倾转旋翼机平均驻留时间切换鲁棒H∞跟踪控制

Average dwell time switching robust H∞ tracking control for a tiltrotor aircraft

针对倾转旋翼飞行器模态转换阶段的飞行控制问题,本文给出了倾转旋翼机纵向运动飞行控制系统模型和一种基于参考模型的鲁棒跟踪控制方法.为了保证闭环系统在切换过程中稳定并同时满足指定的鲁棒H∞性能指标,利用状态观测器对系统不可观测状态进行估计,结合模型依赖平均驻留时间方法提出了一种倾转旋翼机切换鲁棒H∞跟踪控制方法,通过求解线性矩阵不等式得到控制器增益,并分析了系统的鲁棒稳定性.仿真结果表明,所提出的方法能够使飞行器系统准确跟踪指令,且对于控制器切换具有鲁棒性.

Considering the tracking control problem in the process of mode transition phase of tiltrotor aircraft, the model of the longitudinal motion flight control system and a reference model based robust tracking control scheme for tiltrotor aircraft are given in this paper. In order to ensure that the closed-loop system is stable and meets the specified robust H∞ performance indicators, a state observer is used to estimate system unmeasured states, with mode-dependent average dwell time, a robust H∞ tracking control switching method for tiltrotor aircraft is proposed. The controller gain is obtained by solving linear matrix inequality(LMI) and the robust stability of the closed-loop system is analyzed. Simulated results show that the aircraft system is able to track command signal accurately by using the proposed method and is robust to controller switching.