Larry William Purnell
Engineers at Wall St, Spokane, WA

4958306, Sep 18, 1990

Jan 6, 1988

7/141248

Joseph P. Powell - Veradale WA
Donald L. Bender - Spokane WA
Sam C. Saunders - Pullman WA
Larry W. Purnell - Spokane WA
Anwar S. Khattak - Spokane WA

Pacific Northwest Research & Development, Inc. - Spokane WA

G01B 1100, G01N 340

364550

A pavement inspection apparatus 10 is described for inspecting the condition of a full lane of pavement using a vehicle capable of traveling along the lane at normal traffic speeds, such as 55 miles per hour. The apparatus is capable of determing the elevational profile of the pavement and the size and shapes of surface distress features such as longitudinal cracks, transverse cracks, aligator cracks, design cracks, potholes and rutting. The apparatus 10 has two video array cameras 36 and 40 that project downward onto the pavement with overlapping fields of view for generating X-Y pixel data representing the intensities of reflected light from a full lane width of pavement as the vehicle moves over the pavement. The cameras 36 and 40 are mounted at acute angles with respect to each other to enable an elevational profile to be developed for the pavement from correlated pixel data from the two cameras. The apparatus 10 includes distress feature analysis electronics for determining the size, shape and location of surface distress features and evaluates such features against preset values to determine the severity of the determined features.