Automatic 3-D Optical Detection on Orientation of Randomly Oriented Industrial Parts for Rapid Robotic Manipulation

Abstract

This paper proposes a novel method employing a developed 3-D optical imaging and processing algorithm for accurate classification of an object’s surface characteristics in robot pick and place manipulation. In the method, 3-D geometry of industrial parts can be rapidly acquired by the developed one-shot imaging optical probe based on Fourier Transform Profilometry (FTP) by using digital-fringe projection at a camera’s maximum sensing speed. Following this, the acquired range image can be effectively segmented into three surface types by classifying point clouds based on the statistical distribution of the normal surface vector of each detected 3-D point, and then the scene ground is reconstructed by applying least squares fitting and classification algorithms. Also, a recursive search process incorporating the region-growing algorithm for registering homogeneous surface regions has been developed. When the detected parts are randomly overlapped on a workbench, a group of defined 3-D surface features, such as surface areas, statistical values of the surface normal distribution and geometric distances of defined features, can be uniquely recognized for detection of the part’s orientation. Experimental testing was performed to validate the feasibility of the developed method for real robotic manipulation

The Use of 2D/3D Sensors for Robotic Manipulation for Quality Inspection Tasks

“…During recent years vision systems started to play a key role in industrial robot applications. 2D vision systems have been successfully integrated with industrial manipulators enhancing their flexibility and intelligence [1][2][3][4][5][6][7][8][9][10]. Furthermore, considering current economy trends, manufacturing will be more concentrated on providing customized, modular products rather than mass production.…”

“…2D imaging technologies pose limitations when it comes to dealing with complex geometries and conditions. 3D information is now becoming essential for quality assurance of industrial parts application and enabling more intelligent robotic manipulation [3]. The 3D techniques are generally based on optical triangulation, time delay, and the use of monocular images.…”