研究考虑控制输入饱和与状态约束的深空旋转二体库仑卫星构型控制问题,只采用卫星之间的库仑力作为控制力,提出一种基于反步法的非线性控制方法。首先推导了二体库仑卫星在地—月系平动点附近的相对运动方程,利用旋转二体库仑卫星的特性,对方程进行了简化。为了完成禁止相对运动区域的回避,设计了新的状态限制辅助函数,结合抗饱和方法与反步法得到了二体库仑卫星的构型控制器。接着证明了由于状态限制辅助函数的加入,所设计的控制器可以保证卫星相对运动不超出限制范围。进一步应用Lyapunov稳定性定理证明了其闭环系统的一致最终有界性。最后在Matlab/Simulink平台上进行了仿真校验,结果表明了方法的有效性。
The problem of the virtual structure control under control input saturation and state constraints for a spinning two-body Coulomb satellite system in the deep space is investigated, and a nonlinear controller based on backstepping method is proposed. Only Coulomb forces are utilized to control the configuration of the two-satellite formation flying in the vicinity of earth-moon libration point. After deriving the relative motion equation, an auxiliary function used for state constraints is developed. Combining with the anti-windup technique and backstepping philosophy, the reconfiguration of the Coulomb satellite system can be achieved even if the system contains constraints in both state and control. The auxiliary function part of the control law guarantees the system states in the limited region. Within the Lyapunov framework, the uniformly ultimate boundedness of the system states is guaranteed. Numerical simulation results demonstrate the effectiveness of the proposed control strategy.