Modeling for controller design on a steel floor system

Lightweight steel floors sometimes possess levels of vibration, caused by pedestrian movement, found to be objectionable to the occupants. Traditional measures to reduce the motion have generally provided only marginal improvements or great disruption of the occupied space. More recently, active control, using an electro-magnetic proof-mass actuator, has been implemented to combat this problem. To design such a system, an accurate model of the floor system and the associated control system dynamics are necessary. This paper presents a generalized analytical model where parameters can be derived for specific floors, sensors, and actuators. With such a model, controller gains and actuator/sensor locations can be determined by any number of methods. An actual in-place floor is modeled, using experimental modal analysis, to illustrate the implementation of the model in predicting controller effectiveness. Particular attention is focused on the procedures used in defining the actual system parameters.