Robust SLAM localization method based on improved variational Bayesian filtering

一种基于改进变分贝叶斯滤波的鲁棒SLAM定位方法

Aimed at the problem that the state estimation in the measurement update of the simultaneous localization and mapping(SLAM)method is incorrect or even not convergent because of the non-Gaussian measurement noise,outliers,or unknown and time-varying noise statistical characteristics,a robust SLAM method based on the improved variational Bayesian adaptive Kalman filtering(IVBAKF)is proposed.First,the measurement noise covariance is estimated using the variable Bayesian adaptive filtering algorithm.Then,the estimated covariance matrix is robustly processed through the weight function constructed in the form of a reweighted average.Finally,the system updates are iterated multiple times to further gradually correct the state estimation error.Furthermore,to observe features at different depths,a feature measurement model containing depth parameters is constructed.Experimental results show that when the measurement noise does not obey the Gaussian distribution and there are outliers in the measurement information,compared with the variational Bayesian adaptive SLAM method,the positioning accuracy of the proposed method is improved by 17.23%,20.46%,and 17.76%,which has better applicability and robustness to environmental disturbance.

针对非高斯分布的测量噪声、野值点或未知时变的噪声统计特性导致SLAM定位方法的量测更新中状态估计不正确甚至不收敛的问题,提出一种基于改进变分贝叶斯滤波的鲁棒SLAM定位方法.首先,利用变分贝叶斯自适应滤波算法对时变的测量噪声协方差进行估计.然后,通过重加权平均构建的权重函数对估计的协方差矩阵进行鲁棒化处理.最后,对系统状态更新进行多次迭代,逐步修正其估计误差.同时,为了观测到不同深度的特征点,构建了包含深度参数的特征测量模型.实验结果表明,当量测噪声不服从高斯分布且量测信息中有野值点时,与基于变分贝叶斯自适应卡尔曼滤波的SLAM方法相比,所提方法的定位精度分别提高了17.23%、20.46%和17.76%,说明该方法对环境干扰具有更好的适用性和鲁棒性.