NONCONTACT ROAD PROFILING SYSTEM. VOLUME 4--SYSTEM HARDWARE

Road profiles are of interest because they affect vehicle ride quality, the wavelengths of concern ranging from 1/2 to 300 feet (0.2 to 90 m). This report pertains to a class of profile-measuring instruments in which an accelerometer measures vertical vehicle motion and a "noncontact" sensor measures vertical pavement motion-either displacement or velocity-relative to the vehicle. Specifically, a method is developed to process the accelerometer and noncontact sensor signals so as to obtain a measured profile with the following desirable qualities: (a) 1/2 to 300 foot wavelengths are recovered, (b) there is no phase distortion, (c) filtering and output are functions of distance rather than time, and (d) the output is independent of data collection speed and direction. A hybrid processing technique involving a minimal amount of analog processing is used. The digital processing, which is now done offline, makes use of symmetric finite impulse response filters. The processing algorithms are described in detail, and a variety of results are presented. The report is in four separately-bound units: Volume 1-Overview and Operating Manual; Volume 2-Calibration and Maintenance Manual; Volume 3-System Software; Volume 4-System Hardware. (FHWA)

• Corporate Authors:

  ENSCO, Incorporated

  5400 Port Royal Road
  Springfield, VA  United States  22151

  Federal Highway Administration

  Office of Research, 1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Smith, P G
  • Macintyre, S
  • Yang, T-L
• Publication Date: 1981-3

Media Info

• Pagination: 33 p.

Subject/Index Terms

• TRT Terms: Accelerometers; Digital computers; Manuals; Measuring instruments; Profilometers; Riding qualities; Roads; Roughness; Sensors; Vehicles
• Uncontrolled Terms: Road profile
• Old TRIS Terms: Digital systems
• Subject Areas: Highways; Pavements; Vehicles and Equipment; I23: Properties of Road Surfaces;

Filing Info

• Accession Number: 00345753
• Record Type: Publication
• Report/Paper Numbers: FHWA-RD-81- 71 Final Rpt., FCP 39B-014
• Contract Numbers: DOT-FH-11-9551
• Files: TRIS, USDOT
• Created Date: Feb 27 1982 12:00AM