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1.
卫星轨道估计中广义卡尔曼滤波算法改进   总被引:6,自引:0,他引:6  
随着广义卡尔曼滤波越来越广泛的应用,其算法研究越来越深入。文章给出了一种轨道确定方法的广义尔曼滤模型,对广义卡尔曼滤波过程中的状态预报给出了一种修改算法———迭代算法,对这种迭代算法和RKF7(Runge-Kutta-Fehlberg7阶)算法所相应的滤波过程进行了计算机仿真,说明了离散误差对估计轨道的影响,迭代算法可以消减离散误差。通过把两种算法结果进行比较,表明迭代算法简捷、运行较快、且能达到一定的精度。  相似文献   

2.
针对扩展卡尔曼粒子滤波算法中由于粒子退化和贫化而导致的滤波精度降低问题,提出了一种人工鱼群优化的扩展卡尔曼粒子滤波算法.通过人工鱼群优化算法中的觅食和聚群行为,对采样过程进行优化,使得粒子不断地朝高似然域移动来寻找最优位置,从而改善样本分布,加速样本集的收敛,缓解了退化现象;然后对重采样过程进行优化,以提升样本的多样性,从而克服了粒子样本贫化问题.实验结果表明,改进后算法提高了对系统状态的预估精度,更适合在对精度要求高的系统中进行滤波计算.  相似文献   

3.
赵峰  赵清华  陈宏滨 《计算机工程》2012,38(22):244-247
提出一种利用扩展卡尔曼滤波(EKF)算法实现移动台跟踪定位的改进算法。该算法在已获得移动台初始位置估计的基础上,利用 EKF对移动台的运动轨迹进行多次估计,获取多条跟踪轨迹,剔除偏差较大的轨迹并进行加权平均的数据融合处理,获取一条较优轨迹。再结合距离门限值对较优轨迹的点迹进行匹配管理,实现对较优轨迹的平滑处理,获得最优跟踪轨迹。仿真结果表明,该算法计算复杂度低、鲁棒性强,定位精度明显高于传统EKF跟踪定位算法。  相似文献   

4.
针对卫星的姿态和角速度估计问题,分别给出基于Unscented卡尔曼滤波(UKF)与推广卡尔曼滤波(EKF)的估计算法,并做了相应比较.为了避免欧拉角带来的奇异问题,UKF选用Rodrigues参数而EKF选用四元数参数法来描述姿态误差.考虑卫星的非线性模型,UKF采用Unscented变换而EKF采用线性化方法对姿态误差进行估计.利用陀螺和磁强计的测量信息,KF和EKF都可得到三轴稳定卫星的姿态估计值,但UKF的收敛速度高于EKF.数值仿真结果表明,当初始姿态存在大偏差时,所给出的UKF的滤波算法性能明显优于EKF.  相似文献   

5.
一种用于目标跟踪的改进粒子滤波算法   总被引:1,自引:0,他引:1       下载免费PDF全文
张建安  赵修斌  李思佳 《计算机工程》2012,38(5):176-178,182
为解决目标跟踪中粒子滤波算法的估计精度、粒子退化问题,提出一种改进的粒子滤波算法。在粒子滤波的基础上,利用UKF生成粒子滤波的建议分布,以改善滤波效果,在无味粒子滤波的基础上,融合典型的MCMC抽样算法,减少传统算法未考虑当前量测对状态的估计作用所带来的影响,增加采样粒子多样化。将该算法应用于具有非线性、非高斯特点的目标跟踪问题中,仿真结果表明,与普通的粒子滤波算法相比,其跟踪精度和滤波效果有较大提高。  相似文献   

6.
机器人对自身位置的实时感知在机器人技术中非常重要.本文主要研究机器人技术中一类基于视觉与惯性传感器的位置估计问题.与传统的状态估计问题不同的是,所研究位置估计问题为带有隐式观测方程的线性状态估计问题.为此提出一种能够解决此类估计问题的隐式卡尔曼滤波器,并给出了详细的滤波器设计过程.另外采用扩展变量法将加速度信息中的偏移量作为滤波器状态来估计,以补偿其对位置估计结果的影响.仿真结果显示,所给出的隐式卡尔曼滤波器收敛,加速度偏移带来的影响被有效的补偿.  相似文献   

