Design And Experimental Study Of ACFM Detection System Based On ARM

ACFM detecting technology has gradually become an important transplantation method of the nondestructive testing, because of its non-contact measurement, fast detection speed and detection accuracy.Widely using in various industries makes the direction of developments in ACFM detecting instrument becoming more and more digital, intelligent and miniaturization. With the rapid development of the computer technology, the embedded technology and the combination of ACFM detection technology has become a new direction of development of intelligent instrument.Firstly, this paper analyses the situation of the ACFM detection technology at home and abroad, then describes the basic principle of ACFM detection, and study the mathematical model of ACFM detection. Combined with the current development of domestic and international ACFM testing instruments, this paper has designed a set of ACFM detection system based on embedded ARM9. The main content is divided into two parts of hardware and software.The system hardware consists of signal acquisition circuit, signal generator, the embedded processor S3C2440 and embedded processor module. Among them, the signal acquisition circuit mainly comprises a detecting probe, signal processing circuit and AD conversion circuit. The signal generator includes DDS signal module and power amplifier circuit. The processor module mainly consists of S3C2440 processor and processor peripheral interface circuit.The software part of the system mainly includes the processing of building and developing environment and application for embedded system.Because this embedded software development model adopts host/target mode. The building of host development environment and running environment of the target machine is necessary. Finally, using Qt Embedded GUI development tool to achieve the design of ACFM interfacing detection system.According to the actual testing requirements, this paper designed experiments for ferromagnetic and non-ferromagnetic material respectively, and then verified the basic function of this detection system. Finally, doing testing for pressure vessel weld crack, which compared with the ultrasonic testing results, further verified the accuracy and reliability of this detection system.