空间热环境下带大型天线卫星的最优姿态控制

Aiming at the attitude stabilization problem for satellite with large antenna in space thermal environment, an adaptive approximate optimal control method based on sliding mode surface is proposed. Firstly, considering thermal stresses and thermal vibrations of antenna, which bring unknown unmatched disturbances to the attitude control system, a state observer is used to estimate the upper bound of these unmatched disturbances. Secondly, a performance index function with online updating capability is designed based on the disturbance estimation. Then, a single-layer evaluation neural network algorithm based on sliding mode surface is used to solve the uncertain HJB equation. Finally, the approximate optimal control system is combined with the sliding mode controller to improve the convergence of algorithm and the stability analysis is presented. Effectiveness is verified in the simulation scenario of space thermal environment. The control strategy can achieve the attitude stability of satellite with large antenna under the large change of temperature.