Research On 3D Real-time Measurement Technology With LED Linear Light Source

With the rapid growth of the current demand for 3D digital models,the method of artificially designing digital models has been unable to meet its needs while considering the time efficiency.Existing commercial three-dimensional measuring devices have high development and use costs,are bulky and not portable,and measurement efficiency needs to be improved.To solve the above problems,an improved device of the traditional three-dimensional measurement system based on surface structured light is designed,and the real-time 3D measurement technology based on a single-shot fringe projection is deeply studied.The experimental results show the feasibility of the improved device,which greatly promotes the value of production.The main research results of this paper are as follows:(1)Aiming at the problems of high cost and inconvenient carrying of three-dimensional measurement products,a linear light source with LED and a plastic grating are used to implement the projection scheme,and a low-cost,compact and portable three-dimensional measuring device is designed.In the fringe projection morphology measurement system,the projector is removed,the LED patch lamp beads are arranged in a row as a linear light source,the STM32 to drive the LED on/off smoothly,and place a printed plastic grating horizontally in front of the light source.The projection system and the image acquisition system are compactly designed and have a volume of 100 mm×50 mm×100 mm.(2)In order to solve the error propagation problem in phase unwrapping of traditional single-shot methods,a new phase unwrapping algorithm is proposed.The algorithm is based on the wrapped phase obtained by the Fourier transform method,then the known absolute phase of the standard plane as the reference phase and expands the wrapped phase of pixel-by-pixel.Simulation experiments and real experiments show that compared with the existing expansion algorithms based on single-shot,this algorithm has higher recovery accuracy and measurement efficiency.The measurement accuracy RMSE value reaches0.00036 rad,the execution time of single frame(with 260,000 pixels)is 0.04 s,andthe maximum error of real experiment is 0.19 mm.