Design Of Electromagnetic Tomography System In OPC Service Mode

Electromagnetic tomography (EMT) technology is a new kind of process tomography technology (PT) based on the principle of electromagnetic induction. The basic principle of the EMT technique is when the alternating magnetic field stimulates the object space that contains conductive or magnetic incentive material from different angles, the conductive incentive material in the field would generate electric eddy current with different intensity according to its own electric conductivity, and the magnetic incentive material would produce different intensity inducting magnetic according to their permeability. Both the eddy currents and induced magnetic fields can affect the distribution of the electromagnetic properties of the object space. If the detection coil can obtain object space magnetic field distribution respectively from different directions, after contrasting to the data of empty space, the distribution of conductive and magnetic materials in the field can be reconstruct by data processing and image reconstruction.In this paper, the EMT forward problem and inverse problem are analyzed based on the theory of electromagnetic tomography. Combined with the research of EMT electromagnetic tomography system at home and abroad, a new structure of the EMT system that is more suitable for the industrial field is put forward. This kind of structure is verified further by an online electromagnetic tomography system that designed and programmed in OPC service mode. The experimental results show that the stability of the EMT system of the OPC service mode has been greatly improved. And the speed of generating an image is increased by several times.The specific content of this paper are as follows.1. This paper introduces the electromagnetic tomography technology research status at home and abroad, analyzes the principle and mathematical model of forward problem and inverse problems of electromagnetic tomography according to the basic theory of electromagnetic tomography. Then this paper analyses the disadvantages that EMT system structure may exist, and puts forward the corresponding solutions.2. This paper mainly make a concrete analysis of component and corresponding functions of an EMT system. And then points out impact of every component performance to the EMT system. The electromagnetic tomography system in OPC service mode (EMT OPC UA) with a new mode data transmission is designed. Then introduces the EMT OPC UA system structure, information model, data transmission etc. Finally, the steps of establishing EMT OPC UA server and client are illustrated, and the operation of EMT system imaging are described.3. According to the characteristics of EMT OPC UA technology, the design of electromagnetic tomography system in OPC service mode can bring to the enhancement of EMT technology. In order to build a perfect framework for the expansion of OPC UA EMT, an idea and implementation platform of parallel computing for EMT OPC UA system is presented.