GNC MODELING, SIMULATION AND TESTS FOR FLEXIBLE ROBOTIC ARMS IN SPACE

Servicing robotic systems can be used in space operations to perform several autonomous tasks, achieving longer operational lifetime and larger efficiency. This paper presents the approach and the results regarding the guidance, navigation and control of an orbiting robotic system, including theoretical and numerical aspects. A simulation software tool has been developed in order to focus on the different aspects of such a multidisciplinary problem. The kinematics and dynamics of a manipulator mounted on the orbiting platform has been studied, modeled, and simulated, taking into account orbital motion and structural flexibility of links. Different control strategies have been developed to perform the desired manoeuvres, such as classical proportional derivative control, linear optimal control (LQR), nonlinear feedback regulators based on dynamics inversion (Feedback Linearization Technique). Filtering techniques are added to process data to compensate for poor sensors’ accuracy. As a result of this study, a complete set of models and simulation tools for the GNC subsystem of an orbiting manipulator is developed. The simulations for a given test-case mission show the tight interaction among each of the different aspects of the manipulator design. An experimental setup is also described for the on-ground test of the proposed navigation and control algorithms. 1