移动双臂机械手系统协调操作的视觉伺服技术

Visual servo technology for coordinated manipulation of a mobile dual-arm manipulator system

中文关键词  移动双臂机械手系统  视觉伺服  协调操作  HSV空间  不变矩

英文关键词  mobile dual-arm manipulator system  visual servo  coordinated manipulation  HSV space  invariant moment

中文摘要

      本文利用双目泛倾斜变焦摄像机(pan-tilt-zoom, PTZ)像机, 实现移动双臂机械手系统的视觉伺服协调操作, 重点研究室内复杂环境和光照变化情况下目标物体的检测、识别和定位问题. 首先, 提出了色调、饱和度、亮度颜色模型(hue-saturation-value, HSV)空间下图像分割的改进算法, 通过阈值更新和外接矩形改善分割结果, 提高检测算法对环境光照变化的适应性; 然后, 基于Hu不变矩, 利用物体形状特征, 对检测得到的物体加以识别; 在此基础上, 利用摄像机投影矩阵, 计算目标物体的空间坐标, 实现其定位测量; 最后, 在实验 室平台上, 通过模拟双臂倒水操作, 验证提出的图像处理和分析算法以及视觉伺服协调操作方案的有效性. 实验结果表明移动双臂机械手系统能够成功完成倒水动作的协调操作.

英文摘要

      Two pan-tilt-zoom (PTZ) cameras are used in this study to realize visual servo for coordinated manipulation of a mobile dual-arm manipulator system. The focus of this study is mainly on the problems of target object detection, recognition and localization in the indoor environment of scattered background and varying illumination. First, a modified algorithm is proposed to detect objects in the hue-saturation-value (HSV) color space based on updated segmentation thresholds and bounding rectangles, which improves the detection algorithm’s adaptability to illumination variation. Second, the target is identified from the detected objects using the target contour features and the Hu’s moment invariants. Then, the spatial coordinates of the target object are computed with the cameras’ perspective matrices, and the target position is consequently determined. Finally, to verify effectiveness of the image processing and analysis algorithms presented and the visual servo technology, experiments are done on a mobile platform in our lab to mimic the manipulation of pouring water with two arms, and the results show that the mobile manipulator system can complete the task successfully.