关键词: 四元数, 姿态跟踪, 非线性Kalman滤波, 旋转运动合成

Abstract: The matrix representation，Euler angles and quaternions are commonly used in computer graphics.There are weaknesses by matrix representation and Euler angles，such as high computational cost，gimbal lock and so on.Quaternions are well-suited for the representation of rotations as they are free from singularities，numerically well-conditioned.In this paper，pose representation by quaternions are researched.With the basic quaternion algebra，the “quaternion based rotations combination theorem” is introduced and proved theoretically.On the basis of this theorem，a method for compute of pose nonliear state transfer function and its linearization is purposed.Then，the computing of the measurement function and the linearization is studied.With the Extended Kalman Filter（EKF），the pose is tracked and estimated.Finally，the experiment results show this quaternion-based algorithm for pose nonliear tracking is effective.

Key words: quaternion, pose tracking, nonlinear Kalman filter, combination of rotations