Gap准则在Ⅱ型PIO预测中的应用

针对Ⅱ型PIO(Pilot Induced Oscillations)严重威胁先进战斗机飞行安全的问题,提出运用Gap准则对纵向Ⅱ型PIO进行预测.建立了舵机速率限制的正弦输入/三角输出描述函数模型,改进了Neal-Smith驾驶员模型.提出运用描述函数法研究Ⅱ型PIO的产生机理,推导了非线性人机系统失稳公式,得到了Gap准则的一般计算方法.应用Gap准则对某型飞机纵向Ⅱ型PIO敏感性展开了研究,并进行了时域仿真验证.结果表明:Gap准则物理意义明晰、结果直观、计算高效,能有效地预测Ⅱ型PIO的发生.研究结果可为先进战斗机飞行控制系统的设计提供重要理论依据.

Application of Gap criterion in prediction of category Ⅱ PIO

To solve advanced fighter flight safety problem caused by category Ⅱ PIO (pilot induced oscillations), the Gap criterion was applied to predict category Ⅱ longitudinal PIO. The sinusoidal input/triangle output describing function model of rate limiting was built and the Neal-Smith pilot model was improved. The describing function method was proposed to investigate the mechanism of category Ⅱ PIO. The stability formula of nonlinear pilot-vehicle system was derived. The calculation method of Gap criterion was attained. The category Ⅱ longitudinal PIO sensitivity of a certain fighter was predicted by Gap criterion and the results were verified by time domain simulation. The results prove that Gap criterion has specific physical significance and illustrative results, calculate efficiently, and can predict the occurrence of category Ⅱ PIO accurately. The important theoretical references can be provided for designing flight control systems of advanced fighter.