Abstract
Authors develop a flexible fish-like robot for use in a flow in narrow passage actuated by shape memory alloy (SMA) actuators, which realizes the downsizing and lightening of the moving body. Overheating of an SMA actuator, however, causes saturation of phase {transition,} and a consequent decrease in the fin vibration amplitude that leads to decrease of thrust force. This paper proposes a new driving method that utilizes a self-excited oscillator in order to solve this problem with simple implementation, which was named as the self-excited drive method. Moreover, we introduce coupling among actuators to obtain synchronization with a desired phase difference which generates traveling wave on the moving body. Experimental results showed that moving body with our proposed driving method realizes higher thrust performance in flow passage than that without control.
