CAD-based path planning for 3-D line laser scanning

The problem of path planning for 3-D line laser scanning is addressed in this article. The path under study is for a line, as opposed to a point in conventional CNC and CMM toolpath planning. While the objective of the latter case is to drive a point along a curve, that of the former case is to drive a line across a surface. To solve this problem, a path planning method is developed. First, a slicing approach is put forward to divide a part CAD model into a number of sections, since the laser scanning line is limited by the scanning width and a single scanning pass cannot cover the whole surface. Second, for each section, a scanning pass is generated to cover the section surface. To ensure a maximum coverage for each section, the surface profile is determined, and the top of the scanning window is set along the upper boundary of the surface profile. Third, combination of scanning all the sections forms a complete scan of a surface. It is shown that with the proposed method a 3-D line laser scanning process can be effectively automated. q 1999 Elsevier Science Ltd. All rights reserved.