一种改进的基于双矢量观测的姿态确定算法

Improved determination algorithm using two vector measurements

为了提高飞行器姿态确定的精度和姿态矩阵的解算速度,提出了一种改进的双矢量定姿算法.这种算法利用测量系统的方差对两个观测矢量进行加权处理,求得一个新的矢量,以两观测矢量夹角为判断依据选取加权系数;以新矢量为基准矢量,利用双矢量定姿算法求解姿态矩阵,并对求得的姿态矩阵进行修正.仿真结果表明:这种算法所需时间为优化算法的50%,当两个传感器测量误差不同、两矢量为任意夹角时,这种算法比优化的双矢量算法精度高;当两个传感器测量误差相同时,除了两矢量夹角为90°外,这种算法均比优化的双矢量算法精度高.

To improve the spacecraft attitude determination accuracy and the computational efficiency of attitude matrix, an improved TRIAD algorithm was proposed. In this algorithm, the two observation vectors was weighted utilizing the variance of the measurement system, the weighting coefficient was selected according to the angle between the two observation vectors, the attitude matrix was solved using TRIAD algorithm, and then the matrix was amended. It shows that the computation time of this algorithm is half of the optimized TRI- AD algorithm. When the measurement error of two sensors is difference, the accuracy of this algorithm is bet- ter than the optimized TRIAD algorithm for any angle of the two vectors. When the two sensors have the same measurement error, the accuracy of this algorithm is better than the optimized TRIAD algorithm except the an- gle of the two vectors is 90.