System for Inventorying Road Surface Topography (SIRST)

摘要

An experimental trailer-mounted instrumentation system which surveys and records data on the roadway topography while being towed at normal highway speeds has been developed and tested. The system uses non-contacting electro-optical sensors to measure the relative height of the roadway surface along 12 selected paths which are spaced at intervals across the 12-ft width of a normal traffic lane. Data on the cross slope and longitudinal slope of the surface and the direction of travel are obtained from a gyro-type inertial reference unit mounted on the instrumentation trailer. Compensation for vehicular bounce is obtained through use of a double integrated vertical accelerometer. At intervals of one (or two) feet along the roadway a solid-state data acquisition system samples the output from each height sensor; the roll, pitch and azimuth signals from the inertial reference system; the output from the accelerometer and the double integrated accelerometer signal. This data is digitized and recorded on a digital cassette type magnetic tape recorder. The cassette tape is used to provide an input to a computer for analysis and plotting purposes. Programs to permit computer plotting of the data to show the topography of the roadway surfaces were developed.