Meteorology-Aware Multi-Goal Path Planning for Large-Scale Inspection Missions with Solar-Powered Aircraft

摘要

Solar-powered aircraft promise significantly increased flight endurance over conventional aircraft. Although this enables large-scale inspection missions, their fragility necessitates that adverse weather is avoided. This paper therefore presents MetPASS, the Meteorology-aware Trajectory Planning and Analysis Software for Solar-powered unmanned aerial vehicles (UAVs). MetPASS is the literature's first path planning framework that considers all safety- and performance-relevant aspects of solar flight: It avoids terrain collisions and no-fly zones, integrates global weather data (sun radiation, wind, gusts, humidity, rain, and thunderstorms), and features a comprehensive energetic model to avoid system risks such as low battery charge. MetPASS leverages dynamic programming and an A*-search-algorithm with a custom cost function and heuristic to plan globally optimal point-to-point or multi-goal paths with coverage guarantees. A full software implementation is provided. The planning results are analyzed using missions of ETH Zurich's AtlantikSolar UAV: an 81 h stationkeeping flight, a hypothetical 4000 km Atlantic crossing, and two multiglacier inspection missions above the Arctic Ocean. It is shown that integrating meteorological data is indispensable for reliable large-scale solar aircraft operations. For example, the nominal no-wind flight time of 106 h across the Atlantic is reduced to 52 h by selecting the correct launch date and flight path.