基于平方根UKF的多传感器融合跟踪

为了提高融合算法的精度,将UKF(Unscented Kalman Filter)算法与多传感器顺序滤波融合跟踪算法相结合,提出了基于UKF的多传感器序贯融合算法.UKF算法利用非线性方程自身的传播,估计系统状态,避免了对非线性方程线性化的过程.顺序滤波融合算法用同一时刻的量测依次更新状态,计算复杂性低.仿真结果表明,UKF顺序滤波融合跟踪算法比传统的扩展卡尔曼滤波(EKF)算法有更高的跟踪性能,是一种有效的非线性融合算法.     

联合高斯回归的平方根UKF方法

针对传统的滤波方法容易受系统动态模型不确定性和噪声协方差不准确的限制这一问题,提出一种将高斯过程回归融入平方根不敏卡尔曼滤波（unscented Kalam filter,UKF）算法中的滤波算法。该算法用高斯过程对训练数据进行学习,得到动态系统的回归模型及系统噪声的协方差;采用标准的平方根UKF算法,状态方程和观测方程,相应的噪声协方差由高斯过程实时自适应调整。将应用于飞行器SINS/GPS组合导航,结果表明,该方法能够自适应系统噪声,收敛速度快,导航精度高。     

基于多传感器数据融合的机动目标跟踪自适应学习方法

考虑到传感器对目标的观测都存在有偏差，同时针对雷达系统检测中存在漏检的现象，提出了一种适用于处理传感器漏检现象的多传感器融合方法。并以雷达／红外成像复合的双模制导体系下红外和雷达两种传感器对目标状态的检测和跟踪为例，给出一个完整的多传感器数据融合和目标跟踪自适应方法。该方法简单易行，鲁棒性强，通过对红外成像和雷达系统的数据融合和目标跟踪的数字仿真，表明该方法有效。另外，该方法同样适用于多于两个多传感器系统。     

改进的强跟踪平方根UKF在卫星导航中应用

针对应用于受不确定性干扰和噪声影响的卫星自主导航系统中的无迹卡尔曼滤波（unscented Kalman filter,UKF）存在估计精度低、跟踪性能差和鲁棒性弱等缺陷,提出一种改进的强跟踪平方根UKF(strong tracking square-root UKF, STSRUKF)导航方法。该方法中利用星敏感器和光学导航相机设计出导航方案,并通过转换方程将间接量测量转换为观测量。针对平方根UKF（square-root UKF, SRUKF）在高阶系统中因为sigma点的零权值系数是负的或者数值计算误差太大时而可能造成滤波器发散问题,采用一种改良的平方根分解方法,改善了滤波器的稳定性。同时,基于强跟踪滤波器理论（strong tracking filters, STF）,引入多重自适应衰减因子调节协方差矩阵,使得滤波器具有强跟踪能力和克服系统模型不确定的鲁棒性,改善了滤波器的估计精度。将该方法应用于卫星自主导航系统中,实验仿真结果表明,相对于平方根UKF和STF,该方法不仅保证了系统的可靠性,还提高系统的导航精度和改善系统的鲁棒性及跟踪能力。     

多被动传感器UKF与EKF算法的应用与比较

针对多被动传感器条件下的目标跟踪问题,给出了推广卡尔曼滤波在多被动传感器条件下的具体算法;考虑到多被动传感器目标跟踪需要解决观测非线性的问题,故而将用于非线性系统的基于UT变换的UKF算法应用于所讨论的跟踪问题中,采用检测融合方案,将多个被动传感器的角度观测组合成量测向量,推导了多被动传感器的UKF滤波算法,实现了对目标在三维空间中的全被动跟踪.将两种算法进行了仿真比较,结果表明,采用多被动传感器的UKF算法可以获得比传统的推广卡尔曼滤波算法更为精确的跟踪效果.     

