Pilot-Induced Oscillations and Control Surface Rate Limiting: Comprehension, Analysis, Mitigation, and Detection

Abstract

From the Wright Flyer to fly-by-wire, the phenomenon of pilot-induced oscillations (PIO) has persisted, evolving with the complexity of the airframes and their associated flight control systems. Though airframe designers have long recognized the threat posed by PIO, each generation has been forced to address the issue whether identified in developmental flight test, operational flight test, or mission operations. A desired outcome of the research presented in this thesis is that these occurrences may be minimized in the second century of powered flight through enhanced comprehension and mitigation methods. To begin, it is recognized that the most significant threat of PIO in fly-by-wire aircraft comes from pilot interactions with a nonlinear flight control system response characterized by control surface actuator rate limiting, the so-called Category II PIO, and as such is the focus of this thesis. As this work was carried out over three decades, the thesis is separated into three distinct parts that address Comprehension and Analysis Methods, Category II PIO Mitigation Methods, and PIO Detection…