Research on Identification Method of Secondary Channel Transfer Function in Active Control Based on LMF Algorithm

Active control algorithms for structural vibration control encounter problems with secondary channels that involve the transmission of control signals through a transmission path to error sensors, resulting in the existence of secondary channel transfer functions that affect the performance of adaptive active control systems, causing instability and a decrease in stability. The FxLMS algo-rithm effectively solves the problems caused by secondary channels when there is accurate error channel transfer function involved in calculations. This paper proposes an online secondary channel identification method based on the LMF algorithm, which abandons the traditional LMS online identification method. Using the LabVIEW programming language, a simulation program for on-line identification of secondary channels is designed and simulated experiments are conducted to compare the performance of LMS and LMF algorithms in filter identification. The results show that when the signal-to-noise ratio of the active control system is greater than zero, the LMF algorithm has the advantages of fast convergence speed, strong result stability, and accurate identification of the transfer function compared to the commonly used LMS algorithm, and can be used as a more applicable algorithm for practical active control systems.