可重复使用运载器大姿态机动自抗扰控制

针对可重复使用运载器大俯仰角或偏航角转弯机动而产生的姿态角奇异的控制问题,提出了基于四元数的自抗扰控制方法。通过两级跟踪微分器从期望四元数中逐步得到三通道解耦的角加速度信号,然后利用扩张状态观测器观测模型中的不确定项,最终采用动态逆得到解耦的三通道发动机等效摆角或RCS(Reaction Control System)等控制信号,并设计了数字滤波器对弹性振动与液体晃动信号进行滤波处理。考虑到系统模型具有非线性、不确定性、11阶弹性振动、一阶液体晃动、风干扰和气动偏差等多种外部扰动条件,对可重复使用运载器从主动段到再入飞行段进行了非线性六自由度仿真分析。仿真结果表明,基于四元数的自抗扰姿态控制器具有快速、平稳、超调量小、抗干扰能力强、无系统抖振且控制参数较少的特点。

Active disturbance rejection control for reusable launch vehicle with large attitude maneuver

In view that the reusable launch vehicle has the attitude singularity problem caused by large pitch or yaw maneuver,an active disturbance rejection controller (ADRC) based on quaternion is proposed.The decoupling of three-channel angular acceleration is obtained by two tracking differentiators,and the uncertainties of the model are estimated by using an extended state observer.The equivalent pendulum angle or RCS (Reaction Control System) control signals of three-channel engine is calculated through dynamic inversion and is filtered by digital filter.Nonlinear 6-D simulation analysis on the reusable launch vehicle is carried out from the ascent phase to the reentry phase,which takes into account the system model's various external disturbances,such as nonlinearity,uncertainty,1 lth-order elastic vibration,liquid sloshing,wind disturbance,and the aerodynamic deviation,etc..Simulation results demonstrate that the proposed quartemion-based ADRC has the advantages of rapid response,robust operation,small overshoot,strong anti-interference ability,chattering-free,and less control parameters.