罗德里格参数和修正罗德里格参数是用于描述卫星姿态运动的最小表示法,计算量小,精度高;以修正罗德里格参数为工具研究了卫星姿态确定中的误差估计问题,建立了乘性和加性修正罗德里格参数误差模型,并将这两种误差模型应用到"星敏感器+陀螺仪"组合模式下,采用EKF算法估计卫星姿态,建立误差状态方程和观测方程;仿真结果表明,基于AMRPs和MMRPs姿态角估计误差均达到10-2°级别以内,基于MMRPs误差模型的估计精度高于AMRPs,且计算更为简便,收敛效果更好。
Rodrigues parameters and modified Rodrigues parameters are the least expression describing satellite attitude motion, which is of low computation and high accuracy. Using MRPs as a tool, estimation error problems in satellite determination have been studied in this paper, construeting multiplieative and additive error models in MRPs. And these error models are used in the combination of star sensor discretely sampling and gyro continuously measuring. Based on EKF algo-rithm, error state equations and observed equations have been built. Simulation results show that under AMPRs and MMRPs attitude estimation accuracy ean reach 10-2. level. Furthermore, the estimation accuracy of MMRPs is higher than that of AMPRs, which is of less computation complexity and eonvergenee effeet is much better.