Mobile Floor-Marking Robot, utilizing Feedback from Laser Tracker

Abstract: Equipment installation at MAX IV, a state-of-the-art particle accelerator in Sweden, requires accuracy and precision in the range of micrometers. The measurement technology used is laser tracking, with which the position of a movable reflector is determined, by reflecting the laser beam emitted from a stationary tracker. Data describing the real-time position of the reflector is handled in a software called SpatialAnalyzer, managing it within the point cloud of statistically secured reference nodes, located all around the facility. The laser tracker is operated via a PC, whereas adjustment of the position of the reflector-equipped inventory is a manual, sometimes trying exercise, performed by measurement engineers. If this task were to be automated, it would free up time and resources, as well as improve the working condition for the employees. The purpose of this master’s thesis was to develop a mobile floor-marking robot to performbluelining atMAXIV. Bluelining is the first step of equipment installation and it is a process of projecting reference points from a 3D-model to a drawing on the floor. In this step, for example, drill marks for bolts of a foundation of an optic table are to be drawn. A 1,5 mm radius marker-pen is used and a guiding tool, holding the reflector, is positioned by hand to mark the target. The proposed design consists of a modified 3D-printer attached to a mobile robot equipped with omni wheels. It is controlled via a main program that runs on a Raspberry Pi and it is powered via rechargeable batteries. Performancewas evaluated in case studies and the average deviation from target achieved was six millimeters. As the testing was brief, it is recommended to perform further activities to define accuracy, precision and repeatability. However, the indications are that it is possible to perform automatic bluelining with modified off-the-shelf products, receiving positional coordinates from a laser tracker system. The result could be further improved with a custom-made robot, preventing compromises in its automation and design.