Modeling and Autonomous Flight Simulation of a Small Unmanned Aerial Vehicle

This paper describes the use of FlightGear, an open-source flight simulator, and JSBSim, an open source flight dynamics model, to model and simulate a small autonomous Unmanned Aerial Vehicle (UAV). A small commercial electric engine Cessna-182 radio controlled (RC) aircraft was chosen to represent the UAV. The first step was to create the required JSBSim aircraft configuration files by using the Aeromatic v0.8, a free web application to create aircraft configuration files for use with the JSBSim. The next step was to make educated guesses to refine important sections in the created configuration files with the assistance of available data of similar UAV. In order to perform a visual simulation, a 3D model for the Cessna-182 (RC) was created using AC3D, a commercial 3D modeling software tool. To fly the modeled UAV autonomously a tuning process was made for the built-in generic PID (proportional, integral, and derivative) autopilot of FlightGear, which has the ability to hold aircraft velocity, vertical aircraft speed, altitude, pitch angle, angle of attack, bank angle, and true heading. Finally, a flight path, which contains a number of waypoints chosen over a selected area using Google Earth map, was constructed. In order to use the chosen waypoints with FlightGear navigation system, a unique ID was assigned to each waypoint, and the FlightGear database was altered to include the new waypoints with their IDs. The outcome of the paper was a complete JSBSim flight dynamic model for the Cessna-182 (RC), with 3D model for visual simulation and an effective autopilot. A good autonomous flight simulation was performed. This paper concluded that modeling and simulating a UAV accurately is not an easy task, due to the need to calculate many parameters either by physical measurements, experiments, or estimation from available data of similar UAV, or by software tools.