AUTOMATIC CONTROL OF ULTRASONIC RAIL-INSPECTION TRANSDUCERS

In a recent program at Battelle, supported by the Transportation Systems Center and the Federal Railroad Administration, technology was developed for automatically controlling the lateral position of the ultrasonic transducers used in rail-flaw inspection equipment. Several concepts were evaluated, two of which are described in this paper. One of these was a "trial and error" control technique in which an automatic control system would move the transducer a small amount, determine if the change in positions produces an increase or decrease in the signal level, and then move the transducers in the direction that increases the signal level from the ultrasonic transducer. The second concept evaluated was one where two additional receiver-only transducers are added on each side of an existing transducer. This measures an ultrasonic signal that has been transmitted through the web of the rail. The difference in signal levels at these receiver transducers is a continuous indication of the lateral position error of the transducers and is used as the control signal in a feedback control system to position the transducer laterally over the rail. Evaluation of the concepts consisted of experimental measurements and calculations to determine the desired transducers configuration and other system parameters. The continuous type system was selected as being better for the application and several systems were constructed and are currently operating on both government- and railroad-owned vehicles. The preferred concept can be adapted, with minimal design modification, to most rail-inspection systems in use today.

Media Info

  • Features: Figures;
  • Pagination: p. 30-36

Subject/Index Terms

Filing Info

  • Accession Number: 00194632
  • Record Type: Publication
  • Source Agency: Institute of Electrical and Electronics Engineers (IEEE)
  • Report/Paper Numbers: IEEE 79CH1454-8 IA Tech Paper
  • Files: TRIS
  • Created Date: Jun 30 1979 12:00AM