Energy-Efficient Flight

Diamond DA42 in automatic flightPicture: © Diamond Aircraft



Optimal Control for hybrid-electric Flight

Everyday flight missions are subject to different optimization objectives as maximizing the range, reducing noise or minimizing the demand for energy. The optimization of those objectives is usually subject to constraints which might stem from restrictions given by the aircraft‘s capabilities, noise control regulations, or features of the landscape.
Hybrid propulsion, when compared to a conventional aircraft propulsion system, yields additional control variables which can be utilized. By applying an optimal control approach, the overall energy consumption can be minimized while also taking constraints into account.
The optimal control is based on an analytic model of the propulsion and aircraft dynamics while numeric simulations are used to prove the feasibility and the robustness of the approach. So called "Hardware in the Loop" simulations ensure the functionality of the integral system. The expected energy savings will be verified by an implementation on-board of the hybrid aircraft e-Genius hybrid.
Optimal Control for a hybrid Propulsion System




Updraft Estimation

Updraft Estimation

Using solar energy provides the opportunity to operate aircrafts completely emission-free. Apart from using photovoltaics, atmospheric energy in the form of thermals can be easily exploited. Glider pilots are already taking advantage this form of energy and they use to record their cross-country flights with GPS devices. Those flight logs are then given to central organizations for the purpose of sporting comparative. Given such a large database of historical flight information, methods for analyzing this form of data are developed. This information needs to be combined with weather data, such that an estimate of the occurrence of an updraft can be given based on the current weather.

The results are then used by path planning algorithms to compute an energy-optimal flight path. Furthermore, the suitability of probabilistic filtering for an online estimate of the strength and location of updrafts is investigated. Given this information, the optimal flight path with respect to minimal energy consumption is continuously replanned. In particular, mission objectives need to be balanced with exploration and updraft exploitation.

  • Stefan Notter, Philipp Schrapel, Pascal Groß, and Walter Fichter. "Estimation of Multiple Thermal Updrafts Using a Particle Filter Approach", 2018 AIAA Guidance, Navigation, and Control Conference, AIAA SciTech Forum, (AIAA 2018-1854)


@2015 iFR - Flight Mechanics and Controls Lab


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