一种新的滤波x-LMS算法研究

STUDY ON FILTERED X-LMS ALGORITHM

次级通道阻尼特性对滤波x-LMS算法稳定性和收敛速度有较大影响。证明了对次级通道进行阻尼补偿可以显著提高滤波x-LMS算法性能;将两参数构型实现方法拓展到带有采样时延的离散系统,设计阻尼补偿子系统;将该子系统作为内环串入到滤波x-LMS算法中。新的滤波x-LMS算法稳定性和收敛速度均有明显提高。仿真结果验证了所提出方法的有效性。

Damping characteristics of secondary path have great effect on stability and convergence rate of filtered x-LMS algorithm. The effect is studied by giving a theorem, which is then proved. On this basis , a damping compensation subsystem for secondary path is presented to improve the performance of filtered x-LMS algorithm. To achieve it, the two-parameters configuration implementation method is widened to discrete system with sampling delay, and the design of damping compensation subsystem is provided, which is then added into the standard algorithm as an inner loop to form a new filtered x-LMS algorithm. A cantilever is taken as simulated object, for the purpose of controling its second-mode vibration by the method provided in the paper. Simulation results show that the new algorithm is capable of suppressing the second-mode vibration of cantilever in far less time then the standard one and reveal improvement of algorithm stability.