A novel method for measuring pose of hydraulic supports relative to inspection robot using LiDAR

摘要

Unmanned working face is a promising direction of coal mining, in which automatic measurements of the pose and straightness of hydraulic supports are critical to intelligent mining. In order to establish an automatic measurement system and to perform such measurement online, a novel method for measuring the pose and straightness of hydraulic supports is designed based on the "motion process restoration method". In this paper, we demonstrate one of the processes of this method, which is using LiDAR to measure the pose of hydraulic supports relative to an inspection robot. In addition, corresponding mathematical and theoretical model was established and the relative pose calculation formulas were given. Subsequently, a comprehensive experimental setup was designed, including a LiDAR testing device, a support feature, and a pose regulator. The experimental results showed that the maximum angular error and the maximum distance error of the LiDAR testing device are 0.44 degrees and -6.73 mm in the univariate pose test of the support feature, respectively, and the corresponding maximum errors are 0.48 degrees and 6.04 mm in the multivariate pose test. By converting the angular error into the distance error, the maximum distance error is 19.3 mm, which fully satisfies the requirements of the straightness of the hydraulic supports in the working face. By measuring the characteristic moving lengths of the support feature along the Y-axis, we studied the gauge repeatability and reproducibility (GR&R) by the average and range method. The results showed that the measurement system is qualified. Furthermore, this study provides a theoretical basis and engineering reference for the automatic measurement of pose and straightness of hydraulic supports in unmanned working face. (C) 2020 Elsevier Ltd. All rights reserved.