Alignment of a flexible sheet object with position-based and image-based visual servoing
Alignment of a flexible sheet object with position-based and image-based visual servoing
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DOI：
10.1080/01691864.2016.1183518
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发表时间：
2016-05
影响因子：
2
通讯作者：
S. Kagami;Kotaro Omi;K. Hashimoto
中科院分区：
文献类型：
--
作者：
S. Kagami;Kotaro Omi;K. Hashimoto
本文描述了视觉伺服方法，以对齐一个灵活的片状物体，如纸张的端部边缘到一个指定的线段在3D空间。为了操纵端部边缘的姿态，这可能是远离一个灵活的片材上的机器人手的抓取点，我们将在线估计的端部边缘和机器人手之间的相对姿态到视觉伺服控制律。定义了两种待调节的特征值，基于位置的特征值和基于图像的特征值。基于位置的一个由3D姿态参数的结束边缘，这是通过拟合多项式表面模型立体测量的边缘点周围的片材估计。基于图像的一个由图像像素值的狭窄区域内的结束边缘。通过数值模拟，我们确认，基于位置的功能是有效的，在实现快速响应，而基于图像的功能是强大的测量噪声。为了联合收割机这些对比的行为，我们引入了基于位置和基于图像的特征的加权组合。实验结果表明，基于位置的方法和加权组合方法都能很好地工作，并表明加权组合方法可以减少最终的对准误差。图形摘要
This paper describes visual servoing methods to align an end edge of a flexible sheet object such as paper to a specified line segment in 3D space. In order to manipulate the end edge pose which may be distant from a grasping point by a robot hand on the flexible sheet, we incorporate online estimation of the relative pose between the end edge and the robot hand into visual servoing control laws. Two types of feature values to be regulated, position-based and image-based ones, are defined. The position-based one consists of 3D pose parameters of the end edge, which are estimated by fitting a polynomial surface model to stereo-measured edge points around the sheet. The image-based one consists of image pixel values within narrow regions around the end edge. Through numerical simulations, we confirm that the position-based features are effective in achieving quick response while the image-based features are robust against measurement noise. In order to combine these contrasting behaviors, we introduce a weighted combination of the position-based and image-based features. Experimental results show both of the position-based method and the weighted combination method work well and suggest the possibility that the weighted combination method can reduce final alignment errors. Graphical Abstract