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.