An underactuated robot with a hyper-articulated deployable arm working inside an aircraft wing-box

We propose a novel concept for the actuation of a hyper-articulated robot arm for assembly operations inside an aircraft wing-box. The wing-box has a large span, but is only accessible through multiple small portholes along its length. The arm should be compact enough to enter the wing-box through the small portholes, yet capable of subsequent reconfiguration so as to access a number of assembly points inside the wing-box. Traditional electromechanical actuators powering individual joints are unsuitable for our purpose, because of limited space and large payload requirements. We propose an underactuated system which uses a single actuator at the base for the deployment of a multi d.o.f. serial linkage structure. Our proposed system exploits gravitational and gyroscopic torques in the system dynamics to rapidly deploy the system. We develop a methodology for determining the input required for a desired output trajectory and verify the results through simulation.