Static Balancing of an Exechon-Like Parallel Mechanism

The compensation of gravity loads can represent a convenient strategy to enhance the opera-tion of manipulators with heavy end-effector/moving platform and/or moderate veloci-ties/accelerations, particularly in terms of energy efficiency. This work deals with the static balancing of a 5-DOF manipulator characterized by a serial/parallel hybrid architecture. Approximate gravity compensation of the parallel mechanism is achieved by means of an auxiliary leg comprising four tension springs. Numerical multibody models of the studied manipulator and of its balanced variant are implemented and simulated by using a commer-cial software package (MSC Adams™). The simulation results confirm the effectiveness of the proposed balancing solution, with the residual motor loads required for the static equi-librium of the balanced variant not exceeding 5% of the motor loads characterizing the un-balanced mechanism, in terms of both peak and rms values.