A tracking algorithm based on improved Camshift and UKF is proposed in this paper to deal with the problems which exist in traditional Camshift algorithm, such as artificial orientation and tracking failure under colo...A tracking algorithm based on improved Camshift and UKF is proposed in this paper to deal with the problems which exist in traditional Camshift algorithm, such as artificial orientation and tracking failure under color interference as well as object’s changed illumination occlusion. Meanwhile, in order to solve the sheltered problem, the UKF is combined with improved Camshift algorithm to predict the position of the target effectively. Experiment results show that the proposed algorithm can avoid the interference of the background color and solve the sheltered problem of the object, so that achieving a precise and timely tracking of moving objects. Also it has better robustness to color noises and occlusion when the object’s scale changes and deformation occurs.展开更多
针对传统Unscented卡尔曼滤波器(Unscented Kalman filter,UKF)在噪声先验统计未知时变情况下非线性滤波精度下降甚至发散的问题,设计了一种带噪声统计估计器的自适应UKF滤波算法.首先根据极大后验(Maximum a posterior,MAP)估计原理,...针对传统Unscented卡尔曼滤波器(Unscented Kalman filter,UKF)在噪声先验统计未知时变情况下非线性滤波精度下降甚至发散的问题,设计了一种带噪声统计估计器的自适应UKF滤波算法.首先根据极大后验(Maximum a posterior,MAP)估计原理,推导出一种次优无偏MAP常值噪声统计估计器;接着在此基础之上,采用指数加权的方法,给出了时变噪声统计估计器的递推公式;最后对自适应UKF算法进行了性能分析.相比于传统UKF,该自适应UKF算法在噪声统计未知时变情况下不仅滤波依然收敛,滤波精度及稳定性显著提高,而且其具有应对噪声变化的自适应能力.仿真实例验证了其有效性.展开更多
针对舰船捷联惯性导航系统姿态控制计算精度要求,提出一种高阶矩匹配UKF(high-order moment matching UKF,Ho MM-UKF)的SINS系统四元数模型姿态估计算法.在UKF迭代递推计算过程中利用高阶矩匹配方法计算系统状态参数的预测采样点集及其...针对舰船捷联惯性导航系统姿态控制计算精度要求,提出一种高阶矩匹配UKF(high-order moment matching UKF,Ho MM-UKF)的SINS系统四元数模型姿态估计算法.在UKF迭代递推计算过程中利用高阶矩匹配方法计算系统状态参数的预测采样点集及其权值的概率分布平均偏态和峰值,使其精确逼近状态参数最优估计.采用四元数姿态建模方法构建新型SINS状态变量与噪声向量相关的姿态方程模型,利用伪观测向量构建观测噪声与四元数相关的观测方程模型,设计系统噪声方差分离计算算法开展系统噪声方差计算,引入拉格朗日乘子算法计算四元数估计均值,最后利用SINS四元数姿态估计模型对HoMM-UKF算法开展仿真试验研究.通过UKF算法、CDKF算法与HoMM-UKF算法对比,验证了HoMM-UKF算法计算精度高,并且算法计算量负担较小,计算效率较高.展开更多
文摘A tracking algorithm based on improved Camshift and UKF is proposed in this paper to deal with the problems which exist in traditional Camshift algorithm, such as artificial orientation and tracking failure under color interference as well as object’s changed illumination occlusion. Meanwhile, in order to solve the sheltered problem, the UKF is combined with improved Camshift algorithm to predict the position of the target effectively. Experiment results show that the proposed algorithm can avoid the interference of the background color and solve the sheltered problem of the object, so that achieving a precise and timely tracking of moving objects. Also it has better robustness to color noises and occlusion when the object’s scale changes and deformation occurs.
文摘针对传统Unscented卡尔曼滤波器(Unscented Kalman filter,UKF)在噪声先验统计未知时变情况下非线性滤波精度下降甚至发散的问题,设计了一种带噪声统计估计器的自适应UKF滤波算法.首先根据极大后验(Maximum a posterior,MAP)估计原理,推导出一种次优无偏MAP常值噪声统计估计器;接着在此基础之上,采用指数加权的方法,给出了时变噪声统计估计器的递推公式;最后对自适应UKF算法进行了性能分析.相比于传统UKF,该自适应UKF算法在噪声统计未知时变情况下不仅滤波依然收敛,滤波精度及稳定性显著提高,而且其具有应对噪声变化的自适应能力.仿真实例验证了其有效性.
文摘针对舰船捷联惯性导航系统姿态控制计算精度要求,提出一种高阶矩匹配UKF(high-order moment matching UKF,Ho MM-UKF)的SINS系统四元数模型姿态估计算法.在UKF迭代递推计算过程中利用高阶矩匹配方法计算系统状态参数的预测采样点集及其权值的概率分布平均偏态和峰值,使其精确逼近状态参数最优估计.采用四元数姿态建模方法构建新型SINS状态变量与噪声向量相关的姿态方程模型,利用伪观测向量构建观测噪声与四元数相关的观测方程模型,设计系统噪声方差分离计算算法开展系统噪声方差计算,引入拉格朗日乘子算法计算四元数估计均值,最后利用SINS四元数姿态估计模型对HoMM-UKF算法开展仿真试验研究.通过UKF算法、CDKF算法与HoMM-UKF算法对比,验证了HoMM-UKF算法计算精度高,并且算法计算量负担较小,计算效率较高.
