Structural Control with Multi-Subnet Wireless Sensing Feedback: Experimental Validation of Time-Delayed Decentralized H∞ Control Design

This study investigates the feasibility of deploying wireless communication and embedded computing for structural control applications. A feedback structural control system involves a network of sensors and control devices. As control devices are becoming smaller, more cost effective and reliable, opportunities are now available to instrument a structure with large number of control devices. However, instrumenting a large scale centralized control system with cables can be time consuming, labor intensive, and difficult to maintain and reconfigure. This study explores decentralized feedback control using wireless sensors incorporated with a computational core and a signal generation module. Decentralized control architectures are designed to make control decisions based on data acquired from sensors located in the vicinity of a control device. Specifically, this paper describes the experimental validation of a time-delayed decentralized structural control strategy that aims to minimize the H∞ norm of a closed-loop control system. The decentralized controller design employs a homotopy method that gradually transforms a centralized controller into * Corresponding author: Yang Wang, 790 Atlantic Dr NW, Atlanta, GA 30332-0355, USA. Tel: +001(404)894-1851, Fax: +001 (404)894-2278. E-mail: [email protected]. 2 multiple decentralized controllers. Linear matrix inequality constraints are included in the homotopic transformation to ensure optimal control performance. The paper also describes our first implementation of a real-time wireless sensing and control system that achieves simultaneous communication within multiple wireless subnets. Different decentralized H∞ control architectures are implemented with a network of wireless sensing and control units instrumented on a six-story scaled steel frame structure controlled by magnetorheological dampers. Shake table experiments are conducted to demonstrate the performance of the wireless decentralized control architectures.