摘要
螺纹中径是衡量螺纹联接质量的重要标志,为实现利用机器视觉技术测量得到满足螺纹作用效果的中径值,并进行有效评价。提出了一种扩展虚拟三针法结合理论螺纹牙廓测量螺纹中径的方法。该方法通过在轴截面上构建扩展虚拟三针法测量中径模型,获取符合实际螺纹轴线作用效果的作用点并进行拟合,然后利用螺纹轴线与最大实体尺寸找到与实际螺纹牙廓相配合的理论牙廓,并将扩展虚拟三针法应用于理论牙廓中获取更接近实际作用效果的中径值,最后以平均相对误差、标准偏差和均方根误差作为评价指标对不同实验设备测得中径值进行评价。实验数据表明,该算法测得的中径值相比于螺纹综合测量仪和测长仪测得中径值的相对误差均不超过0.013%,尺寸测量的结果能稳定地满足螺纹中径测量需求。
Thread pitch diameter is an important symbol to measure the quality of thread connection.In order to achieve the use of machine vision technology to measure to meet the thread effect of the middle diameter value,and effective evaluation.In this paper,an extended virtual three ball method combined with theoretical thread profile is presented to measure the thread middle diameter.In this method,the middle diameter model of the extended virtual three ball method is constructed on the shaft section,and the action point which accords with the actual thread axis effect is obtained and fitted.Then the theoretical tooth profile matched with the actual thread tooth profile is found by using the thread axis and the maximum solid size,and the extended virtual three ball method is applied to the theoretical tooth profile to obtain the middle diameter value which is closer to the actual effect.Finally,the mean relative error,standard deviation and root mean square error are used as evaluation indexes to evaluate the mean diameter measured by different experimental equipment.The experimental data show that the relative error of the middle diameter value measured by this algorithm is less than 0.013%compared with that measured by the thread comprehensive measuring instrument and the length measuring instrument,and the result of size measurement can stably meet the needs of thread diameter measurement.
作者
林葵
陈曼龙
余智超
邹滨阳
景敏
LIN Kui;CHEN Manlong;YU Zhichao;ZOU Binyang;JING Min(School of Mechanical Engineering,Shaanxi University of Technology,Hanzhong 723000,China;Shaanxi Key Laboratory of Industrial Automation,Shaanxi University of Technology,Hanzhong 723000,China)
出处
《组合机床与自动化加工技术》
北大核心
2023年第8期135-139,共5页
Modular Machine Tool & Automatic Manufacturing Technique
基金
陕西省科技攻关计划项目(2022SF-469)。
关键词
机器视觉
扩展虚拟三针法
螺纹中径
螺纹轴线
machine vision
extended virtual three ball method
thread pitch diameter
axis of threa
