Research On A3D Measurement System Using3-Coding Circle Triangular Gray Distribution Structured Light

In many structured light3d measurement technology, coding structured lightwith its agile method, high accuracy, speed and robust and good real-time, hasbecome the research hot spot and the direction of the structured light3dmeasurement technology.It has been successfully applied to the robot navigation,face recognition, reverse engineering and medical diagnosis, etc.In a single scan on the target object, using the traditional coding structuredlight3d measurement system, it usually can not be measured object complete3dinformation for the barrier of the shape and observation angle limits. To solvethis problem, this paper adding another camera to the coding structured light3dmeasurement system,increases the measurement system’s visual range andcomplete information of the object through the single measurement.According to the two-camera coding structured light3d measurement system,this paper uses a new coding structured light3d measurement system self-calibrationmethod. The polar constraint is applied to the self calibration of the coding structuredlight3d measurement system and a self-calibration mathematical model isestablished. Compared with the other calibration method, this method candetermine the camera and the projector all the parameters without moving targetplane in more than one position to be measured.The coding structured light can be coding can be divided into space codingand time coding. At present, the time coding because of its high accuracy and moreflexible coding way has become the research hotspot. Phase shifting method is akind of important method of the time coding. It can realize the continuoussampling for the measurement space. But when in decoding of phase shifting method, there will be a large number of the arctangent calculations and it need tosolve the problem of wrapped phase Aiming at the shortcomings of the phase shiftmethod, this paper introduces the Chinese remainder theorem to structured lightcoding and decoding method, adopts three coding-cycle, and makes each codingpattern is carried out in accordance with the gray symmetric linear rule changes, tofurther improve the measurement speed and precision of the system, and effectivelymake up for the deficiency in the phase shift method.The experimental results show that the proposed3-coding cycle triangulardistribution structured light3d measurement system can effectively improve themeasurement system’s visual range and accuracy.