Active flutter suppression, which is a part of the group of flight vehicle technologies. Another adaptive control application for the transonic flutter suppression. A general discussion of the airplane applications of active flutter sup pression systems is presented with focus on supersonic cruise aircraft configu rations. Bo proposed a novel selfsensing vibration control method and applied a selfsensing electromagnetic transducer to suppress the vibration of a space antenna reflector. Stability augmentation and active flutter suppression of a. The active flutter suppression afs technology evaluation. The controller consists of an optimized robust stabilizer in the. 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. Flight demonstration of the active flutter suppression system. This paper describes an experimental study involving the implementation of the method of receptances to control binary flutter in a windtunnel aerofoil rig. This active element drives the mass by a controlling force using feedback signal from the response of the aeroelastic system. The windtunnel model used for the active fluttersuppression program is a simpli fied version of a proposed supersonic transport wing design.
The smart fin consists of a cantilever aluminum platelike. Nissim langley research center summary the problem of flutter suppression is treated from an energy point of view, whereby. A flutter suppression active controller sage journals. This flexible mount has to provide a welldefined twodegreesoffreedom system on which rigid wings encounter flutter.
Active flutter suppression afs has the goal of preventing flutter. Active flutter suppression controllers derived from. 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. Eigenvalue placement is used to synthesize a full state controller that satisfies performance specifications on control surf ace activity and. 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 schemes for flutter suppression can be tested using this experimental setup. Control surface spanwise placement in active flutter. 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. To numerically test the developed concept a gfrp composite plate, surface bonded with eight multilayered benders and collocated pzt wafers has been considered.
Numerical and experimental study of active flutter. 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. Aeroelasticity, flight dynamics and control laboratory, engineering school. 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. Jan 12, 2009 this video presents experiments performed at straero s. In this paper, active flutter suppression is demonstrated in a simulation using a navierstokes aero dynamics code, fun3d, and a realistic transport aircraft. Pdf active flutter suppression by feedback compensation.
The model was equipped with an active fluttersuppression system consisting of hydraulically operated leading edge and trailicgedge control surfaces. Active flutter suppression of airplane configuration with. Huttsellwing store active flutter suppression correlation of analysis and wind tunnel data. Active flutter suppression of a composite plate with pzt. 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 control method on flutter suppression of a highaspectratio twodimensional airfoil with a control surface. 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. 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.
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. Yavuz yaman september 2008, 112 pages this study presents the theoretical analysis of an active flutter suppression methodology applied to a smart fin. 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. Active flutter velocity enhancement scheme is developed, employing lqg based mimo controller with pzt actuators and sensors. Preliminary design and assessment part ii assessment of system performances ion predoiu1, corneliu berbente2 this paper refers to active flutter suppression. Aerothermoelastic flutter analysis and active vibration. Flutter suppression using active controls based on the. For example, forces originating from the coupling of the structure with the aerodynamic flow may be modified and flutter suppressed by actively controlling the. Design and flight test of active flutter suppression on the x56a multiutility technology testbed aircraft volume 120 issue 1228 e. These studies consider both classical singleinput and singleoutput siso control approaches and more modern multivariable synthesis methods. The statespace aeroelastic model is used to design an active control system for simultaneous flutter suppression and gust alleviation. Flutter is an inflight vibration of flexible structures caused by energy in the airstream absorbed by the lifting surface.
