基于傅里叶级数分解的示功图位移测量算法

提出一种基于傅里叶级数分解的加速度、速度和位移转换算法. 在抽油机示功图位移测量中,传统的二重积分算法存在初始条件不确定的问题,这将导致位移不闭合. 通过对加速度、速度和位移进行傅里叶级数分解,直接利用级数间的关系实现二重积分,能有效克服上述初始条件不确定的问题. 利用能量主要集中在低频的特点,给出了快速转换算法,同时还提高了算法的信号处理增益和抗噪声性能. 对现场实验数据的分析结果表明,该算法可以快速实现加速度、速度和位移之间的转换,能有效应用于油井示功图的位移测量中. 

A Dynamometer Card Displacement Testing Algorithm Based on DFT

A conversion algorithm of acceleration, velocity, and displacement based on Fourier series decomposition was proposed. Uncertainty of initial conditions exists in the traditional double integral algorithm, thus leading disclosure of dynamometer card. It will be effectively solved by decomposing acceleration, velocity, shift in Fourier series and directly using the relationship of Fourier series to achieve double integral. A fast conversion algorithm was raised to improve signal process gain and anti-noise performance based on the feature that energy was mainly distributed in the low frequency. The analysis of experimental results shows that the algorithm can achieve the conversion of acceleration, velocity and displacement and can also be applied in testing the dynamometer card displacement in oil well.