Research On Semi-axle Testing System Based On Pulsed Eddy Current Testing Technology

With the continuous development of the automotive industry, road transportationplays an increasingly important role in the safety testing of the vehicle to get peop le’sattention in the logistics industry. Heavy truck rollover and body sway as a result ofaxis collision cause property damage and serious casualties. Pulsed Eddy Current(PEC) detection technology which is regarded as a new and effective electromagneticnondestructive testing technology becomes a research hotspot in recent years. Testingaxle of automotive using PEC method is proposed in the thesis. Axle testing based onPEC have the ability to rapidly detect the existence of defects, and obtain theinformation of defects.First, the finite element simulation of the eddy current field generated by theprobe is completed using FEA software, the design principles are obtained with thecomparison of effects on eddy current field excited by different dimensions of probe,different amplitude of driving signal and different driving frequency of signal. AndSemi-axle Testing experimental device is specially designed which consisted of probe,the signal excitation and signal reception processing system modules. Detection probestructure is designed and the Hall sensor is adopted as the detecting sensor. Twodifferent types of probes which can detect different directions are designed to testmagnetic field in X and Y direction. The experimental device adoptsMCU-MC9S08QG to generate pulse excitation signal, and the push-pull poweramplifier circuit realized by TDA2030chips excites the coil to work. The receivermodule is composed of bias voltage comparator circuit and filter-amplifier circuit tocomplete the signal conditioning. The scanning voltage of single point is recorded byOscilloscope, and then gets the voltage scan curve by Post-processing.Finally, the surface defects detection experiments of semi-axle are finished onthe experiment devices, the acquired signals are analyzed based on the defectsprinciples, the length and depth of the defects can be processed and then obtained.The actual experiment results accords with the detecting principles and simulationresults of the model. The experiment device is reliable and proper for the detection ofautomobile axle.