Design and flight-testing of non-linear formation control laws

This paper presents the results of a research effort focused on the modeling, identification, control design, simulation, and flight-testing of YF-22 research aircraft models in closed-loop formation. These models were designed, manufactured, and instrumented at West Virginia University (WVU). The first phase of flight tests was performed with the goal of exciting all the aircraft dynamic modes. The recorded flight data were then used for a parameter identification study. The output of this study was a mathematical model of the WVU YF-22 aircraft, which was then used for the design of the formation control laws. The design of the formation control laws is based on an inner/outer loop design with the objective of controlling the forward, lateral, and vertical distances between two aircraft in the formation. The design for the outer loop scheme was based on feedback linearization while a root locus-based approach was used for the design of the inner loop scheme. The paper presents experimental results validating the performance of the formation control laws using a ‘virtual leader’ configuration.