scholarly journals Limit cycle oscillation suppression controller design and stability analysis of the periodically time-varying flapping flight dynamics in hover

2022 ◽  
Author(s):  
Liang Wang ◽  
Wuyao Jiang ◽  
Zongxia Jiao ◽  
Longfei Zhao
Keyword(s):  
Stability Analysis ◽  
Limit Cycle ◽  
Controller Design ◽  
Flight Dynamics ◽  
Flapping Flight ◽  
Limit Cycle Oscillation ◽  
Time Varying ◽  
Oscillation Suppression ◽  
Cycle Oscillation

scholarly journals Limit Cycle Oscillation Suppression Controller Design and Stability Analysis of the Periodically Time-varying Flapping Flight Dynamics in Hover

2021 ◽  
Author(s):  
Liang Wang ◽  
Wuyao Jiang ◽  
Zongxia Jiao ◽  
Longfei Zhao
Keyword(s):  
Stability Analysis ◽  
Limit Cycle ◽  
Controller Design ◽  
Stability Result ◽  
Multiple Shooting ◽  
Limit Cycle Oscillation ◽  
Time Varying ◽  
Oscillation Suppression ◽  
Cycle Oscillation ◽  
The Stability

Abstract The periodically time-varying forces make the equilibrium state of Beihawk, an X-shaped flapping-wing aircraft, to be a periodic limit cycle oscillation. However, traditional controllers based on averaging theory fail to suppress this oscillation and the derived stability result may be inaccurate. In this study, a period-based method is proposed to design the oscillation suppression controller, locate the corresponding cycle and analyze its stability. A periodically time-varying wing–tail interaction model is built and Discrete Fourier Transform is applied to adapt the model for controller design. The harmonics less than quintuple flapping frequency account for more than 96 percent of the total harmonics and are reserved to present a concise model. Based on this model, Active Disturbance Rejection Controller (ADRC) is designed and its Extended State Observer can observe the disturbance to suppress the oscillation. Poincaré map is introduced to convert the stability analysis of the cycle to a fixed point. A multiple shooting method is adopted to locate several points on the cycle and the map is obtained by calculating the submaps between the adjacent points with the Floquet theory. The located points are proved to be accurate compared with the numerical solved cycle and the stability analysis result of the cycle is verified by the dynamic evolution. Compared with the State Feedback Controller, the ADRC performs better in suppressing the limit cycle oscillation and eliminating the attitude control error. The oscillation suppression is meaningful in maintaining a stable flight and capturing high quality images.

scholarly journals Reducing parametric uncertainty in limit-cycle oscillation computational models

2017 ◽  
Vol 121 (1241) ◽  
pp. 940-969 ◽  
Author(s):  
R. Hayes ◽  
R. Dwight ◽  
S. Marques
Keyword(s):  
Limit Cycle ◽  
Computational Models ◽  
Structural Parameters ◽  
Parametric Uncertainty ◽  
Limit Cycle Oscillation ◽  
Posterior Distributions ◽  
Input Parameters ◽  
Data Points ◽  
Cycle Oscillation ◽  
True Values

ABSTRACTThe assimilation of discrete data points with model predictions can be used to achieve a reduction in the uncertainty of the model input parameters, which generate accurate predictions. The problem investigated here involves the prediction of limit-cycle oscillations using a High-Dimensional Harmonic Balance (HDHB) method. The efficiency of the HDHB method is exploited to enable calibration of structural input parameters using a Bayesian inference technique. Markov-chain Monte Carlo is employed to sample the posterior distributions. Parameter estimation is carried out on a pitch/plunge aerofoil and two Goland wing configurations. In all cases, significant refinement was achieved in the distribution of possible structural parameters allowing better predictions of their true deterministic values. Additionally, a comparison of two approaches to extract the true values from the posterior distributions is presented.

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