Research On Image Measurement System For Shaft Parts

At present,the measurement work of shaft parts is mainly performed by the inspectors using universal measuring tools or high-precision measuring instruments for operation.This type method relies on manpower and has low work efficiency,high detection cost,and can not be operated continuously for a long time.And so on.With the popularization of the automatic production technology of shaft parts,manufacturers hope to carry out online measurement and real-time supervision of part quality.However,current online measurement methods are difficult to achieve a good balance between performance,accuracy,speed,cost,and automation.Image measurement technology can measure small structures and elastic material parts,and has the advantages of low cost,high precision,high speed,non-contact,etc.,and is widely used in industry.Based on the above background,this paper develops an image measurement system for shaft parts,which can automatically read the drawing information of parts and automatically measure the diameter,angle,roundness and cylindricity of the shaft parts.The measurement system does not require human intervention.This paper first analyzes the research background of the current production methods of shaft parts,the advantages and disadvantages of common measurement methods,and the development status of image measurement technology.Through the analysis of the research background,the overall research plan is formulated,including structural layout plan,hardware composition plan and algorithm plan.Aiming at the axial position distribution of the shaft parts and the large change of the length of the parts,the layout of the parts around the axis and the linear movement of the industrial camera along the axial direction are designed.This method makes the measurement system have certain flexibility of use;The characteristics are designed with PLC as the mechanical control core and multi-core DSP as the hardware component of the computing core.Secondly,the image processing algorithms used in this paper are introduced,including image graying,filtering,pixel-level edge detection and sub-pixel edge detection.The method of measuring the shaft diameter,angle,roundness and cylindricity using the contour of the part in the digital image is again introduced.The implementation process of automated measurement is mainly introduced,including:using the perceptual hash algorithm to identify the measurement items in the part drawing;using the identified measurement items combined with computer technology to control the mechanical system,image sensor,and actively calling the relevant program to complete the collection of the part image and error assessment work.Finally,an image measurement experiment platform was built,experimental parts were designed and manufactured,and the measurement test was carried out.The feasibility and measurement accuracy of the measurement system were verified,and the factors affecting the measurement accuracy were analyzed.