Parameter Identification and Lyapunov Function Based Adaptive Switched Control for Underwater Electroacoustic Transduction System

The underwater electroacoustic transduction system is widely used in underwater navigation, ranging, and communication. However, it is difficult to control the current of the giant magnetostrictive transducer (GMT) for a voltage mode amplifier, because nonsinusoidal waves without constant fundamental frequencies may be required, and the load parameters of the GMT vary greatly with its working frequency, current, and condition. A parameter online identification algorithm is proposed for the GMT, where only one matrix inversion and one filtering for a two-dimensional matrix are required. A discretized switched control is derived, which selects the subsystem minimizing the Lyapunov function of tracking error in each control period. In addition, a switching state selection method making the switching frequencies lower and consistent is also used to cooperate with the switched control. Finally, the adaptive switched control is experimentally verified on the designed 1-kW electroacoustic transduction platform.