Study Of Detecting Aircraft Skin Joint Based On Structured Light Vision

It is always scientists'goal that how to make machines with human visual function. With the development of computer technology, image processing, biomedical technology, and pattern recognition technology, an unprecedented development of the machine vision technology is obtained. Because it has many advantages, such as range large, non-contact, speed, system flexibility, and high precision, the structured light vision measurement becomes the most potential engineering applications of three-dimensional data acquisition. According to the request of detecting the aircraft skin joints quickly and accurately, the line structured light vision measurement is studied, a calibration which the camera and laser are calibrated synchronously is designed, and a structured light measurement instrumentation is developed. At the same time, in order to improve the overall system accuracy, and make the system has the capabilities of self-calibration, the nonlinear least squares optimization of the entire model of the system is carried out, and the result is very satisfactory. The main work:(1) The line structured light vision measurement principle is studied. The mathematical models of the entire system, as well as the camera and laser are established.(2) In order to get a better system calibration accuracy, the basic data on the calibration has been studied, such as the calibration board design, image preprocessing, feature point detection, laser centerline extraction and fitting and so on.(3) A precise calibration of cameras and laser calibration is designed. The specific steps and the error evaluation criteria are given.(4) In order to make the system has self-calibration function, the nonlinear least squares algorithm is studied. Only collecting a picture of the standard block image, the optimal objective function is obtained, and the optimization is completed, the on-site rapid calibration is achieved.(5) The different influence of different structural parameters is analyzed, The equipment parameters are designed.The experiments and field application show: the detector is small volume, simple operation, high speed and precision, the measurement accuracy of the system is less than 0.035mm, and the system also has a very high robustness.