Vision-based Mobile Robotic Grinding for Large-scale Workpiece and Its Accuracy Analysis

Abstract

In this article, a mobile robotic grinding system for large-scale workpiece is proposed. The mobile robot is equipped with a laser sensor, fringe projection scanner, and force-controlled grinding tool. The mobile robot can move in large spaces, calibrate the workpiece accurately, and perform grinding work automatically. A vision-based grinding strategy for the mobile robot is proposed, where the workpiece surface reconstruction and grinding path planning are generated by the measured point clouts. An error index is proposed to analyze the machining accuracy, which can reveal the primary error factor in the error transfer chain. Compared with the mobile robotic grinding based on the global measurement system in (Zhao et al., 2021), the proposed vision-based grinding process requires no precise CAD model of the workpiece and achieves better machining accuracy. Two experiments are conducted in this article, where a wind turbine blade and a part of the aircraft skin have been ground by the mobile robot. Experiments show that the mobile robot under the vision-based grinding strategy is suited for different continues surfaces, and it has great application prospects.