Research And Development Of 3D Vision Measurement Technology

With the rapid development of modern industrial technology, the traditional measure methods are hard to meet the requirements for industry manufacture and testing that are automatical, efficient and unmanned. Vision Measurement is playing an important role in Non-contact measurement with its advantages that are Non-contact ,high-precision field and good real-time performance. Combined with Optomechatronics technology, vision with laser scaning system is becoming mainstream in 3D measurement .The system contains computer, image gathering module card and precise machine.3D Laser vision measuring technology appeared in the 1970s firstly.it not only contains the general content of machine vision such as visual perception, image processing and analysis and pattern recognition but also it contains the particularity of measurement field such as space 3D measurement, position and recognition.In order to make dot laser measuring system realize precision measurement. The structure-adjustable dot laser measuring system is established. We do research on machine vision imaging principle and laser triangulation measurement principle. Firstly, camera's pin-hole imaging model is used. The intrinsic camera parameters of this model are got with Zhang's algorithm."Optical center angle"in dot laser measure system is defined and the formula which can calculate the"optical center angle"with intrinsic camera parameters that we have got firstly and coordinates of laser spot is given. Then, the mathematical model of dot laser measure system is established, and"baseline length"and"base angle"which are called structure parameters of the system are introduced. Method to calculate the structure parameters is given. At last, dot laser measure system does on-line measurement with the result of dot laser measuring system calibration. Experiment results show: dot laser measure system's maximum error is below 0.06mm. This calibration algorithm meets the precision measurement requirements.In order to scan objects full 3D information and find the feature points to track, the translational and rotational line laser scanning system is established. With the projective geometry knowledge, mathematical model of the line laser scanning system is established. Using of the points that the"General Algorithm of Planar Corners Match Their World Coordinate Automatically"provides, the system model is calibrated. The data model of the system is established and is optimized with iotimization algorithm. The laser line and the feature points are extracted based image processing algorithm. The object 3D structure was reconstructed with the mathematical model of the line laser scanning system and the feature points are sended to robot controller to track.In a word, in order to supply the demand for different industrial field applications, one system for one-dimensional depth measure and another translational and rotational line laser scanning system are designed. The system are used for Plane butt weld and helix weld trackeing and welding automatically.