A 26-Gram Butterfly-Inspired Robot Achieving Autonomous Tailless Flight (arxiv.org)

If anyone is clicking but noping out of a white paper, deep in the paper are remarkably wonderful charts explaining what's going on to pull this off.

I wish there were a video of this linked from the research paper.

Not a single decent photo of the butterfly robot

https://en.wikipedia.org/wiki/Danny_Dunn%2C_Invisible_Boy - leaving the realm of science fiction at long last.

>Accurate and low latency attitude estimation is critical for stable flight of the flapping-wing platform. We implemented a quaternion-based Madgwick filter (80) on the ESP32-S3 (dual-core 240 MHz with floating-point unit) to fuse IMU measurements in real time. This approach was selected for its low computational cost, fast convergence, and robustness under dynamic motion, outperforming complementary filters in accuracy and avoiding the high complexity and matrix operations of extended Kalman filters.

Bravo, quaternion is the (only) way to go, the sooner UAV/UAS system designer realize this the better.

"Their non-invasive maneuverability is ideally suited for real-world applications, such as confined-space inspection and ecological monitoring, inaccessible to traditional drones"

I'm having a hard time imagining a situation where flapping wings would be superior to a rotary winged drone. Anyone have any insight?