It’s Not Just a Phase: Real-Time Aeroelastic Flutter Control Optical Flow Sensing and Piezoelectric Control of Aeroelastic Flutter

Aeroelastic flutter poses a critical threat to aircraft safety, occurring when aerodynamic forcescouple with structural dynamics to create potentially catastrophic, self-amplifying oscillations that lead to structural failure. Traditional active flutter detection and control methods rely on accelerometers and strain gauges at predetermined locations, but these approaches may miss flutter onset or provide insufficient spatial resolution for early warning systems. Flutter mitigation typically requires adding stiffer materials, which increases weight and decreases flight efficiency. This study presents a closed-loop aeroelastic flutter suppression framework using optical flow as the sole sensing modality, with phase-locked piezoelectric control, inspired by active damping and noise-canceling techniques. A flexible wing model constructed of 0.5 mm thick PETG was outfitted with two macrofiber composite (MFC) piezoelectric actuators mounted in a back-to-back configuration at the wing root. A Basler acA1300-200um camera was aimed at the free end of the airfoil. A ROS-based control framework computed optical flow from live camera images; the dominant frequency (5.3–5.6 Hz) was identified using FFT analysis. A Hilbert transform obtained instantaneous waveform phase. Phase-locked square wave actuation (0–4.2 V, amplified 300×to 0–1260 V) was applied at the measured flutter frequency with user-adjustable phase offset (0–360°). Systematic phase sweep experiments tested 12 phase offsets (0–330° in 30° increments) with eight paired on/off trials per phase (n=96 total measurements). Peak effectiveness occurred at 300° phase offset with 23.4% mean reduction in dominant frequency magnitude (n=8), while minimum effectiveness occurred at 180° with 16.4% mean reduction (n=8). Overall mean reduction across all phases was 19.6%. Individual t-tests confirmed that all twelve phases demonstrated statistically significant suppression (p<0.05), with no significant differences between phase means (ANOVA: p=0.52), demonstrating robust performance across the entire 360° phase space. A separate validation at 255° phase offset achieved 27.3% magnitude reduction (n=30 combined trials, t=13.634, p<0.00001). Off-frequencycontrolvalidationconfirmedthatfrequencymatching is critical: matched-frequency control achieved 20% reduction in dominant frequency magnitude, while off-frequency actuation (0, 3, 8, 10 Hz) provided minimal effect (<6% reduction). This work validates optical flow as a viable non-contact sensing modality for active flutter control, achieving performance suitable for practical flutter suppression applications. This optical approach minimizes added sensor mass, enables distributed sensing across the wing surface, and provides a pathway toward lightweight adaptive flutter suppression for high-aspect- ratio airfoils found in ultralight aircraft, high-altitude long-endurance aircraft, and unmanned aerial vehicles.

Level thesis:degree_level

Master’s Degree

Year dc:date.issued

2026

Author dc:creator

• Rothman, Paul

Advisors dc:contributor.advisor

• van Breugel, Floris
• Nair, Aditya G

Committee members dc:contributor.committeemember

• Ma, Ben
• Aureli, Matteo

• Aeroelastic Flutter
• Aerospace
• Optical Flow
• Piezoelectric

Language dc:language.iso

en_US, English

Repository record dc:identifier.uri

https://scholarwolf.unr.edu/handle/11714/11868

OAI identifier oai:identifier

oai:scholarwolf.unr.edu:11714/11868