Modeling and Control of a NextGen Circulation Control Based Unmanned Aerial Vehicles

University Of Denver, Denver CO

Investigators

Abstract

This project aims at characterizing and accurately modeling the dynamics of fixed wing aerial vehicle with novel control concept, namely circulation control. Circulation control is the most effective active flow control method for lift enhancement purposes when compared to traditional control surfaces commonly used in aircraft. The circulation control wing (CCW) includes an air delivery system that "blows" air uniformly on the trailing edge of the wing through an air supply unit that is integrated with the main fuselage of the vehicle. While the CCW concept has huge benefits over the current state-of-the-art, there is a distinct need for improvements in the fundamental modeling and control aspects of such design. This project will lead to a comprehensive and verifiable theoretical and experimental methodology to develop the mathematical model and control strategies using an unmanned aerial vehicle (UAV) platform as the test-bed. The results from this project will lay a foundation for designing a full-scale unmanned circulation control aerial vehicle and contribute to a general understanding of implementation of circulation control in other applications. The fundamental understanding gained from this project will help design new aerial vehicles with the CCW concept that can deliver significantly enhanced aerodynamic efficiency, increased useful payload during cruise flight, delayed likelihood of stalling, and reduced runway requirements during take-off and landing. The project activities are also integrated with undergraduate and graduate educational experience. There exist several mathematical models for conventional UAVs, but there is no analytical or experimental model of the circulation control-based aerial vehicle designs. Also, the effect of circulation control on the aerodynamic characteristics of the new configuration aircraft are not known and, as a result, standard design techniques for control design cannot be applied to these new UAV designs. The research focus of this project is on providing a comprehensive methodology to derive a detailed mathematical model and equations of motion for the UAV with circulation control. The design methodology will be developed for various cases: CC-on, CC-off and CC-on-demand. The newly formulated models and derived controllers will be validated first through extensive simulation studies using X-Plane simulator environment and then through flight experiments using a retrofitted ReadyMadeRC Ananconda test platform. The outcome of the research is expected to be a verified and validated design. The project's methods will accurately characterize the effect of pitching moment, stability and control derivatives due to circulation control. A unique feature is the navigation controller derivation that accounts for changing blowing conditions depending on the on-going mission. Further, the circulation control system controller dynamically adjusts the blowing rate in accordance to set objectives and/or the required lift enhancement; this prevents operating the control system at full capacity at all times.