Active sound quality control of engine noise transmitted intocavities

摘要

The successful development of new products relies on the capability of assessing thernperformance of conceptual design alternatives already in an early design phase. In recent yearsrnmajor progress was made in this direction, based on the extensive use of virtual prototyping,rnparticularly in the automotive industry. The efficiency of present CAE techniques allows the usernof optimization for improving the NVH and sound quality characteristics of a full vehicle.rnAdditionally, active control has shown the potential to enhance dynamic systemrnperformance which allows for lighter and improved products. Research done in the last years onrnsmart materials and control concepts has led to practical applications with promising results forrnthe automotive industry.rnHowever, to make the step into the design of active sound quality control (ASQC), therncontrol schemes, along with appropriate simulation procedures, need to become an integral partrnof the development process. This requires: (ⅰ) the control strategies and product performancernmetrics to be based on human perception attributes and (ⅱ) the simulation models to support thernspecific aspects related to smart structures (active systems, actuators, sensors and control logic).rnThis paper discusses two types of active control systems: ⅰ) a collocated velocity feedbackrncontroller designed to reduce the total sound pressure level and ⅱ) an adaptive feedforwardrncontroller that allows tuning and balancing order components. The control design and soundrnquality performance of both control systems is demonstrated on a vehicle mock-up. The enginernexcitation is provided by a real-time engine simulator, delivering a harmonic excitation inrnfunction of the driving condition. The sound quality performance of the two control systems isrnevaluated in terms of loudness and roughness.