Dynamic Walking with a Soft Limb Robot

Abstract

We present a novel soft limb quadruped robot "FASTT," with a simple and cheap design of its legs for dynamic locomotion aimed to expand the applications of soft robotics in mobile robots. The pneumatically actuated soft legs are self-stabilizing, adaptive to ground, and have variable stiffness, all of which are essential properties of locomotion that are also found in biological systems. We tested the soft legs for the pace, trot, and gallop gait and found them to move with a forward velocity for each gait with robustness. The legs were able to produce a flight and stance phase as a result of the body-environment interaction and also support the weight of the body while two legs were in flight phase and two in stance phase. The soft robot also exhibited two different postures i.e. sprawl and semi-erect which can also be found in some biological species as the crocodile. Moreover, the robot is safe to interact with. The results highlight the effectiveness of the soft limbs to produce dynamic locomotion which provides potential for application in uncertain environments

A virtuous cycle between invertebrate and robotics research: perspective on a decade of Living Machines research

“…Incorporating elastic elements between the actuators and environment, for example, via a compliant joint drive [48] or an elastic foot [49], also has benefits such as reducing the impact forces experienced by the robot. Some legged robots are built with entirely soft legs, granting them all these benefits simultaneously [50]. Even if legged robots are not purely 'soft robots' , they benefit Reproduced from [39], with permission from Springer Nature.…”

“…(top row, right column) Reproduced from [48], with permission from Springer Nature. (2nd row, right column) Reproduced from [50], with permission from Springer Nature. (3rd row, right column) Reproduced from [45], with permission from Springer Nature.…”

A review on the evolvement trend of robotic interaction control

“…Soft robots are capable of manipulation (Calisti et al , 2011) and locomotion (Cianchetti et al , 2015) efficiently, but just when they are suspended in water or are under ground. Although performing a dynamic task (Ansari et al , 2015) outside of such environments is possible for soft robots but not in a controlled and of course not in an efficient way. It means the softrobots are capable of providing variable impedance but just in the presence of external forces, making the stiffness/impedance controllability as the main problem of softrobots.…”

A Bio-Inspired Adjustable Posture Quadruped Robot with Laterally Undulating Spine for Terradynamically Challenging Environments

“…To the best of our knowledge, there is currently no known quadruped robot that integrates both a geardriven symmetrical parallelogram mechanism for posture adjustment and body undulation, all designed based on bio-inspired principles of stability and gait selection. While few bio-inspired robots with variable posture exist (e.g., Bongard [1], Ansari et al [37], Juárez-Campos et al [38]), their approaches have limitations. Bongard's robot [1] relies on a complex gear train and leg stands, limiting agility.…”

“…Bongard's robot [1] relies on a complex gear train and leg stands, limiting agility. Ansari et al's [37] utilize soft legs for posture, but possess a rigid spine, restricting gait versatility. Juárez-Campos et al's [38] Peaucellier-Lipkin mechanism offers limited posture variations.…”