Development Of Three-dimensional Digital Model Projector

Function representation of space information is patterning modality,and its information representation is relative abstract.With the diversification of information expression forms,it gradually extends from the planar space to the three-dimensional space.The tradition method is to use tools such as templates and tape measures or determine the position of markings based on drawings when its need to be painted on equipment surface in areas such as shipbuilding,aircraft and railway equipment.Such methods rely on the technical level of staffs,which not only time and vigour and error-prone,and it may cause irreversible damage to the surface to device.The use of a three-dimensional digital model projector can quickly orient the spatial position of device.Therefore,it is very necessary to develop a three-dimensional digital model projector to realize fast and automatic digital marking.The three-dimensional digital model projector consists of an industrial camera,an auxiliary camera,and a DLP projector.The camera and projector are packaged and controlled by a controller,and its need building a software platform to form the three-dimensional digital model projector system.The projector system is a high-precision projection measurement system with the advantages of non-contact,high-precision,rapidity and maneuverability.The three-dimensional digital model projector developed in this paper can direct the equipment in the three-dimensional space in real time,establish the spatial relationship between the projector and the equipment.Then it converts the technical indicators to be projected into the images to be projected,and projects the images to be projected to the three-dimensional space by the projector.It can be used to realize the digital marking on the surface of blanks and large-sized equipment.The main research contents are as follows:1.According to the technical indicators of the three-dimensional digital model projector,the model of each component of the hardware is selected.Select the type of coding mark and design the DLP projector calibration image according to the selected type,and design software function interactive interface according to the function of the three-dimensional digital model projector to be implemented.2.The algorithms and technical methods used to develop the three-dimensional digital model projector are researched.The image preprocessing,circular marker edge detection and center positioning,automatic matching of homonym points,spatial rectangular coordinate system conversion and single image space resection are researched,and the overall calibration of the three-dimensional digital model projector is completed.3.Implement the software interaction interface and briefly introduce the function modules involved.Calibrate camera's internal parameters using the ten parameter model.The projector calibration image is designed and the projector is calibrated based on ZhangZhengyou calibration method,and the reverse projection error is calculated.The external parameters of the projector relative to the camera are obtained by converting the spatial rectangular coordinates system.The real-time spatial orientation of the physical object is real-timely directed using the spatial resection,the technical indicators are written into corresponding positions of the image to be projected,and finally the projected image is projected onto the physical surface.