Hand-eye-vision based control for an inspection robot’s autonomous line grasping
来源期刊：中南大学学报(英文版)2014年第6期
论文作者：WANG Wei(王伟) WU Gong-ping(吴功平) BAI Yu-cheng(白玉成) XIAO Hua(肖华) YANG Zhi-yong(杨智勇) YAN Yu(严宇) 何缘 XU Xian-jin(徐显金) SU Fan(苏帆)
文章页码：2216 - 2227
Key words：inspection robot; line grasping control; visual servo; overhead transmission line; autonomous obstacle-crossing
Abstract: In order to ensure that the off-line arm of a two-arm-wheel combined inspection robot can reliably grasp the line in case of autonomous obstacle crossing, a control method is proposed for line grasping based on hand-eye visual servo. On the basis of the transmission line’s geometrical characteristics and the camera’s imaging principle, a line recognition and extraction method based on structure constraint is designed. The line’s intercept and inclination are defined in an imaging space to represent the robot’s change of pose and a law governing the pose decoupling servo control is developed. Under the integrated consideration of the influence of light intensity and background change, noise (from the camera itself and electromagnetic field) as well as the robot’s kinetic inertia on the robot’s imaging quality in the course of motion and the grasping control precision, a servo controller for grasping the line of the robot’s off-line arm is designed with the method of fuzzy control. An experiment is conducted on a 1:1 simulation line using an inspection robot and the robot is put into on-line operation on a real overhead transmission line, where the robot can grasp the line within 18 s in the case of autonomous obstacle-crossing. The robot’s autonomous line-grasping function is realized without manual intervention and the robot can grasp the line in a precise, reliable and efficient manner, thus the need of actual operation can be satisfied.
WANG Wei(王伟)1, WU Gong-ping(吴功平)1, BAI Yu-cheng(白玉成)1, XIAO Hua(肖华)1, YANG Zhi-yong(杨智勇)1, YAN Yu(严宇)1, HE Yuan(何缘)1, XU Xian-jin(徐显金)2, SU Fan(苏帆)1
(1. College of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China;
2. College of Mechanical Engineering, Hubei University of Technology, Wuhan 430068, China)
Abstract:In order to ensure that the off-line arm of a two-arm-wheel combined inspection robot can reliably grasp the line in case of autonomous obstacle crossing, a control method is proposed for line grasping based on hand-eye visual servo. On the basis of the transmission line’s geometrical characteristics and the camera’s imaging principle, a line recognition and extraction method based on structure constraint is designed. The line’s intercept and inclination are defined in an imaging space to represent the robot’s change of pose and a law governing the pose decoupling servo control is developed. Under the integrated consideration of the influence of light intensity and background change, noise (from the camera itself and electromagnetic field) as well as the robot’s kinetic inertia on the robot’s imaging quality in the course of motion and the grasping control precision, a servo controller for grasping the line of the robot’s off-line arm is designed with the method of fuzzy control. An experiment is conducted on a 1:1 simulation line using an inspection robot and the robot is put into on-line operation on a real overhead transmission line, where the robot can grasp the line within 18 s in the case of autonomous obstacle-crossing. The robot’s autonomous line-grasping function is realized without manual intervention and the robot can grasp the line in a precise, reliable and efficient manner, thus the need of actual operation can be satisfied.
Key words:inspection robot; line grasping control; visual servo; overhead transmission line; autonomous obstacle-crossing