7.
研究了无线传感器网络中的分布式鲁棒状态信息融合问题. 在局部状态估计层, 基于鲁棒统计学理论提出了适用于噪声相关情况的抗差(扩展)卡尔曼滤波器. 在融合中心层, 针对局部估计相关未知性和不完整性, 给出了不依赖于互协方差阵的稳健航迹融合方法—–内椭球逼近法. 仿真结果证实了算法的有效性: 所提出的抗差卡尔曼滤波器在野值存在情况下, 性能退化远低于传统卡尔曼滤波器(28.6%比428.6%); 所提出的内椭球逼近法获得比协方并交叉法更好的融合估计性能, 且不需要局部估计相关性的先验知识.  相似文献   

8.
将粒子滤波理论和宏观随机交通流模型结合,对高速公路交通状态进行实时估计。在该方法中,高速公路被看作是由等距离的路段首尾相接而形成的模型,交通传感器通常设置在路段的交界处,而且数量远少于所需估计的交通状态。采用压缩状态空间的形式,将模型参数也作为交通状态而非常量进行估计。仿真结果表明粒子滤波方法能够有效地估计和跟踪交通状态的变化,并且与扩展卡尔曼滤波方法相比具有更高的精确度。  相似文献   

9.
广义卡尔曼滤波是针对状态方程和观测方程均为非线性方程的最小方差迭代方法,随着广义卡尔曼滤波越来越广泛的应用,其算法研究越来越深入.对广义卡尔曼滤波过程中的预报值的算法进行改进,即给出了在常微分方程欧拉算法的基础上增加了迭代过程的迭代方法.该方法简捷、运行较快且能达到一定的精度,还可以节省计算机空间.针对组合大视场星敏感器自主定轨方法进行了计算机仿真,且与RKF7 (Runge- Kutta-Fehlberg 7阶)方法进行了仿真结果比较.比较结果说明了该方法的有效性.  相似文献   

10.
基于扩展卡尔曼滤波的船舶横向运动扰动估计   总被引:2,自引:0,他引:2  
建立了船舶横向运动状态方程和测量方程,利用扩展卡尔曼滤波方法对海浪扰动下的船舶横向运动的扰动力和力矩作出估计。仿真结果表明,扩展卡尔曼滤波法比有色卡尔曼滤波法估计效果更优。  相似文献   

11.
无味变换与无味卡尔曼滤波   总被引:4,自引:1,他引:4       下载免费PDF全文
综述了非线性估计问题的由来、无味变换(UT,Unscented Transformation)的基本思路与基本算法、各种衍变形式、σ点集的设计原则、无味卡尔曼滤波(UKF,Unscented Kalman Filtering)的基本算法及其各种改进算法、UT的本质、UKF与几种免微分非线性滤波方法的比较、UT与UKF的相关应用、针对几种UKF算法的仿真实例,以及目前在UT与UKF的研究中尚存在的一些问题和对今后研究的展望等;提出了笔者的一些最新研究成果和见解。  相似文献   

12.
13.
In recent years particle filters have been applied to a variety of state estimation problems. A particle filter is a sequential Monte Carlo Bayesian estimator of the posterior density of the state using weighted particles. The efficiency and accuracy of the filter depend mostly on the number of particles used in the estimation and on the propagation function used to re-allocate weights to these particles at each iteration. If the imprecision, i.e. bias and noise, in the available information is high, the number of particles needs to be very large in order to obtain good performances. This may give rise to complexity problems for a real-time implementation. This kind of imprecision can easily be represented by interval data if the maximum error is known. Handling interval data is a new approach successfully applied to different real applications. In this paper, we propose an extension of the particle filter algorithm able to handle interval data and using interval analysis and constraint satisfaction techniques. In standard particle filtering, particles are punctual states associated with weights whose likelihoods are defined by a statistical model of the observation error. In the box particle filter, particles are boxes associated with weights whose likelihood is defined by a bounded model of the observation error. Experiments using actual data for global localization of a vehicle show the usefulness and the efficiency of the proposed approach.  相似文献   

14.
In this paper, a mobile robot control law for corridor navigation and wall-following, based on sonar and odometric sensorial information is proposed. The control law allows for stable navigation avoiding actuator saturation. The posture information of the robot travelling through the corridor is estimated by using odometric and sonar sensing. The control system is theoretically proved to be asymptotically stable. Obstacle avoidance capability is added to the control system as a perturbation signal. A state variables estimation structure is proposed that fuses the sonar and odometric information. Experimental results are presented to show the performance of the proposed control system.  相似文献   

