I using the Three-sample Rotation vector algorithm to calculate the human body's attitude via gyroscope's angular rate. According to my experimental data, my error draft is about 20 degrees per second. But the theoretical error draft should be less than 10 degrees per HOUR!
So how to update the attitude correctly by using the angular rate from gyroscope? The attached file is the three-sample formula used in my algorithm. By the way, the angular rate is about 300 degrees per second.