改进的数据采集系统性能测试的正弦拟合法

在一般正弦拟合法的基础上，提出正弦信号源谐波失真时测试Ａ／Ｄ动态性能的一种新的近似求解法。利用循环逼近拟合残差最小值的方法求得正弦拟合函数，要用二分法提高算法的收敛速度，此方法既剔除了信号源谐波失真对系统性能测试的影响，又可避免一般正弦拟合法中求解非线性方程组的麻烦，同时还能满足ＡＤＣ性能测试的精度要求，测试实例分析表明了此方法的有效性。

An Improved Sine Fitting Test for the Data Acquisition System

On the basis of studying the general method of sine fitting, a new approach of testing the A/D dynamic characteristic with the harmonic distortion existing is put forward. This approach uses the idea of circularly approximating the minimum of the fitting error to get the function of sine fitting. At the same time, dichotomy is used to improve the algorithmic velocity. It not only gets rid of the influence of harmonic distortion but also avoids the trouble of getting the solution of nonlinear equations, and it can satisfy the precise demand of ADC. The analysis of testing example shows the efficiency of this method.