Using a laser sheet beam projector combined with a CCD-camera, an efficient technique to recognize thecomplex surfaces of curvature and plane has been demonstrated for the purpose of mobile robotnavigation. In this study, detected pixel images of elliptical arc obtained by laser sheet beam have beenconverted into a corresponding circular arc in the real-world coordinates so that the image processing for theposition and radius measurement became more precise and efficient than conventional techniquesbased ondirect elliptical arc analyses. Advantages of this method includes i) higher measurementaccuracy and shorter processing time, and ii) the capability of distinguishing curvature/planecomplexsurfaces. This technique yields an accuracy less than 2 cm for a 28.5 cm radius column at the distance of 70-250 cm from the robot, the obtained accuracy is significantly small enough to navigate a mobile robotoperating in indoor environments.