Body freedom flutter, caused by coupling of the short period mode of the rigid body and the low order bending mode of the wing, easily occurs on flying wing aircraft. Since the flight control system has a significant influence on the short period modal characteristics of the aircraft, the closed-loop body freedom flutter characteristics considering the flight control system needs further study. In this paper, a pitching pose holding control law was developed for the self-designed flutter test model. The wind tunnel test and simulation calculation were used to conduct the research. The open-loop/closed-loop body freedom flutter characteristics under different free-free boundary conditions were obtained. The closed-loop gain on the flutter characteristics was studied, and the influence mechanism analyzed briefly. The results showed that the pitching pose holding control law obviously changed the original trend of modal damping, and the body freedom flutter characteristic of the closed-loop changed obviously. Based on the open-loop flutter velocity, using a smaller proportional loop gain KP or a larger differential loop gain KD, the flight control law can increase the pitch damping of the aircraft and the body freedom flutter velocity. Otherwise, the flight control law would reduce the flutter velocity. For the control law in this paper, when KP<0.07 or KD>0.2, the pitching pose holding control law can suppress the body freedom flutter.
LEI Pengxuan
,
YU Li
,
CHEN Dehua
,
LYU Binbin
. Influence of flight control law on body freedom flutter characteristics: Experimental study[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2021
, 42(6)
: 124378
-124378
.
DOI: 10.7527/S1000-6893.2020.24378
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