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1.
In centralized multisensor tracking systems, there are out-of-sequence measurements (OOSMs) frequently arising due to different time delays in communication links and varying pre-processing times at the sensor. Such OOSM arrival can induce the “negative-time measurement update” problem, which is quite common in real multisensor tracking systems. The A1 optimal update algorithm with OOSM is presented by Bar-Shalom for one-step case. However, this paper proves that the optimality of A1 algorithm is lost in direct discrete-time model (DDM) of the process noise, it holds true only in discretized continuous-time model (DCM). One better OOSM filtering algorithm for DDM case is presented. Also, another new optimal OOSM filtering algorithm, which is independent of the discrete time model of the process noise, is presented here. The performance of the two new algorithms is compared with that of A1 algorithm by Monte Carlo simulations. The effectiveness and correctness of the two proposed algorithms are validated by analysis and simulation results.  相似文献   

2.
Increasing the integration time is an effective method to improve small maneuvering target detection performance in radar applications.However,range migration and Doppler spread caused by maneuvering target motion during the integration time make it difficult to improve the coherent accumulation of target’s energy and detection performance.In this study,a new method based on Radon Fourier transform(RFT) and keystone transform(KT) for high-speed maneuvering target detection is proposed.The proposed algorithm utilizes second-order KT to correct the range curvature,and the improved dechirping method to compensate for the Doppler spread.RFT is then used to correct the range walk for target coherent detection.The method is capable of correcting the range migration and the time-varied Doppler frequency of the target without knowing its velocity and acceleration.The advantage of the proposed method is that it can increase the coherent integration time and improve detection performance under the condition of Doppler frequency ambiguity.Compared with the second-order RFT algorithm,the computational burden of the proposed method is greatly reduced under the premise that the two methods have similar estimation accuracy of range,velocity and acceleration.Numerical experiments demonstrate the validity of the proposed algorithm.  相似文献   

3.
It is difficult to track multiple maneuvering targets of which the number is unknown and time- varying, especially when there is range ambiguity. The random finite sets (RFS) based probability hypothesis density filter (PHDF) is an effective solution to the problem of multiple targets tracking. However, when tracking multiple targets via the range ambiguous radar, the problem of range ambiguity has to be solved. In this paper, a multiple model PHDF and data association (MMPHDF-DA) based method is proposed to address multiple maneuvering targets tracking with range ambiguous radar in clutter. Firstly, by introducing the turn rate of target and the discrete pulse interval number (PIN) as components of target state vector, and modeling the incremental variable of the PIN as a three-state Markov chain, the problem of multiple maneuvering targets tracking with range ambiguity is converted into a hybrid state filtering problem. Then, by implementing a novel "track-estimate" oriented association with the filtering results of the hybrid filter, target tracks are provided at each time step. Simulation results demonstrate that the MMPHDF-DA can estimate target state as well as the PIN simultaneously, and succeeds in multiple maneuvering target tracking with range ambiguity in clutter. Simulation results also demonstrate that the MMPHDF-DA can overcome the limitation of the Chinese Remainder Theorem for range ambiguity resolving.  相似文献   

4.
In this paper, a novel concept of the joint state of input and output of encoder is proposed. Based on it, a recursive algorithm that implements the multi-symbol differential detection in criterion of maximum likelihood is proposed. Simulation results show that its performance can approach to the theoretical boundary of multi-symbol differential detection without increasing the complexity per symbol, and it is effective in practical systems. It is also an optimal algorithm to solve the problems of estimating the state sequence of finite-state Markov process observed in memoryless noise.  相似文献   

5.
A stochastic sliding-mode variable structure guidance law involving optimal control theory is presented for the missile target intercept model, in which state noise, uncertain system parameters, target movement and measured noise are considered. This guidance law synthesizes the merits of optimal guidance law with line-of-sight rate convergence and sliding-mode guidance law with strong robustness. Through theoretic analysis, it is proved that the sliding mode hyperplane is sub-achievable in the closed loop system. The numerical results show the effectiveness of the proposed control algorithm.  相似文献   

6.
Recently, lots of smoothing techniques have been presented for maneuvering target tracking. Interacting multiple model-probabilistic data association (IMM-PDA) fixed-lag smoothing algorithm provides an efficient solution to track a maneuvering target in a cluttered environment. Whereas, the smoothing lag of each model in a model set is a fixed constant in traditional algorithms. A new approach is developed in this paper. Although this method is still based on IMM-PDA approach to a state augmented system, it adopts different smoothing lag according to diverse degrees of complexity of each model. As a result, the application is more flexible and the computational load is reduced greatly. Some simulations were conducted to track a highly maneuvering target in a cluttered environment using two sensors. The results illustrate the superiority of the proposed algorithm over comparative schemes, both in accuracy of track estimation and the computational load.  相似文献   

