorithms. The resultant reactionless linkage is analysed in ADAMS solver to know the effective reaction forces and couples.