Does a steady wind change which purpose-built observation UAV is lightest, and what is wind worth to a multirotor?

What it found

A stdlib extension of the osrobot-uav mass-closure sizing adds a steady wind: headwind out, tailwind back, airspeed re-optimised, and station-keeping at airspeed equal to the wind. For 3 km out, 20 min on station and 0.5 kg the plain fixed wing stays lightest at every wind from 0 to 18 m/s (1.27 kg at 0, 1.30 at 10, 1.50 at 18); the quadrotor goes 2.14 → 2.33 → 2.86 → 7.0 kg at 0, 10, 15 and 18 m/s and the VTOL wing 2.08 → 2.54. The multirotor’s one win in still air (1 min on station) lasts to about 8 m/s. Designs sized for still air keep 17.2 (fixed wing) and 18.5 min (multirotor) of 20 at 9 m/s and 8.8 and 13.8 at 15 m/s; building for 15 m/s costs 34% (multirotor) and 9% (fixed wing) in mass. Crediting the multirotor with translational lift makes its mass fall to 1.71 kg at 10 m/s, an optimistic artefact of a steady known wind. Stylised: assumed coefficients, no gusts, crosswind or launch limits, nothing flown.

A figure from its own output

Paper, code and results

• README and method
• Experiments and results
• Code
• Tests

More in Open-source purpose-built robots

• How much heavier must an observation UAV be if the wind is uncertain, and is designing to a wind quantile cheaper than a bigger battery reserve?How much heavier must an observation UAV be if the wind is uncertain? Designing to the 95th-percentile of wind ~ N(8, 3) m/s costs the fixed wing +3.7% and the multirotor +11.7% mass, and a bigger battery reserve buys about the same reliability for about the same mass; stylised, one steady wind per mission.
• If an observation UAV only launches when the forecast wind is below a limit, how much does forecast error bring failures back, and what does it cost in scrubbed missions?If an observation UAV launches only when the forecast wind is under a limit, how much does forecast error bring failures back? A perfect forecast turns every failure into a scrub (fixed wing, wind ~ N(5, 4) m/s: 4.6% scrubbed at the 95th-percentile limit); a 2 m/s error gives 6.8% failures at the median limit but 1.1% at the 95th. Stylised, one steady wind per mission.
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• What is a UAV launch wind limit worth in money, and should the launch threshold sit below the design limit when the forecast is wrong?What is a UAV launch wind limit worth in money, and should the launch threshold sit below the design limit when the forecast is wrong? With an assumed expensive airframe and a 2 m/s forecast error the best threshold sits 1 to 6 m/s below the design limit, worth up to $284 per attempt, with failures at or below 0.1%; with a cheap airframe the best design covers nearly every wind. Stylised, assumed prices.
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Produced with AI assistance (Claude). Results are from the code in this repository and are simulated or stylised unless the abstract says otherwise; nothing here implies affiliation with or endorsement by any lab, researcher or company cited. MIT licensed.