Sidewinding with minimal slip: Snake and robot ascent of sandy slopes

  title={Sidewinding with minimal slip: Snake and robot ascent of sandy slopes},
  author={Hamid Marvi and Chaohui Gong and Nick Gravish and Henry C. Astley and Matthew J. Travers and Ross L. Hatton and Joseph R. Mendelson and Howie Choset and David L. Hu and Daniel I. Goldman},
  pages={224 - 229}
Limbless organisms such as snakes can navigate nearly all terrain. In particular, desert-dwelling sidewinder rattlesnakes (Crotalus cerastes) operate effectively on inclined granular media (such as sand dunes) that induce failure in field-tested limbless robots through slipping and pitching. Our laboratory experiments reveal that as granular incline angle increases, sidewinder rattlesnakes increase the length of their body in contact with the sand. Implementing this strategy in a physical robot… 
Side-impact collision: mechanics of obstacle negotiation in sidewinding snakes
An algorithm is developed to reproduce the Propagate Through behavior in a robophysical model using a modulation of the two-wave template, which provides sidewinders with a versatile range of options for effectively negotiating obstacles in their natural habitat.
Comments on "sidewinding with minimal slip: snake and robot ascent of sandy slopes"
Evidence is shown that there should be three phases that fully represent the snake locomotion behaviors during ascent of sandy slopes, namely lifting, descending, and ceasing, and that such interaction during the lifting phase in fact contributes resistance.
Crab-Like Hexapod Feet for Amphibious Walking in Sand and Waves
The modified 1.2 kg HEXY robot is demonstrated with crab-like legs, which can allow the robot to resist vertical forces greater than the body weight, and the modified foot designs are compatible with legged walking gaits (slow, medium, and fast).
Of snakes and robots
The physics of sidewinding in animal and robot is explored, revealing how limbless locomotors can move up sandy slopes.
Locomotion of Ants Walking up Slippery Slopes of Granular Materials
An abnormality index is defined that allows us to quantify the locomotory difficulties of insects walking up a granular incline, and reveals the local slipping of the granular media as a consequence of the pressure exerted by the ant’s legs.
Snakes partition their body to traverse large steps stably
Generalist snakes divide their body into sections, each using distinct movement patterns, to get over large step-like obstacles, and such body partitioning may be generally useful for diverse, complex 3-D terrain.
Robotic modelling of snake traversing large, smooth obstacles reveals stability benefits of body compliance
This work developed a snake robot with this gait and snake-like anisotropic friction and used it as a physical model to understand stability principles and achieved high traversal speed surpassing most previous snake robots and approaching snakes, while maintaining high traverseal probability.
Snakes combine vertical and lateral bending to traverse uneven terrain
Direct measurements of contact forces are necessary to further understand how snakes coordinate 3D bending along the entire body via sensory feedback to propel through 3D terrain, and this study studied how the generalist corn snake traversed an uneven arena of blocks of random height variation five times its body height.
The dynamics of legged locomotion in heterogeneous terrain: universality in scattering and sensitivity to initial conditions
A fully-automated terrain creation system, the SCATTER (Systematic Creation of Arbitrary Terrain and Testing of Exploratory Robots), to control the initial conditions of the substrate, including sand compaction, boulder distribution, and substrate inclination, and analysis of the robot’s trajectory indicates that the interaction with a boulder can be modeled as a scatterer with attractive and repulsive features.
Lateral oscillation and body compliance help snakes and snake robots stably traverse large, smooth obstacles
The combination of lateral oscillation and body compliance to form a large, reliable base of support may be useful for snakes and snake robots to traverse diverse 3-D environments with large, smooth obstacles.


A Terradynamics of Legged Locomotion on Granular Media
A force model for arbitrarily-shaped legs and bodies moving freely in granular media is developed, and used to predict a small legged robot’s locomotion on granularMedia using various leg shapes and stride frequencies, and gives insight into the effects of leg morphology and kinematics on movement.
Friction enhancement in concertina locomotion of snakes
  • H. Marvi, D. Hu
  • Engineering
    Journal of The Royal Society Interface
  • 2012
Theoretical modelling of a one-dimensional n-linked crawler is used to calculate the transverse force factor of safety: snakes push up to four times more than required to prevent sliding backwards, presumably trading metabolic energy for an assurance of wall stability.
Sensitive dependence of the motion of a legged robot on granular media
A kinematic model of the rotary walking mode based on generic features of penetration and slip of a curved limb in granular media is proposed, which captures the dependence of robot speed on limb frequency and the transition between walking and swimming modes but highlights the need for a deeper understanding of the physics of granularMedia.
Utilization of granular solidification during terrestrial locomotion of hatchling sea turtles
Hatchlings were challenged to traverse a trackway with two surface treatments: hard ground (sandpaper) and loosely packed sand, and comparable performance on sand was achieved by creation of a solid region behind the flipper that prevents slipping.
Snakes mimic earthworms: propulsion using rectilinear travelling waves
This combined experimental and theoretical study film rectilinear locomotion of three species of snakes, including red-tailed boa constrictors, Dumeril's boas and Gaboon vipers, and applies a mathematical model to show snakes have optimal wave frequencies.
Flipper-driven terrestrial locomotion of a sea turtle-inspired robot
In the constant step length regime, kinematic and force-based models accurately predict FBot's motion for free and fixed wrist configurations, respectively and provide insight into how disturbed ground leads to locomotory failure and help explain differences in hatchling sea turtle performance.
A Note on the Sidewinding Locomotion of Snakes
The sidewise, looping motion [of Crotalus cerastes], which gives it its name, is accentuated when the snake is excited or in a hurry. At such times the middle section of the body is thrown out in a
Undulatory Swimming in Sand: Subsurface Locomotion of the Sandfish Lizard
To predict sandfish swimming speed, an empirical model is developed by measuring granular drag force on a small cylinder oriented at different angles relative to the displacement direction and summing these forces over the animal movement profile, which implies that the noninertial swimming occurs in a frictional fluid.
The mechanics of slithering locomotion
A theoretical model for slithering locomotion is developed by observing snake motion kinematics and experimentally measuring the friction coefficients of snakeskin, demonstrating that snake propulsion on flat ground, and possibly in general, relies critically on the frictional anisotropy of their scales.
The mechanism of locomotion in snakes.
  • J. Gray
  • Biology
    The Journal of experimental biology
  • 1946
The muscular cycle of a snake exhibiting ‘crotaline’, or side-winding, movements is essentially the same as that during serpentine motion; the difference in the type of movement relative to the ground is due to a different in the nature of the external resistances offered by the animal9s environment.