Research And Implementation Of The Temperature Field Monitoring System For Intelligent Microwave Heating Based On Image Analysis

Microwave, as a clean and efficient energy, can solve growing levels of pollution and energy problems. But in the process of industrial production, the use of high-power microwave will cause hot spots, thermal runaway, or even explode. Therefore we need to achieve intelligent control of microwave, to ensure the safe and efficient use of microwave energy. Accurate temperature information is the basis for intelligent control, and there are many methods to monitor temperature in microwave oven, for example, optical fiber and infrared temperature measurement and ultrasonic thermometry. But these methods suffer from high attrition rate locality, or difficulty in installation problems. To solve the problems, we propose a temperature monitoring approach using image processing and colorimetric technique. We firstly get real-time image from camera and remove noise from the image; secondly, select out the heating object area through image segmentation; finally, calculate the target zone temperature with a colorimetric technique based temperature-gray model. To evaluate the proposed approach, we established a microwave system with camera and fiber, developed temperature measurement software to process image, reconstruct temperature field, and visualized the temperature field for the heating object in the microwave oven. The experiments show that the proposed approach is non-contact with low cost, easy to installation, and accurate on the reconstruction for the entire temperature field.The main work of the paper can be summarized as follows:①Analysis of the present situation and existing problems of a variety of temperature measuring method existing in microwave environment, such as the price is too expensive, temperature measuring locality, then put forward the research purpose is to realize the real-time monitoring of the temperature field of microwave heating based on image temperature measurement;②By relevant technical analysis, we determined to use MATLAB to do the image processing and real-time temperature field calculation, and select Unity3 D to establish microwave oven 3D model. The development language of the whole system was C#. And by the MATLAB and C# hybrid programming, Unity3 D and C# hybrid programming, the temperature measurement and 3D model were integrated into the monitoring system;③After the analysis of the image processing and temperature measurement model based on image gray, establish the corresponding relationship between image gray and temperature, calibration of the parameters in the temperature measuring formula by experiment, then use the linear regression to correct the parameters, and put forward the fusion temperature measuring method, which improved the temperature measurement precision, and then reconstruct the real-time computing temperature field according to the temperature measurement formula;④After the analysis of the hot spots 3D Coordinates calibration method, put forward the improved algorithm of the Harris feature points extraction algorithm, which improved the accuracy of feature point detection. Then establish the corresponding relationship model between two-dimensional image coordinates and three-dimensional physical coordinates, to calculate the 3D coordinate of the highest temperature point;⑤After implementing the measuring temperature model based on image and hot calibration model, use the selected development tools to implement the microwave heating temperature field monitoring system, establish the real-time temperature field, do the real-time monitoring for the hot spots, and do system software testing.