Design and Evaluation of Active Flutter Suppression Control Laws for the IAWTM Wind Tunnel Test

Active flutter suppression (AFS) control law designs for the Integrated Adaptive Wing Technology Maturation (IAWTM) wind-tunnel tests are discussed. The test article is a half-span version of a transport aircraft model with an extended wingspan that introduced significant flexibility and numerous challenges for AFS control design. The article was tested in the Transonic Dynamics Tunnel (TDT) at NASA Langley Research Center in Hampton, VA. The control laws commanded up to three hydraulically-actuated trailing-edge control surfaces based on measurements from accelerometers, strain gauges, and fiber-optic strain sensor (FOSS) cables distributed along the wing. Control law designs used classical, linear quadratic Gaussian (LQG), generalized predictive control (GPC), robust control (H-Infinity and Mu-synthesis), Hamiltonian control, and modal control design techniques. These control laws were generally based on linear aeroelastic models of the system that were updated using experimental test data and results from computational fluid dynamics (CFD) analyses. Designs and test results are summarized and discussed.