Incorporation of structured uncertainties in a smart structural system identification technique

The performance of smart structural systems is influenced by structural parameter variations, operating conditions and modeling errors. A mathematical model of the smart structural system must include not only the nominal plant, but also the uncertainties in the system. Often information related to these uncertainties is available during the system identification process, however, most system identification techniques do not address these issues. A system identification technique which incorporates structural uncertainties in the model of structural systems is developed in this paper. This comprehensive modeling technique is useful for the analysis and design of robust control systems for smart structures. The structured uncertainty modeling technique is useful for designing robust controllers such as H _∞ and H ₂/H _∞. The H ₂/H _∞ control methodology is particularly useful since it increases the stability robustness of the closed loop system while achieving a specified performance. This methodology is used in this paper for designing robust controllers for smart structural systems. A 2D lattice structure is used as the experimental test bed in laboratory investigation to demonstrate the identification technique. Seven interlaced beams form the lattice structure. A model including the first two modes of the structure is generated incorporating structured uncertainty on the eigenvalues. A H ₂/H _∞ controller is designed and implemented on the lattice structure and closed loop experimental results are included.