抑制俯仰Ⅱ型PIO的四种滤波器性能比较

FWB、DS、DASA、RLF作为4种成熟、有效的非线性滤波器均用于解决以作动器速率饱和为特征的Ⅱ型驾驶员诱发振荡(PIO)相位滞后的问题,从而抑制PIO发生.借助描述函数理论,对各滤波器中非线性环节线性化处理,得到4种滤波器拟线性传递函数和相频特性曲线,研究、比较各滤波器在不同参数、不同输入条件下开环相位补偿能力.针对俯仰PIO问题,选取本机动态特性较差、易发生PIO的纵向飞机模型,构建带速率限制作动器的人机闭环系统,通过3个典型的俯仰飞行仿真任务,从抑制作动器速率饱和能力、俯仰响应特性、相位补偿能力、减轻驾驶员操作负担4个方面全面比较各滤波器性能.实验表明:DASA滤波在抑制PIO、改善飞机俯仰响应特性方面相对较优.实验结果为滤波器设计、俯仰PIO抑制的相关研究提供有益参考.

Performance comparison of four pre-filters used to prevent pitch category Ⅱ PIO

Category Ⅱ PIO cases are mostly characterized by actuator saturation. FWB, DS, DASA, RLF are four nonlinear pre-filters that have already been used to compensate for the phase lag led by actuator saturation, thus to prevent pilot-induced oscillation (PIO). Different means were used to make comparison among four pre-filters. Dscribing function was used to analyze and compare the phase compensation in open loop analysis by linearizing the nonlinear components of the fourpre-filters. The study mainly focused on pitch attitude PIO, in a pilot-vehicle closed loop system with a neutrally stable pitch bare aircraft that could easily cause PIO, three typical pitch flight simulation tasks were used to make comparison in terms of actuator velocity saturation prevention, pitch output dynamic characters, degree of phase compensation and alleviation of pilot operation burden, measured by pilot input magnitude. DASA turns out to be a better design among the four pre-filters. The result can provide a useful reference for filter design and pitch attitude PIO prevention study.