“…Rao and Sana (2001) surveyed the primary feedback control design methods for smart structural systems such as positive position feedback control, independent modal space control, dissipative/ positive real control, robust control, and linear matrix inequalities. Many new control approaches have also been investigated in the vibration control of intelligent structures, such as adaptive control Melcher, 1998, 2003), neural network control (Damle and Rao, 1998;Bosse et al, 2000), fuzzy logic control (Takawa et al, 2000), and their combinations (Mayhan and Washington, 1998;Davis et al, 1999;Shen and Homaifar, 2001). Among these advanced control approaches, adaptive feedforward control is a useful and popular scheme in active vibration and noise control (e.g., see Nelson and Elliott, 1992).…”