Development Of Vision Measurement Equipment With 3D Structured Light

The vision measurement equipment with 3D structured light is a high precision automatic 3D scanning measurement equipment which can achieve non-contact 3D measurement.Through the structured light scanning method,we can measure 3D coordinates of the surface points and obtain the three-dimensional information of the object surface points.Then,we can obtain the 3D model after the processing of computer software tool.Thanks to the advantages of portable,non-contact and high accuracy,3D structured light vision measurement equipment are widely used in industrial design,quality inspection,many fields of reverse engineering.The precision of measuring equipment is an important technical index,while the calibration of space position relations between the parameters of lighting equipment and imaging equipment,and specular reflectance has a direct effect on the imaging quality and accuracy.It is required to calibrate the parameters for camera,optical projector and two spatial position relationship.Besides,the suppression and removal of specular reflection image are also required.This paper mainly describes the design and implementation of 3D structured light vision measurement equipment.This paper first discusses the theory of space structured light and the overall structure design of vision measurement equipment.Then,we introduce two methods for structured light programming,analysis the factors which can affect the accuracy,and then design the measurement process of the whole experiment.According to the performance indicators and requirements of the task book on camera,optical projector and electrical equipment are selected.This paper also discusses the imaging optical projector and camera control,analyzes the encoding,decoding,formal methods for structured light,and integrates the lighting method with gray code phase encoding method.And then we analyze the factors affecting the accuracy and realize the synchronous control of optical projector and camera and the control of signal source and light source of the optical projector.It provides the basis for the follow-up work.This paper analyzes the characteristics and technical indexes of the measurement system and formal simulates the calibration algorithm for camera,projector and their spatial relation.Then,we implement the software engineering and calibrate the parameters of the camera for the visual measurement system,optical projector and their spatial relationship.After that,we evaluate the accuracy and correct the image.At the end of this paper,low reflection and specular reflection objects are measured,the measurement results are analyzed.According to the characteristics of the 3D structured light vision measurement equipment,we propose the measurement method for detail region and specular reflection area.And we also use a filling method with interpolation for the specular reflection image region to restore the damaged image and remove object from the image or reduce the image noise,and finally let the measuring results meet the accuracy requirements.