7.
An efficient algorithm of the edge detection according to integrating the edge gradient with the average filter is proposed, which can significantly reduce sensitivity of the background subtraction method to noise and illumination. Taking into account the features of the target such as color, size, etc., a new modified Nearest Neighbor (NN) algorithm for data association using the target features is designed. A designed Interacting Multiple Model (IMM) filter is utilized to track the maneuvering target motion, i.e. the feature point (called the centroid of the target) motion of the target. The algorithms are validated via an example with natural video sequences. The results show the algorithms are performances and validity for visual tracking. In complex environment, the algorithm can still work well.  相似文献   

8.
In this paper,an improved PID-neural network(IPIDNN) structure is proposed and applied to the critic and action networks of direct heuristic dynamic programming(DHDP).As one of online learning algorithm of approximate dynamic programming(ADP),DHDP has demonstrated its applicability to large state and control problems.Theoretically, the DHDP algorithm requires access to full state feedback in order to obtain solutions to the Bellman optimality equation. Unfortunately,it is not always possible to access all the states in a real system.This paper proposes a solution by suggesting an IPIDNN configuration to construct the critic and action networks to achieve an output feedback control.Since this structure can estimate the integrals and derivatives of measurable outputs,more system states are utilized and thus better control performance are expected.Compared with traditional PIDNN,this configuration is flexible and easy to expand. Based on this structure,a gradient decent algorithm for this IPIDNN-based DHDP is presented.Convergence issues are addressed within a single learning time step and for the entire learning process.Some important insights are provided to guide the implementation of the algorithm.The proposed learning controller has been applied to a cart-pole system to validate the effectiveness of the structure and the algorithm.  相似文献   

9.
In this paper, distributed Kalman filter design is studied for linear dynamics with unknown measurement noise variance, which modeled by Wishart distribution. To solve the problem in a multi-agent network, a distributed adaptive Kalman filter is proposed with the help of variational Bayesian, where the posterior distribution of joint state and noise variance is approximated by a free-form distribution. The convergence of the proposed algorithm is proved in two main steps: noise statistics is estimated, where each agent only use its local information in variational Bayesian expectation (VB-E) step, and state is estimated by a consensus algorithm in variational Bayesian maximum (VB-M) step. Finally, a distributed target tracking problem is investigated with simulations for illustration.  相似文献   

10.
A reduced-order H∞filtering algorithm for navigation with carrier phase is presented.By taking advantage of decoupling between filtering states in a navigation solution,this algorithm reduces computational cost and is robust in colored noise.Furthermore,the estimation precision is also improved by taking ambiguities as nuisance states when the filtering process converges.Applications to kinetic simulations under diferent noise are presented to demonstrate robustness and efciency of the algorithm.  相似文献   

11.
针对交互式多模型粒子滤波在跟踪机动目标时精度受限问题,提出一种基于交互式多模型(IMM)的多传感器顺序粒子滤波算法。采用IMM机制实现目标运动模式的确认;在合理利用单传感器量测和多传感器量测中冗余和互补信息的基础上,引入顺序重抽样方法改善粒子分布,并将改善后的粒子应用于IMM粒子滤波算法框架。仿真实验结果表明:新算法能够估计出强机动目标状态,且精度明显优于标准IMM粒子滤波算法。  相似文献   

12.
具有参数自适应的交互式多模型算法   总被引:11,自引:1,他引:10  
动态多模型估计(SMME)广泛应用于结构和参数的不确定/变化的估计问题中,比如目标跟踪和故障诊断与隔离,然而由先验信息选定的滤波参数是模式切换与模式未切换情况下的折衷,针对SMME,本文通过在每个滤波循环开始处起始多个状态预测器实时辨识滤波参数,包括模式切换概率和基于模型的过程噪声方差,考虑到交互式多模型(IMM)是SMME中比较有效的方法,我们将上述的参数辨识与IMM相结合,提出了一种自适应IMM(AIMM),在跟踪一个机动目标的仿真中,AIMM表现出了比IMM更高的估计精度。  相似文献   

13.
The conventional interacting multiple models (IMM) approach for a hybrid system under the Gaussian assumption is limited for most real applications due to the noisy measurements often being in the presence of outliers. This paper aims at accommodating the IMM approach to the non‐Gaussian cases where outliers exist. In the proposed IMM algorithm, the Student‐t distribution is used to model the non‐Gaussian measurement noise. At the interaction step, the mixed statistics of the noise parameter under a Bayesian framework are obtained via a Gamma approximation and a recently reported moments matching method. To address the state noise‐coupled intractability in Bayesian filtering, a variational Bayesian method is utilized to approximate the posterior distributions of the noise and state recursively. The proposed algorithm is tested with a maneuvering target tracking example and is shown to be robust to the outliers.  相似文献   

