Force-Balanced 2 Degree of Freedom Robot Manipulator Based on Four Bar Linkages

We design a force-balanced 2 degree of freedom planar manipulator, which has minimized ground reaction forces, reaction torques and joint actuation torques. This manipulator is highly suitable for mobile robotics applications, in particular for aerial manipulation, as it enables greater precision and stability. The design synthesizes two four bar linkage mechanisms together in a planar configuration. Each mechanism is optimally force-balanced through an algorithm that extends the links, aggregates additional components, and applies counter-masses. We compare dynamic simulation results for a trajectory between the unbalanced and balanced designs to validate that the latter has 59% reduction in reaction torques and a constant reaction force vector caused by gravity on the base, as well as lower joint actuation torques.