Variable Stiffness Mechanism Design and Analysis for a Snake-Like Robot

Abstract

In this study, a variable stiffness mechanism of snake-like robot comprising of orthogonal joints and magnetorheological fluid brakes (MFB) is proposed and analyzed. The orthogonal joint is adopted in this mechanism to overcome the deficiency of 1-DOF snake-like robot not being able to perform a variety of motion gaits. Compared with devices driven by motors and reduction gears, devices with MFB add intrinsic variable stiffness to the snake-like robot. In addition, the geometric sizes of magneto-rheological fluid brake are optimized through torque equation, volume equation and efficiency equation. Furthermore, magnetic field characteristics of brake and the generated damping torque of variable stiffness joint are analyzed. Finally, a virtual prototype of the proposed snakelike robot is constructed and simulation results demonstrate the feasibility and high-performance of our designed mechanism.