Sliding mode control design for a carangiform robotic fish

In this paper, measures to resist parameter uncertainties and external disturbances are presented for a biomimetic robotic fish. The Carangiform robotic fish consists of N links and N - 1 joints, and its dynamic model of motion is given in previous work [1]. Through this model, the relation between the motion of the fish and the torques added are constructed. By giving particular reference angles of joints, forward locomotion is obtained and serves as an example for the following study. Aiming at parameter uncertainties and environmental disturbances, we adopt sliding mode control (SMC) to attenuate their impacts. Results of numerical examples validate the effectiveness of SMC. Comparison of those results shows that SMC works better than traditional computed torque control when performing the tracking task in joint space.