• IMU: Inertial Measurement Unit
• MARG: Magnetic, angular rate, gravity
• AHRS: Attitude and heading reference system
• Madgwick Filter
• Kalman Fliter
• Extended Kalman Filter (EMF)

Caruso, M.; Sabatini, A.M.; Laidig, D.; Seel, T.; Knaflitz, M.; Della Croce, U.; Cereatti, A. Analysis of the Accuracy of Ten Algorithms for Orientation Estimation Using Inertial and Magnetic Sensing under Optimal Conditions: One Size Does Not Fit All. Sensors 2021, 21, 2543. https://doi.org/10.3390/s21072543

https://www.mdpi.com/1060786

• Patents: https://patents.justia.com/inventor/daniel-roetenberg

https://ahrs.readthedocs.io/en/latest/filters/madgwick.html