Dynamics model and adaptive control of underwater fish-like micro mobile robot with PZT actuator

This paper presents a new dynamic model, motion mechanism, and control for an underwater fish-like micro mobile robot. The micro mobile robot is actuated by two Lead Zirconate Titanate (PZT), each of which operates independently; this means that the robot has 2 Degrees of Freedom (DOF). PZT actuators are considered linear models without dynamics. Displacements of PZT actuators are quite limited so magnification mechanisms are used as displacement amplifiers. Fins consist of one part and have been connected to the end of magnification mechanisms. Fins generate propulsion force which results in the movement of the robot. Since this robot moves in any aqueous medium with various liquid densities, parameters of the micro mobile robot are uncertain; thus a controller based on adaptive control technique is designed. The main purpose of designing this adaptive controller is to make the robot track the desired trajectory. We present simulations to demonstrate the validity of this approach.