Enhancing 3D coordinate measurements in laser scanner by friction compensation

Abstract

This study addresses the challenge of precise laser ray spatial positioning in the presence of nonlinear friction dynamics during 3D coordinates measurement. We developed a novel control strategy integrating friction compensation to enhance the reliability and accuracy of 3D laser scanning instrument to enhance measurement quality. Our approach updates the classic LuGre friction model using Scanning Electron Microscope (SEM) analysis of micro-relieved surfaces, aiding in the dynamic characterization of the internal variable ‘z’ for the laser positioner control synthesis. The global asymptotic stability of the system was proven using Lyapunov’s direct method and Barbalat’s lemma. Experimental results validate the improved accuracy in positioning, demonstrating a significant reduction in the uncertainty of measurement spatial coordinates using the friction-compensated laser scanning system. Our study implemented and evaluated three control algorithms, including two advanced compensation controls, highlighting their effectiveness in reducing friction-induced errors and improving laser positioning accuracy. Our contribution advances the instrumentation precision through friction compensation, improving the nonlinear friction dynamics to enhance the stable laser ray positioning and, correspondingly, the accuracy of 3D coordinate measurements.