Department of Mechanical and Electrical Engineering, Xiamen University, Xiamen 361005, China.
State Key Laboratory of High-Performance Complex Manufacturing, Central South University, Changsha 410083, China.
Sensors (Basel). 2022 Dec 27;23(1):265. doi: 10.3390/s23010265.
The precise three-dimensional measurement of fuel nozzles is of great significance to assess the manufacturing accuracy and improve the spray and atomization performance. This paper proposes an improved fast shape from focus (SFF) method for three-dimensional measurement of key features of fuel nozzles. In order to ensure the measurement accuracy and efficiency of the SFF, the dispersion of the measured points from a standard flat plane was used to select the optimal combination of the focus measure operator, window size and sampling step size. In addition, an approximate method for the focus measure interval is proposed to improve the measurement efficiency, which uses the peak region of the central pixel to replace the peak region of other pixels. The results show that the proposed method decreased the average computation time of the focus measure by 79.19% for the cone section and by 38.30% for the swirl slot. Compared with a reference laser scanning microscope, the measurement error in length is within 10 μm and the error in angle is within a maximum 0.15°.
精确测量燃油喷嘴的三维形状对于评估制造精度和改善喷雾及雾化性能具有重要意义。本文提出了一种改进的快速聚焦形状（SFF）方法，用于测量燃油喷嘴关键特征的三维形状。为了确保 SFF 的测量精度和效率，使用测量点相对于标准平面的离散度来选择最佳的聚焦度量算子、窗口大小和采样步长组合。此外，还提出了一种聚焦度量间隔的近似方法，以提高测量效率，该方法使用中心像素的峰值区域来代替其他像素的峰值区域。结果表明，与参考激光扫描显微镜相比，该方法使圆锥段的聚焦度量平均计算时间减少了 79.19%，旋流槽段的聚焦度量平均计算时间减少了 38.30%。在长度测量方面，测量误差在 10μm 以内，角度测量误差最大为 0.15°。
