This aeroelastic phenomenon is a problem of considerable interest in the aeronautic industry, because flutter is a potentially. The finitestate, inducedflow theory and equilibrium beam finite element method are chosen to formulate the aeroservoelastic governing equations in statespace form, which is necessary for active flutter suppression design with. The paper describes the process of designing a controller for active flutter suppression on a small, flexible unmanned aircraft. Flightdynamics, flutter, and activefluttersuppression. Pdf robust control design for active flutter suppression. Aeroelasticity, flight dynamics and control laboratory, engineering school. Model reduction of flexible aircraft for flutter suppression using smart sensors. Active flutter suppression of a nonlinear aeroelastic system. Active control method on flutter suppression of a highaspectratio twodimensional airfoil with a control surface. The smart fin consists of a cantilever aluminum platelike. This paper describes an experimental study involving the implementation of the method of receptances to control binary flutter in a windtunnel aerofoil rig. Design and flight test of active flutter suppression on the x. The model was equipped with an active flutter suppression system consisting of hydraulically operated leading edge and trailicgedge control surfaces.
The windtunnel model used for the active flutter suppression program is a simpli fied version of a proposed supersonic transport wing design. A typical active control system for flutter suppression is. With this technique, the control surfaces of the aircraft are used to counteract the positive feedback e ect of utter, thus increasing the damping and reducing the oscillation of the wings. Stability augmentation and active flutter suppression of a flexible flyingwing drone dr. The adva is introduced by adding an active element to a classical massspringdamper system. A flutter suppression active controller sage journals. It was indicated that the parameter estimator possibly failed to follow the aeroelastic system change depending on the flight paths. Design of robust active control for flutter alleviation. Developed with lockheed martins famed skunk works, it is a modular aircraft designed to test an unusual method of alleviating flutter in lightweight aircraft. Numerical and experimental study of active flutter. A thorough bibliography contains references that cover all. The active flutter suppression university of washington.
Active flutter suppression has shown promise of preventing store flutter and has the potential for providing significant improvements in aircraft operational and mission effectiveness. For example, forces originating from the coupling of the structure with the aerodynamic flow may be modified and flutter suppressed by actively controlling the. Analysis, design, smart structures and materials select article simultaneous vortex and wakeinduced vibration suppression of tandemarranged circular cylinders using active feedback control system. Conference paper pdf available june 20 with 352 reads. Aerothermoelastic flutter properties of nonlinear composite laminated panels in supersonic airflow are studied, and investigations on active flutter and aerothermal postbuckling suppression for the panels with timedependent boundary conditions are also carried out. The scope of this work is to study computationally both passive and active flutter suppression characteristics of a cantilever cork agglomerate core sandwich with cfrp facings and an aluminum plate, the latter through the application of piezoelectric patches, respectively. Modeling the benchmark active control technology windtunnel model for application to flutter suppression martin r. Consequently, the use of active control systems to counter these adverse aeroservoelastic effects becomes an increasingly important aspect for future flight control systems. In this paper, active flutter suppression is demonstrated in a simulation using a navierstokes aero dynamics code, fun3d, and a realistic transport aircraft. Active flutter suppression afs has the goal of preventing flutter. To numerically test the developed concept a gfrp composite plate, surface bonded with eight multilayered benders and collocated pzt wafers has been considered. Use flexibility to an advantage, mdao, active control active flutter suppression is a key enabling technology critical paaw program components three different vehicles will be developed and flight tested the first will be very similar to lockheed martins ffad x56 which is the vehicle being discussed here. Active flutter suppression, which is a part of the group of flight vehicle technologies known as active controls, is an important contributor to the effective solution of aeroelastic instability problems when they pop up late in the development of a new aircraft or, if used from the start of the design process, it is a key element in.
Huttsellwing store active flutter suppression correlation of analysis and wind tunnel data. Design of an active flutter suppression system experts. Control surface spanwise placement in active flutter suppression systems author. This video presents experiments performed at straero s. Pdf active flutter suppression of a wind tunnel multiple. Active flutter suppression is the prevention of flutter by utilizing a controllable. Active flutter suppression of a smart fin karadal, fatih mutlu m. Active flutter suppression since the focus of the aeroservoelastic community moved to afs methods, there have been a large number of theoretical studies presented in literature. Active control schemes for flutter suppression can be tested using this experimental setup. The model was equipped with an active fluttersuppression system consisting of hydraulically operated leading edge and trailicgedge control surfaces.
Schmidt1 university of colorado monument, co 802 abstract integrated control laws are developed for stability augmentation and active flutter suppression afs of a flexible, flyingwing drone. Active flutter suppression, which is a part of the group of flight vehicle technologies known as active controls, is an important contributor to the effective solution of aeroelastic instability. Robust control design for active flutter suppression. Eigenvalue placement is used to synthesize a full state controller that satisfies performance specifications on control surf ace activity and that exhibits excellent gain and phase margins.
A general discussion of the airplane applications of active flutter sup pression systems is presented with focus on supersonic cruise aircraft configu rations. In the numerical study, a previously proposed control method in which the blade trailing edges were actively oscillated was analyzed in detail toward realistic application by a developed numerical method with flowstructure coupling. A timedomain aeroservoelastic model is developed to calculate the flutter speed and an active flutter suppression system is designed by model predictive control. Active flutter suppression of a composite plate with pzt. Flutter suppression of a flexible flyingwing uav using the. An active control law is synthesized for the suppression of wing flutter for a mathematical model of a flight test vehicle. A novel flutter suppression technique is proposed using an active dynamic vibration absorber adva. Flutter is an inflight vibration of flexible structures caused by energy in the airstream absorbed by the lifting surface. The active flutter suppression afs technology evaluation. Active flutter suppression, which is a part of the group of flight vehicle technologies. X56a tests active flutter suppression this is a more recent picture of the x56a the latest x plane unveiled by the united states air force and nasa.
