基于CCD图像传感器的高温温度场非接触软测量研究

【作者】 孙元；

【导师】 彭小奇；

【作者基本信息】 中南大学 ， 电路与系统， 2007， 硕士

【摘要】 基于CCD(电荷耦合器件)图像传感器的非接触高温温度场软测量方法将CCD技术、数字图像处理技术与传统辐射测温方法相结合，能够实现快速、准确的高温场测量，显著提高测量技术水平，因而成为高温检测领域近年来的研究热点。本文在研究分析CCD辐射测温的研究历史和现状的基础上，通过深入的理论分析与大量的实验研究，提出了一种新型的基于CCD图像传感器的高温场软测量方法。取得了如下的研究成果：1．提出了一种新型的含有CCD响应带宽校正系数和发射率校正系数的比色测温公式。以此为基础构建的高温场软测量系统可以减少CCD光谱响应特性非理想和被测辐射体发射率变化带来的测量误差。2．提出了利用黑体炉实验标定CCD响应带宽校正系数、利用现场实验标定发射率校正系数的方法。实验表明，该方法能有效地减小测温误差，具有较强的实用性。3．提出了一种基于高温辐射体颜色信息的图像目标识别方法。通过对红、绿基色图像分别进行分割来减小甚至消除高温辐射体图像的各种噪声，然后综合红、绿基色图像分割结果实现高温辐射体的准确识别，并运用数学形态学方法对分割结果进行后处理以消除游离点和孔洞，使图像边缘平滑。实验表明，该方法可以快速有效地实现高温辐射体的正确识别。4．通过理论推导和实验研究指出，在摄像头前加中性滤光片可以扩大CCD的测温范围，但是扩大的程度有限，且测温下限随滤光片透过率的减少而上升。5．提出利用调节光圈和快门组合的方法扩大CCD的测温范围，并通过实验验证了该方法的有效性。6．在研究测温系统标定实验原理的基础上，提出了标定实验方案，研发了标定实验系统和基于CCD的高温场软测量实验系统，并完成了对测量系统的标定。7．在上述工作的基础上，利用基于CCD图像传感器的高温场软测量系统对工业现场的高温熔体进行了测温实验。实验结果表明，所研发的高温场软测量系统测温精度较高，具有较强的实用性和推广价值。更多还原

【Abstract】 The contactless soft measurement technology of high-temperaturefield based on CCD (charge-coupled device) image sensor, whichcombines the CCD technology, digital image processing and traditionalradiation thermometry, has the characteristic of measuring temperaturefield rapidly and accurately, and enhances the level of measurementtechnology significantly. Therefore, it becomes the research hot point inthe high-temperature measurement field recently. A new method forhigh-temperature field soft measurement based on CCD image sensor isproposed from the research of history and present situation for CCDthermometry, theoretical analysis, and a mass of experiments. The mainresults for the research are as follows:1. A new type of two-color thermometry formula is proposed, whichcontains the revision coefficients of emissivity and CCD response bandwidth. And then a soft measurement system of high-temperature field isconstructed based on that formula, which can reduce the measurementerrors resulted from the emissivity of a measured object changing and thenonideal CCD spectrum response characteristic.2. A new calibration method is proposed, which calibrates CCDresponse band width revision coefficients and emissivity revisioncoefficient by the blackbody furnace experiment and locale experimentrespectively. The experiments show that the method could reduce themeasuring error effectively and has the strong usability.3. An image recognition method for high-temperature radiator isproposed, which based on the color information of a high-temperatureradiator. By segmenting the red and green color images, the variousnoises in high-temperature radiator color image are reduced or eveneliminated. And then, by synthesizing the results of the red and greencolor image segmenting, the high-temperature radiator is recognizedaccurately. Finally, in order to smooth the image’s edge, the morphologymethod in mathematics is applied to process the segmented image andremove the dissociations and narrow holes. The experiments show that the method can recognize high-temperature radiator with high accuracyand practicability.4. Theoretical analysis and experimental research indicate that usingneutral filter can expand CCD measuring range with limited effect.Furthermore, the lower limit of temperature measurement will rise withthe reducing of filter transmittance.5. CCD measurement range can be expanded by adjusting thecombination of aperture and shutter automatically. The experimentalresults prove the practicability of the method.6. Based on the research of calibration experiment principle oftemperature measurement system, the calibration experiments are planed.Then the calibration experiment system and high-temperature fieldmeasurement system based on CCD are built. Finally the measurementsystem is calibrated.7. On the basis of above works, a high-temperature field softmeasurement system based on CCD image sensor is used to measuretemperature of high-temperature metal melt in industrial locale. Theexperimental results indicate the system can measure temperature withhigh accuracy, practicability and promotion values.更多还原