A method of improving CCD's resolution in laser triangulation measurement

The precision of laser triangulation system is mainly decided by the locating of image-spot on detector. The resolution of CCD limits the locating precision in laser triangulation measurement where CCD camera is used as detector. The method,using light-spot's sampling gray-center of mass to decide its accuracy situation,can improve the resolution of CCD to sub-image element. However,this method has its own limits; rim jamming of light-spot gray and high-frequency noise. In this paper,we discuss a practical method using gray-center of mass to locating light-spot after its gray distribution is fitted with multinomial, and it can overcome the above limits very well . At last , the result of experiments shows that this method can arise the resoltion of CCD camera to 0. 017 picture element better than that (0.15)of gray-center of mass.