Direct velocity feedback versus a geometric controller design of remotely located vibration control systems

Abstract

The mitigation of human induced vibrations in floors continues to be a key area of research particularly as a result of advancement in material and design technologies enabling the design of light, slender and more open plan structures. These floors are typically characterised by low and close natural frequencies as well as low modal damping ratios, and these combinations of factors contribute to their increased susceptibility to human induced vibrations. Amongst the remedial measures pursued to enhance their vibration serviceability performance, active vibration control (AVC) technologies are emerging as a viable technology and predominantly direct output feedback approaches have been pursued in past analytical studies and field trials. It has often been assumed that actuators and sensors can be located where vibration attenuation is desired and this may not always be feasible. The research work presented in this paper compares the vibration mitigation performances of the direct velocity feedback scheme that has been extensively used in past floor vibration control researches against a geometric controller design approach that has been developed to provide a design freedom for reducing vibration in both local and remote locations. The geometric controller design approach assumes the inability to locate the actuators and sensors at the remote location but acknowledges that this measurement can be obtained during the commissioning stage and used during the design phase to enhance both local and remote locations. All the analytical and experimental studies are based on a laboratory structure. The work demonstrates comparable vibration mitigation performances of the dominant mode of vibration of the laboratory structure for both approaches but also demonstrates potential for additional enhancement to the second vibration mode of the laboratory structure with the geometric controller design approach. Approximately 20-25 dB attenuation in the first and second vibration modes of the laboratory structure were achieved. © 2013 Taylor & Francis Group, London, UK.