在捷联寻北中采用正切查表法需要的制表空间大且代码执行效率较低,不便于采用单片机的实现方位角解算。将最小二乘线性拟合原理应用于反正切函数的分段线性化中,得到了不同精度的分段线性方程;通过仿真分析了该快速正切算法的计算误差;通过计算得到了不同精度时的分段数;通过比较得出了不同精度时在制表空间上相对于正切查表法的优势。研究表明该算法简捷快速,能有效提高代码的执行效率,节省大量的制表空间。

SINS north-seeking needs large table storage and the code is inefficient based on the method of looking-up table to calculate the arc tangent function. The piecewise linear equations were found by application the principle of the least square linear fitting to the arc tangent function: the calculation error of this algorithm was analyzed; the number of piecewise linear equations was calculated; the advantage of this rapid algorithm in the table storage was elicited through comparing with the method of directly looking-up table. The research shows that this algorithm is simple and fast and space-saving, and can effectively boost the code efficiency.