关键词: 机器视觉, 梯度算子, 最小二乘圆, 自动定位

Abstract: The automatic positioning technology of optical target based on computer vision is investigated.The method to identify goal rapidly is proposed by using label processing，neighborhood filter，and corrosion processing of images.Gradient operator and least-squares algorithm is employed to determine the parameters of the target center.Pulse equivalent can be calculated automatically by testing step length.To achieve high precision and fast localization of a target center on the FPCB，the technology to control servo motor running at variable speeds by higher and lower frequencies is used.The experimental results show that positioning technology for FPCB base-holes based on machine vision can achieve high precision and fast localization of a target center on the FPCB，and the system has good application prospects.

Key words: machine vision, gradient operator, least squares, automatic positioning