A polynomial eigenstructure assignment ( PEA ) approach for a quasi-linear parameter-varying ( QLPV ) system is presented and a corresponding control algorithm is designed for the high accuracy position keeping for formation flight in Sun-Earth L2 point. For the control design of QLPV model formation flight, the PEA approach used for LTI system is extended to QLPV systcm to ensure the independence between the closcd-loop system performance and the time-varying parameters and states. During the procedure of PEA, a parameter-and state-varying controller construct is presented firstly,and the designed closed-loop transfer function with unknown controller gains is calculated. Then the desired transfer funetion is chosen by considering the required performance of closed-loop system, and the controller gains is developed by matehing conditions between the designed and the desired transfer functions. To implement the approach for the spacecraft formation flight relative position MIMO contrnl, the desired transfer function is chosen as independent form in each channel to decouple the three axis control system to improve the control performance. Considering the differences between QLPV system and LTI system, the stability of QLPV closed-loop system is analyzed. Finally, a simulation is carried out to validate feasibilily and validily of the designed control algorithm.%针对日地L2平动点相对运动拟线性变参数(QLPV)动力学模型,提出一种改进的多项式特征结构配置(PEA)方法实现日地L2平动点编队飞行高精度相对位置保持.建立日地L2平动点编队飞行相对运动QLPV动力学模型,将基于线性时不变系统(LTI)的PEA方法进行改进,设计参数/状态变化的控制方法来获取闭环系统设计传递函数,与期望传递函数进行类似于线性系统的条件匹配,获得含时变参数和状态的多项式控制器,确保系统在参数和状态变化时能保持控制系统性能不变.在进行多输入多输出(MIMO)系统的算法设计时,将系统期望传递函数设为解耦形式,实现飞行器三轴位置间的解耦控制,以确保系统的控制精度.考虑到拟线性变参数系统与传统线性系统的不同,对拟线性变参数闭环系统的稳定性进行分析.最后进行了相应的数学仿真验证算法的可行性和有效性.
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