Optimization of Parameter Identification for Flutter and Flying Qualities

An important outcome of both flutter and flying qualities flight testing is the assurance of safe aircraft operation within its operational flight envelope. Thus, the objective of flutter testing is to demonstrate that the aircraft is aeroelastically stable within the envelope, while the objective of flying qualities testing is to demonstrate that the aircraft is controllable within the envelope. Although the frequency ranges of interest are quite different, both flutter and flying qualities testing traditionally require several minutes of data at a given flight condition using frequency sweep, chirp, or other long duration inputs from which critical parameters can then be estimated. To dramatically reduce this time to five seconds or less, Systems Technology, Inc. (STI) proposes to use an innovative wavelet-based parameter identification technique that has been shown to work best with simple pulse-like inputs that are easily generated in a flight test environment. The technique can be used to identify transfer functions (or state space matrices) from which damping and frequency of critical flutter modes or flying qualities metrics can then be determined