Contactless measurement of tunnel profile or road surface e.g. motorway

摘要

The profile measurement involves using a source i.e. a laser (1) which emits a fan-shaped light beam in conjunction with a video camera (3), with subsequent application of digital or analogue signal processing to the images obtained. The light source and camera are mounted on a vehicle (21). Each illuminated point is assigned to a point in the video camera image. A geometric transformation is performed in the plane of the light beam (23), where the position of the points of the profile (22) of e.g. a tunnel wall (11) is determined with reference to a vehicle centred coordinate system.