基于机器视觉的电视机背板检测及自适应抓取研究

机器视觉广泛应用于装配、制造和加工等工业领域，用来保证产品质量，控制生产流程。将图像处理技术应用于自动化装配生产线，对电视机背板质量进行在线检测。为了实现对不同型号和尺寸的电视机背板的抓取，使用图像模板匹配方法确定当前背板的型号和检测当前背板的品质，并开发基于采集图像的视觉伺服自适应控制系统，该控制系统以西门子 PLC（programmable logic controller，可编程逻辑控制器）作为控制核心，通过串口通信实现PLC与Halcon软件的数据对接。使用Halcon中的工具箱对电视机背板采集图像进行运算以抽取目标的特征，并分析出抓取过程的坐标值，进而根据判别的位置坐标误差结果来控制步进电机调节偏移量以实现自适应抓取过程。针对图像处理后产生的电视机背板位姿累计误差，设计了一种标准模板中心参数值与增量误差值求差的方法，对背板位姿视觉定位误差进行补偿。通过抓取实验验证了视觉伺服自适应控制系统的可靠性较高，能满足自动化装配的工业生产需求。在生产实际中，电视机背板自动检测及抓取平台的应用能极大地提高电视机生产效率、节约人工成本、降低劳动强度和提高生产精度，该平台具有很好的应用前景。

Research on TV backboard detection and adaptive capture based on machine vision

Machine vision is widely used in assembly, manufacturing，processing and other industrial fields to guarantee the product quality and control production procedure. Image processing technology is applied to automatic assembly production line, and the quality of TV backboard is detected online. In order to realize the capture of TV backboards with different models and sizes, the image template matching method was used to determine the current backboard model and detect the quality of the current backboard, and adaptive control system based on the visual servo was developed based on the collected images. The control system with Siemens PLC (programmable logic controller) as the control core, achieved PLC and Halcon software data docking through serial communication. The Halcon tool box was used to calculate the collected image of the TV backboard and extract the features of the target. The coordinate value of the capute process was analyzed, and the stepper motor adjustment offset was controlled to realize the adaptive capture process according to the result of position coordinate error. Aiming at the accumulative errors of position and posture of TV backboard obtained from image processing, a method was proposed to compensate the errors of visual positioning of position and posture of backboard by calculating the difference between the center parameter values of standard template and the incremental errors. The capture experiment proved that the adaptive control system based on the visual servo had high reliability and met the industrial production requirements of automated assembly. In the production practice, the application of the TV backboard automatic detection and capture platform can greatly improve the production efficiency of TV set, save labor cost, reduce labor intensity and improve production accuracy，and the platform has a good application prospect.