基于单应性矩阵的移动机器人视觉伺服切换控制

Switching control for homography-based mobile robot visual servoing

中文关键词  视觉伺服  移动机器人  单目视觉  单应性  视野约束  切换控制器

英文关键词  visual servo  mobile robot  monocular vision  homography  field of view  switched controller

中文摘要

      针对具有单目视觉的移动机器人, 本文提出了一种基于单应性矩阵的视觉伺服控制算法, 在缺乏深度信息 的情况下利用视觉反馈实现了移动机器人的控制目标, 即给定机器人目标位姿下拍摄得到的图像, 通过视觉伺服使 机器人从初始位姿准确到达目标位姿. 视觉反馈环节采用单应性矩阵中的元素构造状态变量, 而非利用常见的单 应性分解, 此外, 考虑到视野约束, 本文提出的算法在计算单应性矩阵时结合了单应性的传递特性, 从而避免了参考 目标的实时可见性. 伺服环节设计了切换控制器, 在满足非完整约束的同时可驱动机器人到达期望位姿. 理论分析 及实物仿真验证了该算法的可行性和有效性.

英文摘要

      For a monocular camera-based mobile robot system, a novel visual servo approach based on homography matrix is proposed. This approach realizes the control target by visual feedback with the lack of depth information, the robot can arrive at the position accurately by given an image taken under the position. Instead of common homography decomposition, this approach takes use of homography matrix elements to structure state varibles. In addition, considering the field of view constraint, the proposed approach doesn’t need the reference target to be visible in real time by the transitivity of homography. A switched controller is designed to drive the robot to reach desired position under the satisfaction of the nonholonomic constraints. In this paper, theoretical analysis and simulation verify the feasibility and effectiveness of the approach.