Research On Robot-based Ultrasonic Defect Detection Technology

With the rapid development of manufacturing technology,complex forgings with precision machining have become irreplaceable core components in many equipment,and they often play important roles such as core support,special structure and heavy load.At present,due to the complex structure of this kind of workpiece,most of them are detected by manual flaw detection.There are many blind spots in the detection,with low efficiency,and the accuracy of the detection result is too affected by human factors.In order to ensure the quality and reliability of forgings,it is of great practical value to study the ultrasonic automatic inspection system based on mechanical arm.First of all,the overall design plan is formulated.According to the structural characteristics and testing requirements of complex forgings,an ultrasonic automatic testing system for complex forgings was designed and developed in order to solve the problems and shortcomings of manual testing,replace manual work,improve efficiency and ensure testing accuracy.Then,based on the six degrees of freedom of the industrial robot,an automatic scan was designed and developed,include industrial robot selection,ultrasonic testing end design and coupling agent supply system design.The communication between robot and IPC was established to realize the motion control of scanning mechanism,and the path planning method for complex forgings with multiple geometric configurations was designed to realize the full coverage detection of complex forgings.Secondly,in order to intuitively reflect the internal defect information of the measured workpiece,ultrasonic C-scan imaging software system was designed by combining the ultrasonic scanning imaging principle and DAC curve.High speed data acquisition card was used to collect the amplitude of the ultrasonic flaw detector output and the analog voltage signal of the sound path,after a DAC modulation imaging,real-time display internal scan of workpiece,at the same time,in view of the scan image noise,fuzzy problems,the corresponding image processing module is designed to enhance image quality and extract and quantify defects more accurately.Finally,in the complete system design,integration,alignment,on the basis of testing the performance of the system,the results showed that the complex forging automatic ultrasonic testing system meet the design requirements,the repeated positioning accuracy of the system scan is better than the 0.03 mm,the equivalent diameter of 0.5 mm above the defects can be effectively detected,C scan image color evaluation is accurate.The system improves the detection efficiency,avoids the problem of manual scanning,and has good applicability.