Research Of Self-calibration Monocular Vision Measurement System

Compared with the traditional measuring technique, vision measuring has manyadvantages, for example, high speed, high accuracy, non-contact, high automation, etc.This thesis focuses on the self-calibration monocular vision measurement system,researches the key techniques of three-dimensional reconstruction, corner detection,camera calibration and so on.Based on the traditional modeling of pinhole camera, this thesis studythree-dimensional reconstruction of cylinder, through image reconstruct the size ofmeasured object. A method of equivalent draft is put forward, and an algorithm expandedfrom cylinder to revolving body is achieved. In addition, the correctness of the algorithmis validated by simulation.The improvement of corner detection based on the edge is put forward. According togeometric characteristics of the object, the parameters are adjusted automatically, theoptimal solution in the edge extraction and corner extraction link can be obtained, whichcan reduce the leak and false drop of the traditional corner detection. The correctness ofthe algorithm is validated by the examples.An internal parameters self-calibration method of fixed-focus and whole groupmobile focus lens is put forward, which reduces the number of changing internalparameters. Based on equivalent principle of actual camera lens and pinhole cameramodeling, and using laser ranging to obtain object distance, thus the changing internalparameters are calibrated in real time. An external parameter self-calibration method basedon shape characteristics is put forward, which uses the measured object as calibrationobject, research the imaging law of object’s geometry characteristic when process ofexternal parameter is changing. The correctness of the algorithm is validated bysimulation.The monocular vision measuring system is established, the hardware is single lensreflex camera with software development kit, the software includes camera control module,image processing module, camera calibration module, three-dimensional reconstruction module and so on. The system can achieve the measurement accuracy of designrequirements, which is validated by the test.