摘要
卫星多种姿态敏感器数据更新频率不同,如陀螺的输出频率远高于星敏感器。常用的姿态估计步长较大,当卫星角速度较大时,估计精度下降。论文设计了多步长姿态确定方案,在星敏感器输出之间,利用陀螺数据积分进行姿态估计,在星敏感器输出测量值后更新姿态,并校正陀螺漂移。数学仿真表明该方案能够获得高精度、高更新频率的卫星姿态信息。在卫星角速度为1×1-0 4(°/s)情况下,三轴姿态角估计误差方差为1.20×1-0 4(°),与常用定步长方案的效果相同;在卫星角速度为5×1-0 3(°/s)情况下,姿态角估计误差方差为1.51×1-0 4(°),而定步长方案姿态角估计误差方差为1.10×1-0 3(°)。该方法能够有效提高卫星姿态确定精度,适用于其它多种敏感器数据更新频率不同的应用要求。
Typical algorithms for estimating satellite attitude employ fixed step-length, For rapidly changing attitude about 5 ×10^-3（°/s） or faster, fixed step-length algorithms provide unsatisfactory precision. We now present an estimation algorithm that can provide satisfactory precision. In the full paper, we explain our estimation algorithm in some detail; in this abstract, we just add some pertinent remarks to listing the three topics of explanation. The first topic is. the attitude sensor measurement model. In this topic, we discuss the gyro measurement model and star sensor measurement model. The second topic is. the working principles of attitude estimator. Its three subtopics are ： state vector and state equations （subtopic 2.1）, star sensor measurement equations and their linearization （subtopic 2. 2） and the model of satellite attitude estimator （subtopic 2. 3）. The third topic is, the estimation algorithm considering multi-output frequencies. Its three subtopics are： forecast calculation （subtopic 3.1 ）, updating calculation （subtopic 3.2）, and updating the attitude quaternion and gyro drift （subtopic 3.3）. Finally we simulate the attitude estimation algorithm, and the simulation results, shown in Figs. 1 and 2 in the full paper, indicate preliminarily that： （1） the error variance of estimated attitude is 1.20×10^-4（°/s） when the angular velocity of a satellite is 1 ×10^-4（°/s）, the same as that of the typical fixed step-length algorithm; （2） the error variance of estimated attitude is 1.51 ×10^-4（°/s） when the angular velocity a satellite is 5 ×10^-3（°/s） but that of fixed step-length algorithm is 1.10 ×10^-3（°/s）.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
2008年第2期189-193,共5页
Journal of Northwestern Polytechnical University
基金
民用航天计划(C5120062702)资助
关键词
卫星
计算机仿真
多输出频率
姿态确定
陀螺
星敏感器
satellites, computer simulation, multi-output frequency, attitude estimation, gyro, starsensor
