Developing a Novel Robotic Fish With Antagonistic Artificial Muscle Actuators

Super-coiled polymer (SCP), one of the newly-developed artificial muscles, has various advantages over traditional artificial muscles in terms of cost, flexibility and power-to-weight ratio. This paper investigates the performance of super-coiled polymer-based actuation in underwater robotics, and presents a novel design of robotic fish using antagonistic SCP actuators. Dynamic model of the robot is derived. An example robotic fish prototype is developed and used in experiments to study SCP actuation for underwater robots. Furthermore, experimental results show that using SCP actuators in robotic fish solves the challenging heat-dissipation problem at ease, thus improving the dynamic response of SCP actuation significantly. A PID controller is designed to regulate the tail flap angle of the designed robotic fish. Simulation results of the closed-loop system are presented to validate the proposed robot design and actuation approach.