Locomotion with continuum limbs

Abstract

This paper presents the kinematics, dynamics, and experimental results for a novel quadruped robot using continuum limbs. We propose soft continuum limbs as a new paradigm for robotic locomotion in unstructured environments due to their potential to generate a wide array of locomotion behaviors ranging from walking, trotting, crawling, and propelling to whole arm grasping as a means of negotiating difficult obstacles. A straightforward method to derive the kinematics and dynamics for the proposed quadruped has been demonstrated through numerical simulations. Initial experiments on a prototype continuum quadruped demonstrate the ability to stand up from a flat-belly stance, absorb external disturbances such as maintaining stability after dropping from a height and after being perturbed by a collision, and crawling on flat and cluttered environments. Experiment results provide evidence that locomotion with soft continuum limbs are feasible and usable in unstructured environments for variety of applications.

Fundamentals of soft robot locomotion

“…Most soft multi-legged robots employ a different principle for walking: they move legs and body to keep the centre of gravity always inside the polygon of support (table 2). This was the first strategy used by rigid legged robots [57], and it is a concept often used by robots with soft pneumatic legs [16,58,59], SMA and spring systems [60], and EAPs [61]. In those gaits, soft bodies or structures are exploited to adapt to different conditions, move inside confined spaces, or reduce the force exerted on the environment.…”

Robotic Granular Jamming: A New Variable Stiffness Mechanism

“…This type of hybrid technology can extend the capabilities of current soft robots, such as the flexible legged robot by Ref. [25]. Not only can the pneumatic actuators move the robot, but the integrated granules can stiffen to vary the impedance of the legs.…”

Tendon-Based Stiffening for a Pneumatically Actuated Soft Manipulator

“…In particular, animals' appendages such as the elephant trunk or the octopus arm have become the focus of studies creating soft, hyper-redundant robots, with capabilities similar to those of the biological role models [2]- [5]. The application of these types of robots can result in significant improvements within a number of fields where traditional robots are currently deployed [6]- [8]. One of these areas is Minimally Invasive Surgery (MIS) -also called laparoscopic or keyhole surgery [9], [10].…”