Abstract: Backswimmers exhibit a high degree of mobility in water, and their different motion patterns have important implications for the design of micro-biomimetic underwater robots. This paper used three-dimensional high-speed cameras to extract the key points on the hind legs. The hind leg motion laws and the deformation laws of the setae were obtained in four motion patterns: rapid forward, cruising, in-motion turning, and in-place turning. The motion laws of each joint on the hind leg are modeled using a Fourier series. A kinematic model of hind legs was established based on the DH method, and the motion characteristics of hind legs under different motion patterns were analyzed. This paper provides basic data and theoretical models for micro-biomimetic robots.

Key words: Backswimmer, Hind leg, Setae, Motion pattern, Kinematic model')">Backswimmer, Hind leg, Setae, Motion pattern, Kinematic model