管路脉动有源控制邻频插值次级通道建模方法

Secondary path modeling method in active control of pipe pulsation using adjacent frequencies interpolation

管路脉动有源控制系统中,泵源工作时产生的线谱噪声会对次级通道辨识结果造成较大误差。为解决泵源运行状态下次级通道建模的问题,理论分析了泵源关闭和启动两种状态下给次级通道建模造成的影响。设计了邻频插值次级通道建模的方法,有效地避开了线谱噪声源。该方法首先辨识得到待建模频率点ω0处相邻两侧频率点的次级通道模型,并提取两侧频率点处模型的幅值和相位,对其线性插值作为ω0处次级通道的幅值和相位特征。在管路脉动有源控制实验系统中,利用邻频插值建模方法进行了建模实验,验证了方法的可行性,并将模型应用在改进后的FxLMS算法中,在实验系统中取得了多根线谱均在25 dB以上稳定的控制效果。

In an active control system of pipe pulsation,line spectrum noise generated by pump source operation can cause larger errors to the secondary path identification results.Here,in order to solve this problem,effects of shutdown and starting of pump source on the secondary path modeling were theoretically analyzed.The adjacent frequencies interpolation method was proposed to model the secondary path,and effectively avoid the line spectrum noise source.Under the condition of pump source working,two secondary path models at adjacent frequency points on both sides of the frequency point were identified.Amplitudes and phases of the two models were extracted,respectively and then linear interpolations were done for them,respectively.The gained results were taken as amplitude and phase features of the secondary path at the frequency point.The feasibility of the adjacent frequencies interpolation modeling method was verified with the identified results in a test system for active control of pipe pulsation.The proposed modeling method was applied in the improved FxLMS algorithm to obtain the good control effect of multi-line spectrum being stable at level of more than 25 dB in the test system.