Abstract
Distributed sensing and control of flexible shells and continua using distributed transducers has posted challenging issues for decades. This chapter focuses on distributed sensing and control of a generic double-curvature elastic shell and its derived geometries laminated with distributed piezoelectric transducers. Generic distributed orthogonal sensing and actuation of shells and continua are proposed. Spatially distributed orthogonal sensors/actuators and self-sensing actuators are presented. Collocated independent modal control with self-sensing orthogonal actuators is demonstrated and its control effectiveness evaluated. Spatially distributed orthogonal piezoelectric sensors/actuators for circular ring shells are designed and their modal sensing and control are investigated. Membrane and bending contributions in sensing and control responses are studied.
Introduction
Control of distributed parameter systems has posted many challenging problems and issues stimulating sophisticated research for decades (Balas, 1988; Brichkin et al., 1973; Butkovskii, 1962; Lions, 1968; Meirovitch, 1988; Oz and Meirovitch, 1983; Robinson, 1971; Sakawa, 1966; Tzafestas, 1970; Tzou, 1988, 1991, 1993; Vidyasagar, 1988; Wang, 1966; Zimmerman, Inman, and Juang, 1988). However, implementing distributed control of elastic continua, e.g., shells, plates, etc., using distributed devices has continuously been hampered by the practical availability of distributed sensing/actuation devices. Recent development of smart structures and intelligent structural systems (or structronic (structure-electronic) systems, in a new generic term) using active electromechanical materials has revealed the missing link of distributed transducers.