Research On Dynamic Measurement Of Color Crosstalk Based On Fringe Projection

Low-frequency vibration detection is more and more widely used in the field of industrial measurement.Considering the distance between the measured object is far away from the measurer,or that the object is soft and prone to deformation,the traditional contact measurement method can only measure the static object.In order to make fast full-field measurement,non-contact optical measurement method is needed.Fringe projection technology is an important part of non-contact measurement.By comparing the phase difference between two fringe images taken by the camera before and after the object is placed,the 3d depth information of the object can be obtained.The fringe projection technology based on color multi-channel has the advantages of fast calculation speed,instantaneous information acquisition,high accuracy,good anti-noise performance and wide application,which can meet the requirements of vibration measurement.Firstly,this paper introduces the necessity of vibration measurement and the method of surface measurement of the current stage.The principle of phase shift transformation profilometry and color coupling elimination is theoretically expounded,and the phase shift measurement method based on color composite fringe projection is derived.Real-time measurement of dynamic objects.Under the premise of solving the color crosstalk problem,the phase shift method is used for height recovery,and a specific reference point in the height restoration map is extracted,and the frequency and amplitude of the vibrating object are analyzed by the height variation curve.Then,the principle of 3D reconstruction theory based on HSI color space is expounded in detail,and a new hue-height mapping based measurement method is proposed.The monotonicity of hue and periodicity are used to avoid the influence of color crosstalk on measurement.A flexible measurement of vibrating objects is achieved.This measurement method can detect the vibration of 253 micrometers,and the cost is low,the precision is high,and it is easy to put into use in large quantities,meeting the needs of most industrial real-time measurement.Finally,the error of the measurement process is measured.The error distribution can be visually seen through the error experiment diagram,based on this,the discussion and theoretical analysis are carried out.The method of reducing the measurement error is proposed from different angles.With the prospect,we plan the future research direction.