A Robotic grinding station based on an industrial manipulator and vision system

PLoS One. 2021 Mar 24;16(3):e0248993. doi: 10.1371/journal.pone.0248993. eCollection 2021.

Abstract

Due to ever increasing precision and automation demands in robotic grinding, the automatic and robust robotic grinding workstation has become a research hot-spot. This work proposes a grinding workstation constituting of machine vision and an industrial manipulator to solve the difficulty of positioning rough metal cast objects and automatic grinding. Faced with the complex characteristics of industrial environment, such as weak contrast, light nonuniformity and scarcity, a coarse-to-fine two-step localization strategy was used for obtaining the object position. The deep neural network and template matching method were employed for determining the object position precisely in the presence of ambient light. Subsequently, edge extraction and contour fitting techniques were used to measure the position of the contour of the object and to locate the main burr on its surface after eliminating the influence of burr. The grid method was employed for detecting the main burrs, and the offline grinding trajectory of the industrial manipulator was planned with the guidance of the coordinate transformation method. The system greatly improves the automaticity through the entire process of loading, grinding and unloading. It can determine the object position and target the robotic grinding trajectory by the shape of the burr on the surface of an object. The measurements indicate that this system can work stably and efficiently, and the experimental results demonstrate the high accuracy and high efficiency of the proposed method. Meanwhile, it could well overcome the influence of the materials of grinding work pieces, scratch and rust.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Imaging, Three-Dimensional
  • Industry*
  • Robotics*

Grants and funding

This work was supported in part by National Natural Science Foundation of China under Grant 51609033, Natural Science Foundation of Liaoning Province under Grant 20180520005, the Key Development Guidance Program of Liaoning Province of China under Grant 2019JH8/10100100, the Soft Science Research Program of Dalian City of China under Grant 2019J11CY014 and Fundamental Research Funds for the Central Universities under Grant 3132019005, 3132019311. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.