基于单目视觉的机械臂灯具清洗定位系统

Manipulator positioning system of lamps cleaning based on monocular vision

在机场嵌入式助航灯具自动清洗过程中,为了取得灯具发光口中心和机械臂的相对位置实现机械臂精准定位,设计了基于单目视觉的机械臂灯具清洗定位系统。首先,采用D-H法建立机械臂运动学模型;然后,根据夜间灯具发光的强逆光性以及环境干扰,提出一种优化阈值准则和缩小阈值搜索范围的改进Otsu算法对图像进行分割,再利用质心法提取灯具发光口中心位置;最后,在夜间条件下,进行实验分析并对定位误差采用最小二乘法进行补偿。实验结果表明,所设计的机械臂灯具清洗定位系统速度快、精度高,与传统Otsu算法和改进的随机霍夫变换算法相比,定位精度分别提高72.5%和55.5%,且平均定位精度达到8.7 mm,满足灯具清洗要求。

In the automatic cleaning process of embedded aeronautical ground lights in airport,in order to obtain the center of lamps emitting port and the relative position of the manipulator to achieve precise positioning of the manipulator,a positioning system of lamps cleaning for manipulator arm based on monocular vision is designed.Firstly,the kinematics model of the manipulator was established by D-H method.Then,according to the strong backlight characteristics of lamps and environmental interference at night,an improved Otsu algorithm was proposed to segment the image by optimizing the threshold criterion and reducing the search range of threshold,and then the center of mass method was used to extract the center position of the lamps emitting port.Finally,under night conditions,the experiment was analyzed and the least square method was used to compensate the positioning error.The experimental results show that the designed manipulator arm positioning system of lamps cleaning has high speed and high precision.Compared with the traditional Otsu algorithm and the improved random Hough transform algorithm,the positioning accuracy was improved by 72.5%and 55.5%respectively,and the average positioning accuracy reaches 8.7 mm,which meets the requirements of lamp cleaning.