Research On Vision Measurement Module For Assembly System Of Micro Inertial Device

With micro-electromechanical products having been widely used in various engineering fields, it may become higher demand for the accuracy. At present, micro-electromechanical products mainly rely on the experienced staff with the aid of a microscope, which results in poor consistency of product quality and low efficiency of assembly work. In view of the above problem, assembly system of micro device emerges as the times require, in-depth research begins in many institutions at home and abroad.In order to reduce the development time of assembly system of micro inertial device and save the cost of development and use, the modular structure is applied to the assembly system, including vision measurement module, manipulator module and assembly platform module. This paper mainly studies the vision measurement module in the assembly system. Vision measurement is the main method of assembly system to obtain the position and orientation information, it may become higher demand for the measurement accuracy. This paper gets into the research mainly from the structure and control of vision measurement module, the model of error compensation, the calibration of module parameters and the drive control software.The mechanical structure of vision measurement module mainly includes 3-DOF precision motion stage and machine vision device. In order to solve the contradiction between the small field-of-view of machine vision device and the large range of size of assembly work area. The structure of 3-DOF precision motion stage with machine vision measurement device is composed, the machine vision device moves in the assembly area with the motion of 3-DOF precision motion stage, so the image of micro parts can be taken in the different location.In order to improve the accuracy of vision measurement, this paper analyzes the error source and determines the error parameters of the module from two perspectives including 3-DOF precision motion stage and machine vision device. Through the kinematics model of 3-DOF precision motion stage and the coordinate transformation model of machine vision device, this paper finally gets the error compensation model. In addition, this paper designs the calibration experiment scheme of the module parameters, customizes high-precision calibration template and selects the related experiment equipment.In order to realize modularization and general utilization better, this paper designs the drive control software, including module control class and a library of performance function, its main purpose is to facilitate the user to write assembly program and reduce the development time of the assembly program. The module control class is mainly based on object-oriented programming idea to distinguish the performance of vision measurement module and get single function control class. The library of performance function provides performance functions for the vision measurement.Finally, vision measurement module is integrated into the assembly system of various micro inertial devices. The result shows that the accuracy of vision measurement meets the assembly requirement.