基于漏磁检测机理的钢丝绳小缺陷精确化识别系统研究

Research on Precise Recognition System of Steel Wire Rope’ Small DefectsBased on Magnetic Flux Leakage Testing Method

摘要:

针对电磁检测法中钢丝绳小缺陷产生的漏磁信号比较微弱、往往容易漏检,采用STM32处理器及AD7606模数转换等器件设计了钢丝绳小缺陷精确化识别系统。在硬件上,采用了稳定的双励磁回路结构,多通道均匀密布的集成HALL元件拾取漏磁信号,经微弱信号放大滤波,小距离等间隔采样,高精度数据采集等方法提高信噪比；在软件上,采用了FFT、数字滤波剔除股波干扰。经试验表明,该系统能够较准确地检测钢丝绳上的小缺陷,同时也能检测大的缺陷,准判率大于90%,较好地满足了现场钢丝绳检测要求。

Abstract:

Aiming at the weak magnetic flux leakage signals generated by small defects of steel wire rope in electromagnetic detection method, which were often easy to be missed, an accurate identification system for small defects of steel wire rope was designed by using STM32 processor, AD7606 analog-to-digital conversion and other devices. In hardware, a stable double excitation circuit structure was adopted, multi-channel uniform and densely distributed integrated HALL elements picked up magnetic leakage signals, and the signal-to-noise ratio was improved by methods such as weak signal amplification and filtering, small-distance equidistant sampling, high-precision data acquisition, etc. In the software, FFT and digital filtering were used to eliminate the interference of the wave. Tests show that the system can accurately detect small defects on steel wire ropes, and can also detect large defects. The accurate judgment rate is more than 90%, which is better satisfied to the requirements of on-site steel wire rope detection.