反馈结构RLF补偿器在抑制Ⅱ型PIO中的应用研究

Research on the feedback-structural RLF compensator to prevent category Ⅱ PIO

现代电传飞行控制系统中由于作动器速率饱和产生的突然的附加相位滞后以及系统操纵增益的降低,是触发Ⅱ型PIO的主要原因,对此通常采用相位补偿的方法进行抑制。为研究补偿器的抑制效能,建立了非线性的人机闭环系统模型。在分析基于反馈结构的RLF补偿器频域特性及其相位补偿能力的基础上,采用离散俯仰跟踪任务与正弦跟踪任务在时域内仿真研究了补偿器对Ⅱ型PIO的抑制效能。仿真结果表明,RLF补偿器可以有效抑制Ⅱ型PIO,经地面飞行模拟器进一步验证,表明补偿器明显改善了飞机飞行品质,可以用于Ⅱ型PIO的抑制。

Actuator rate saturation in modern fly-by-wire flight control systems resulting in the sudden introduction of significant added phase lag as well as the effective reduction in gain of the pilot-vehicle closed-loop system has been shown as a main contributor to the triggering category Ⅱ PIOs.The phase compensating method is a practical means to avoid the PIO.A nonlinear pilot-vehicle closed-loop system was established in order to investigate the prevention efficiency of compensator.The phase compensation properties of the RLF compensator was analyzed with describing function method in frequency domain.The discrete and sine tracking tasks were employed to research the prevention capability of the RLF compensator in time domain simulation.The simulation results indicate this compensator produces good performance on preventing the category Ⅱ PIO.Finally the effectiveness of this prevention method was tested by use of further validation on ground-based flight simulators.The test results also demonstrate the RLF compensator could improve flying qualities of aircraft and prevent the category Ⅱ PIOs effectively.