Abstract: An automatic detection system based on machine vision is designed to measure the verticality of elevator guide rail more effectively. A verticality measuring robot for elevator guide rail moves along the rail with a vertically fixed lighten ring. Canny transform is used to extract the elliptical edge points acquired by a video camera. Then ellipse parameters are fitted. The relationships between lighten ring geometrical parameters and ellipse parameters are derived. So its geometric center and the normal vector are determined. The changes in the center of the lighten ring reflect those in the verticality of elevator guide rail, and the changes of the angle between normal vector and the vertical reflect the distortion direction of the guide rail. Experimental results show that the proposed system can measure the deformation of the guide rail easily and accurately.
elevator guide rail,