基于相位映射的结构光相位误差补偿方法研究

Research on structured light phase error compensation based on phase mapping

为减小结构光投影视觉测量系统中相位失真对测量结果的影响,基于最小二乘法和线性插值方法,建立实际光栅相位与理想光栅相位映射关系,并以此关系对投影条纹的相位误差进行校正。在校正过程中,为满足线性插值的单调性、有效性和唯一性,对所采集到的相位进行线性拉伸变换,使其覆盖全部投射相位值,并引入微调函数使其形成单调变化的相位序列。为验证该方法的有效性,搭建由摄像机、投影仪组成的光栅投影结构光三维测量系统。实验结果表明:该方法能够对投影仪生成的光栅条纹的非正弦畸变进行补偿和校正,并最终给出合理的相位测量结果。该方法简单可行,可用于实际结构光测量系统的校正。

To reduce the influence of phase distortion of structured light projection visual measurement system on measurement results,the mapping relationship between actual raster phase and ideal raster phase is established based on the least squares method and linear interpolation method,and then this relationship is adopted to correct the phase error of projection fringes.In order to satisfy the monotonicity,validity and uniqueness of the linear interpolation in the process of correction,linear stretch transformation is carried out for collected phase to cover all the projected phase values,and a trimming function is introduced to form a monotonic phase sequence.In order to verify the effectiveness of this method,a raster projection structured light 3D measurement system composed of camera and projector is designed.The test results indicate that the method can compensate and correct the non-sinusoidal distortion of the raster fringes generated by the projector,and give a phase measurement reasonable result eventually.This method is simple and feasible and can be used to correct structured light measurement system in practice.