Dynamic Modeling of Underwater Snake Robot by Hybrid Rigid-Soft Actuation

Abstract

For decades, underwater vehicles have been performing underwater operations, which are critical to the development and upgrading of underwater robots. With the advancement of technology, various types of robots have been developed. The underwater robotic snake is a bioinspired addition to the family of underwater robotic vehicles. In this paper, we propose an innovative underwater snake robot actuated by rigid propulsions and soft joints, which can improve the swimming efficiency and flexibility of the robot and reduce the probability of collision leading to damage. Existing math models of robotic snakes typically incorporate only planar motion, rarely considering spatial motion. So, we formulate a complete three-dimensional dynamic model for the robotic snake, which is extended by deriving expressions for the geometric Jacobians. This modeling approach is well suited since it provides compact matrix expressions and easy implementation. We use the constant curvature method to describe the configuration of the soft joint, use the Lagrangian method to obtain its dynamic characteristics, and focus on deriving the visco-hyperelastic mechanical energy of the soft material. Next, the local dynamics of soft members are extended as a nonholonomic constraint form for modeling the snake robot. Finally, the multi-modal swimming behavior of the robot has been verified by simulations, including forward and backward rectilinear motion, yaw turning, pitch motion, and spiral rising motion. The overall results demonstrate the effectiveness and the versatility of the developed dynamic model in the prediction of the robot trajectory, position, orientation, and velocity.

Using Reinforcement Learning to Develop a Novel Gait for a Bio-robotic California Sea Lion

“…Biological swimmers utilize their bodies and propulsors to achieve remarkable maneuverability and agility, inspiring engineers to model these systems for improving the performance of underwater vehicles [1][2][3]. Existing bio-inspired swimming robots include fish robots that make use of multiple fins to produce propulsive forces and maneuvers [4][5][6], sea turtles with soft actuator driven flippers [7], and sea snakes capable of contorting to navigate tight areas [8]. The California sea lion is an excellent model for bio-inspired swimming systems due to its exceptional maneuverability and agility, especially in high-energy flow environments [9].…”

Generalized Design, Modeling and Control Methodology for a Snake-like Aerial Robot

“…The most unique feature of snake-like robots compared to other legged robots is obstacle-aided locomotion [ 11 ], which depends on explicit obstacles for pushing itself and moving forward. During the last decade, underwater snake-like robots have undergone considerable development [ 12 , 13 , 14 ]. These robots demonstrate a similar mechanism to obstacle-aided locomotion by utilizing the fin structure to generate sufficient reactive forces from the surrounding water.…”

Studying the Physical Characteristics of the Snake Robot Motion Based on the “Bioloid Premium Kit” Construction

“…Other driving mechanismschain tracks and feet were introduced in the twentieth century, in 1920 in particular, since then the first prototypes of snake-like robots appeared. There are various models of snake robots [10]: waver; active cord mechanisms; manipulator without support; shan; the quake snake, etc.…”