Researches On The Control Technology Of Hull Block Marking Manipulator Based On Machine Vision

With the advent of industry 4.0,the role of intelligent manufacturing in all walks of life is becoming more and more important.As one of the important tools of intelligent manufacturing,robots are becoming more and more popular in various filed.As an important pillar of the state,shipbuilding industry will benefit greatly from automation and intelligent shipbuilding technology.As a kind of robot,the manipulator has excellent working characteristics,especially in the complex and dangerous working environment of shipbuilding.Hull block marking and cutting is one of important processes of hull block building,existing in manual operation characteristics of high labor intensity,difficulty in operation,difficulty in control precision and so on,so it is of great significance to control manipulator to carry out hull block marking task automatically.Machine vision,as an important way for robots to get rich information and make feedback and decision-making,has developed rapidly in recent years,and has made great breakthroughs and has entered a period of rapid development.Therefore,the researches on the control technology of manipulator based on machine vision is both practical needs and industry trend.This paper takes hull block marking manipulator as the research object,adopting method of the stereo vision,and launches a vision-based hull block marking manipulator control technology research and design.Firstly,this paper studies and analyzes the hull block marking manipulator control system based on vision,determining the overall hardware scheme of system,and shows image acquisition and image processing equipment of the core part of the system.Secondly,the method of general manipulator pose description is showed and the kinematics model of manipulator with D-H method is established,confirming the pose transformation matrix of adjacent joint units and analyzing the motion of manipulator.The concrete method of calculating the manipulator motion is proposed,in view of the particularity of the structure and the work environment of the hull block marking manipulator.Thirdly,the basic principle of binocular stereo vision system and 3D reconstruction is showed,and the method of camera calibration is explored,especially ZHANG's method.The binocular camera in laboratory is calibrated and its parameters are obtained.Besides,the matching problem of binocular stereo vision is analyzed and the relationship between parallax and depth of stereoscopic vision is showed,which this paper adopts.Finally,combining work characteristic of the hull block marking manipulator and binocular stereo vision system,the system process design and program module design of hull block marking manipulator control system based on vision are carried out,and this paper provides a new way of thinking and method to hull of block intelligent marking.The research of this technology can not only be applied to the hull of block marking,but also can be applied to the hull painting,cutting and other aspects,providing reference for intelligent shipbuilding.