MFA12 (MFA 2012)

Catalogue of a culminating student exhibition held at the Mildred Lane Kemper Art Museum May 4-Aug. 6, 2012. Contents include Introduction / Buzz Spector -- Think, make, show and tell / Patricia Olynyk -- Ifeoma Ugonnwa Anyaeji -- J.E. Baker / Elissa Yukiko Weichbrodt -- Natalie Baldeon / Emily Hanson -- As in a turning gear : E. Thurston Belmer / Rickey Laurentiis -- Lauren Cardenas / Nicholas Tamarkin -- Megan Sue Collins / Catherine Chiodo -- Adrian Cox -- Maya Durham / Dolly Laninga -- Erin Falker / Melissa Olson -- St. Louis dreamscape : Jieun Kim / Caitlin Tyler -- Howard Krohn -- Scape : Robert Long / Robert Whitehead -- Marie Bannerot McInerney / Elissa Yukiko Weichbrodt -- Ghost : Nikki McMahan / Rickey Laurentiis -- Michael T. Meier -- Katie Millitzer -- Reid G. Norris / Ross Rader -- Kathleen Perniciaro / Melissa Olson -- Emily Squires / Nicholas Tamarkin -- Jamie Presson Wells -- Whitney Lorene Wood / Reid G. Norris -- Andrew Woodard -- Kelly K. Wright -- Contributors -- About the Sam Fox School.https://openscholarship.wustl.edu/books/1003/thumbnail.jp

Integrated solutions for noise and vibration control in vehicles

The automotive industry is aiming at both reducing the weight of the vehicles while improving a high level of comfort. This causes contradicting requirements for the systems used for noise and vibration control. Thus, active systems are investigated which may enhance the performance of passive noise and vibration control in vehicles without adding excessive weight. In this paper, basic principles for the implementations of those systems with a focus on the control systems are reviewed. Examples from implementations in automotive applications are presented, including control of engine vibrations, structure borne noise transmitted from the road into the passenger compartment and low-frequency chassis vibrations. Based on adaptive filter systems already widely used in active noise control adaptation of the control algorithms to the specific application scenarios are discussed. This includes different configurations for feedforward and feedback control, single- and multichannel control systems and the utilization of different actuator concepts like active mounts, inertial mass actuators and active tuned absorbers, as well as different control sensors like accelerometers and microphones. Finally, current research topics and respective concepts for the improvement of active control systems are introduced

Self-tuning velocity feedback control for a time varying structure using a voltage driven electrodynamic inertial mass actuator

This paper presents research work on self-tuning velocity feedback control units with voltage driven electrodynamic inertial mass actuators (IMAs). Due to the IMAs dynamics such feedback loops are only conditionally stable. Feedback compensators can improve the feedback loop stability. In the literature often ideal current driven IMAs are assumed, while most practical power amplifiers are actually voltage sources. In this paper a feedback compensator for voltage driven IMAs is derived and experimentally validated. The primary structure considered is a base excited single degree of freedom system with variable stiffness. For each stiffness setting there is a specific feedback gain setting that provides optimal control performance. Therefore a self-tuning algorithm is developed that tunes the feedback gain to minimize the kinetic energy of the primary structure, while also considering the stroke and current limits of the IMA. The self-tuning algorithm is experimentally validated for different natural frequency settings

Aktive Vibrationskontrolle einer Leichtbaustruktur mit EAP-Aktorik

A new actuator type based on electroactive polymers (EAPs) comprises perforated, metallic electrodes to realise a compressible stack. Such an actuator is experimentally characterized and a fully coupled simulation model derived. The actuator is then used for the active vibration control of a lightweight truss structure. For this purpose a hybrid approach is chosen. The actuator is both used as passive absorber and as active inertial mass actuator. By using special control algorithms a broadband damping of the structure can be achieved. A comparison of the experimental results with the corresponding system simulation proves the validity of the simulation model and demonstrates the potential of EAP actuators for applications in the field of active systems