Viewpoint Generation Using Geodesics and Associated Semi-Automated Coverage Path Planning of Panels for Inspection

Abstract

The coverage of a surface using multiple viewpoints is a topic of great interest for robotic path planning in inspection applications. Two approaches for coverage path planning are broadly addressed in the literature—geometric methods and optimization methods. While the optimization methods may be the most flexible, they are frequently difficult to implement in practical applications due to their NP hard nature. We present here a geometric algorithm for the coverage path planning of panels used for aerospace applications using a generic camera model that can represent area inspection techniques like thermography and laser shearography. This algorithm relies on drawing a 2D grid on the 3D surface of the panel using geodesic lines on the surface. The coverage of the surface is performed by propagating geodesic lines from a starting point until the patch thus covered diverges too much from a flat surface, and after that, the coverage is continued from another point. The propagation of the geodesic lines is stopped when they begin to converge or diverge, and we define two criteria for the stoppage. We show that the proposed algorithm has good results for 3D virtual models and emphasize its speed, simplicity, and reliability for such applications.

Keywords

• coverage path planning
• geometric algorithms
• panel inspection
• non-destructive testing