Control of rotation-floating space robots with flexible appendages for on-orbit servicing

On-orbit operations are facing a growing need for autonomous robotic systems. Debris removal, on-orbit servicing and in-space deployment/assembly are examples of applications considering the use of robot manipulators. This paper addresses design and control problems related to autonomous space manipulator systems when using kinetic moment exchange devices in presence of flexible appendages. The paper introduces a method to develop a common control of the spacecraft base and manipulator. An extended state observer is used in the Nonlinear Dynamic Inversion (NDI) in order to improve performances and reduce vibration disturbance impacts on the base attitude. A simultaneous synthesis of a control law and an observer gain is proposed with Linear Matrix Inequalities (LMI) resolutions which allow system variation considerations. Simulations are run on an actual assembly scenario to illustrate the proposed method.