2009/06/14 by Abhijit Chakraborty, Peter Seiler, Gary Balas · 1 citation
Engineering · #Control Systems and Identification #Stability and Control of Uncertain Systems #Advanced Control Systems Optimization
paper · doi:10.2514/6.2009-5675
openalex publication_date 2009/06/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
The F/A-18 Hornet aircraft with the original ight control law exhibited an out-ofcontrol phenomenon known as the falling leaf mode. Several aircraft were lost due to the falling leaf mode and which led NAVAIR and Boeing to redesign the ight control law. The revised ight control law successfully suppressed the falling leaf mode during ight tests with aggressive maneuvers. This paper compares the robustness of the original (baseline) and revised control laws using linear analyses, Monte Carlo simulations, and nonlinear region-of-attraction analyses. The linear analyses indicate the revised controller only marginally improves the closed-loop robustness while the nonlinear analyses indicate a substantial improvement in robustness over the baseline controller. This example demonstrates the potential for nonlinear analyses to detect out-of-control phenomenon that are not evident from linear analyses.