Publications

Vertical takeoff and landing (VTOL) aircraft design requires consideration of an efficiency trade-off between various flight conditions, including hover, transition, and cruise. To capture this trade-off, we propose simultaneous optimization of aircraft conceptual design and takeoff trajectory. Design- trajectory optimization, also called open-loop control co-design, allows us to find the optimal aircraft design that balances the flight efficiency between various flight conditions for maximum system-level performance. In this paper, we maximize the payload weight capacity of a lift-plus-cruise unmanned aerial vehicle (UAV) for package delivery. As a result, simultaneous optimization increases the payload weight by up to 5.3% compared to the conventional approach, which does not couple takeoff trajectory optimization to UAV conceptual design. We identify that the cruise speed and pusher motor sizing have a significant influence on takeoff trajectory. Simultaneous optimization finds the optimal cruise speed and motor sizing that enables energy-efficient wing-borne climb, which is not always possible with conventional sequential optimization.