Three-Dimensional Profile Measurement For Human Body Based On Grating Projection Under The Synchronous Trigger

3-D profile measurement technology based on frequency multiplication grating projection is used to measure unstable and uncontrollable human body,a synchronous trigger device is designed to trigger grating projection and image acquisition simultaneously.By means of frequency doubling grating phase-shifting technology,the three-dimensional shape of five parts of the human body is measured,and the height of each sampling point on the surface of the part to be measured is calculated independently.In order to adapt to the measurement of human body's three-dimensional shape,it is necessary to ensure that the experimental system has good stability.On this basis,the synchronous trigger device with MC100 chip as the core is added,and the corresponding control software is designed.The system ensures the stability,rapidity and efficiency of the image acquisition process,and realizes the automatic control of the system for the three-dimensional measurement of human body.It provides an effective measure for 3-D profile measurement in the field of uncontrollable living areas.The main research work is as follows:(1)In order to measure the three-dimensional shape of human body,a system based on double-frequency grating phase-shifting controlled by synchronous triggering is established.The projection system is controlled by computer,and the sinusoidal gratings at various spatial frequencies are projected onto the surface of the human body to be measured.The acquisition system is controlled by synchronous trigger device,and a large number of deformed gratings modulated by the surface of the object are quickly collected.(2)The hardware and software features of MC100 chip are studied,and a synchronous trigger device controlled by computer is designed to ensure the high synchronization of grating switching and image acquisition.According to the relationship between the grating switching speed,the time delay time of the image acquisition and the speed of the image acquisition,the best parameters of the synchronous trigger device for the 3-D profile measurement of the human body are found.(3)The corresponding control program of synchronous acquisition system and the processing program of the aberration stripes are written.The driver of synchronous triggering device is written by Visual Basic platform,the projection system and the acquisition system can not only synchronize but also have controllability.A computer program performs phase unwrapping operations from the lowest frequency to the highest frequency step by step,andthen combining the mapping between height and phase in the distorted stripe image,thus the3-D profile of the object is reconstructed.