The mathematic model of concentricity error and a advanced optimal method - "cosine shift plus" are put forward.
提出了同轴度误差的数学模型，其中给出一种高效的优化方法一余弦移位相加法。
Methods of spherical trigonometry and direction cosine matrix were applied respectively to derive the bracket error, and the two methods had the same error formula and the same calculation results.
应用球面三角法和方向余弦矩阵法分别推导出双轴陀螺平台的支架误差公式，发现由这两种方法推导出来的公式计算结果是一致的。
Methods of spherical trigonometry and direction cosine matrix were applied respectively to derive the bracket error, and the two methods had the same error formula and the same calculation results.
应用球面三角法和方向余弦矩阵法分别推导出双轴陀螺平台的支架误差公式，发现由这两种方法推导出来的公式计算结果是一致的。
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