Abstract: Stiction is the most common problem in control valves，which causes oscillations in control loops.This paper proposes a spectral method based on Discrete Fourier Transformation to detect valve stiction for diagnosis of oscillations.The spectral method can be used for both self-regulating processes and integrating processes.The effectiveness of the proposed method is demonstrated with the studies of simulation.

Key words: stiction, control valve, spectrum analysis, Fourier series

摘要： 控制阀粘滞特性是导致控制回路振荡的主要原因之一，对控制阀粘滞特性进行了详细分析，在此基础上使用离散傅里叶变换分析振荡的偏差信号，提出了一种频域分析、适用范围较广的控制阀粘滞特性检测方法。通过仿真研究，表明了该方法的有效性。

关键词: 粘滞特性, 控制阀, 频域分析, 傅里叶级数