Developed Of Piezoelectric Ceramic Piece Surface Defect Based On Online Visual Inspection

Piezoelectric ceramic is a kind of information functional ceramic material with piezoelectric effect,which capable of mutual conversion from mechanical energy and electrical energy,piezoelectric ceramic have piezoelectric,dielectric,elastic and other performance,also with excellent physical and mechanical properties such as high temperature resistance,corrosion resistance,wear resistance,low density,has been widely used in medical,industrial,aerospace and other electronic fields.Piezoelectric ceramic piece will appear pits,holes,cracks defects in the process of production and processing because of improper processing method,which will deteriorate its performance,affect the quality of components,so it is very meaningful to inspect the quality of piezoelectric ceramic piece.But at present,the inspection of piezoelectric ceramic piece surface defect is still stay in the stage of artificial visual inspection,accuracy cannot meet requirements,lacking check easily and low efficiency,and affected by the subjective factors,the quality test results cannot be guaranteed.In the view of above problems,combined with piezoelectric ceramic piece itself material and structure and characteristics of defect,come up with a complete system of inspection of surface defects on piezoelectric ceramic piece based on vision inspection technology,to realize the effective identification of various defects and quality classification.The development of the system includes the design and implementation of the hardware platform and the analysis and processing of the software algorithm.(1)The analysis of the principle of the piezoelectric ceramic piece imaging,to determine the light source,industrial camera,lens and the construction of the model,combined with the actual to add two-dimensional mobile platform,which set up a complete online testing hardware platform to obtain a clear image of piezoelectric ceramic piece with defects.(2)Design image processing algorithm to complete the defect region extraction effectively and quality classification.Including target extraction of piezoelectric ceramic piece by threshold segmentation;a new image enhancement method is proposed to improve the contrast between defect area and non defect area;exacting the defect's information on the region of the enhanced image,and the defect is selected based on the shape feature of the region.(3)Based on the Visual Studio 2010 software development environment,complete the overall framework design,writing,testing and implementation.Using multithread parallel operation to accomplish image acquisition and algorithm processing and accomplish simultaneously control and application of industrial camera and mobile platform for communication with PC,and a friendly man-machine interface is developed,which can be used as the information exchange between the system and the user.According to the design,the prototype of the testing system is made,and it is tested and debugged several times,the system meets the requirements of automatic detection of piezoelectric ceramic piece,detection accuracy and speed both higher than manual detection.