基于修正Rodrigues参数和UKF的姿态估计算法  

Attitude Estimation Using Modified Rodrigues Parameters and UKF

作　　者：陈记争[1] 袁建平[1] 方群[1] 

机构地区：[1]西北工业大学航天学院,西安710072

出　　处：《宇航学报》2008年第5期1622-1626,共5页Journal of Astronautics

基　　金：国家自然科学基金(10572114)

摘　　要：以修正Rodrigues参数作为姿态参数,利用无味Kalman滤波(UKF)设计了一种全姿态估计算法。修正Rodrigues参数在姿态估计中具有简洁高效的优点,然而,因其奇异性不能用于全姿态运动情况。利用修正Rodrigues参数与其影子参数相互切换的方法可以避免奇异现象的发生。UKF直接利用非线性模型而不需要线性化,适用于高精度的姿态估计。本文针对"陀螺+矢量观测"这种典型的姿态确定模式,以修正Rodrigues参数与其影子参数相互切换的方法描述姿态,利用UKF设计了姿态估计器。状态协方差阵在姿态参数切换时发生突变,引起姿态估计器的滤波波动。为此,提出了在姿态参数切换时对姿态估计器进行修正的方法。最后通过仿真验证了算法的有效性。An all-attitude estimation algorithm is proposed using unscented Kalman filter （UKF） with the modified Rodrigues parameter representing the attitude. The modified Rodrigues parameters are simple and efficient in the problem of attitude estimation, but they can not be used in all-attitude motions, because they will be singular. It is possible to describe any rotations without encountering singularity by switching between the modified Rodrigues parameter and their shadow parameters. UKF uses nonlinear models directly and is suitable for precise attitude estimation. In this paper, an attitude estimator for the typical attitude determination mode composed of gyros and vector observations is designed by using the UKF, in which the attitude is presented by the way of switching between the modified Rodrigues parameters and their shadow parameters. There will be a jump of covariance matrix of state at the switching point, which brings the disturbance for the estimator. Therefore, a modification for the estimator is introduced at the switching point. Simulation results demonstrate the efficacy of the presented algorithm.

关 键 词：修正Rodrigues参数 无味Kalman滤波 姿态估计 奇异性 

分 类 号：V412[航空宇航科学与技术—航空宇航推进理论与工程]