An active noise control system for tuning steady-state and transient responses within a vehicle compartment

Traditional vehicle active noise control (ANC) is designed to suppress unwanted vehicle response. In this study, an ANC system is proposed for tuning rather than suppressing vehicle interior response. The proposed concept is studied numerically, utilizing simulated control input speakers inside the passenger compartment. The proposed control algorithm is adapted from the basic filtered-x least mean squares (FXLMS) algorithm. In this case, instead of using the FXLMS algorithm to minimize the resultant sound pressure level, a set of target functions is added to the controller for shaping the vehicle interior response. The proposed computer simulation can incorporate either measured or predicted cavity acoustic transfer functions. Using this analysis model, the proposed approach is demonstrated using a powertrain noise example in which individual engine firing orders are targeted for shaping either by reducing or enhancing the spectral content.