The Study Of The System For Non-contact Body 3D Measurement

We mainly researched the theory of 3-D shape measurement and basing it wedeveloped an applying system. Using of the optic theory and the computertechnique, we acquired the information of 3-D shape from the picture. Currently,the technique of 3-D shape measurement is in the stage of start in our country andis popular in the world, so its research has very large space. Because the techniqueis simple in structure, easily in applying, lower cost and is suitable for actualitem to development, we applied it to body measurement and developed a set ofproduction. The following are researched in this paper.1.The general situation of 3-D measurement technique is summarized.3-D measurement technique mainly includes contact-measurement andnon-contact-measurement, and in which the contact-measurement is alreadymature , but it has the lower speed and lower efficiency , While thenon-contact-measurement which including laser scanning , stereoscopicmeasurement, CT and structural light shining etc has the high resolution,no-broken and quickly data-acquiring, so on the basis the analysis of many bodymeasurement we put forward the system using the Phase Detection of ProjectedGrating2.The basic theory of non-contact 3-D measurement system is introduced.First, the optic theory of Phase Detection of Projected Grating is elaboratedand the height formula of measured object compared to reference plane wasdeduced. Second we introduced several kinds of expand phase theory, systemdemarcate and height solve etc. We improved the phase moving technique toacquire the actual phase of anamorphic grating, which improves the accuracy andefficiency of the measurement. In the aspect of demarcate, a few differentdemarcate method were introduced which guarantees the position among CCD,projector and objection. Because we adopted the projector to take place of themechanical moving equipment, the accuracy and feasibility of system is improvedand the time of data acquiring is shorten. We elaborated the image connectiontheory. In order to need the demand of the system we put forward a work plane.3.The hardware and software of the system are researched.We developed a platform that can circle and put the projector, CCD, motorand platform to together. Another, we chose the motor and its controlling mode.At the same time, the style of the image collection board, CCD and projector arealso confirmed.4.The error of measurement and its reason is analyzed.We analyzed the error causing by projection, imaging, demarcate,parameter of grating etc and improve the method to reduce the error. Another, weimprove the method of objection image stripe and image dark to identify the imageborderline and carry on its test.5.The applying of system is introduced.In order to the attain effect of the system, we carried on a set of test on modelbody and the result all are ideal. If we carry this technique on CAD/CAM, RE,RP and VR etc, we will acquire a larger value and better benefit.