It describes the investigations pertaining to the optimal size, thickness and locations of piezo actuators on. Development and flight test of an active flutter suppression system for the f4f with stores. Optimal sizing and placement of piezo actuators for active. The purpose of this paper is to design an active control system for flutter suppression of laminated plate wing model by using the segmented piezo actuators. A preliminary study on passive and active flutter suppression. Since flutter suppression systems can use electrohydraulic feedback networks to counteract the flutter conditions, the eventual. Adaptive linear quadratic gaussian optimal control. Model reduction of flexible aircraft for flutter suppression. Aerothermoelastic flutter analysis and active vibration. Preliminary design and assessment part ii assessment of system performances ion predoiu1, corneliu berbente2 this paper refers to active flutter suppression. Active dynamic vibration absorber for flutter suppression article in journal of sound and vibration december 2019 with 179 reads how we measure reads. Use flexibility to an advantage, mdao, active control active flutter suppression is a key enabling technology critical paaw program components three different vehicles will be developed and flight tested the first will be very similar to lockheed martins ffad x56. This active element drives the mass by a controlling force using feedback signal from the response of the aeroelastic system.
These studies consider both classical singleinput and singleoutput siso control approaches and more modern multivariable synthesis methods. Flutter suppression using active controls based on the. Active flutter suppression, which is a part of the group of flight vehicle technologies known as active controls, is an important contributor to the effective solution of aeroelastic instability problems when they pop up late in the development of a new aircraft or, if used from the start of the design process, it is a key element in multidisciplinary design optimization that could lead to. This flexible mount has to provide a welldefined twodegreesoffreedom system on which rigid wings encounter flutter.
Active dynamic vibration absorber for flutter suppression. Finally, the trailingedge inboard flaps and the fuselage flaps are selected to achieve a 14. Afs may reduce the need for structural sti ening masses, which could lead to aircraft. Bo proposed a novel selfsensing vibration control method and applied a selfsensing electromagnetic transducer to suppress the vibration of a space antenna reflector. A typical active control system for flutter suppression is designed to perform three functions. Robust control design for active flutter suppression julian theis, harald p feryand peter seilerz university of minnesota, minneapolis, mn 55455, usa flutter is an unstable oscillation caused by the interaction of aerodynamics and struc. Download pdf active and adaptive control of sound and vibration. The windtunnel model used for the active fluttersuppression program is a simpli fied version of a proposed supersonic transport wing design. Possibility of active suppression for transonic cascade flutter with piezoelectric device was studied both numerically and experimentally.
This role is accomplished through an additional functionality of the primary flight control surfaces and of their actuation system. Active flutter suppression techniques in aircraft wings. This is not the same as using active flutter suppression to fly beyond the flutter speed of an airframe, where loss of the control system would lead to immediate divergent. Control surface spanwise placement in active flutter. Jsv journal of sound and vibration vol 469, 17 march 2020. Active flutter suppression of a nonlinear aeroelastic system using piobserver fanzhanganddirksoffker abstract in this paper a novel robust control is proposed for the purpose of active. The statespace aeroelastic model is used to design an active control system for simultaneous flutter suppression and gust alleviation. Timedomain aeroservoelastic modeling and active flutter. Aerothermoelastic flutter properties of nonlinear composite laminated panels in supersonic airflow are studied, and investigations on active flutter and aerothermal postbuckling suppression for the panels with timedependent boundary conditions are also carried out using macro fiber composite actuator and sensor. Active flutter suppression, which is a part of the group of flight vehicle technologies known as active controls, is an important contributor to the effective solution of aeroelastic instability problems when they pop up late in the development of a new aircraft or, if used from the start of. Pdf active flutter suppression by feedback compensation. Nowadays, it is used both for flutter suppression and structural load alleviation. Department of aerospace engineering and mechanics, university of minnesota, minneapolis mn55455, usa. In this paper a novel robust control is proposed for the purpose of active flutter suppression of a nonlinear 2d wingflap system in the incompressible flow field.
Active control method on flutter suppression of a highaspect. This analytical study of active flutter suppression systems for military aircraft was directed toward the accomplishment of two broad objectives. Stability augmentation and active flutter suppression of a. The results have been obtained in a joint effort by a research. Adaptive feedforward compensating selfsensing method for. Active flutter velocity enhancement scheme is developed, employing lqg based mimo controller with pzt actuators and sensors. Flutter suppression using active controls based on the concept of aerodynamic energy by e. Active flutter suppression of a wind tunnel multipleactuatedwing model. Nissim langley research center summary the problem of flutter suppression is treated from an energy point of view, whereby. Eigenvalue placement is used to synthesize a full state controller that satisfies performance specifications on control surf ace activity and. Active flutter suppression systems for military aircraft. Another adaptive control application for the transonic flutter suppression.
Pdf active flutter suppression in a 2d airfoil using. Active flutter suppression, which is a part of the group of flight vehicle technologies known as active controls, is an important contributor to the effective solution of. Jan 12, 2009 this video presents experiments performed at straero s. The controller consists of an optimized robust stabilizer in the. Lqgltr control synthesis the goal is to find a control such that the system is stabilized and the control minimizes a cost function, which means implicitly a minimizion of the effect of disturbances on the controlled output and, in fact, an active alleviation of the flutter. A flexible mount system has been developed for flutter tests with rigid wings in wind tunnels. Yavuz yaman september 2008, 112 pages this study presents the theoretical analysis of an active flutter suppression methodology applied to a smart fin. Jams meeting, seattle, wa, march 2014 the active flutter suppression afs technology evaluation project. Active flutter suppression of airplane configuration with. Flight demonstration of the active flutter suppression system.
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