测试科学与仪器2023，Vol.14Issue(4)：452-462,11.DOI:10.3969/j.issn.1674-8042.2023.04.008
基于FPGA的实时线结构光传感器激光条纹中心提取方法
A real-time laser stripe center extraction method for line-structured light system based on FPGA
摘要
Abstract
Laser stripe extraction serves to be a crucial technique in the line-structured light system, and its accuracy and speed are directly related to the measurement performance. However, the traditional Hessian matrix method may produce redundant centers and missing centers, which will limit its accuracy and robustness. Besides, the complex calculation of the method makes it difficult to be applied in real-time measurement. In order to overcome these issues and achieve real-time center extraction, an improved FPGA-friendly laser stripe center extraction method is proposed. A novel judgment function is designed to replace the maximum eigenvalue, and the numerical difference between the centers and the other domains is more salient. The center judgment criteria are modified and the non-maximum suppression is used to deal with the redundant and missing centers. Furthermore, the proposed method is implemented in FPGA to achieve real-time processing. The calculations are rationally optimized to reduce resource utilization and delay time without reducing the accuracy. The mean absolute errors are 0.0039 pixel, 0.0373 pixel, 0.0520 pixel, and 0.0646 pixel, and the root mean square deviations are 0.0068 pixel, 0.0469 pixel, 0.0654 pixel, and 0.0811 pixel, respectively, in the accuracy experiment with the noise deviations of 0, 0.01, 0.02, and 0.03. The running and delay time of the proposed method in FPGA are 14.89 ms and 216.42 μs. The experimental results verify that the proposed method is highly accurate, robust, and time-efficient.关键词
激光条纹中心提取方法/Hessian矩阵法/多余中心点和缺失中心点/现场可编程门阵列(FPGA)/线结构光传感测量系统Key words
laser stripe extraction method/Hessian matrix method/redundant and missing centers/field programmable gate array (FPGA)/line-structured light system引用本文复制引用
苏中元,康杰虎,冯橹源,李泓彤,张振,孙泽峰,吴斌..基于FPGA的实时线结构光传感器激光条纹中心提取方法[J].测试科学与仪器,2023,14(4):452-462,11.基金项目
National Natural Science Foundation of China(No.62071325) （No.62071325）
Open Foundation of Beijing Laboratory of Optical Fiber Sensing and System(No.GXKF2022001) （No.GXKF2022001）
