>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.