Wind tunnel test and gust load alleviation of flexible wing including geometric nonlinearities with servo control

2018 ◽  
Author(s):  
Chao An ◽  
Changchuan Xie ◽  
Yang Meng ◽  
Chao Yang
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Servo Control ◽  
Geometric Nonlinearities ◽  
Flexible Wing ◽  
Gust Load Alleviation

scholarly journals Gust Load Alleviation including Geometric Nonlinearities Based on Dynamic Linearization of Structural ROM

2019 ◽  
Vol 2019 ◽  
pp. 1-20
Author(s):  
Chao An ◽  
Chao Yang ◽  
Changchuan Xie ◽  
Yang Meng
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Kernel Functions ◽  
Structural Deformation ◽  
Control Technique ◽  
Feedback Signal ◽  
Response Analysis ◽  
Geometric Nonlinearities ◽  
Gust Load Alleviation ◽  
Gust Response

This paper describes a framework for an active control technique applied to gust load alleviation (GLA) of a flexible wing, including geometric nonlinearities. Nonlinear structure reduced order model (ROM) and nonplanar double-lattice method (DLM) are used for structural and aerodynamic modeling. The structural modeling method presented herein describes stiffness nonlinearities in polynomial formulation. Nonlinear stiffness can be derived by stepwise regression. Inertia terms are constant with linear approximation. Boundary conditions and kernel functions in the nonplanar DLM are determined by structural deformation to reflect a nonlinear effect. However, the governing equation is still linear. A state-space equation is established in a dynamic linearized system around the prescribed static equilibrium state after nonlinear static aeroelastic analysis. Gust response analysis can be conducted subsequently. For GLA analysis, a classic proportional-integral-derivative (PID) controller treats a servo as an actuator and acceleration as the feedback signal. Moreover, a wind tunnel test has been completed and the effectiveness of the control technology is validated. A remote-controlled (RC) model servo is chosen in the wind tunnel test. Numerical simulation results of gust response analysis reach agreement with test results. Furthermore, the control system gives GLA efficacy of vertical acceleration and root bending moment with the reduction rate being over 20%. The method described in this paper is suitable for gust response analysis and control strategy design for large flexible wings.

scholarly journals Design and Optimization of an Aeroservoelastic Wind Tunnel Model

Fluids ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 35 ◽  
Author(s):  
Johannes K. S. Dillinger ◽  
Yasser M. Meddaikar ◽  
Jannis Lübker ◽  
Manuel Pusch ◽  
Thiemo Kier
Keyword(s):  
Finite Element ◽  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Objective Functions ◽  
Dynamic Identification ◽  
Wind Tunnel Model ◽  
Design And Optimization ◽  
Aeroelastic Model ◽  
Tunnel Model ◽  
Gust Load Alleviation

Through the combination of passive and active load alleviation techniques, this paper presents the design, optimization, manufacturing, and update of a flexible composite wind tunnel model. In a first step, starting from the specification of an adequate wing and trailing edge flap geometry, passive, static aeroelastic stiffness optimizations for various objective functions have been performed. The second optimization step comprised a discretization of the continuous stiffness distributions, resulting in manufacturable stacking sequences. In order to determine which of the objective functions investigated in the passive structural optimization most efficiently complemented the projected active control schemes, the condensed modal finite element models were integrated in an aeroelastic model, involving a dedicated gust load alleviation controller. The most promising design was selected for manufacturing. The finite element representation could be updated to conform to the measured eigenfrequencies, based on the dynamic identification of the model. Eventually, a wind tunnel test campaign was conducted in November 2018 and results have been examined in separate reports.

scholarly journals Fault Tolerant Control of an Experimental Flexible Wing

Aerospace ◽  
2019 ◽  
Vol 6 (7) ◽  
pp. 76
Author(s):  
Daniel Ossmann ◽  
Manuel Pusch
Keyword(s):  
Wind Tunnel ◽  
Filter Design ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Control Allocation ◽  
Detection Scheme ◽  
Single Input Single Output ◽  
Flexible Wing ◽  
Output Controller ◽  
Gust Load Alleviation

Active control techniques are a key factor in today’s aircraft developments to reduce structural loads and thereby enable highly efficient aircraft designs. Likewise, increasing the autonomy of aircraft systems aims to maintain the highest degree of operational performance also in fault scenarios. Motivated by these two aspects, this article describes the design and validation of a fault tolerant gust load alleviation control system on a flexible wing in a wind tunnel. The baseline gust load alleviation controller isolates and damps the weakly damped first wing bending mode. The mode isolation is performed via an H 2 -optimal blending of control inputs and measurement outputs, which allows for the design of a simple single-input single-output controller to actively damp the mode. To handle actuator faults, a control allocation scheme based on quadratic programming is implemented, which distributes the required control energy to the remaining available control surfaces. The control allocation is triggered in fault scenarios by a fault detection scheme developed to monitor the actuators using nullspace based filter design techniques. Finally, the fault tolerant control scheme is verified by wind tunnel experiments.

scholarly journals Flutter predictions for very flexible wing wind tunnel test

2021 ◽  
Author(s):  
Norberto Goizueta ◽  
Ariel Drachinsky ◽  
Andrew Wynn ◽  
Daniella E. Raveh ◽  
Rafael Palacios
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Flexible Wing
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