Calibration Methods And Experiments Evaluation For A Line Structured Light Vision Measurement System

As a non-contact measurement technology, line structured light vision incorporateslaser measurement technique, electromechanical integration technology and digitalimage processing technology. This method has been the focus of the research in thefield of on-line measurement since the advantages of high accuracy, wide range, simplestructure and high speed. However, the calibration of line structured light visionmeasurement system with high accuracy is difficult, expensive and complex. But theaccuracy of calibration have a direct effect on the final measurement accuracy.Therefore, it has important significance in the scientific research and industrialengineering to study calibration methods for the line structured light vision measuringsystem.The main works as follows:(1)A line structured light vision measurement system is established, and then theactual imaging model is constructed based on the classic model of pinhole imaging.Some key problems in the process of calibration are discussed and the basic theory ofseveral common calibration methods are studied. At last, a calibration experiment isconducted based on image processing software HALCON.(2)Several common methods for calibration of the light plane are researched andanalyzed. A new method for calibration of the light plane is presented based on gaugeblock target.The image pretreatment methods is studied by analyzed the characteristic ofnoise in line structured light stripe image.According to the characteristics of linestructured light stripe during experiment, a algorithm of center extraction of linestructured light stripe has been designed.(3)Experimental platform of line structured light vision measurement is designedand made. Calibration of camera and line structure light plane has completed.Experiments for measurement was performed using this system. Finally, systemmeasurement accuracy are verified with grade00gauge block.Experiments indicate that the calibration method for the system have advantagessuch as simple process, high accuracy，and the accuracy of system within0.05mm indepth range0~80mm and in view within150mm×200mm, which satisfy theapplication of most industrial detection.