Destabilize/Stabilize Approach to Experimental Active Flutter Suppression Technology Development

Testing aeroelastic systems close to, at, and beyond their flutter speeds is extremely important for the experimental development of active flutter suppression technology. Such tests make possible the identification, based on input/output measurements, and, in turn, the fine tuning of aeroservoelastic-system mathematical models that would serve as a basis for designing control laws for flutter suppression and for a variety of other active control tasks, such as gust alleviation and ride comfort improvement. Such tests, however, are dangerous, costly, and, in many cases, not possible. This paper presents a safe wind-tunnel and flight-test technique in which, out of an array of multiple control surfaces, some are used, via closed-loop control, to generate deliberate instabilities of desired nature as well as desired dynamic characteristics of an aeroservoelastic system to be studied, whereas other control surfaces are used for the development of the active control technology required to meet active control targets for the resulting systems.