无人机侧向系统LPV模型降阶

LPV model reduction of UAV lateral system

无人机线性参变(LPV)模型能准确描述其非线性动态特性,但初始建立的LPV模型阶数较高,控制过程计算量较大.为此,提出一种基于平衡截断的LPV模型降阶方法.首先给出LPV系统的适定性、稳定性和平衡实现的定义;然后,提出LPV模型的平衡截断降阶方法.针对无人机侧向系统LTI模型,通过多项式拟合来建立LPV模型,并实现模型降阶.仿真结果表明,降阶模型的阶跃响应满足输出响应的精度要求.

Unmanned aerial vehicle（UAV） linear parameter-varying（LPV） models can capture the possible nonlinear dynamics.When pursuing an LPV formulation,one ends up with models of relatively large dimension.Accordingly,finding control syntheses usually requires substantial computation.Therefore,an LPV model reduction theory based on balanced truncation method is proposed.First,the concepts of well-posedness,stability and balanced realizations in a linear fractional transformation framework are given.Then a generalization of the balanced truncation procedure for the LPV model reduction is presented.Finally,LPV model is built with linear time-invariable（LTI） models of UAV lateral system by polynomial fitting.The proposed method is applied to reduce the lateral system LPV model.Simulation results show that the step response of the reduced-order model meets the accuracy specification of output response.