Redundant Kalman Estimation for a Distributed Wireless Structural Control System

Eliminating the need for extensive wiring between sensors, actuators and a controller could reduce the cost and enhance the attractiveness of control systems for civil structures. In this study, wireless sensors are proposed for a structural control system with the wireless sensors responsible for the collection of state response data, calculation of control forces, and the issuing of command signals to actuators. While wireless sensors are attractive because of their easy installations, they are limited by the amount of bandwidth available in the wireless communication channel. To address this limitation, the on-board computational resources of wireless sensors are leveraged to alleviate the need for continued use of the wireless channel. Specifically, redundant Kalman state-estimators are encoded in each wireless sensor to estimate the state response of the structure, using only local output measurements. At each time step, the estimated state is compared to the measured system output; when the estimation error exceeds an established threshold, only then is the wireless communication channel used to broadcast updated state information to the remaining wireless sensors. This partially decentralized control method is validated using a 20-story building modeled in a simulation environment. Furthermore, an experimental study is conducted using a three story test structure in which magnetorheological dampers and wireless sensors are installed for the purpose of real-time feedback control during base excitation.