针对最小二乘法在卫星故障检测和识别中存在的问题,研究将加权最小二乘算法用于卫星故障检测和识别,该算法将测量方程的协方差矩阵对角线元素作为加权因子,进而得到基于加权最小二乘法的卫星故障检测算法。通过各颗卫星伪距残差的平方和建立检验统计量,根据故障检测误警率和概率密度函数得到检测门限,将计算得到的伪距残差平方和与检测门限进行比较,进而实现故障的检测和隔离。结合实测数据,验证对比了两种算法的性能,结果表明: 加权最小二乘RAIM算法在故障检测的灵敏度和故障识别性能方面优于最小二乘RAIM算法的性能。

In order to solve the problems of the least-square method in satellite fault detection,a Weighted Least-Square (WLS) algorithm is proposed for satellite fault detection and recognition.The algorithm uses the diagonal-line factor in the covariance matrix of the measurement equation as the weighting factor.Then the satellite-fault-detection algorithm based on the WLS method is obtained.The test statistic is established by using the quadratic sum of the pseudo-range residual errors of each satellite.The detection threshold is obtained from the false alarm rate of the fault detection and the probability density function.The calculated quadratic sum of the pseudo-range residual error is compared with the detection threshold,and then the fault detection and isolation is realized.Analysis is made to the performance of the two algorithms according to the measured data.The results show that the WLS RAIM algorithm is superior to the least-square RAIM algorithm on the fault detection sensitivity and fault recognition performance.