Discrete-time integral terminal sliding mode-based speed tracking control for a robotic fish

This paper proposed a discrete-time integral terminal sliding mode (DITSM)-based forward speed tracking control for a robotic fish (RF). Due to the difficulty of quantification for the hydrodynamic model of RF during swimming, the head-yawing effect is considered in the obstructive thrust and then the RF dynamic model is further optimized via a data-driven approach. Compared with the traditional robotic fish model, the established model can provide sufficient thrust for the swimming of robotic fish and effectively improve the model accuracy. The DITSM control based on the accurate RF model is proposed by considering the head-yawing effect in order to achieve high-precision and robust speed tracking performance. The real-time experimental results are demonstrated to verify that the proposed control with head-yawing can provide with high-accuracy speed tracking for the RF.