人-机系统纵向动态特性的研究——PIO问题研究方法的探讨

本文根据PIO问题研究的需要,考虑到操纵系统非线性（间隙和摩擦等）对PIO问题影响的严重性,推导了包括非线性环节在内的,驾驶员-操纵系统-飞机本体组合系统的纵向动态结构图,并用DMJ-3A电子模拟计算机,以某歼击机低空大速度正常状态（力臂处于小臂）和故障状态（力臂处于大臂）为例进行了模拟计算。计算结果与飞行实践是一致的。从而初步说明作者提出的结构图（即PIO计算方法）既是可信的,也是具有实际分析使用价值的。

STUDY ON LONGITUDINAL DYNAMIC CHARACTERISTICS OF PILOT-AIRPLANE SYSTEM--APPROACH TO THE METHOD FOR STUDYINGPIO PROBLEM

In order to meet the needs for studying PIO（Pilot-Induced Oscillation） and take serious influence of control system nonlinearity（e. g. clearance and friction, etc. ） on PIO into account, a dynamic structure diagram （see Fig. 2） and an analog structure diagram （see Fig. 3） in longitudinal motion of pilot-control-airframe with nonlinearity have been derived, and a new method which further ap-proa ches to the actual case has been provided for studying PIO problem. Moreover computations have been carried out on a DMJ-3A analog computer for three cases as examples, i. e. the moment arm at normal state（short arm）, the moment arm at trouble state（long arm）, and the moment arm still at trouble state （long arm） without pilot's correction, for a fighter flying at low level and high speed. The results are shown in Fig. 4, Fig. 5 and Fig. 6. It is obvious that they coincide with the actual flight and thereby it is proved preliminarily that the structure diagram and the analog structure diagram（i. e. the computation method for PIO） proposed are not only reliable, but also of value in pra-tical analysis and use. The results obtained also demonstrate that the phenomenon of the longitudinal oscillation with big amplitude for a fighter at low level and high speed is the problem of PIO.In order to get a clear understanding of influence of pilot on the pilot-airplane system, different pilot's transfer functions have been adopted to compute the pilot-airplane system on DMJ-3A analog computer. The results obtained prove that the mathematical model of pilot exerts a great influence on pilot-airplane system（see Fig. 7）.