A new actuator for on-orbit inspection

Can you move along a surface in space without propellant or mechanical contact? This paper presents a new actuator, the induction coupler, which generates an eddy-current force between a robotic inspector and the conductive exterior of its target. This force allows the inspector to crawl along the surface of a target without mechanical contact. Sets of induction couplers composed of spinning arrays of permanent magnets can exert control force and torque in all six rigid-body degrees of freedom by strategically repelling and shearing across the surface of the target. This paper uses an analytical model of eddy-current forces to simulate the set of maneuvers necessary to produce the control force and torque that can move and orient a robotic orbital inspector. Experiments on a low-friction test bed demonstrate a successful implementation of the actuator and verify the feasibility of this approach.