论文部分内容阅读
研究了一种适用于椭圆轨道航天器自主接近任务的滑模制导方法。针对自主接近模型中存在目标轨道不可知信息量问题,根据多输入系统滑模控制思想,设计了系统误差收敛时间有限的自主接近非线性滑模制导方法,解决了自主接近系统中存在的时变性和参数不确定问题。引入剩余飞行时间,改进定义误差的参数,使自主接近过程的距离和速度具备更好的协调收敛性。根据距离收敛特性,利用线性插值方法自适应地设定期望收敛时间进而确定切换系数,在较小延长接近时间的情况下,较好地保证了变结构制导的鲁棒性,并抑制了指令抖振问题。数值仿真验证了设计的制导策略对不同的初始条件表现出良好的适应能力,满足自主接近停泊点精度要求,且自主接近所需时间较短,尤其对较远距离自主接近任务表现出很好的快速性能。
A sliding mode guidance method suitable for elliptic orbit spacecraft autonomous proximity mission is studied. According to the idea of sliding mode control in multi-input systems, an autonomous approach to nonlinear sliding mode guidance with limited system error convergence time is proposed to solve the problem of target orbit unknowns in autonomous proximity model, which solves the problem of time-varying And the parameters of uncertainty. By introducing the remaining flight time and improving the parameters of the definition error, the distance and speed of the autonomous approach process are better coordinated and convergent. According to the characteristics of distance convergence, the linear interpolation method is used to adaptively set the desired convergence time and then to determine the switching coefficient. With a small extension of the approach time, the robustness of the variable structure guidance is better ensured and the command shaking Vibration problem. Numerical simulations show that the proposed guidance strategy shows good adaptability to different initial conditions, meets the requirement of autonomous approach to the anchorage point, and the autonomic approach time is short, especially for long-range autonomous autonomous mission Fast performance.