Application of rotation vector algorithm for SINS attitude updating

The primary task of strap down inertial navigation system (SINS) algorithms is updating attitude timely and precisely. This paper presents an ARM based quad copter, using low-cost MEMS inertial sensors. In this paper we propose to use three methods, namely linear interpolation, gradient descent and complementary filter for attitude-updating. Meanwhile, an idea that the quaternion attitude could be updated by constructing micro-rotation quaternion from rotation vector in the sampling interval is proposed. The idea is based on geometric interpretation of space rotation transformation, while the general method is the differential equations of quaternion about rotation vector. Therefore the new method is an approximation method within enough short update intervals. Experiments on different methods show the effectiveness and accuracy of three improved algorithms with the rotation vector algorithm.