Railroad inspection based on ACFM employing a non-uniform B-spline approach

摘要: Abstract The stresses sustained by rails have increased in recent years due to the use of higher train speeds and heavier axle loads. For this reason surface near-surface defects generate Rolling Contact Fatigue (RCF) become particularly significant as they can cause unexpected structural failure rail, resulting severe derailments. accident that took place Hatfield, UK (2000), is an example a derailment caused rail section RCF. Early detection RCF therefore paramount importance industry. performance existing ultrasonic magnetic flux leakage techniques detecting surface-breaking defects, such head checks gauge corner cracking, inadequate during high-speed inspection, while eddy current sensors suffer from lift-off effects. results obtained through inspection experiments under simulated conditions using Alternating Current Field Measurement (ACFM) probes, suggest technique be applied for accurate reliable at high speeds. This paper presents B-Spline approach used filtering noise raw ACFM signal speed tests improve reliability measurements. A non-uniform B-spline approximation employed calculate exact positions dimensions defects. method generates smooth similar dataset points related defect.