Adaptive feedforward compensating selfsensing method for. Jams meeting, seattle, wa, march 2014 the active flutter suppression afs technology evaluation project. Active flutter suppression has shown promise of preventing store flutter and has the potential for providing significant improvements in aircraft operational and mission effectiveness. Control surface spanwise placement in active flutter suppression systems author. Possibility of active suppression for transonic cascade flutter with piezoelectric device was studied both numerically and experimentally. Pdf active flutter suppression in a 2d airfoil using. A timedomain aeroservoelastic model is developed to calculate the flutter speed and an active flutter suppression system is designed by model predictive control. A typical active control system for flutter suppression is. This role is accomplished through an additional functionality of the primary flight control surfaces and of their actuation system. Active flutter suppression is the prevention of flutter by utilizing a controllable. High aspectratio wings, flutter suppression, active control the benefits of increasing wing aspectratio are well known, such as higher lifttodrag ratio and lower induced drag, although current commercial aircraft wings do not present high aspectratio. Consequently, the use of active control systems to counter these adverse aeroservoelastic effects becomes an increasingly important aspect for future flight control systems. Optimal sizing and placement of piezo actuators for active.
This analytical study of active flutter suppression systems for military aircraft was directed toward the accomplishment of two broad objectives. Active flutter suppression systems for military aircraft. The windtunnel model used for the active flutter suppression program is a simpli fied version of a proposed supersonic transport wing design. Active flutter suppression plans for assessing the technologys state of the art eli livne. 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. Active control method on flutter suppression of a highaspect. 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. 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. A typical active control system for flutter suppression is designed to perform three functions. It describes the investigations pertaining to the optimal size, thickness and locations of piezo actuators on. 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. Model reduction of flexible aircraft for flutter suppression. Robust control design for active flutter suppression. 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.
Flutter suppression using active controls based on the concept of aerodynamic energy by e. Afs may reduce the need for structural sti ening masses, which could lead to aircraft. This aeroelastic phenomenon is a problem of considerable interest in the aeronautic industry, because flutter is a potentially. Conference paper pdf available june 20 with 352 reads. Developed with lockheed martins famed skunk works, it is a modular aircraft designed to test an unusual method of alleviating flutter in lightweight aircraft. Download pdf active and adaptive control of sound and vibration. Active dynamic vibration absorber for flutter suppression article in journal of sound and vibration december 2019 with 179 reads how we measure reads. A thorough bibliography contains references that cover all. Active dynamic vibration absorber for flutter suppression. A preliminary study on passive and active flutter suppression.
The results have been obtained in a joint effort by a research. Active flutter suppression techniques in aircraft wings. Nowadays, it is used both for flutter suppression and structural load alleviation. Stability augmentation and active flutter suppression of a flexible flyingwing drone dr. Department of aerospace engineering and mechanics, university of minnesota, minneapolis mn55455, usa. A novel flutter suppression technique is proposed using an active dynamic vibration absorber adva. Analysis, design, smart structures and materials select article simultaneous vortex and wakeinduced vibration suppression of tandemarranged circular cylinders using active feedback control system. Since flutter suppression systems can use electrohydraulic feedback networks to counteract the flutter conditions, the eventual. 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. Pdf active flutter suppression of a wind tunnel multiple. The model was equipped with an active flutter suppression system consisting of hydraulically operated leading edge and trailicgedge control surfaces. Active flutter suppression of a nonlinear aeroelastic system.
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. Development and flight test of an active flutter suppression system for the f4f with stores. 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. The paper describes the process of designing a controller for active flutter suppression on a small, flexible unmanned aircraft. Active flutter suppression of a wind tunnel multipleactuatedwing model. Active flutter suppression of a smart fin karadal, fatih mutlu m.
Flightdynamics, flutter, and activefluttersuppression. 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. Waszak, nasa langley research center, hampton, virginia abstract this paper describes the formulation of a model of the dynamic behavior of the benchmark active controls technology bact windtunnel model for. Finally, the trailingedge inboard flaps and the fuselage flaps are selected to achieve a 14. 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. Model reduction of flexible aircraft for flutter suppression using smart sensors. Flutter suppression of a flexible flyingwing uav using the. Adaptive linear quadratic gaussian optimal control. Design of robust active control for flutter alleviation. This video presents experiments performed at straero s. 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. Design of an active flutter suppression system experts. Modeling the benchmark active control technology windtunnel model for application to flutter suppression martin r.
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