Laser Measuring System for Tool and Surface Relative Positioning When Robotic Processing

The paper considers the task of determining the normal to the surface during technological processing by an industrial robot. A system for measuring the normal via a group of lasers and a camera that allows additional visual inspection in the processing zone is proposed and investigated. A relationship between the coordinates of laser projections in the camera frame and the distance to the surface is determined. A method for opting the design of the measuring module that allows a high resolution is detailed. The procedures for image processing, calculating the position of the laser projection on a track, calibrating the measuring module, estimating distances to the surface and the normal to it are described. An experimental measurement module is demonstrated. Its analysis is carried out via an industrial robot. The impact of the measuring module's design parameters on its resolution is investigated. The measurement precision is assessed. Recommendations for constructing a system for measuring the normal with one camera and a group of lasers are proposed.