Generation of optimal swimming algorithm using reference velocity for robotic fish "ichthus V3"

Reference velocity is a performance index required to derive the efficient movement of each joint from pseudo-inverse which is a joint movement optimized based on the speed of front joint in a multi-body with hyper redundancy and has been applied in finding the optimal solution of each joint at kinematic level when creating the swimming motion of a bio-inspired robotic fish. The motion of each joint in creating the movement of a bio-inspired robotic fish has been programmed based on sinusoidal motion inspired by the swimming pattern of an actual fish and successful in creating a flexible movement up to this point, but it turns out that the actual movement of a bio-inspired robotic fish in the water is different from what is expected when the analyzed optimal solution of joint motion in a bio-inspired robotic fish's movement is applied since the thickness, length and width of the target fish affects the result of analysis. When the solution of joint motion based on reference velocity is applied, on the other hand, more flexible swimming movement than those in other existing researches has been observed even though there are still some differences between the movements of an actual fish and a bio-inspired robotic fish such as forward-speed, turning radius and so on.