International Society for Industrial Process Tomography

New developments for an on-line FPGA-based Electromagnetic Tomography (EMT) System

Jianxing Xu², Ziqi Chen¹, J R Salas-Avila¹, Yining Zhang¹, Wuliang Yin^1*, Yuedong Xie³, Shupei Wang⁴, Mingyang Fan², Haibin Hao² and Jiyao Li³

¹Department of Elec. and Electronic Engineering, University of Manchester, Manchester, M13 9PL, UK

²Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, PR China

³School of Instrument Science and Opto-electronic Engineering, Beihang University, Beijing, China

⁴Manchester Advanced Intelligent Equipment Research& Innovation Centre Ltd, Manchester, UK

^*Email: wuliang.yin@manchester.ac.uk

ABSTRACT

This paper presents an FPGA-based digital MIT (Magnetic Induction Tomography) system designed for online real-time monitoring in the metal production industry. A Zynq-7020 Soc-based module is used to generate excitation signal, implement I/Q demodulation, control channel multiplexing and the communication with a host PC. All the hardware has been integrated together in a standard 19inch rack instrument with the size of 25mm×33mm×15.5mm. The excitation signal frequency covers a wide range from 0.1 Hz to 500 kHz. When fitted with an 8-coil MIT sensor, the system is capable of real-time imaging with a fast speed of 131 frames/s and typical SNR of between 65 dB – 92 dB.. A high temperature sensor is designed with cobalt-oxide as formers, which can be used for process in excess of 1200 degrees. A Graphical User Interface (GUI) based on LabVIEW situated on the host PC is designed for communicating with the instrument and perform real time imaging reconstruction with an LBP algorithm. Additional algorithms such as Tikhonov regulation, SVD (singular value decomposition) and SIRT (Simultaneous Iterative Reconstruction Technique) are implemented in MATLAB for offline data analysis and further image processing. During the experiments, the system has been tested in a molten converter slag solidification process gaining useful new insights.

Keywords: Electromagnetic Tomography, High Temperature Electromagnetic Sensor, Online Imaging

Industrial Application: Melting Process Monitoring, Industrial Tomography