Experimental Studies on Different Actuator-Sensor Configurations of Active Control Systems for the Reduction of Noise and Vibration in Vehicles

Current developments in the automotive industry such as downsizing, the use of cylinder deactivation and consistent lightweight construction increasingly enable the application of active control systems for the further reduction of noise and vibration in vehicles. In the past few years, different configurations of actuators and sensors for the realization of an active control system have been investigated and evaluated experimentally. Active engine mounts, inertial mass actuators and structural integrated actuators can be used to reduce either structural vibrations or the interior noise level. As a result, a variety of different topology concepts for the realization of an active control system arises. These can be divided into an active vibration control scenario, the direct influence of the sound field with loudspeakers or the application of structural actuators for the reduction of the interior sound pressure. In the latter case, microphones are used as error sensors for the active control system. With regard to the selection of a suitable actuator-sensor configuration special attention is required as several transfer paths for airborne and structure borne noise are existing. Furthermore, the attainable bandwidth of the applied control systems topology depends on the selection of a suitable actuator-sensor configuration and an adequate number of actuators and sensors in order to enable global control and to avoid local effects. This paper summarizes and compares different actuator-sensor configurations for the control of noise and vibration in vehicles. Beside the control performance, it highlights the electrical power requirements for the control of engine induced interior noise as a function of the selected actuator-sensor configuration.