Metal Label Detection Based On Eddy Current Technology

With the development of networking technology, it is becoming increasingly important to classified, information, discriminated, and recognition things. In the traditional identification technology, which application is limited in some eras, therefore, it is becoming increasingly important that the new identification is developed to adapt to market demand. Among them, Metal tag detection and identification systems are more and more the majority of electronics manufacturers, electronics manufacturers and other enterprises attention. It is based on metal as a carrier, and which is used for recording information labeling system, therefore, the study of metal symbolic information recognition technology is particularly important. In this design, the theoretical study of the non-destructive testing by eddy current testing technology, the use of eddy current coil, combined with the principle of non-destructive testing circuit design, design eddy current probe and data collection platforms, completed the metal sign detection and recognition system.This paper describes the basic principle of eddy current testing, the basic model and some influencing factors. With the current embedded technology, in order to achieve the detection and identification of metal tag system, the introduction of the eddy current sensor detection technology and metal tag identification technology, through in-depth analysis of metal detection and identification tags of two parts, the use of eddy current coil as a signal detection sensors to embedded systems as the control center of the whole system is designed data acquisition platform and metal tag identification algorithm, write algorithm code, verify the metal tag detection and identification systems. Depending on the structure of the eddy current coil arrangement, the coil design suitable vortex sensor network, eddy current detection signal, the pre-amplifier design, the eddy current signal was amplified. The phase detection circuit was designed to detect the signal of the magnetic field, which is converted into DC voltage, and then through the low- pass filter and a differential amplifier circuit, complete DC voltage and de-noising, zero, amplification, and ultimately the detection of metal tag signal. According to the rules of codecs metal label, designed codec algorithm, and then the variation detection signal coding techniques were investigated and the probe signal decoding technology effectively extract character recognition on the metal, and the metal surface to achieve the different size detection and identification tags.