Design and Flight Testing Evaluation of Formation Control Laws

This brief presents the results relative to the design and flight testing of formation control laws using a set of YF-22 research unmanned aerial vehicles (UAVs) designed, built, and instrumented at West Virginia University, Morgantown. In the formation flight configuration, a radio control pilot maintains ground control of the “leader” aircraft while the autonomous “follower” aircraft maintains a predefined position and orientation with respect to the “leader” aircraft. The formation controller was designed to have an inner and outerloop structure, where the outerloop guidance control laws minimized the forward, lateral, and vertical distance error by controlling the engine propulsion and generating the desired pitch and roll angles to be tracked by the innerloop controller. The horizontal components of the outerloop controller were designed using a nonlinear dynamic inversion (NLDI) approach, while the vertical channel of the outerloop controller and the innerloop control laws were instead linear. Flight testing results from two-aircraft formation flights confirmed the performance of the designed formation controller.