一种应对窄带主动噪声控制中频率不匹配的方法

A Method for Accommodating Frequency Mismatch in Narrowband Active Noise Control

窄带前馈主动噪声控制系统中,参考信号通常通过非声学传感器获取。由于传感器老化磨损等原因,所测同步频率与目标噪声真实频率间将存在误差,即产生频率不匹配(FM)。结合AR模型,提出一种改进的FM补偿方法,加入一个延迟模块和一个相应的幅值相位调节器,本质上是通过延迟和叠加构造出隐含真实频率的信号,同时提高相位匹配速度和精度。仿真结果与分析表明,设计的FM补偿方法能有效应对15%以上的频率不匹配量,且系统收敛速度更快。

In a narrowband active noise control (ANC) system, the reference signals are usually generated through non-acoustic sensors. The measured synchronous frequencies of the reference signals will be different from the true frequencies of the objective noise due to the sensor’s aging or fatigue accumulation. This difference is referred as frequency mismatch (FM). In this paper, based on AR model, an improved FM compensation method was proposed by adding a delay module and a corresponding amplitude and phase adjuster. In fact, this method constructs the signals containing implied true frequencies through delays and superposition so as to raise the phase matching rate and accuracy. Simulation and analysis show that the designed FM compensation method can effectively deal with more than 15 % of the FM with faster convergence rate.