Robust Tracking of Rhythmic Gait for a Biomimetic Robot

Rhythmic movements show fundamental motion patterns in the locomotion of animals. Inspired by real animals, biomimetic robots also adopt similar locomotion pattern in order to obtain versatile mobility. For the motorized mechatronic systems in robots, trajectory tracking control of rhythmic motions is a challenge because periodical friction and other unmodeled dynamics may exist and they bring disturbance to the system. In order to enhance the tracking performance, a robust tracking controller for a biomimetic fish robot is discussed in this paper. The disturbance and the command signal will be modeled in the controller design. The controller can yield theoretically zero tracking error to a sinusoidal command input. The formulation of the controller and experimental results are presented in the paper.