基于自抗扰技术的挠性航天器高精度指向控制

Active Disturbance Rejection Control for Flexible Spacecraft High-Accuracy Attitude Pointing

针对存在外部干扰和模型不确定性的挠性航天器,提出了一类新颖的基于自抗扰技术的控制方案,实现无姿态角速度反馈的航天器对目标高精度姿态指向控制。对目标相对姿态指向控制系统进行建模,引入一光滑连续秦函数,构造三阶扩张观测器,观测系统姿态角速度和总扰动,并利用其实现动态补偿线性化及扰动抑制。针对单框架控制力矩陀螺群作为执行机构常存在的奇异,引入零空间空转指令设计了一类奇异避免操纵律。将控制系统方案用于某挠性航天器模型,仿真结果验证了方案的有效性、合理性。

For one space-target, a novel active disturbance rejection controller （ADRC） was proposed for the high-accuracy pointing control of attitude velocity-free flexible spacecraft in present of external disturbances and model uncertainties in this paper. The numerical model of the relative attitude pointing control system of the flexible spacecraft was constructed, then a three-order extended state observer （ESO） was proposed to estimate the system states and the specified total disturbance, which was utilized to achieve dynamic compensative linearization and disturbance rejection. For the singular phenomena derived from the actuators configured by single gimbal control moment gyro （SGCMG）, a steering law was presented by introducing a null space motion command to avoid the singular problem. The numerical simulation was carried out for one flexible spacecraft, which validated the efficiency and availability of the proposed scheme.