Real Time Recognition Of Weak And Small Target In Magnesium Melt And Design Of Measurement And Control System

This paper was depended on the National Natural Science Foundation of China “The automatic detection method and experimental study of hydrogen content in magnesium melt based on real-time image processing”(51374007).Detection of hydrogen content in magnesium melt is an important step to ensure the quality of magnesium alloy castings,the real-time identification of the first bubble on the surface of magnesium melt and the automatic detection of the hydrogen content in magnesium melt are the key points and difficulties of the whole problem,therefore,it is significance to study the first bubble detection algorithm and the automatic detection method of hydrogen content.Firstly,the characteristics of the first bubble in the magnesium melt image were studied;secondly,combining the advantages of semi-causal support region and background prediction algorithm;then,a first bubble detection algorithm for magnesium melt based on E shape semi-causal support region and double-layer pipeline is proposed;finally,using MATLAB tools to simulate the algorithm,the simulation results show that the algorithm not only can detect the first bubble target,but also has more advantages in image noise suppression and real-time performance.Aiming at the problem of the algorithm based on E shape semi-causal support region and double-layer pipeline is limited to MATLAB simulation,the algorithm is transplanted to the DSP platform through software programming,then,in order to solve the problem of the automatic detection of hydrogen content in magnesium melt,two kinds of hydrogen content measurement and control system for magnesium melt were designed,one considers DSP as an image processing unit,PLC as control unit,then design the communication hardware circuit based on digital I/O and MODBUS RTU protocol,the other considers DSP as an image processing unit,GTS-400 series motion controller as control unit,and the communication hardware circuit based on digital I/O and RS232 interface is designed respectively,finally,the image processing unit and control unit of the two systems are programmed by software,experimental results show that the two systems can not only successfully detect the first bubble of magnesium melt,but also after the image processing unit detect the first bubble,the control unit can respond quickly and output according to the program,the communication between image processing unit and control unit is realized successfully.The algorithm based on E shape semi-causal support region and double-layer pipeline successfully detected the first bubble of magnesium melt on MATLAB platform and DSP platform,it has important guiding significance for real-time identification of the first bubble in magnesium melt,in addition,design and communication realization of measurement and control system based on DSP and PLC,DSP and motion controller,it is of great scientific value and far-reaching significance to explore the method of automatic detection of hydrogen content in magnesium melt.