Laser profiler model for robot-based pipe inspection

Laser profilers for pipe inspection have been recently proposed. Most of these systems are based on the geometrical analysis of pipes, measuring radial distance by means of changes in the pipe images by the method known as triangulation. In this work, a novel approach that uses the intensity distribution of the reflected light is proposed in order to assess the condition of the structure under test, identifying discontinuities in the acquired data. The proposed approach appears to be very robust with respect to misalignments, an aspect, particularly important in robot-based systems. This paper describes a comprehensive sensor model including the optical path of the laser light, the surface reflection from the pipe walls and the image formation in the camera. This model is validated using experimental data and simulations. This paper demonstrates the method and shows its usefulness for sensor design