Research On 3D Measurement System Of Missile Based On Point Cloud Data And Structured Light

With the development of modern industry,many large-scale parts have complex surface morphology.How to carry out accurate inspection is the main problem facing modern industry.Structured light technology is an active test measured by non-contact means.This technique has the characteristics of high accuracy,wide range,easy expansion and strong adaptability.The most advanced active visual non-contact measurement has been widely used in various fields such as industrial automation,medical auxiliary instruments,reverse engineering,etc.This paper briefly introduces the optical three-dimensional measurement method and describes the format and application of structured light measurement.The encoding and decoding algorithms of optical instrument and turntable calibration and system Gray fringe processing are also studied.On this basis,the hardware and software design of the missile three-dimensional measurement system is completed.Firstly,the formula of the measured object's space attitude is obtained by analyzing the measurement model.The calibration methods and algorithms of two kinds of optical instruments in the measurement system are studied and analyzed,and a reasonable calibration scheme is designed.The non-linear calibration of the camera is realized by using the technology that the three-dimensional position of the object to be measured changes at will.The calibration technique of local single stress matrix is used to solve the problem of low accuracy of projector calibration technique,and the internal and external parameters and distortion coefficient of projector in the system are given.This paper studies the model of dual camera system,analyzes the difference between single camera and dual camera in measuring objects at the same level,and determines the selection of dual cameras for testing in the structured light three-dimensional measuring system.Secondly,the system's optical instrument calibration parameters and decoded data are combined to calculate the appearance cloud data of the measured object.The sparse noise reduction technique of multi-point cloud is analyzed,and the linear rotation axis equation based on chessboard calibration board position is obtained.A three-dimensional measurement system using motion control card to control the turntable is designed and implemented.The automatic collection of multi-view cloud is realized by rotating the platform.Finally,different encoding techniques of the projector are discussed and compared.Finally,the method of obtaining invalid regions by forward and backward Gray encoding and combining direct and indirect light components of the projected image is adopted,and Gray gray values are obtained by the intersection method.The system is used to test the standard measuring tool and the missile.The experimental data show that the missile three-dimensional measurement system has high measurement accuracy and can meet the measurement requirements of the missile.