Straightness measurement using laser diode and CCD camera

A method of using laser diode fiber alignment, diffraction imaging technique, and a CCD camera to measure the straightness of large-scale dimension was put forward, in which, a laser diode fiber alignment beam is used as the datum reference of straightness, while any deviation of measured data from this datum can be detected by a CCD camera directly. Besides, a novel image processing algorithm was also presented. The experimental results showed that for the measurement range of L (m), the measurement accuracy of the system reaches 3+10^-6 micron.