共查询到20条相似文献,搜索用时 156 毫秒
1.
2.
改进LCMV算法在抑制干扰噪声中的应用 总被引:1,自引:0,他引:1
根据波束空间理论提出了一种自适应波束形成算法。通过对输入数据矩阵进行预处理,使得协方差矩阵中不再包含信号子空间向量。为进一步抑制杂波干扰,新算法还引入对角加载,使得改进后的LCMV算法对于不同信噪比的期望信号与干扰信号都能形成特性良好的方向图,提高了阵列天线的输出SINR。仿真证明了算法的有效性。 相似文献
3.
4.
由于单循环频率盲波束形成算法仅利用了循环平稳信号的某个典型的循环频率,其性能对循环频率的选择有较大依赖性,只要循环频率存在偏差会导致整个算法失效,因此基于单循环频率的算法在实际应用中存在局限性。针对该问题,为了充分利用信号的多循环频率信息,消除循环频率偏差对算法的影响,研究并首次提出了一种加权的多循环频率盲波束形成算法,给出了多循环频率的最优加权组合方案,该方法采用迭代的方法寻找最优循环频率加权矢量。仿真实验和理论分析表明,在存在循环频率偏差的情况下,本文提出的算法性能优于基于单循环频率算法。 相似文献
5.
大容量混合滤波系统的应用前景十分广阔,其滤波器组的参数优化,尤其是无源滤波器的参数设计对综合性能的影响很大。本文提出基于双因子改进型粒子群优化算法的混合滤波系统中无源滤波器组的多目标优化设计方法。通过将加速因子和交叉因子引入优化算法,针对无源滤波器的多目标优化,高效搜索参数空间以获得最优解。与以往的优化设计相比,带双因子的改进型粒子群算法采用自适应的惯性权重,交叉因子增加了粒子的多样性,克服了算法寻优过程中易局部收敛等问题,提高其全局搜索能力。而收缩因子可以加快PSO的运算速度,明显提高了算法的寻优速度。测试结果表明利用该算法设计的混合型滤波系统具有较强的鲁棒性。 相似文献
6.
7.
针对小快拍情况下的空时自适应处理(STAP)算法滤波性能下降,提出了基于多级嵌套维纳滤波(MSNWF)的自适应对角加载算法。算法充分利用MSNWF给出的干扰和噪声特征值信息,在分析MSNWF后向迭代实现过程基础上,推导出能递推实现的等价的自适应对角加载算法。通过在后向迭代过程中自适应选择加载量,增加稍许运算量的同时,较大程度地提高了空时自适应处理算法的滤波性能。仿真结果验证了算法的有效性。 相似文献
8.
9.
本文提出了一种改善分布式参数检测性能的集中式最优加权融合算法,建立了该算法的数学模型.仿真结果表明,该方法在数据处理的精确性和稳健性方面都优于普通的处理方法,并且多次仿真实验表明该方法具有良好的鲁棒性. 相似文献
10.
11.
陶震 《国外电子测量技术》2017,36(7):23-26
针对目标导向矢量与波束指向失配导致自适应波束形成输出信干噪比下降问题,研究了一种基于导向矢量失配估计的鲁棒波束域自适应波束形成算法。该算法首先在信号与噪声子空间内,基于阵列主瓣宽度自适应迭代估计待检测目标导向矢量的失配误差,进而基于目标估计导向矢量计算波束域ADBF权值。仿真实验表明,算法在较低信干噪比条件下即能准确估计目标真实导向矢量,进而避免ADBF由于导向矢量失配引起的输出信干噪比损失。鲁棒波束域ADBF算法收敛速度快,易于工程实施。 相似文献
12.
Ayman Elnashar Said Elnoubi Hamdi Elmikati 《International Journal of Adaptive Control and Signal Processing》2009,23(3):293-310
A novel low computational complexity robust adaptive blind multiuser detector, based on the minimum output energy (MOE) detector with multiple constraints and a quadratic inequality (QI) constraint is developed in this paper. Quadratic constraint has been a widespread approach to improve robustness against mismatch errors, uncertainties in estimating the data covariance matrix, and random perturbations in detector parameters. A diagonal loading technique is compulsory to achieve the quadratic constraint where the diagonal loading level is adjusted to satisfy the constrained value. Integrating the quadratic constraint into recursive algorithms seems to be a moot point since there is no closed‐form solution for the diagonal loading term. In this paper, the MOE detector of DS/CDMA system is implemented using a fast recursive steepest descent adaptive algorithm anchored in the generalized sidelobe canceller (GSC) structure with multiple constraints and a QI constraint on the adaptive portion of the GSC structure. The Lagrange multiplier method is exploited to solve the QI constraint. An optimal variable loading technique, which is capable of providing robustness against uncertainties and mismatch errors with low computational complexity is adopted. Simulations for several mismatch and random perturbations scenarios are conducted in a rich multipath environment with near–far effect to explore the robustness of the proposed detector. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
13.
14.
