Measurement method of asphalt pavement mean texture depth based on multi-line laser and binocular vision

A new measuring method of mean texture depth of asphalt pavement is proposed based on the technology of multi-line laser and binocular vision. The developed method is incorporated with the profile method and the digital image technology. A three-dimensional mathematical model is established based on the triangulation measuring principle in order to implement the three-dimensional reconstruction of asphalt surface profile. Image processing technology helps locate the exact coordinates of each point on the model. In addition, the techniques of multi-line laser pairing and epipolar restriction are introduced for the image matching between multi-line laser and binocular vision. Through the model and the spatial equations obtained, the values of the mean profile depth of asphalt pavement can be figured out. According to the profile method, an integrated calculation procedure of texture depth is established. A set of sand patch field tests are implemented to verify the reliability of the developed method.