Improving the measurement accuracy of an absolute imaging position encoder via a new edge detection method
Improving the measurement accuracy of an absolute imaging position encoder via a new edge detection method
复制标题
通过新的边缘检测方法提高绝对成像位置编码器的测量精度
DOI：
10.1049/iet-smt.2016.0181
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发表时间：
2017-07-01
影响因子：
1.4
通讯作者：
Ling, Bingo Wing-Kuen
中科院分区：
文献类型：
--
作者：
Cai, Nian;Xiao, Pan;Ling, Bingo Wing-Kuen
为了提高绝对成像位置编码器的测量精度，开发了一种基于经验模式分解（EMD）的新型边缘检测方法来准确检测光栅线的边缘。首先，根据绝对位置编码图像（APCI）的特点，通过常规灰度变换实现灰度APCI的垂直投影。然后，通过EMD方法分解垂直投影轮廓，得到有限数量的本征模态函数(IMF)。接下来，使用最后两个IMF来描述投影轮廓的趋势。该趋势被用作自适应阈值，将垂直投影轮廓划分为不同的区间。最后，应用垂直投影轮廓的二阶导数来获得每个间隔中的准确边缘。实验结果表明，与现有的边缘检测方法相比，该方法对重噪声、不良光照和斜率具有更强的鲁棒性。此外，所提出的方法比现有方法实现了更好的测量精度。
To improve the measurement accuracy of an absolute imaging position encoder, a novel edge detection method is developed to accurately detect the edges of grating lines based on empirical mode decomposition (EMD). First, according to the characteristics of the absolute position coding image (APCI), the vertical projection of the grey-level APCI is achieved by conventional grey-level transformation. Then, the vertical projection contour is decomposed by an EMD method and a finite number of intrinsic mode functions (IMFs) are achieved. Next, the last two IMFs are used to describe the trend of the projection contour. The trend is used as adaptive thresholds to divide the vertical projection contour into different intervals. Finally, the second derivate of the vertical projection contour is applied to obtain the accurate edges in each interval. Experimental results indicate that the proposed method is more robust to heavy noise, bad illumination and a slope compared with the existing methods with respect to edge detection. Also, the proposed method achieves better measurement accuracy than the existing methods.