基于PEA的椭圆轨道航天器编队飞行高精度位置保持

High Accuracy Relative Position Keeping Based on PEA Approach for Spacecraft Formation Flight around Eccentric Orbits

针对航天器编队飞行时相对位置保持精度要求高的特点,采用基于线性变参数模型的多项式特征结构配置方法设计椭圆轨道航天器间相对位置控制算法。对于线性变参数控制系统,本文将基于线性定常系统的多项式特征结构配置方法推广以确保系统性能与变化参数间的独立性。在特征结构配置时,先设计带参数变化的控制器结构后计算出带未知控制器增益的设计闭环传递函数,接着将其与含有闭环系统性能的期望传递函数在三个条件下进行匹配,进而获得未知控制器增益的表达式。在设计实际控制椭圆轨道编队飞行MIMO相对位置保持算法时,将系统期望传递函数设为解耦形式来实现三轴位置控制间的解耦控制,达到提高系统控制性能的目的。最后进行相应的数学仿真,其结果表明该算法能够保证系统的高精度位置保持要求。

Focusing on the high precision of relative position keeping for formation flying,a controller based on linear parameter varying（LPV） polynomial eigenstructure assignment（PEA） is presented for the formation flight control of spacecrafts around eccentric orbits.For LPV control system,a PEA approach based on LTI model is extended to ensure the independence between closed-loop system and system varying parameters.During the procedure of PEA,a controller construct is presented firstly,and then the designed closed-loop transfer function with unknown controller gains is expressed.The desired transfer function including the required performance of closed-loop system,is used to evaluate the unknown controller gains under three matching conditions.To implement the approach for relative position MIMO control spacecraft formation flight around eccentric orbits,the desired transfer function is chosen as independent form in each channel to decouple MIMO system and improve system performance.Finally,a simulation is carried out and the results indicate that the algorithm can obtain the required high performance of system.