Modeling and position control of IPMC actuators for the underwater biomimetic microrobot

Underwater microrobots are in urgent demand for applications such as pollution detection and video mapping in limited space. Compact structure, multi-functionality, flexibility, and position precision are normally considered incompatible characteristics for underwater microrobots. To accomplish our objectives, we developed several novel bio-inspired biomimetic locomotions with ionic polymer metal composite (IPMC) actuators. IPMC actuator could implement a fast response and high bending deformation, which could be used as artificial muscles to propel robots backwards and forwards with a compact structure. To implement the position precision of IPMC actuator, we proposed an electromechanical model and analyzed the deformation and actuating force of the IPMC equivalent cantilever beam, which were used for the biomimetic locomotion. Then a conventional PID controller for IPMC actuators was designed from the identified model. Based on the IPMC equivalent cantilever beam model, we developed several kinds of underwater microrobots with the compact structure, multi-functionality, flexibility, and position precision.