Development of a Flight Performance Assessment Service for Small Multirotor Aircraft

This paper presents the development of a Flight Performance Assessment Service (FPAS), intended to support pre-flight and in-flight trajectory planning. The service provides users with a capability to simulate flight trajectories and predict performance characteristics for small multirotor aircraft in nominal and motor failure scenarios. Users input flight plans to the service that can be designed using conventional ground control station software along with vehicle characteristics such as the number of motors, airframe dimensions, and aircraft mass properties. Wind information may also be provided if available. FPAS outputs simulated aircraft states and performance characteristics such as battery consumption profiles, control margin, and trajectory tracking accuracy. FPAS provides high-fidelity results by utilizing a large database of aerodynamic and power consumption models developed from extensive wind tunnel testing of representative small multirotor aircraft. These aerodynamic models are combined with a guidance and control architecture that mimics typical sUAS autopilot modes and behaviors to enable waypoint following. To enable fast repeatable simulation, models were converted to C++ code using Mathworks® Embedded Coder® and integrated into a standalone software application. The developed software includes an interface to communicate with an external commercial weather service to provide wind data and atmospheric conditions to be used within the vehicle simulations. The service can be run from a command line environment or from a graphic user interface, which also provides visualizations of the simulated flight trajectories. An example is provided that compares FPAS outputs to measured flight data of a small multirotor test aircraft. The predicted outputs, which include ground trajectory and energy usage, match the flight data within acceptable margins for performance assessment and trajectory planning applications. In terms of service response times, FPAS has been demonstrated to produce the trajectory and performance predictions at approximately 100 times faster than real-time on a typical business laptop, even for complex flight plans that span long distances or contain many waypoints.