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目前,基于自适应滤波的噪声主动控制系统目标有:声势能控制、均方声压控制、声能量密度控制,声势能和均方声压控制忽略了声场动能,使得某处声势能的降低的同时动能增加,以至于封闭声场的总能量增加,产生控制溢出.以矩形封闭空间结构振动-声耦合系统的为研究对象,采用力控方式,建立了以声能量密度最小为控制目标的自适应主动结构声控制系统(ASAC).在应用模态叠加法建立低频声传递函数基础上,分别对腔体弹性壁单频激励振动噪声、有限带宽随机激励振动噪声进行了控制仿真研究.仿真结果表明,基于声能量密度的主动控制比基于均方声压的主动控制降噪效果明显,并使控制后封闭空间声场较为均匀,对溢出问题有明显的改善.此外,还研究了平面上传感器位置变化对降噪效果的影响. 相似文献
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振动控制研究中的小波包降噪处理 总被引:1,自引:0,他引:1
在土木结构振动控制研究中,通常采用人工地震波或实测地震波进行输入,这些地震波往往受到椒盐噪声、脉冲噪声、高斯噪声等多种高频噪声的干扰,影响了振动控制研究的效果.提出一种小波包降噪的处理方法,用以降低高频噪声干扰和简化地震波有效特征向量提取.把实测地震波与降噪处理的地震波应用在一般结构主动控制理论研究中,运用LQR控制算法,通过编制计算机程序进行仿真分析.分析结果表明:地震波经降噪处理前后主动控制地震响应变化非常小,控制系统对于实测地震波的干扰成分具有良好的鲁棒性. 相似文献
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三维闭空间主动噪声控制的实验研究 总被引:1,自引:1,他引:0
本文在一封闭的房间内通过实验研究主动噪声控制技术的特性。采用一个多阶谐频信号在实验房间产生模拟的原始声场,并应用一多通道自适应控制系统进行降噪实验,获得了一些对工程实际有意义的实验结果。 相似文献
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本文阐述了前馈式有源噪声控制系统原理及FxLMS算法。设计了一种基于DSP的前馈式自适应有源低频噪声控制系统,采用LMS算法实现次级通路辨识,采用FxLMS算法实现自适应有源噪声控制。实验结果表明,对于频率为300Hz的低频噪声,能够取得14dB左右的降噪量。 相似文献
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传统的吸、隔声等被动噪声控制方法,适用于中、高频噪声的控制;主动噪声控制是利用声波的相消性干涉来达到降噪的目的,能够有效降低500 Hz以下的低频噪声。针对各自的不足,提出结合使用二者控制噪声的方法,在传统消声结构的基础上附加采用多通道FXLMS算法的主动消声系统。该装置充分发挥主、被动控制的长处,使用被动方法控制中、高频噪声,采用主动控制抵消低频声。实验结果表明主、被动噪声控制方法扩展降噪频带范围,改善降噪效果,是可行和有效的。 相似文献
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基于智能模糊控制策略的有源消声 总被引:3,自引:0,他引:3
有源消声是一种有效的低频噪声控制方法,由于空间有源消声过程具有时变性和非线性,传统的自适应算法不能进行很有效的控制。本文采用智能模糊控制策略,建立了基于智能模糊控制策略的有源消声系统,通过实验与传统自适应控制算法的消声效果作对比分析,证明智能模糊控制器不但控制速度快,易于实现,而且消声效果明显优于后者,具有较大的应用推广价值。 相似文献
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This paper reviews robotic position and force control techniques. The existing fundamental force control algorithms are compared and discussed,including explicit / implicit control,stiffness control,impedance / admittance control,and hybrid position / force control. This work is intended to give a basic guidance for understanding and utilization of the fundamental robotic control algorithm. 相似文献
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噪声主动控制技术目前已用增加双隔板结构对声音进行衰减。在这项研究中,声音穿过双隔板进入房间有三种控制途径:在双隔板的空气间隙中应用声控源(腔控),在辐射板上应用振动控制源(板控),在接收房间内应用声控源(房控),都进行了实验研究和相互比较。每种方法中涉及到的机械装置都有例子,有效减少噪声的状况都经过考查。结果表明,每种方法(腔控、板控和房控)的模态重叠和涉及到的机械装置是两个重要的因素,它决定了每种方法有的有效性。 相似文献
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Douglas C. Montgomery J. B. Keats Mark Yatskievitch William S. Messina 《Quality and Reliability Engineering International》2000,16(6):515-525
Feedforward control is a particular form of engineering process control. If a known input variable zt can be measured and appropriate relationships built between the input variable, a compensatory variable xt, and the desired output yt, then a feedforward control system can be developed. Using feedforward control, we show under both sudden jump shifts and trends in the mean of the input and compensatory variables that the use of statistical process monitoring tools, such as the exponentially‐weighted moving average and the cumulative sum (CUSUM), significantly reduces variability in both the output variable and the controller relative to the use of feedforward control alone. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
