Concern about axle noise/vibration/harshness (NVH) has been increasing with the growing popularity of sport utility vehicles, pick-up trucks, hybrid-vehicles and vans. Consumers want these vehicles to be quieter, with performance more like passenger cars. Traditional controls such as absorber-dampers and isolated/reduced vibration sources can solve some of the noise and vibration problems. An additional approach to enhancing NVH performance, is an active vibration control technique, which deals with the energy at the source.
This paper describes an approach which combines an active vibration control technique with signature analysis, operational modal analysis and transfer path analysis to improve NVH performance. A flow chart of this is shown in Figure 1.
Using this approach, we can identify and verify noise and/or vibration issues, find the root causes, and determine main contribution paths throughout driveline systems. Based on these analyses, an active vibration control system and a control algorithm can be developed and implemented into the vehicle. This technique allows a reduction in NVH drivline systems issues.