DESIGN, ANALYSIS, FLIGHT DYNAMICS MODELING, SIMULATION AND CONTROL OF VTOL HYBRID UNMANNED AERIAL VEHICLE

Abstract

This research is focused on the design, analysis, flight dynamics modeling, and control of a VTOL hybrid UAV. A detailed study was conducted to analyze the design philoso phies, analysis techniques, flight dynamics modeling, and control strategies of all types of VTOL hybrid UAVs. The benefits and shortcomings of each design configuration were expressed in detail, based on which a selection problem was formulated in a fuzzy environment and the Multi-Attribute Decision-Making techniques were employed to select the most suitable configuration for the design of a VTOL hybrid UAV. For the selected configuration, conceptual and preliminary design cycles of the aircraft were presented. Subsequently, a detailed aerodynamic and stability analysis of the aircraft was performed. The vehicle with differential thrust transition was designed to achieve wide-envelope flight control by the use of only four actuators. The flight dynamics model of the vehicle was formulated. Attitude-tracking and altitude-hold controllers were designed to provide adequate control actuation for a smooth transition between the flight modes. The control system was designed for the flight dynamic model of the aircraft and implemented in MATLAB/Simulink environment for flight simulations. High fidelity aerodynamic analysis was performed over the entire flight envelope to obtain the aerodynamic coefficients of the aircraft. Motor dynamics, propeller effects, and airframe aerodynamics were included in the flight dynamics model of the vehicle. Flight simulations verified the effectiveness of the flight control system in tracking the attitude and altitude hold commands. The flight modes transition maneuver was successfully accomplished with the designed transition control system