跨尺度微小型零件的测量与装配

针对跨尺度微小型零件的精密装配中显微视觉视场狭小与零件的特征尺寸跨度较大相矛盾的问题,研究了跨尺度零件的位姿检测技术,基于高、低倍显微视觉单元研制了自动装配系统,系统采用模块化体系结构及先看后动的装配控制模式.提出局部特征拼接法实现了跨尺度零件的定位测量,使用标定尺对系统坐标系之间的误差角进行了标定,采用参考基准法辅助对显微视觉单元切换后的装配基准进行定位.设计测试模板对系统测量精度进行了验证,结果显示高倍显微视觉单元的同轴度测量精度优于1.5 μm,平行度精度优于1μm.利用研制的装配系统进行了装配实验,实验结果表明,关键零件的装配精度满足工艺要求.该装配系统可稳定、可靠地完成跨尺度微小型零件的自动装配.

Measurement and Assembly of Trans-Scale Miniature Parts

To solve the contradiction between small field-of-view of micro-vision and large span of part feature dimension in the precise assembly of trans-scale miniature devices,position and orientation measurement technology for the precise assembly of trans-scale miniature parts was investigated,and the automatic assembly system based on high and low magnification micro-vision units was developed.The modular architecture and the look-and-move control pattern were adopted by the assembly system.The local feature splicing method was introduced for measuring the position and orientation of trans-scale parts.Installation angle errors between the coordinate frames of the assembly system were calibrated by the calibration tools.The reference datum method was applied to assist in locating the assembly reference after the micro-vision units were switched.The test template was used to verify the system measurement accuracy,and the results show that the system coaxiality measurement error of high magnification imaging unit was less than 1 5 μm and the parallelism measurement error was less than 1 μm.Assembly experiment was carried out by the developed system,and the results show that assembly accuracy requirements can be met.The automatic assembly of trans-scale miniature devices can be steadily and reliably realized by the assembly system.