Ornitopter attitude estimation: ground test

This paper introduces the preliminary study on the ornithopter attitude estimation. An ornithopter platform with the payload affordability up to 60gf was designed and developed. Within the maximum take-off weight of the ornithopter, an ornithopter flight data acquisition system was successfully constructed and it consisted of 3-axis accelerometer, 3-axis gyro, magnetometer, hall-effect sensor, low-performance MCU, RF module, and ground station. During the flight test, the ornithopter had a sustained and controlled flight carrying 60gf payload in the range of 100m (line-of-sight). The flight data was sampled with the sampling frequency 40Hz, no data shift or loss during the test. For the development of stability and controllability augmentation system or pitch-hold autopilot for the ornithopter, we implemented the Kalman filter to estimate the pitch attitude by using the accelerometer triad and the gyro. The time history of the estimated, the measured, and the directly integrated pitch attitude were compared with the real one measured using a digital encoder. Though the flapping-wing motion yielded additional low frequency noises, the pitch attitude was successfully estimated using the designed Kalman filter.