Research On Remote Field Eddy Current Testing System Based On FPGA

Pipelines are important transportation facilities and they play an important role in the national economy. Therefore, the non-destructive inspection on pipelines features huge economic value. As an emerging technology for inspecting pipelines, the REFC technology has many advantages, for example, not easily affected by the lift-off effect of probes and environment. Thus, this technology is promising in non-destructive inspection on defects in pipelines. With increasingly deep researches for years, a great progress has been made in the theory of remote field eddy current, but practical and available solutions are actually imperfect and are restricted in actual use. The SOPC technology is a promising technology developed in recent years. It can integrate various components into a programmable device to form a programmable system on a chip. Based on the previous consideration, this paper describes how to design and implement a complete solution for inspecting remote field eddy current in ferromagnetic pipelines by using Altera's FPGA chip as the core device and Altera's SOPC technology.This paper introduces the theoretical basis for inspecting remote field eddy current in ferromagnetic pipelines and provides a complete design solution based on the characteristics and theory of remote field eddy current. Then, this paper describes how to construct a platform for the remote field eddy current inspection solution, including system configurations and software design. The paper details the key parts of the design, for example, the DDS of the analyzer and the component for signal collection. The DSP Builder is used to design and implement a digital signal generator, and the Verilog HDL is used to design and implement the data collection module. Thanks to using the FPGA as the core device, the design solution integrates signal excitation, data collection, and data processing on the same chip, which makes the design more flexible and simple, and improves the efficiency of the system. As compared with traditional researches, all performance indexes of the system are greatly improved. Finally, the implemented remote field eddy current inspection analyzer is used to inspect ferromagnetic pipelines with artificial defects. As a result, an excellent result is obtained.Experimental results show that the inspection speed and precision of the system are greatly improved after the SOPC technology is applied to the remote field eddy current inspection system. In addition, the system is optimized in many aspects, such as in size, reliability, performance indexes, development cost, product maintenance, and hardware and software upgrade.