Research And Design Of Dispensing Machine Servo System Based On Machine Vision

In the structured environment,the dispenser of semi-automatic and automated production line has poor flexibility in position adjustment and device placement.The application of machine vision on the traditional glue dispenser can reduce the requirements for device fixture design,solve the precision problem can not be guaranteed in long-term operation,improve its self-adaptive adjustment capability to the operating environment,and make the system more intelligent.This paper focuses on the research and analysis of the current situation of the glue dispenser control system.Some existing problems were summarized: the dispensing device could not be accurately placed,requirements of fixture design were high,and high-integration devices were difficult to achieve accurate dispensing.A servo system of dispensing based on machine vision is designed.The main research of this paper is as follows:A light source and a camera are mounted on the end of the manipulator,and a motion control card + servo system structure mode is adopted to build a hardware platform for a three-axis linear motion control system.Through the histogram equalization,Gaussian filtering,edge detection and threshold segmentation process of the image captured by the visual system reduce the matching search area,accelerate the matching speed and increase the matching probability.In the template matching,SSDA algorithm is used for similarity measurement.Combined with the hierarchical search strategy of image Pyramid,the matching speed is greatly accelerated.The multi-angle template is used to solve the problem that the large angle deviation can not be matched or the probability of matching is low.The image center coordinates and angle rotation information of each device are obtained through matching.The Zhang's calibration method is used to solve the internal and external parameters and the distortion coefficient.The coordinates of each dispense position in the image are calculated to achieve the conversion from the image coordinate system to the world coordinate system.Then obtain the actual world coordinate according to the relationship between the terminal coordinate system of the tri-axial linear manipulator and the position of the device.Finally,the linear and arc interpolation task of dispensing is completed by the position based control method.The development of the software system implements the fast matching of the dispensing device and the precise control of the glue position,which proves the feasibility of the hardware scheme and the algorithm.