Adaptive Dynamic Programming-Based Tracking Control for Free-floating Space Manipulators

This paper investigates the tracking control problem for free-floating space manipulators (FFSM) in the joint space subject to parametric uncertainties. The parametric uncertainties are converted to a non-quadratic factor in the value function to eliminate their adverse effects on control performance. Then, we propose an approximate optimal tracking control scheme based on adaptive dynamic programming (ADP). The designed control scheme can track the desired joint trajectory and reduce the control costs simultaneously. It is proven in the Lyapunov sense that both the tracking error and the weight estimation error of the critic neural network (NN) are uniformly ultimately bounded (UUB). Besides, numerical simulations are constructed to validate the effectiveness of the proposed control law.