Untethered Cable-driven Soft Actuators for Quadruped Robots

Abstract

Various soft robots have appealing advantages in human-machine interaction and industrial applications due to their intrinsic softness. However, the highly nonlinear response of soft material deformation makes the soft robotic system difficult to model and control. Recent attempts of kinematic modeling and control of soft robots mostly rely on simplified kinematic analysis or machine learning which are not accurate to guild their design and control. This work presents a cable driven untethered soft pneumatic actuator with its chambers inflated and sealed at all time. Its motion, including bending and stretching, can be well controlled by adjusting the cable length, and as a result, repeatable motions could be achieved and an accurate kinematic model can be also established. Based on our design, two untethered soft quadruped robots, one crawling and the other walking, are demonstrated for well-controlled forward and steering motions, which is indispensable toward soft robot control, cooperative operation and intelligent movement.