Research On Depth Perception Technology Based On Structured Light

Depth perception technology based on machine vision has been widely used in fields such as 3D printing,medical imaging,somatosensory equipment,geo-mapping,industrial measurement,3D video and game production due to its features of non-contact,high speed,high precision and wide application range.It has further expanded people's perception to 3D information,thus is of valuable importance in the current scientific research and engineering technology.A key issue in this research field is how to obtain 3D data of objective objects more efficiently and real-time through visual information.Depth perception technology based on structured light has the characteristics of low hardware requirement,simple structure,small amount of data operation and good dynamic adaptability etc.,and has attracted wide attention from researchers.Aiming at improving the calibration speed and perception accuracy,the Paper deeply studies several aspects including camera & projector calibration,non-sinusoidal stripe correction,phase unwrapping algorithm and system hardware & software construction.The main research contents contain:(1)In traditional system calibrations,camera and projector are separately calibrated in general,which often affects the calibration speed.To solve this problem,it is studied in this paper the geometrical models of images formed in camera and the projector,and built inverse camera mathematical model of the projector based on the similarities between the mathematical models of the projector and the camera.Besides,the camera calibrated external parameters are used to determine the plane equation of the projected image on the same calibration plane.Experimental results show that this method can effectively reduce the time spent on system calibration.(2)In this paper,it is also analyzed and compared the advantages and disadvantages of the phase unwrapping algorithms in the time domain and the spatial domain.Since the phase unwrapping algorithm in the spatial domain is based on a continuous path,here comes an error accumulation problem.To solve this,an improved phase unwrapping algorithm based on discontinuous path is used.Results show that this method can effectively suppress the error accumulation.Meanwhile,the triband frequency heterodyne method is adopted in the time domain to eliminate the error accumulation in principle,and experimental results also show that such method can effectively prevent errors.At last,the method of phase unwrapping in noise scene is studied.(3)For non-sinusoidal distortion of projection fringes,phase monotonicity is taken as the correction constraint condition in this paper,and algorithm based on minimum energy principle is used.Aiming at the problem of narrowing the phase range in the experiment,some improvements have been made by stretching the phase amplitude first before the correction.The final experimental results show that the improved method can better meet the experimental calibration requirements,and effectively suppress error accumulation.The aforesaid study mainly covers the data acquisition part of the depth perception technology based on structured light,which lays a theoretical foundation for the further development and application of depth perception technology.Simulation and experimental results show that the method used in this Paper is feasible and effective.