基于推广卡尔曼滤波的多站被动式融合跟踪

将推广卡尔曼滤波(EKF)算法与集中式融合跟踪算法相结合，用于被动式多站跟踪，给出了基于EKF的被动式多站集中式融合跟踪算法。该算法可解决被动式跟踪系统的可观测性及非线性问题。以三个站进行跟踪为例，进行了仿真研究，结果表明该算法具有满意的跟踪性能。     

杂波环境下多传感器跟踪的数据融合

本文介绍了一种在杂波环境下,利用两个传感器跟踪一个高度机动目标的算法。该算法是由以下两个算法相结合组成：（１）适合杂波环境下机动目标跟踪的概率数据关联滤波算法;（２）适合高度机动目标跟踪的混合多模算法。文中给出了这种新算法的一个计算机模拟结果。     

多传感器异步融合技术研究

多传感器信息融合理论大都是在无系统偏差和量测同步的理想条件下给出的,而实际的工程背景却并非如此。因此,在实际的工程实践中发现融合的效果并不理想,有的甚至不如融合前的效果好。为解决这一问题,研究了系统偏差条件下的多传感器异步融合问题。针对不同的工程背景,提出了两种异步融合算法：异步卡尔曼滤波（asynchronous Kalman filter, ASKF)算法和扩展异步卡尔曼滤波（generalized asynchronous Kalman filter, GASKF）算法。仿真表明,两种算法实现了异步量测条件下目标状态和系统偏差的有效跟踪。     

修正并行式多传感器不敏多假设跟踪算法

为了有效解决非线性系统中的多传感器多目标跟踪问题,提出了一种修正并行式多传感器不敏多假设滤波算法。算法运用概率数据互联的思想对各传感器的估计量进行概率加权,克服了并行式多传感器算法的误差积累现象,得到了一种修正的多传感器并行式算法。各传感器中量测点迹与航迹的数据互联问题通过多假设方法予以解决,并通过不敏卡尔曼滤波器完成非线性系统中的目标跟踪。仿真结果表明,从跟踪精度及稳定性方面看,所提出的算法性能要优于MSJPDA/EKF算法。     

多传感器远距离目标跟踪

本文深入研究了二维平面上多传感器的位置对目标跟踪精度的影响。在理论上推导出：用多传感器同时对同一目标进行跟踪时,其跟踪精度主要受传感器和目标所成夹角及目标到各传感器距离的影响。与夹角的关系是：当有两部传感器时,两传感器和目标所成夹角θ_（１２）＝９０°时对目标的跟踪精度最高;当有三部传感器时,传感器和目标所成的夹角分别为θ_（１２）＝θ_（２３）＝６０°时精度最高;与目标到各传感器的距离的关系是：距离越小则精度越高。     

Modified unscented Kalman filter using modified filter gain and variance scale factor for highly maneuvering target tracking

To improve the low tracking precision caused by lagged filter gain or imprecise state noise when the target highly maneuvers, a modified unscented Kalman filter algorithm based on the improved filter gain and adaptive scale factor of state noise is presented. In every filter process, the estimated scale factor is used to update the state noise covariance Qk, and the improved filter gain is obtained in the filter process of unscented Kalman filter （UKF） via predicted variance Pk｜k-1, which is similar to the standard Kalman filter. Simulation results show that the proposed algorithm provides better accuracy and ability to adapt to the highly maneuvering target compared with the standard UKF.     

Phase noise filtering and phase unwrapping method based on unscented Kalman filter

This paper presents a new phase unwrapping algorithm based on the unscented Kalman filter(UKF) for synthetic aperture radar(SAR) interferometry.This method is the result of combining an UKF with path-following strategy and an omni-directional local phase slope estimator.This technique performs simultaneously noise filtering and phase unwrapping along the high-quality region to the low-quality region,which is also able to avoid going directly through the noisy regions.In addition,phase slope is estimated directly from the sample frequency spectrum of the complex interferogram,by which the underestimation of phase slope is overcome.Simulation and real data processing results validate the effectiveness of the proposed method,and show a significant improvement with respect to the extended Kalman filtering(EKF) algorithm and some conventional phase unwrapping algorithms in some situations.     

Unscented extended Kalman filter for target tracking

A new method of unscented extended Kalman filter (UEKF) for nonlinear system is presented. This new method is a combination of the unscented transformation and the extended Kalman filter (EKF). The extended Kalman filter is similar to that in a conventional EKF. However, in every running step of the EKF the unscented transformation is running, the deterministic sample is caught by unscented transformation, then posterior mean of nonlinearity is caught by propagating, but the posterior covariance of nonlinearity is caught by linearizing. The accuracy of new method is a little better than that of the unscented Kalman filter (UKF), however, the computational time of the UEKF is much less than that of the UKF.     

