基于微惯性/偏振视觉的组合定向方法

Integrated orientation method based on the micro-inertial and polarized vision

本文针对目前偏振视觉定向难以满足三维空间内运动水平姿态变化时的定向需求、动态适应性差以及微惯性系统漂移大的问题,提出了一种基于微惯性/偏振视觉的组合定向方法。首先,为了减少偏振测量噪声,利用标准大气Rayleigh散射模型,给出了一种基于大气偏振视觉图像的太阳矢量优化估计算法;其次推导了基于卡尔曼滤波的微惯性/偏振视觉组合定向算法,该算法利用微惯性信息对偏振视觉定向进行水平角补偿,可以获得三维空间内的运动姿态并且动态性能高;最后进行了飞行仿真与车载实验验证。实验结果表明,融合微惯性信息补偿水平姿态与组合滤波后,车载航向误差不随时间累积且均方根误差仅为0.75°,与偏振视觉定向相比,定向精度提升可达60%以上。同时在不增加偏振图像计算量的基础上,将定向输出频率从1 Hz提高至100 Hz,显著增强了偏振视觉定向的动态适应性,具有较大的应用前景。

Aiming at the problems that the current polarization vision orientation is difficult to meet the high dynamic adaptability in the three-dimensional space and the micro-inertial system has the large drift,an integrated orientation method based on micro-inertia/polarization vision is proposed.Firstly,in order to reduce the polarization measurement noise,an optimized estimation algorithm of the solar vector based on the atmospheric polarized images is provided with the standard atmospheric Rayleigh scattering model.Secondly,an integrated micro-inertial/polarization vision orientation algorithm based on the Kalman filtering is proposed.The algorithm uses the inertial information to compensate the horizontal orientation of the polarized visual orientation,and can obtain the motion attitude in three-dimensional space and has high dynamic performance.Finally,flight simulation and on-board experiment verification are carried out.Experimental results show that the integrated inertial/polarized vision orientation algorithm can effectively suppress the cumulative error of inertial orientation,and the root-mean-square error is only 0.75°in the vehicle experiment.Compared with polarized visual orientation,the orientation accuracy can be improved by above 60%.At the same time,without increasing the amount of polarized image calculation,the orientation output frequency is increased from 1 Hz to 100 Hz,which significantly enhances the dynamic adaptability of the polarized visual orientation and has a large application prospect.