为了降低拖拉机驾驶室耳旁噪声,采集了拖拉机驾驶室耳旁噪声及左右车窗的加速度信号,并对其进行频谱分析;通过分析得到了拖拉机驾驶室耳旁噪声和左右车窗加速度的频率成分大部分与发动机的转速有关(即基频都是发动机转速一半)。提出了...为了降低拖拉机驾驶室耳旁噪声,采集了拖拉机驾驶室耳旁噪声及左右车窗的加速度信号,并对其进行频谱分析;通过分析得到了拖拉机驾驶室耳旁噪声和左右车窗加速度的频率成分大部分与发动机的转速有关(即基频都是发动机转速一半)。提出了一种基于误差信号的FX-LMS主动降噪方法,建立了基于误差信号FX-LMS算法的Simulink仿真模型,并将拖拉机驾驶室内耳旁噪声信号导入到Simulink仿真模型中,把误差信号作为参考信号,对模型进行仿真分析。仿真结果表明:基于误差信号的FX-LMS主动降噪方法在拖拉机驾驶室耳旁有10～15 d B的降噪效果。展开更多
Filtered-x least mean square(Fx-LMS) algorithm is popular in many adaptive processes. As its contradiction between convergence speed and stead-state error, the improvements of Fx-LMS algorithm with variable step size(...Filtered-x least mean square(Fx-LMS) algorithm is popular in many adaptive processes. As its contradiction between convergence speed and stead-state error, the improvements of Fx-LMS algorithm with variable step size(VSS) have been developed. To strengthen the robustness of variable step size least mean square(VSSLMS) algorithms to noise disturbance in active vibration control(AVC) application, nine VSSLMS algorithms are introduced in detail. Then an improved VSSLMS algorithm is proposed for better performance. At last, the performance of these VSSLMS algorithms are compared in AVC experimental system with different noise level. The experimental results verifies the effectiveness and robustness of the proposed VSSLMS algorithm in AVC application.展开更多
风扇噪声在日常生活和工业生产中都是较为普遍的一种噪声源,平时室内的风扇噪声会严重影响人们的正常生活和休息。针对室内风扇产生的大量低频噪声,本文提出一种多通道前馈主动噪声控制系统设计方案,并在此基础上,采集真实的风扇噪声信...风扇噪声在日常生活和工业生产中都是较为普遍的一种噪声源,平时室内的风扇噪声会严重影响人们的正常生活和休息。针对室内风扇产生的大量低频噪声,本文提出一种多通道前馈主动噪声控制系统设计方案,并在此基础上,采集真实的风扇噪声信号,利用MATLAB对多通道Filtered X-Least Mean Square(FX-LMS)算法进行了仿真和分析;实验结果验证了该方案的有效性。展开更多
文摘以压电棒为主动元件构建立方体Stewart隔振平台,采用基于DSP的数字控制系统和Fx-LMS自适应算法进行振动控制。对输入输出通道辨识方法和主动控制模块进行测试,并给出隔振平台隔振效果验证。实验结果表明,对于10 Hz^100 Hz范围内的单频干扰,可实现24 d B以上抑制效果,对于双频干扰,也具有良好的控制效果。
文摘为了降低拖拉机驾驶室耳旁噪声,采集了拖拉机驾驶室耳旁噪声及左右车窗的加速度信号,并对其进行频谱分析;通过分析得到了拖拉机驾驶室耳旁噪声和左右车窗加速度的频率成分大部分与发动机的转速有关(即基频都是发动机转速一半)。提出了一种基于误差信号的FX-LMS主动降噪方法,建立了基于误差信号FX-LMS算法的Simulink仿真模型,并将拖拉机驾驶室内耳旁噪声信号导入到Simulink仿真模型中,把误差信号作为参考信号,对模型进行仿真分析。仿真结果表明:基于误差信号的FX-LMS主动降噪方法在拖拉机驾驶室耳旁有10～15 d B的降噪效果。
基金Supported by the National Natural Science Foundation of China(No.51575328,61503232)the Shanghai Municipal Education Commission and Shanghai Education Development Foundation(No.15CG44)。
文摘Filtered-x least mean square(Fx-LMS) algorithm is popular in many adaptive processes. As its contradiction between convergence speed and stead-state error, the improvements of Fx-LMS algorithm with variable step size(VSS) have been developed. To strengthen the robustness of variable step size least mean square(VSSLMS) algorithms to noise disturbance in active vibration control(AVC) application, nine VSSLMS algorithms are introduced in detail. Then an improved VSSLMS algorithm is proposed for better performance. At last, the performance of these VSSLMS algorithms are compared in AVC experimental system with different noise level. The experimental results verifies the effectiveness and robustness of the proposed VSSLMS algorithm in AVC application.
文摘风扇噪声在日常生活和工业生产中都是较为普遍的一种噪声源,平时室内的风扇噪声会严重影响人们的正常生活和休息。针对室内风扇产生的大量低频噪声,本文提出一种多通道前馈主动噪声控制系统设计方案,并在此基础上,采集真实的风扇噪声信号,利用MATLAB对多通道Filtered X-Least Mean Square(FX-LMS)算法进行了仿真和分析;实验结果验证了该方案的有效性。