Chengjun Lu Weixing Sheng Yubing Han Xiaofeng Ma 《International Journal of Adaptive Control and Signal Processing》2015,29(9):1152-1164
The adaptive phase‐only beamforming technique is very important for suppressing interferences in phased array radar. However, similar to the conventional beamforming technique, which features variable magnitudes and phases, the performance of phase‐only beamforming is severely degraded by steering direction and array geometry errors. No studies on this problem are available. In this paper, the problem of adequate robustness for adaptive phase‐only beamformers is investigated, and a robust phase‐only beamforming algorithm based on semidefinite relaxation is proposed. This algorithm can suppress interferences by minimizing the array output power and maintain the desired signal without distortion. Robust adaptive phase‐only weighting is first converted into a non‐convex quadratic optimization problem and then into a convex optimization problem by the semidefinite relaxation technique, which can be solved easily. Experimental results demonstrate that the new robust adaptive phase‐only beamforming algorithm can significantly reduce performance degradation caused by various array errors. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
15.
Parameter optimization of multimachine power system stabilizers using genetic local search 总被引:12,自引:0,他引:12
A genetic local search (GLS) algorithm for optimal design of multimachine power system stabilizers (PSSs) is presented in this paper. The proposed approach hybridizes the genetic algorithm (GA) with a heuristic local search in order to combine their strengths and overcome their shortcomings. The potential of the proposed approach for optimal parameter settings of the widely used conventional lead–lag PSSs has been investigated. Unlike the conventional optimization techniques, the proposed approach is robust to the initial guess. The performance of the proposed GLS-based PSS (GLSPSS) under different disturbances, loading conditions, and system configurations is investigated for different multimachine power systems. Eigenvalue analysis and simulation results show the effectiveness and robustness of the proposed GLSPSS to damp out local as well as interarea modes of oscillations and work effectively over a wide range of loading conditions and system configurations. 相似文献
16.
Ying LIU Guisheng LIAO Zhengguang ZHOU 《Frontiers of Electrical and Electronic Engineering in China》2008,3(4):425-434
The performance of ground moving target detection for distributed satellites will be affected significantly when there is
an image registration error, clutter decorrelation and array error. In this paper, a new approach to moving target detection
and relocation is proposed based on multi-channel and multi-pixel adaptive signal processing in an image domain. First, multichannel
and multi-pixel joint data are equated to a simple array model. Given that there is an image registration error, the real
steering vector of the moving target can be estimated through a space projection approach. The optimal beam forming approach
is used to cancel clutter, and at the same time the cross-track velocity of the moving target can be determined by searching
for the peak value of the cost function. The moving target can then be relocated on the SAR image. The simulation results
indicate that this method has a good robustness to image registration error, clutter decorrelation and array error. The detection
performance and the estimation accuracy are significantly improved.
__________
Translated from Acta Electronica Sinica, 2007, 35(6): 1009–1014 [译自: 电子学报] 相似文献
17.
内模控制在电流调节器中的应用 总被引:2,自引:1,他引:1
在永磁同步电机(PMSM)的矢量控制中,电机的调速范围很宽时,电阻、电抗等参数对d、q轴电流的控制产生较大的误差,从而影响控制精度和动态响应速度。基于磁场定向的控制原理,提出了永磁同步电机电流调节器的内模控制(IMC)设计。用矩阵奇异值分析了IMC电流调节器的鲁棒性,并将其应用于永磁同步电机转子磁场定向的矢量控制中。对电流调节器的传递函数进行了仿真并用数字信号处理器(DSP)实现电机矢量控制的运行实验,实验表明,用IMC电流调节器实现的电机调速,能够获得良好的跟踪性能和较高的稳态精度。 相似文献
18.
基于变结构模型参考自适应系统的永磁同步电机转速辨识 总被引:7,自引:1,他引:6
提出了一种新颖的变结构模型参考自适应观测器,用于永磁电机无速度传感器矢量控制系统的转速辨识。该方法将变结构控制与模型参考自适应系统(model reference adaptive system,MRAS)进行有机的整合,选取永磁电机本身作为参考模型,而选取永磁电机电流模型作为可调模型,利用两模型输出的误差构造了一个滑模面。理论分析和仿真结果表明,所提出的永磁电机无速度传感器矢量控制系统的转速辨识方法具有较强的鲁棒性和令人满意的动静态性能。 相似文献
19.
With the progress in factory automation in industry has come the demand for higher speed drive and performance for an AGV (automated guided vehicle). A new steering control of the AGV by fuzzy control has been proposed to replace the PI control. However, much time is required to investigate the regulations and to adjust the scaling factors for excellent performance in the fuzzy control. In this paper, a new steering control for an AGV based on the neural network using the backpropagation method is proposed. The good steering control results by the fuzzy control are adopted for the teaching signal of the neural network. First, the effect of the number of learning and the learning errors on the steering control results are discussed by computer simulation using the AGV model. Further, the ability of generalization in the turning radius and the traveling speed also are investigated. It becomes clear that the AGV can travel along a designated route provided the neural network learns both the right and left turning at the maximum traveling speed and the minimum turning radius. Then it is proved by an experiment using the AGV constructed for the test that the proposed steering control method is very affective. 相似文献
20.
在高性能永磁同步电机(PMSM)控制系统中,要求有好的动、静态性能。但是传统的永磁同步电机矢量控制系统速度和电流环采用PI调节器,参数鲁棒性差,在调速范围要求很宽的情况下,无法同时满足响应速度快和稳态精度高的要求。为了获得好的动、静态性能,引入预测控制到速度控制外环,而电流内环采用在传统PI控制基础上增加电压前馈补偿的电流解耦控制。搭建了实验平台,进行了实验研究,验证了设计的控制系统具有动态响应快、静态误差小、受负载扰动影响小的特点。 相似文献