基于线结构光的圆柱型筛框缝宽尺寸检测系统研究

Research on Cylindrical Screen Frame Slit Width Measurement System Based on Line Structured Light

摘要:

由于缝宽尺寸直接影响筛缝的过滤能力和筛分精度，为确保纸浆的处理质量，提高筛缝缝宽检测效率，提出了一种基于线结构光扫描的圆柱型筛框筛缝检测技术；搭建筛框回转实验平台，采用直射式激光三角测量法采集筛框间隙轮廓信息，针对金属表面高反光等图像噪音的难点，结合了中值滤波、双边滤波和自适应权重调整的图像预处理方法，利用基于大津法的灰度图阈值分割法，确定最优的阈值，提取光斑区域，利用Steger算法提取激光光条中心线；测量系统对10条筛缝的16组尺寸进行了重复精度测量，结果显示极差最大为0.27 mm，最大标准差为0.012 466 mm，通过对比系统测量值与人工实测值，最大误差值为15 μm；经实验测试验证了激光扫描法在旋转平台带动筛框恒速转动时筛缝尺寸测量的可行性，对提高纸张的质量和筛框的筛分效率具有很大生产效益和经济效益。

Abstract:

The slit width directly impacts the filtering capability and screening accuracy of screen frames. To ensure the processing quality of pulp and enhance the efficiency of slit width detection, a cylindrical screen frame slit detection technology based on line structured light scanning is proposed. A rotary experimental platform was constructed, employing a direct laser triangulation method to capture the profile information of the screen frame gaps. To address challenges from high reflectivity on metal surfaces and image noise, the system combines median filtering, bilateral filtering, and adaptive weight adjustment in the image preprocessing stage. Using Otsu's grayscale threshold segmentation method, the optimal threshold is determined to extract the light spot region, and the Steger algorithm is applied to extract the laser stripe centerline. The measurement system performed repeatability tests on 16 sets of sizes from 10 slits, showing a maximum range of 0.27 mm and a maximum standard deviation of 0.012 466 mm. Comparing system measurements with manual measurements revealed a maximum error of 15 μm. Experimental testing verified the feasibility of this laser scanning method for slit width measurement while the screen frame rotates at a constant speed on the rotary platform. This method provides substantial production and economic benefits by enhancing paper quality and the screening efficiency of the screen frame.