Research On Microtubule-Microsphere Assembly Based On Multi-Channel Microvision

This article takes micro-assembly based on microscopic vision as the background,and mainly studies the problems related to the assembly process of micro-sphere with a hole and micro-tube in micro-assembly,including fast and accurate positioning of micro-sphere,accurate measurement of the three-dimensional pose of micro-tube based on binocular microscopic vision,image processing algorithm for accurate positioning of the edge of microsphere,high-precision measurement of the three-dimensional pose of micro-sphere using the active motion of two-way micro cameras,visual-based servo control of the micro-tube manipulator and the movement mechanism of the micro camera,in order to achieve the alignment of the micro-parts in three-dimensional space.This thesis mainly studies the assembly of microtubes and microspheres based on multi-channel microvision.Based on the built experimental platform,a method for fast search and positioning of micro-sphere and micro-tubes combined with high and low magnification micro cameras was designed.Taking advantage of the large field of view of the low-magnification microscope camera,the micro-Components is searched in a fast speed.By calibrating the relative positional relationship between the high-magnification microscope camera movement mechanism and the low-magnification microscope camera movement mechanism,the fast and accurate positioning of the target parts is realized by the low-magnification microscope camera guiding the high-magnification microscope camera.Based on the features of the microscopic image,an image processing algorithm is designed to accurately identify the edge points and fit the center of a micro-sphere.The edge of the microsphere was coarsely positioned by two-way gradient combined with gray value,and then the edge of the microsphere was precisely positioned according to the maximum gradient value.By screening the gross error of the set of edge points,the image coordinates of the edge circle and the center of the microsphere are obtained by fitting the edge points with small errors.A high precision method for measuring the attitude of microspheres is proposed based on the active motion of two inclined and orthogonal microscopic cameras.Using the motion amounts and geometric relations of the two inclined micro cameras,the pose vector of the microsphere hole is calculated accurately.Based on the established experimental platform,the multi-purpose microspheremicrotubule assembly task was tested as a whole.The experimental results show that the method can quickly and efficiently complete the assembly of microspheres and microtubes,and the assembly attitude accuracy is less than 0.01 degree,and the position accuracy is less than 1 micron.It is important to improve the automation of microassembly.