Research On Spatial Depth Information Measurement Technology Based On Active Light Illumination

The 3D information sensing technology based on photoelectric imaging system is widely used in industrial automation,medical diagnosis,visual navigation and other fields.Especially in automated assembly line,robot vision navigation and robot arm assembly,the measurement of depth information has become the core of 3D information acquisition.High-precision and high-efficiency deep information acquisition technology is the premise to meet modern high-performance production with high real-time requirements.A technical scheme of miniaturization and rapid measurement of depth information acquisition system,which is based on stereo vision and structured light technology,is studied in the paper.Aiming at high-precision and high-speed depth information acquisition,color-coded is used to assist illumination,and binocular camera is applied to capture images in two orientations,and then a matching algorithm and the triangulation principle are adopted to calculate the 3D information of the object.The main research contents are as follows:1.A technical scheme for measuring the depth information of moving objects is constructed.After comparing the stereo vision model and depth measurement principle,an active stereo vision system is designed to complete the calibration and correction.The system has no shortcomings like small field of view and the need to calibrate the projector,and the problem that passive system is difficult to match the objects with few features is solved.To realize the depth measurement of moving objects,a projector is employed to add texture to the object with one image,and two cameras are used to capture images in two directions at the same time for decoding and matching,and then the 3D information is restored according to triangulation principle.2.A color space image coded and decoded scheme is designed.A color coded image is designed and generated,the disparity map is obtained by sketchy matching and precise matching.A corresponding relationship of two stripes in the left and right images is done according to two stripes matching result.In the same way,a sketchy matching of all stripes in two image can be completed.In order to find a precise matching algorithm with a low error rate for all stripes,the gray correlation calculation in two stripe width area is performed to compare stereo matching results of different region.This method overcomes the limitation of the sparseness of the spatially encoded disparity map,improves the speed and accuracy of measurement.A more accurate disparity map is obtained by adaptive window size and disparity map hole filling algorithm.3.A research of depth information acquisition technology is completed.A graphical user interface is developed using MFC.The depth measurement and contour fitting experiments are performed using the triangulation principle,and the 3D measurement technique is employed to calculate the 3D coordinate.The system accuracy is tested,and the relationship between measurement error and system structure parameters is also analyzed according to experiment results and system model.4.The embedded algorithm transplantation of image processing system is exhibited.The embedded technology is studied after Linux operating system a platform is built and the algorithm is transplanted from PC to embedded system.Then following aims will be realized:the developed technology runs off PC,the efficiency of the designed algorithm is improved,the developed system will be real-time miniaturization and portability.All above research can constitute a set of depth information measurement system based on active light illumination,and an example of 3D measurement of a dynamic object is given with one color structured light image and stereo vision technique.