基于双幂次趋近律柔性火箭滑模变结构控制

Sliding Mode Control of Flexible Launch Vehicles Based on Double Power Reaching Law

为了解决对有外界扰动和不确定参数的柔性运载火箭高精度姿态控制问题,提出一种基于双幂次趋近律滑模的变结构姿态控制算法。首先,针对弹道倾角不可测的柔性运载火箭姿态控制问题,设计了基于弹道倾角观测器的滑模变结构控制系统。其次,针对滑模变结构控制算法切换函数的影响,产生控制力矩高频抖振的问题,提出了一种具有全局固定时间收敛特效的双幂次趋近律姿态控制算法,在保证控制系统鲁棒性的前提下,保证了运载火箭完成姿态机动的速度。仿真结果表明,在外界扰动和箭体高阶弹性模态的耦合作用下,此算法在柔性运载火箭姿态控制中取得了较好的控制效果,同时具有较强的鲁棒性。

Aiming at high-precision attitude control of flexible launch vehicles,a double power reaching law-basedsliding mode control approach is proposed Firstly,for solving the problem of flexible launch vehicle attitude control with obliquity of trajectory which is unable to be measured,the sliding mode control law based on obliquity of trajectory observer is designed. Secondly,for eliminating the chattering which can excite elastic mode with high frequency,a double power reaching law-based sliding mode control approach under the low convergence speed and chattering phenomenon is developed in the scheme with conventional reaching laws. Simulation results demonstrate that the algorithm has good control performance and strong robustness.