Performance and maintenance requirements of active control systems

Vehicle designers are continually looking for methods to improve in‐cabin noise vibration and harshness (NVH). Active control systems offer a variety of techniques for low‐frequency NVH control. Active systems allow the designer to trade between the factors of NVH performance, weight, package space, and cost. Examples of systems are active interior sound control and active‐mounts/active‐vibration control. The performance of these systems directly impacts the sound and vibration field, to which the operator and passengers are exposed. The system stability and robustness must be monitored and maintained at all times. The focus of this paper will be on active interior systems, highlighting performance and diagnostics. The closed loop control functions found in most active systems present unique opportunities for system maintenance and diagnostics. Several methods for component diagnostics will be discussed. Also, the diagnostic advantages of stand‐alone and integrated active systems will be considered.