Distributed Approximate Optimal Attitude Control of Combined Spacecraft With Parameters Identification

The distributed attitude takeover control problem of a target spacecraft with unknown inertia matrix by using multiple service satellites is investigated in this article. Based on the time-interval integration model of the attitude dynamics, an extended linear regress model is established to design the distributed inertia matrix identification law. In the approximate optimal control scheme, a set of basis functions are weighted to approximate the optimal value function and another adaptive law is designed to estimate the weight parameters of the basis functions. An approximate optimal control law considering actuator saturation and inertia matrix identification is proposed based on the method of approximate dynamic programming for multiple service satellites. Finally, simulation results show that accurate attitude control and inertia matrix identification are both achieved with the proposed distributed approximate optimal control law.