Research On Error Analysis And Optimal Design Of Stereo Vision Measurement

With the rapid development of manufacturing industry, the persistent growth of material requirements and the strong desire to explore the unknown of the field, part outer dimensions become more and more complicated and irregular. It is obviously inadequate for traditional measurement method to accomplish the work of modern surveying, especially, in the field of reverse engineering technology, non-destructive deformation testing, 3-D printing and so on. What's more, current technology, such as CMM, laser interferometry and ultrasonic ranging precision, cannot be economic,efficient and perceptive to the whole part. Integrated with modern technology such as computer technology, digital image processing and data analysis, vision measurement has been becoming the most popular technology and playing an important role in industry, agriculture, defense, medicine, aviation and aerospace.According to the status and trend of vision measurement and the requirement of large-scale measurement, a new 3-D vision measurement program based on the optical probe is presented. The combination of IR LEDs and infrared filter is used for acquiring high quality image with less background noise. Two synchronous images which reflect the different position of probe are acquired through digital CCD cameras set in advance. And then, the three dimensional coordinate of measured points can be calculated according to the position of IR LEDs.The light intensity of LED and structural parameters are emphasized to analyze the influence factors of measuring accuracy. In order to diminish error by improving features localization, adaptive regulation program is designed to make the LED work at the optimum state. At the same time, with the efficient use of MATLAB, the optimal range of structural parameters which determines external attitudes of two cameras and the scale of viewing field are found. The validity of the theory is verified by experiment, including measurements of a fixed point and gauge block, which also shows the practicability of the measuring scheme.