Study on Swimming Curve Fitting of Biomimetic Carangiform Robotic Fish

At present, the biomimetic carangiform robotic fish with infinite flexible structure has not been presented. In order to facilitate the robotic fish swimming mode control, based on a finite flexible structure a number of rigid joints are used instead. In order to overcome the existing curve fitting method which endpoint of each joint falls on the swimming curve, causing the deviation between the fitting curve and the real swimming curve is larger. In this paper, a minimum error criterion is proposed to fit the swimming curve for a three-joint biomimetic carangiform robotic fish. Experimental results show that the proposed method which causes the endpoints of robotic fish moving joints not falling on the fitted swimming curve can obtain more accurate swimming motion according to the real fish than that uses the conventional endpoints-on-fitted-curve method. Moreover and thus, using the proposed method the swimming velocity of the robotic fish is improved rapidly.