Non-contact railway inspection

VALUE PROPOSITION

Rail transportation is periodically marred by accidents, highlighting ongoing safety challenges. There is a need for effective rail inspection methods. Current techniques are hindered by limitations such as low detection accuracy and sensitivity, particularly at high speeds. This technology introduces a novel method for high-speed, high-accuracy rail inspection. The technology employs an electromagnet to generate motion-induced eddy currents in the rail track with high Signal-to-Noise Ratios and sensitivity, capable of detecting defects at speeds up to 60 mph. The uniqueness of this method lies in the alignment of the magnetic field with the direction of motion, enabling zero motion-induced current at the center under defect-free conditions. The proposed self-nulling probe simplifies analysis and reduces bias in signal processing. Additionally, the use of a sensor array, as opposed to a single sensor, allows for adapting to different velocities, maintaining a null signal under defect-free conditions. There is a signal enhancement with speed with higher velocities enhancing the amplitude of defect signals. This translates to superior inspection capabilities compared to existing methods.

DESCRIPTION OF TECHNOLOGY

The present technology is a novel system for high-speed, high accuracy rail inspection. The system employes an electromagnet to generate motion-induced eddy currents in the rail track. The system delivers higher signal-to-noise and sensitivity, capable of detecting at speeds up to 60 mph. This technology is a hybrid electromagnetic Acoustic transducer (EMAT) + Magnetic flu leakage (MFL) + Motion-Induced Eddy current (MIEC) transducer. The transducer coupled with a laser generated ultrasonic approach will be a fully non-contact nondestructive evaluation tool that is useful for rail inspection at full speed. The combination of measurement techniques are effectively coupled to complement each capability and provide characterization and localization of defects. For example, the phase transformation from pearlitic steel to martensitic or mixed phase can be identified. This typically forms a thin layer on the top surface due to deformations from rail wheel braking. As the microstructure evolves, it results in cracks, which can be normal or oblique to the surface. The system measures transmitted energy as a function of crack length and orientation providing details for maintenance planning.

BENEFITS