Adaptive Fuzzy Relative Pose Control of Spacecraft during Rendezvous and Proximity Maneuvers

A six-degrees-of-freedom integrated adaptive fuzzy nonlinear control method is presented in this paper for uncertain spacecraft proximity systems subject to unknown model uncertainties and complex kinematic couplings. Adaptive fuzzy logic systems are developed to approximate the unknown nonlinear functions, and an adaptive fuzzy backstepping relative pose controller is designed. To overcome the drawback of 'curse of dimensionality' in adaptive fuzzy systems for multiple variable systems, all of the parameters in membership functions are updated to reduce the amount of fuzzy rules and computational burden. It is proven via Lyapunov theory that the proposed adaptive fuzzy nonlinear controller ensures the boundedness of all signals in overall system, and the relative motion information ultimately converges to adjustable small neighborhoods of zero. A computer experiment with numerical example is carried out to demonstrate the performance of the proposed control approach.