Closed-chain motion with large mechanical advantage

One of the constraints that severely limit the capability of highly redundant manipulator arms is the actuator torque limits. This paper presents a way to achieve large effective forces from weak actuators by exploiting the large mechanical advantage that results from systems near singularities. While large mechanical advantages have been applied near singularities in many instances, this method allows the application of this large force over a large distance. It is applied specifically to closed chain mechanisms and demonstrated on the PolyBot modular self-reconfigurable robot