小型固体运载器一级飞行段姿态控制方案研究

Atmospheric flight attitude control strategy for a small solid launcher

为降低结构质量、提高运载能力,某小型固体运载器采用复合材料箭体结构设计方案和静不稳定气动设计方案,运载器具有较大的挠性,一级飞行过程中,由于稠密大气的影响,结构和控制耦合现象明显,对控制系统设计提出巨大挑战;同时,控制系统还面临发动机结构引起的干扰、风干扰、质量质心时变特性以及气动参数不确定性等问题。针对这些问题,设计了带有主动振动补偿和漂移控制的Backstepping控制器,通过滑模观测器估计低频弹性振动的影响,并给予补偿,采用反演控制技术设计非线性鲁棒控制器,以适应系统中存在的较强的不确定性,确保在一级飞行过程中的全局渐进稳定,提供可选择的漂移控制通道,修正由于风干扰引起的横向、法向漂移。通过运载器飞行仿真环境验证了控制器性能。Montr Carlo仿真结果表明,在各种干扰影响下,所设计的非线性鲁棒控制器的姿态跟踪误差不超过2°,控制舵偏角不超过5,°满足总体方案要求。

This paper describes the control challenges which by a novel small solid launcher is confronted with.The atmospheric flight control system design is presented and performance analysis is given.The launcher is aerodynamically unstable and structurally flexible.The major difficulties in developing the control system deal with structural dynamics,dynamic disturbance from the main engine,aerodynamic disturbance and uncertainties in all these models.Back-stepping control techniques were employed with active compensation for low frequency flexible modes and an optional anti-drift design to overcome translational and rotational disturbances.Performances of the controller were validated on the basis of complete evaluation models of the launcher.The obtained controller is a nonlinear time-variant robust design for the entire ascent range of the launcher operation.A tracking performance very close to that of the rigid body launcher is achieved.