Real-Time Mode Shape and Aeroelastic System Identification Toolset for Flight Test

ABSTRACT: The ability to extract structure mode shapes, accurate system frequency/damping and to predict the onset of flutter/LCO in a real-time capacity from flight/wind tunnel test data are some of the toughest challenges facing control room engineers today. In Phase I, ZONA Technology successfully developed prototype IADS ActiveX controls (i.e., the ZAMS+ Toolset) towards meeting these challenges. In Phase II we propose to mature and extend the ZAMS+ Toolset to establish a simple-to-use, user-friendly, commercially-viable software for the entire IADS flight test community. First, a Windows pre-processing program will be developed to provide a fast and parametrical graphical approach to setup the ZAMS+ 3D surface panel models and all required input for mode shape visualization. Second, the system identification capability of ZAMS+ OMS will be extended with a broadened CDSS method and innovative Physical Modes Selection Algorithm to support real-time flutter predictor capability. The new ZAMS+ OMS will provide both a full user-interactive and automated "hands free" approaches towards system identification and flutter prediction. Third, to support Ground Vibration Test (GVT) derived modes, a new data loader will be added for loading and display of GVT derived modes to supplement the current analytical mode capability used for overlaid mode shape correlation. BENEFIT: The proposed research and development effort will enhance flight test control room personnel's capability to obtain: (1) overlaid mode shape correlation of flight test system extracted modes versus analytical or GVT derived modes on 3D surface panel models, (2) the modal participation of the natural modes to the aircraft's aeroelastic response, (3) accurate aeroelastic system frequency and damping to gauge aircraft stability, and (4) flutter/LCO prediction via two flutter prediction approaches. The mode shape correlation display, in conjunction with the aircraft aeroelastic response displayed in the existing ZAMS tool, will help engineers identify how the structure modes interact with the aerodynamics throughout all flight conditions. The commercial potential for ZAMS+ Toolset is great as real-time mode shape identification, accurate system frequency/damping, and flutter prediction capability are crucial data to obtain for all wind tunnel and flight tests. The resulting ZAMS+ toolset will also provide valuable insight into the aero-structure interaction phenomenon that can lead to reduced flight testing. Mode shape correlation can also alleviate costs and burden associated with GVT. Users of these tools will include IADS customers, such as, Edwards AFB, Eglin AFB, Naval Air Weapons Center, Korean Aerospace, Pratt & Whitney, Israeli Air Force, Singapore Air Force, Cessna, Bell Helicopter, Northrop Grumman, Alenia/Italy, General Atomics, Boeing, Gulfstream, Holloman AFB, Raytheon, Hill AFB, and Lockheed.