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自适应前馈振动主动控制的参数选择与稳定性 总被引:2,自引:2,他引:2
基于自适应滤波的自适应前馈振动主动控制系统的等效传递函数,对控制系统的参数选择及稳定性进行研究。将受控结构模型变换到Z域,推导控制系统的等效Z域传递函数,把朱利(Jury)稳定判据引入控制系统的稳定性研究,探讨采样频率、滤波器阶数、参考信号等对系统稳定性的影响,得出了具有指导意义的结论 相似文献
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This paper provides a survey of the main advanced control techniques currently adopted in factory automation. In particular, it focuses on five classes of control approaches, namely: model-based control, control based on computational intelligence, adaptive control, discrete event systems-based control and finally event-triggered and self-triggered control. A particular focus is put on the most significant and recent contributions in these areas with attention to their application in the factory automation domain. Finally, open issues, challenges and the requirements of further research efforts for each class are pointed out. 相似文献
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In this paper, we describe the development of the variable dimension and variable sample size T2 control chart (VSSVDT2), which is an enhancement of the variable dimension T2 chart (VDT2). In the VDT2 control chart, the number of variables that are measured to compute the T2 statistic is made variable. Some of the variables are easy or inexpensive to measure and are always monitored. The variables that are more difficult or expensive to measure are measured only when the T2 value from the previous sample exceeds a specified threshold. The VDT2 control chart performs well for moderate and large shifts in the mean vector. However, its performance for small shifts is poor. To improve the chart’s performance in detecting such shifts, we propose the application of the variable sample size technique to the VDT2 control chart, resulting in the VSSVDT2 control chart. To promote the use of the VSSVDT2 chart, a user-friendly software has been developed, which the final user can use to find the best parameters of the VSSVDT2 chart for a particular process. 相似文献
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The idea of a variable sampling interval with sampling at fixed times (VSIFT) has been presented by Reynolds. This paper extends this idea to the other two adaptive ―X charts: the variable sampling rate with sampling at fixed times (VSRFT) ―X chart and the variable parameters with sampling at fixed times (VPFT) ―X chart. The VSIFT, VSRFT and VPFT ―X charts are inclusively called the adaptive with sampling at fixed times (AFT) ―X charts in this paper. The control scheme and the design issue are described and discussed for each of the AFT ―X charts. A comparative study shows that the AFT ―X charts have almost the same detection ability as the traditional adaptive ―X charts. However, from the practical viewpoint, the AFT ―X charts are considered to be more convenient to administer than the traditional adaptive ―X charts. Overall, this paper advances the application of ‘sampling at fixed times’ to the adaptive ―X control charts. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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变风量空调系统控制方法及试验台搭建 总被引:2,自引:0,他引:2
介绍了变风量(VAV)空调系统的特点,分析了VAV系统末端控制、AHU等控制方法,着重对末端控制方法与AHU控制方法进行了多种形式的比较,并以实际工程实例加以说明. 相似文献