3D Surface Temperature Field Reconstruction Based On Thermal Paint

Thermal paint is a temperature-sensitive paint.When thermal paint covers the surface of the object,Its color changes permanently with the temperature of the object.It can be used to detect the maximum temperature the object experienced by observing its color.It is widely used in the surface temperature measurement of aeroengine's high-temperature parts.The image-based automatic interpretation technology can quickly obtain the thermal paint temperature distribution by means of image segmentation and machine learning.However,the 2D interpretation results are inconvenient for the designer to directly compare with the 3D surface temperature field obtained by the simulation calculation.This thesis realizes 3D surface temperature field reconstruction to achieve the goal of improving the visibility of the interpretation results by combination of the thermal paint automatic interpretation technology and the 3D reconstruction technology.Firstly,By researches on the algorithm principle,reconstruction precision and application of common 3D reconstruction methods,a scheme of 3D surface temperature field reconstruction combining depth camera and SLR camera is proposed: depth camera is used for object surface reconstruction,SLR camera is used for thermal paint automatic interpretation,and the temperature interpretation result is mapped to the surface to obtain the 3D surface temperature field model.Then,in order to verify the feasibility of the scheme,this thsis uses Kinect's depth camera and color camera to develop a schematic exploration implementation,which explains the methods and principles of two camera calibration,depth image filtering,pointcloud segmentation,registration and fusion,surface reconstruction,the thermal paint temperature interpretation and mapping.Finally,the principle test platform was built and tested.The accuracy of 3D reconstruction was verified by bench and small box.The texture mapping was verified by plush bears.The 3D surface temperature field reconstruction based on thermal paint was verified by flame tube simulation.The 3D reconstruction can flexibly adopt two different ways of hand-held and rotating towards to the different sizes of the objects.The error of the reconstructed model size is about 1.5 cm compared to the real object.The 3D temperature field reconstruction can be correctly displayed on the 3D surface model,which verifies the feasibility of the proposed algorithm.