共查询到18条相似文献,搜索用时 265 毫秒
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为了有效解决主动降噪耳机系统的低频噪声,采用变步长FXLMS自适应滤波算法,克服传统定步长收敛速度与稳态误差相互制约的不足,通过构造合适的变步长因子,不但改善算法的收敛速度,而且减少了稳态误差.构建主动降噪耳机模拟控制系统,模拟次级通道路径,对噪声进行处理,仿真实验表明,该算法可以有效降低频噪声,相较于传统算法,该算法具有较好的性能. 相似文献
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基于DSP的耳机噪声抵消系统的设计与实现 总被引:2,自引:0,他引:2
设计和实现了基于DSP的自适应有源降噪耳机系统。分析了有源降噪耳机系统的原理,基于SEED-DEC6416开发板实现了有源降噪耳机系统的硬件和软件设计,为保证系统的实时性对程序进行优化,降噪耳机系统实现了对实际环境中噪声信号的提取、自适应滤波和噪声抵消。实验结果表明系统,在实际噪声环境中可以对噪声进行抵消,并良好地恢复语音信号,验证了系统设计的可行性和算法的正确性。 相似文献
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针对图像噪声大和对比度差特点,提出了一种水下图像快速中值滤波算法及FPGA硬件实现。通过分析中值滤波算法,以3×3窗口为数学模型,以CycloneIIIEP3C40F324I7为核心处理芯片,用VHDL语言实现模型中所需要的模块,实现了快速中值滤波算法对图像的处理。通过硬件实验结果对比,系统达到了抑制噪声保持原图像的目的。该设计在水下图像处理中具有一定的工程参考及应用价值。 相似文献
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This paper presents a Volterra filtered-X least mean square (LMS) algorithm for feedforward active noise control. The research has demonstrated that linear active noise control (ANC) systems can be successfully applied to reduce the broadband noise and narrowband noise, specifically, such linear ANC systems are very efficient in reduction of low-frequency noise. However, in some situations, the noise that comes from a dynamic system may he a nonlinear and deterministic noise process rather than a stochastic, white, or tonal noise process, and the primary noise at the canceling point may exhibit nonlinear distortion. Furthermore, the secondary path estimate in the ANC system, which denotes the transfer function between the secondary source (secondary speaker) and the error microphone, may have nonminimum phase, and hence, the causality constraint is violated. If such situations exist, the linear ANC system will suffer performance degradation. An implementation of a Volterra filtered-X LMS (VFXLMS) algorithm based on a multichannel structure is described for feedforward active noise control. Numerical simulation results show that the developed algorithm achieves performance improvement over the standard filtered-X LMS algorithm for the following two situations: (1) the reference noise is a nonlinear noise process, and at the same time, the secondary path estimate is of nonminimum phase; (2) the primary path exhibits the nonlinear behavior. In addition, the developed VFXLMS algorithm can also be employed as an alternative in the case where the standard filtered-X LMS algorithm does not perform well 相似文献
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This paper presents an adaptive bacterial foraging optimization (ABFO) algorithm for an active noise control system. The conventional active noise control (ANC) systems often use the gradient-based filtered-X least mean square algorithms to adapt the coefficients of the adaptive controller. Hence, there is a possibility to converge to local minima. In addition, this class of algorithms needs prior identification of the secondary path. The ABFO algorithm helps the ANC system to prevent falling into local minima. The proposed ANC system is also simpler since it does not need any prior information of the secondary path. Moreover, the adaptive strategy of the algorithm results in improved search performance compared with the basic bacterial foraging optimization algorithm, as well as other conventional algorithms. Experimental studies are performed for nonlinear primary path along with linear and nonlinear secondary path. The results show the effectiveness of the proposed ABFO-based ANC system for different kinds of input noise. 相似文献
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详细推导了基于虚拟传感器的有源噪声控制系统的算法结构。在TMS320C6727硬件平台上,采用LMS算法完成了误差通道模型的传函辨识,用FXLMS算法对虚拟传感器的系统性能进行了试验分析。试验结果表明,该方法可以有效地将噪声控制范围向虚拟传感器处转移。 相似文献
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为了处理脉冲噪声,传统的滤波x最大相关熵准则(filtered-x maximum correntropy criterion,FxMCC)自适应算法具有良好的降噪性能在主动噪声控制(active noise control,ANC)系统中。然而,FxMCC算法具有单一的高斯核,其降噪性能和收敛速度易受到核宽度取值的影响。因此,在ANC系统中,本文采用最大混合相关熵准则(maximum mixture correntropy criterion,MMCC),以两个高斯核的混合作为代价函数来推导滤波x最大混合相关熵准则(filtered-x maximum mixture correntropy criterion,FxMMCC)算法。仿真结果表明,在标准对称α稳定(symmetric α-stable, SαS)分布的脉冲噪声的主动噪声控制中,本文提出的FxMMCC算法比其它ANC算法具有更好的降噪性能。 相似文献
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无模型技术在有源噪声控制中的应用 总被引:2,自引:0,他引:2
根据无模型自适应控制的基本原理,采用同时扰动算法对有源噪声控制系统中的测量误差信号进行直接处理,不再需要建立次级声学路径模型。分别就前馈控制和反馈控制两种情况加以研究。仿真结果表明,该算法不仅使主噪声信号得到明显的衰减,而且对系统次路径的变化也不敏感。 相似文献
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多通道有源噪声控制算法的仿真研究 总被引:2,自引:1,他引:1
由于FXLMS算法结构简单、性能稳定和具有全局收敛的特点,在各种自适应有源噪声控制领域中,多采用FXLMS算法及其改进形式。着重讨论了3种多通道有源噪声控制算法,对3种算法收敛性进行了比较,并利用实际采集的车内噪声对算法性能进行了验证。仿真结果表明3种多通道算法能有效地降低车内的低频段噪声。 相似文献