Evaluation of Driving Method of the Flexible Body Moving in Narrow Flow Passage

Abstract

A flexible fish-like biomimetic robot developed for use in narrow passage flows was downsized using shape memory alloy (SMA) actuators. We constructed a fluid-body-coupled model of the robot and considered undulatory swimming and the effect of nonlinear SMA characteristics. An experimental model was also constructed to confirm the analytical model’s feasibility. Shrinkage due to temperature depends on the temperature of the SMA actuator, in which overheating may decrease the fin-vibration amplitude. To avoid this problem, a new driving method was introduced that used a self-excited oscillator with an actuator. Simulation results showed that this method achieves constant thrust in the moving body.