基于红外成像的FDM打印轨迹测量及质量评价方法

FDM printing trajectory measurement and quality evaluation method based on infrared imaging

熔融沉积型(fused deposition modeling, FDM)增材制造是一个热加工过程,打印温度与运行精度的研究是2个相对独立的方向,红外成像中高温熔丝的形状信息通常得不到有效的利用,无法在温度监控的同时对打印设备的实时运行状态进行检测。提出了一种基于红外成像的FDM打印轨迹测量及质量评价方法,采用红外相机对FDM打印机的热加工过程进行连续测量,通过建立打印机系统坐标系与相机世界坐标系的位姿解算模型,以及动态帧间红外特征匹配的全局相机运动位姿解算模型,实现了对末端喷嘴运行位姿的实时测量,得到了精确的打印轨迹信息。在此基础上,建立了空间打印轨迹与红外图像中高温熔丝间的物像映射关系,并在图像域对打印过程中的典型缺陷进行了质量评价,其中图像处理平均耗时为25.9 ms,红外相机位姿测量的重投影误差为0.7像素,正常打印状态下,系统计算得到的理想打印轨迹与红外图像内高温区域的平均交并比为0.61。实验结果表明,该方法能够对打印过程中出现的模型错位、出料异常等典型问题进行准确识别,为打印质量在线评价的相关研究提供了一种新的解决途径。

Fused deposition modeling(FDM)is a hot working process,the research on temperature and motion accuracy in the printing process are independent directions,and the shape of the high temperature filament in the infrared image is usually not concerned,making it impossible to detect the operating status and temperature of the printer at the same time.An FDM printing trajectory measurement and quality evaluation method based on infrared imaging was proposed.The method adopted infrared camera to continuously monitor the FDM printing process,and established the pose solution model of the printer coordinate system and the camera world coordinate system,as well as the global camera motion pose solution model matching the infrared features between dynamic frames.The real time measurement of the running position of the end nozzle was realized,and the accurate print trajectory information was obtained.On this basis,the object image mapping relationship between the spatial print trajectory and the high temperature filament in the infrared image was established,and the quality of the printing process and typical defects were evaluated in the image domain.The average time of image processing was 25.9 ms,and the reprojection error of infrared camera posture measurement was 0.7 pixel.Under normal printing conditions,the average IoU between the ideal print trajectory calculated by the system and the high temperature region in the infrared image is 0.61.The experimental results show that the proposed method can accurately identify the typical problems such as model dislocation and abnormal extruding in the printing process,which provides a new solution for the related research of online print quality evaluation.