15.
设计了一种分布式扩展卡尔曼滤波器(Extended Kalman filter, EKF), 对非线性目标状态进行估计.在设计过程中, 对滤波误差上界进行优化, 获得了最优滤波增益.此外, 在通信过程中, 考虑恶意攻击信号的同时引入了分布式事件触发机制, 使得系统在保持一定的估计精度的情况下节省通信资源.最后, 以室内的机器人定位问题为例, 验证了提出的滤波器的有效性.  相似文献   

16.
A hierarchical extended Kalman filter (EKF) design is proposed to estimate unmeasured state variables and key kinetic parameters in a first principles model of a continuous ethylene–propylene–diene polymer (EPDM) reactor. The estimator design is based on decomposing the dynamic model into two subsystems by exploiting the triangular model structure and the different sampling frequencies of on-line and laboratory measurements directly related to the state variables of each subsystem. The state variables of the first subsystem are reactant concentrations and zeroth-order moments of the molecular weight distribution (MWD). Unmeasured state variables and four kinetic parameters systematically chosen to reduce bias are estimated from frequent and undelayed on-line measurements of the ethylene, propylene, diene and total polymer concentrations. The state variables of the second subsystem are first-order moments of the MWD. Given state and parameters estimates from the first subsystem EKF, the first-order moments and three non-stationary parameters added to the model for bias reduction are estimated from infrequent and delayed laboratory measurements of the ethylene and diene contents and number average molecular weight of the polymer. Simulation tests show that the hierarchical EKF generates satisfactory estimates even in the presence of measurement noise and plant/model mismatch.  相似文献   

17.
In this paper, we consider the design problem of optimal sensor quantization rules (quantizers) and an optimal linear estimation fusion rule in bandwidth-constrained decentralized random signal estimation fusion systems. First, we derive a fixed-point-type necessary condition for both optimal sensor quantization rules and an optimal linear estimation fusion rule: a fixed point of an integral operation. Then, we can motivate an iterative Gauss–Seidel algorithm to simultaneously search for both optimal sensor quantization rules and an optimal linear estimation fusion rule without Gaussian assumptions on the joint probability density function (pdf) of the estimated parameter and observations. Moreover, we prove that the algorithm converges to a person-by-person optimal solution in the discretized scheme after a finite number of iterations. It is worth noting that the new method can be applied to vector quantization without any modification. Finally, several numerical examples demonstrate the efficiency of our method, and provide some reasonable and meaningful observations how the estimation performance is influenced by the observation noise power and numbers of sensors or quantization levels.  相似文献   

18.
《Journal of Process Control》2014,24(9):1371-1381
This paper deals with the estimation of the plate temperature in heavy plate rolling. An Extended Kalman Filter (EKF) is designed and its initialization and parametrization are discussed in detail. The observer is validated by means of experimental data recorded during a measurement campaign with a special developed test plate instrumented with thermocouples. It is shown that a good estimation accuracy can be achieved under normal production conditions despite the scarcity of measurements. Furthermore, the coupling effect between the plate and the work rolls is investigated in more detail. Based on this analysis, the validity of a computationally inexpensive reduced observer is demonstrated.  相似文献   

19.
In this paper, we consider a networked estimation problem in which sensor data are transmitted only if their values change more than the specified value. When this send-on-delta method is used, no sensor data transmission implies that the sensor value does not change more than the specified value from the previously transmitted sensor value. Using this implicit information, we propose a modified Kalman filter algorithm. The proposed filter reduces sensor data traffic with relatively small estimation performance degradation. Through experiments, we demonstrate the feasibility of the proposed filter algorithm.  相似文献   

20.
This paper describes the implementation of an intelligent navigation system, based on the integrated use of the global positioning system (GPS) and several inertial navigation system (INS) sensors, for autonomous underwater vehicle (AUV) applications. A simple Kalman filter (SKF) and an extended Kalman filter (EKF) are proposed to be used subsequently to fuse the data from the INS sensors and to integrate them with the GPS data. The paper highlights the use of fuzzy logic techniques to the adaptation of the initial statistical assumption of both the SKF and EKF caused by possible changes in sensor noise characteristics. This adaptive mechanism is considered to be necessary as the SKF and EKF can only maintain their stability and performance when the algorithms contain the true sensor noise characteristics. In addition, fault detection and signal recovery algorithms during the fusion process to enhance the reliability of the navigation systems are also discussed herein. The proposed algorithms are implemented to real experimental data obtained from a series of AUV trials conducted by running the low-cost Hammerhead AUV, developed by the University of Plymouth and Cranfield University.  相似文献   

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