航天器高精度悬停的改进型重复控制

Improved Repetitive Control for High-Precision Satellite Rendezvous

研究了以高精度为目的的航天器悬停系统控制设计。采用相对轨道要素描述目标航天器和跟踪航天器之间的相对运动模型,具有清晰的几何意义和较高的精度。为了实现高精度的相对位置和相对速度跟踪,提出了一种改进型重复控制方案,该方案利用重复控制能够精确跟踪目标信号的优点,并通过加入非奇异终端滑模控制器克服了传统重复控制器易受非周期干扰影响的缺点。此外,利用非线性状态误差反馈改善了重复控制器的动态性能,并利用径向基函数神经网络逼近悬停模型的未知非线性项。通过严格的李雅普诺夫稳定性分析,保证了整个闭环控制系统的稳定性。最后,通过数值仿真验证了所提控制方案的有效性和优越性。

This paper is focused on control design for high-precision satellite rendezvous systems.A relative motion model of leader-follower satellites described by relative orbit elements(ROE)is adopted,which has clear geometric meaning and high accuracy.An improved repetitive control(IRC)scheme is proposed to achieve high-precision position and velocity tracking,which utilizes the advantage of repetitive control to track the signal precisely and conquers the effects of aperiodic disturbances by adding a nonsingular terminal sliding mode(NSTSM)controller.In addition,the nonlinear state error feedback(NLSEF)is used to improve the dynamic performance of repetitive controller and the radial basis function(RBF)neural networks are employed to approximate the unknown nonlinearities.From rigorous Lyapunov analysis,the stability of the whole closed-loop control system is guaranteed.Finally,numerical simulations are carried out to assess the efficiency and demonstrate the advantages of the proposed control scheme.