Paul T Schrum

US Patent:

57994030, Sep 1, 1998

Filed:

Dec 20, 1996

Appl. No.:

8/771180

Inventors:

Paul T. Schrum - Raleigh NC

International Classification:

G01C 500

US Classification:

33290

Abstract:

This invention is a method for remotely obtaining roadway crown point elevation and horizontal location based on projecting a horizontal laser beam configured vertically in either a continuous or discrete manner across the roadway surface at a predetermined elevation substantially coincident with the crown point of the roadway. The highest elevation of the roadway partially occludes the vertically configured laser beam. The lowest elevation of the laser beam which contacts an array of vertically configured laser receivers positioned on the opposite side of the roadway is by necessity the highest elevation of the roadway crown. By using an optical detector at a known vertical offset from the laser beam emitter, the angle and hence the distance can be determined to the furthest laser impact with the roadway. This distance information can be combined with the known line between the laser emitter and laser receivers to resolve the horizontal coordinates of that point. In the case where the roadway is found in transition from normal straight roadway to curved roadway, the present method may be modified to calculate the slope of individual segments of the roadway on either side of a break point in order to determine the horizontal location of the break point.

US Patent:

56317328, May 20, 1997

Filed:

Jun 20, 1995

Appl. No.:

8/492790

Inventors:

Paul T. Schrum - Raleigh NC

International Classification:

G01C 100

US Classification:

356147

Abstract:

This invention is a method for remotely obtaining roadway crown point elevation and horizontal location based on projecting a horizontal laser beam configured vertically in either a continuous or discrete manner across the roadway surface at a predetermined elevation substantially coincident with the crown point of the roadway. The highest elevation of the roadway partially occludes the vertically configured laser beam. The lowest elevation of the laser beam which contacts an array of vertically configured laser receivers positioned on the opposite side of the roadway is by necessity the elevation of the roadway crown. By using an optical detector at a known vertical offset from the laser beam emitter, the angle and hence the distance can be determined to the furthest laser impact with the roadway. This distance information can be combined with the known line between the laser emitter and laser receivers to resolve the horizontal coordinates of that point. In the case where the roadway is found in transition from normal straight roadway to curved roadway, the present method may be modified to calculate the slope of individual segments of the roadway on either side of a break point in order to determine the horizontal location of the break point.