14.
总结了常用的自适应滤波的方法,并提出了一种基于模糊逻辑的自适应卡尔曼滤波技术,用模糊逻辑自适应推理器来“在线”修正卡尔曼滤波系统噪声协方差Q和测量噪声协方差R,从而使滤波器不断执行最优估计。仿真结果表明该方法可以提高GPS/INS组合导航系统的精度和可靠性。  相似文献   

15.
薛丽  潘欢  魏文辉 《计算机仿真》2020,37(1):121-125
针对粒子滤波中重要性密度函数难以选取和粒子退化导致的计算精度下降的问题,提出一种新的自适应高斯粒子滤波算法。通过高斯混合密度函数和UT变换来获取状态均值和协方差阵,选择并计算合适的自适应因子来调节均值和方差,在迭代过程中可动态调节重要性密度函数,并用WEM和EM步骤代替重采样,上述滤波算法考虑了最新量测信息的影响,使滤波性能明显改善,能更好地解决非线性非高斯系统模型的抗干扰问题。将提出的算法应用于SINS/GPS组合导航系统跑车试验中,结果表明上述滤波算法能提高导航解算的精度,其性能明显优于已有滤波,同时验证了当系统出现噪声干扰突然变化时提出算法的有效性。  相似文献   

16.
针对机动目标跟踪中由于目标机动使系统的非线性强度增大,导致系统的线性误差增大和跟踪精度明显下降、甚至发散的问题,提出了基于高斯混合的交互式多模型容积信息滤波( GMIMM-CIF)算法,实现对机动目标的精确跟踪。新算法在每次输入交互之后,保留概率较大的几个假设,并利用一个高斯混合项替换最优多模型算法中剩余的假设,从而使算法中假设的数量保持恒定;用容积信息滤波器( CIF)代替传统的非线性滤波器,通过估计信息状态向量和信息矩阵而不是估计状态向量和协方差,可以减小系统的非线性误差。通过仿真对比实验,验证了该算法可以提高机动目标的跟踪精度。  相似文献   

17.
针对传统的IMM算法采用固定测量噪声协方差矩阵和Markov转移概率矩阵导致模型切换缓慢,跟踪精度下降的问题,提出了一种具有模型概率实时修正的IMM机动目标跟踪算法。该算法在监控区域上建立无线电指纹库,利用支持向量回归算法训练得到观测模型。引入模糊神经网络,在模型交互输出阶段自适应地调整测量误差协方差矩阵。根据IMM子模型中连续时间点之间的模型概率的比值,对Markov转移概率进行修正。仿真结果表明,提出的方法在实时性、跟踪精度方面具有良好的性能。  相似文献   

18.
Adaptive fuzzy IMM algorithm for uncertain target tracking   总被引:2,自引:0,他引:2  
In real system application, the interacting multiple model (IMM)-based uncertain target tracking system operates with the following problems: it requires less computing resources as well as a robust performance with respect to the maneuvering such as a sub-model mismatched case, and further, it requires an easy design procedure related to its structures and parameters. To solve these problems, an adaptive fuzzy IMM (AFIMM) algorithm, which is based on well-defined basis sub-models and well-adjusted mode transition probabilities (MTPs), is proposed. The basis sub-models are defined by the detailed analysis in terms of kinematic models as well as the maneuvering property and the MTPs are adjusted by the fuzzy adaptor as well as the fuzzy decision maker. To verify the performance of the proposed algorithm, an airborne target tracking is performed. Simulation results show that the AFIMM effectively solves the problems experienced in the uncertain target tracking system online. Keywords: Adaptive fuzzy IMM, basis sub-models, mode transition probabilities, uncertain target.  相似文献   

19.
为了解决雷达目标跟踪的非线性估计问题,提出了一种基于最优线性无偏估计的交互式多模型(IMM)机动目标跟踪算法.该算法采用最优线性无偏估计(BLUE),把目标的状态在笛卡尔坐标来表示,而把雷达测量误差保留在极坐标下,并结合交互式多模型算法,实现对机动目标的有效跟踪.仿真实验验证了该算法的准确性和有效性.  相似文献   

20.
为了进一步提高含噪环境下谐波检测的精确度,提高卡尔曼滤波器的稳定性,对系统噪声协方差进行了分析,通过不断的在线辨识出过程噪声协方差,提出了一种自适应过程噪声协方差卡尔曼滤波算法。该算法利用序贯最大化可信度更新先验信息来辨识过程噪声,然后通过卡尔曼滤波器进行迭代运算,估计出相应的幅值和相位。该算法最大的特点就是辨识出的过程噪声Q的骤然增大匹配的即是谐波幅值暂降的出现。通过在MATLAB环境下进行谐波仿真验证,结果表明该算法在准稳态条件下较好地跟踪电力系统谐波状态,且与常规卡尔曼、基于最大似然准则的卡尔曼、小波/小波包变换相比,该自适应算法的收敛速度较快、滤波精度高、实时性以及稳定性较好,具有重要的工程实际意义。  相似文献   

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