具有预设性能的近距离星间相对姿轨耦合控制

针对存在系统不确定性和外界干扰的接近绕飞阶段跟踪航天器相对目标航天器的姿态与轨道一体化控制任务,设计了一种具有预设性能的鲁棒反演控制器。该控制器能预先设计系统的稳态与暂态性能,保证相对姿轨跟踪误差满足预先设计的性能指标要求;为避免传统反演控制方法中存在的"微分膨胀"问题,引入滑模微分器对虚拟控制量的导数进行估计;同时利用自适应控制技术估计不确定模型参数及包含滑模微分器估计误差和外界干扰的集总干扰上界,并引入鲁棒补偿项处理这些不确定性带来的影响。理论分析证明所设计的控制方法能保证相对姿轨跟踪误差满足预设性能指标要求,仿真结果验证了所设计控制方法的有效性。

Coupled control of relative position and attitude for spacecraft proximity operations with prescribed performance

An integrated coupled control strategy with prescribed performance is proposed for proximity-operations of spacecraft formation flying in the presence of mutual couplings, model uncertainty and unknown but bounded external disturbance. On the basis of the prescribed performance control theory, the prescribed steady state and transient performance for the tracking error of the original relative translation and rotation system can be guaranteed through the stabilization of the transformed system. Sliding mode differentiator is introduced to overcome the problem of explosion of complexity inherent in traditional backstepping design. In addition, the requirements of knowing the system parameters and the unknown bound of the lumped uncertainty, including external disturbance and the estimate error of sliding mode differentiator, have been eliminated by using adaptive updating technique. Within the framework of Lyapunov theory, the stability of the transformed system is obtained. Finally, numerical simulations are carried out to verify the effectiveness of the proposed control scheme.