Active control of structure-borne road noise: A control strategy based on the most significant inputs of the vehicle

Road noise cancellers have been applied to several vehicles for demonstrating reductions at frequencies where the vehicle's chassis cannot be further optimized for NVH and structure-borne sound becomes audible in the cabin. In the past multiple coherence has been proposed for selecting a set of accelerometer that provide the inputs for an adaptive feedforward controller.In this paper a continuation of this work is presented that is an improvement of the coherence technique and it relates to path analysis as the idea of the technique is to take into account parts of the chassis that are typically optimized for road noise NVH. It is also demonstrated that with a specific combination of sensors that sense a particular frequency areas of road noise can be combined with a set of loudspeakers that is optimized by a novel technique for the loudspeaker-microphone arrangement inside the cabin. As a result, the overall targeted refinement road noise level can be achieved at a range of speeds and driving conditions by using the most important road noise inputs and thus taking into account the variability of the primary paths of road noise, which is very important for the optimal adaptation of the adaptive algorithm.