Research On Key Technologies Of Light Stripe In Laser Measurement

In the field of modern machinery manufacturing, laser and optical technology inmeasure has become a practical and effective non-contact measurement method. Thedirection and the coherence of laser were utilized in this method. The imaging law ofgeometrical optics and efficient data processing ability of computer technology wereused too. Among them, the laser stripe center detection is a key step in obtainingobject size information and the visual sensor calibration. Therefore, the actualmeasurement requires in-depth research in improving the quality of the laser beam,looking for the accurate algorithm of detecting laser stripe center, and precisionevaluation.The linear laser is used in size measurement of this issue. This kind of laser isusually made up by the semiconductor laser. To improve the measurement precision,the shaping technique that turn Gauss beam to the flattop beam is explored to makethe laser beam has a very uniform intensity distribution and narrow line width. Basedthe experiment of I.Powell prism, the beam shaping system and the expression ofaspheric lens is solved by the law of energy conservation and refraction rule. The raytracing and the optimization of the whole system will be performed by the opticaldesign software. According to the expression of the vector height, the aspheric columnlens can be fabricated through the diamond lathe. Comparing with the traditionallinear laser, the intensity distribution of this designed laser is more uniformity.The light strip gray that improved laser projects on the measured object surfacepresents distribution of two steps, so two edges were detected at first using thesub-pixel edge detection method, and then seek the centerline. Comparing with theeffects of the light strip edge detection using gray Moment Method, polynomialinterpolation method, and Gaussian fitting method, the experiment results show thatGaussian fitting method has good noise robustness. It can obtain higher precision inthe light strip edge detection.Respectively, using the traditional evaluation methods and evaluation methods inthis article to compared experiments on detecting laser strip center, the test resultsproved this method effective.Finally, in order to verify the accuracy of the size measuring used improved linelaser, constructed line laser measurement system based on improved laser for gauge blocks comparative experiments. Measurement results prove that relative accuracy isless volatile, and measurement stability is good using this method. The improved linelaser of this article and the corresponding light strip center extraction method canimprove the measure precision.