Fault tolerant navigation method for satellite based on information fusion and unscented Kalman filter

An effective autonomous navigation system for the integration of star sensor, infrared horizon sensor, magnetometer, radar altimeter and ultraviolet sensor is developed. The requirements of the integrated navigation system manager make optimum use of the various navigation sensors and allow rapid fault detection, isolation and recovery. The normal full fusion feedback method of federated unscented Kalman filter (UKF) cannot meet the needs of it. So a no-reset feedback federated Kalman filter architecture is developed and used in the autonomous navigation system. The minimal skew sigma points are chosen to improve the calculation speed. Simulation results are presented to demonstrate the advantages of the algorithm. These advantages include improved failure detection and correction, improved computational efficiency, and reliability. Additionally, its’ accuracy is higher than that of the full fusion feedback method.     

基于平方根CKF的多传感器序贯式融合跟踪算法

为了提高非线性序贯式融合跟踪算法的精度,提出了基于平方根容积卡尔曼滤波器的多传感器序贯式融合跟踪算法。该算法使用三阶容积数值积分原则计算非线性过程的均值和方差,克服了扩展卡尔曼滤波器存在的滤波精度低及平方根无迹卡尔曼滤波器存在的参数复杂的缺点。同时,在滤波递归过程中以协方差平方根矩阵代替协方差矩阵,这样确保了滤波算法的数值稳定性,提高了跟踪的精度。最后用已知弹道系数的再入段弹道跟踪模型对所提算法的性能进行仿真测试。仿真结果表明,所提算法具有很好的跟踪性能,是一种有效的非线性序贯式融合跟踪算法。     

基于修正的自适应平方根容积卡尔曼滤波算法

目标建模不确定性会造成滤波算法性能下降,通过构建强跟踪滤波器(strong tracking filter,STF)可以提升滤波算法的自适应性,但是构建STF时存在理论推导复杂、求解计算量大等局限和不足,针对上述问题,在平方根容积卡尔曼滤波(square-root cubature Kalman filter,SRCK...     

基于平方根UKF的车辆组合导航

针对扩展卡尔曼滤波(EKF)在车辆导航中存在着计算复杂、线性化误差大等缺点,将一种新的非线性滤波方法--平方根UKF方法(SRUKF)用于车辆GPS/DR组合导航中.和普遍采用的EKF方法相比,SRUKF方法不仅提高了车辆组合定位的精度和稳定性;而且不需要模型的具体解析形式,避免了复杂的Jacobi-an矩阵的计算,算法更简单,也更加易于实现.为了检验其有效性,将两种方法分剐对车辆GPS/DR组合导航系统进行滤波仿真,仿真结果进一步表明SRUKF方法明显优于EKF方法,是车辆组合导航中一种更理想的非线性滤波方法,真正实现了车辆低成本、高精度的实时定位.     

Modified unscented particle filter for nonlinear Bayesian tracking

A modified unscented particle filtering scheme for nonlinear tracking is proposed, in view of the potential drawbacks （such as, particle impoverishment and numerical sensitivity in calculating the prior） of the conventional unscented particle filter （UPF） confronted in practice. Specifically, a different derivation of the importance weight is presented in detail. The proposed method can avoid the calculation of the prior and reduce the effects of the impoverishment problem caused by sampling from the proposal distribution, Simulations have been performed using two illustrative examples and results have been provided to demonstrate the validity of the modified UPF as well as its improved performance over the conventional one.     

基于unscented粒子滤波的红外弱小目标跟踪

为有效解决非线性环境中的红外弱小目标跟踪问题,提出基于unscented粒子滤波的目标跟踪算法。状态转移先验概率中未考虑当前测量对状态估计的作用,为克服传统粒子滤波算法采用状态转移先验概率作为粒子滤波建议分布的缺点,采用UKF生成粒子滤波的建议分布(UPF),并从中抽样粒子。由于考虑到当前观测值在状态后验估计中产生的影响,改善了目标状态估计的性能,且实验所需粒子数目大大少于传统粒子滤波算法所需粒子数目。用实际红外图像对所提算法做了仿真实验,结果表明,用该方法得到的状态估计结果优于用传统粒子滤波算法和用扩展卡尔曼滤波作为建议分布的粒子滤波算法获得的结果。     

基于自适应UKF算法的机载INS/GPS空中对准研究

在空中对准失准角不满足小角度假设的条件下,推导了一种新的机载INS/GPS大失准角空中对准的误差模型。将基于极大似然估计的自适应估计器与无迹卡尔曼滤波(unscented Kalman filter, UKF)算法相结合,修改自适应滤波算法中自适应参数的表达式。提出将自适应UKF算法用于非线性误差模型的空中对准方案中。仿真表明,自适应UKF算法能够克服噪声统计模型不准确对滤波结果的影响,失准角估计的精度好于UKF算法的精度。