基于LQR的无人倾转旋翼机全模式控制律设计

Design of Full Mode Control Law for Unmanned Tiltrotor Aircraft Based on LQR

针对无人倾转旋翼机的倾转过程阶段存在操纵舵面冗余、垂纵向通道耦合的问题,对倾转过程中的冗余操纵量分配策略和垂纵向通道控制量融合策略进行分析,开展基于线性二次型调节器(linear quadratic regulator,LQR)的姿态控制器的设计与验证。以短舱倾角作为权重因子综合2套基于LQR的多环控制器,通过增益调度对其进行优化,克服倾转过程中由模型特性差异引起的控制效果不佳的问题,实现无人倾转旋翼机倾转过程中的姿态平滑控制;最后进行“直升机前飞-倾转过渡-固定翼巡航”的全模式飞行仿真。结果表明:控制系统能够有效解决舵面冗余及通道耦合问题,在倾转过程中体现出较优的系统性能。

Aiming at the problem of control surface redundancy and vertical-longitudinal channel coupling in the tilting process of unmanned tilt-rotor aircraft,this paper analyzes the allocation strategy of redundant control variables and the fusion strategy of vertical-longitudinal channel control variables in the tilting process.The attitude controller based on linear quadratic regulator (LQR) is designed and verified.2 sets of LQR-based multi-loop controllers were synthesized with the nacelle tilt angle as the weighting factor,and optimized by gain scheduling to overcome the problem of poor control effect caused by the difference of model characteristics in the tilt process,and the attitude smooth control of unmanned tilt-rotor aircraft in the tilt process was realized.Finally,the full-mode flight simulation of “helicopter forward flight-tilt transition-fixed-wing cruise” was carried out.The results show that the control system can effectively solve the problem of rudder redundancy and channel coupling,and the system performance is better in the tilting process.