The research on the effects of the pilot model parameter to the PIO of the helicopter

Closed-loop analysis method is proposed for pilot induced coupling caused by the pilot in closed loop. Basing on the longitudinal identification model of a certain type of helicopter, combining with the McRuer pilot model, and the designed stability augmentation system, the pilot-vehicle closed-loop model for pilot induced coupling analysis is established. By applying the basic analytical methods of the classical automatic control theory and the actual backgrounds, the properties of the root locus and the characteristics of the time domain as well as the frequency domain are studied, the features as well as the reasons of the PIO are also analyzed in comparison with the change of the parameter k
_pl
of the pilot model. Meanwhile, according to the closed-loop robustness properties and the damping characteristics of the system response, with the level judge criteria on the flight quality in the ADS-33E-PRF, the properties of the helicopter closed-loop robustness are simulated and analyzed as the pilot-model parameters change. Then feasible measures to improve the stability, robustness as well as the flight quality in order to solve the PIO are discussed in terms of the pilot's manipulation. Results show that the analysis method on the PIO proposed can not only reveal the physical nature of PIO qualitatively, but also quantitatively, which have theoretical reference significance in pilot's manipulation applications.