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The retroreflective-enhanced system combines PSP/TSP with specially treated glass microspheres to enable simultaneous surface and flow field measurements. The process involves a multi-layer coating system including primer, epoxy base coat, and acrylic polymer/ceramic binder, with microspheres applied while the binder retains adhesive properties. The glass microspheres may be uncoated, half-coated with aluminum, or pre-processed to be coated in another chemical. The system leverages dual optical characteristics: the underlying PSP/TSP responds to pressure and temperature changes through luminescence intensity variations at specific wavelengths, while embedded microspheres provide retroreflective properties enabling focused SAFS, shadowgraph, or BOS visualization techniques. This configuration allows simultaneous capture of on-body surface measurements and off-body flow field disturbances. The invention enables measurements from a single viewing orientation rather than requiring orthogonal optical access points. While specific excitation lighting, wavelength filtering, and camera positioning are still necessary, the system significantly streamlines experimental setup compared to traditional separate approaches. While initially developed for aerodynamic testing and flow visualization research, this invention supports optical measurement and surface analysis applications. By enabling simultaneous measurements from a single optical access point, the retroreflective-enhanced PSP/TSP offers a streamlined solution for systems where optical access limitations are critical. The system is a TRL 6, having undergone successful validation in wind tunnel testing, and is available for patent licensing.

Proprotors on tiltrotor aircraft have complex aeroelastic properties, experiencing torsion, bending, and chord movement vibrational modes, in addition to whirl flutter dynamic instabilities. These dynamics can be stabilized by high-frequency swashplate adjustments to alter the incidence angle between the swashplate and the rotor shaft (cyclic control) and blade pitch (collective control). To make these high-speed adjustments while minimizing control inputs, generalized predictive control (GPC) algorithms predict future outputs based on previous system behavior. However, these algorithms are limited by the fact that tiltrotor systems can substantially change in orientation and airspeed during a normal flight regime, breaking system continuity for predictive modeling. NASA’s Advanced GPC (AGPC) is a self-adaptive algorithm that overcomes these limitations by identifying system changes and adapting its predictive behavior as flight conditions change. If system vibration conditions deteriorate below a set threshold for a set time interval, the AGPC will incrementally update its model parameters to improve damping response. AGPC has shown significant performance enhancements over conventional GPC algorithms in comparative simulations based on an analytical model of NASA’s TiltRotor Aeroelastic Stability Testbed (TRAST). Research for Hardware-In-the-Loop testing and flight vehicle deployment is ongoing, and hover data show improved vibration reduction and stability performance using AGPC over other methods. The example presented here is an application to tiltrotor aircraft for envelope expansion and vibration reduction. However, AGPC can be employed on many dynamic systems.