scholarly journals Rapid GAIT adoption for snake-like locomotion (RGASL)

2021 ◽  
Author(s):  
Nhan Trung Tran
Keyword(s):  
Gait Training ◽  
Trial And Error ◽  
Snake Robot ◽  
Flat Surfaces ◽  
Robot Locomotion ◽  
The Third ◽  
Centre Of Gravity ◽  
Mobility Problem ◽  
Slender Bodies ◽  
Snake Robots

Snake-like robots are low centre of gravity because they are limbless, they also have slender bodies composed of multiple actuating segments. Because of these features, snake robots are widely considered to be most adaptable among all land-based mobile robots. The multi-segmented body that provides their defining characteristic, adaptivity, also brings about the quandary of controlling many actuating segments simultaneously to create directd locomotion. Various methods for snake robot locomotion have been proposed for relatively smooth and flat surfaces. Currently there is no snake robot designed or locomotion method capable of resolving the directed mobility problem in situations where the snake robot is stuck at an impasse, or when it encounters disjointed terrains. There is no method to rapidly create new locomotion that addresses the problem or extensive time delay. This thesis makes the contribution of a modular snake robot called Striker and an elegant solution to create new snake-like robot locomotion on-the-fly, called the Explicit Gait Training (EGT) method. The EGT method allows trainer(s) to rapidly train new kinds of locomotion to address any situation at hand using their knowledge, experiences or even trial and error. The third contribution is the Standard Mobility for Snake Robots (SMMSR) is proposed as a standard platform to evaluate the evvectiveness of snake robot locomotion.

scholarly journals Rapid GAIT adoption for snake-like locomotion (RGASL)

2021 ◽  
Author(s):  
Nhan Trung Tran
Keyword(s):  
Gait Training ◽  
Trial And Error ◽  
Snake Robot ◽  
Flat Surfaces ◽  
Robot Locomotion ◽  
The Third ◽  
Centre Of Gravity ◽  
Mobility Problem ◽  
Slender Bodies ◽  
Snake Robots

Snake-like robots are low centre of gravity because they are limbless, they also have slender bodies composed of multiple actuating segments. Because of these features, snake robots are widely considered to be most adaptable among all land-based mobile robots. The multi-segmented body that provides their defining characteristic, adaptivity, also brings about the quandary of controlling many actuating segments simultaneously to create directd locomotion. Various methods for snake robot locomotion have been proposed for relatively smooth and flat surfaces. Currently there is no snake robot designed or locomotion method capable of resolving the directed mobility problem in situations where the snake robot is stuck at an impasse, or when it encounters disjointed terrains. There is no method to rapidly create new locomotion that addresses the problem or extensive time delay. This thesis makes the contribution of a modular snake robot called Striker and an elegant solution to create new snake-like robot locomotion on-the-fly, called the Explicit Gait Training (EGT) method. The EGT method allows trainer(s) to rapidly train new kinds of locomotion to address any situation at hand using their knowledge, experiences or even trial and error. The third contribution is the Standard Mobility for Snake Robots (SMMSR) is proposed as a standard platform to evaluate the evvectiveness of snake robot locomotion.

Bio-Inspired Snake Robots

2018 ◽  
pp. 246-275 ◽  
Author(s):  
Mohammadali Javaheri Koopaee ◽  
Cid Gilani ◽  
Callum Scott ◽  
XiaoQi Chen
Keyword(s):  
Future Research ◽  
Snake Robot ◽  
Cluttered Environments ◽  
Flat Surfaces ◽  
Robot Locomotion ◽  
Control Schemes ◽  
Unstructured Environment ◽  
And Control ◽  
World Environment ◽  
Snake Robots

This chapter concerns modelling and control of snake robots. Specifically, the authors' main goal is introducing some of the fundamental design, modelling, and control approaches introduced for efficient snake robot locomotion in cluttered environments. This is a critical topic because, unlike locomotion in flat surfaces, where pre-specified gait equations can be employed, for locomotion in unstructured environment more sophisticated control approaches should be used to achieve intelligent and efficient mobility. To reach this goal, shape-based modelling approaches and a number of available control schemes for operation in unknown environments are presented, which hopefully motivates more scholars to start working on snake robots. Some ideas about future research plans are also proposed, which can be helpful for fabricating a snake robot equipped with the necessary features for operation in a real-world environment.

scholarly journals Lateral Oscillation and Body Compliance Help Snakes and Snake Robots Stably Traverse Large, Smooth Obstacles

2020 ◽  
Vol 60 (1) ◽  
pp. 171-179
Author(s):  
Qiyuan Fu ◽  
Sean W Gart ◽  
Thomas W Mitchel ◽  
Jin Seob Kim ◽  
Gregory S Chirikjian ◽  
...  
Keyword(s):  
Surface Friction ◽  
Static Stability ◽  
Three Dimensions ◽  
Step Height ◽  
Snake Robot ◽  
Flat Surfaces ◽  
Lateral Oscillation ◽  
Continuous Body ◽  
Base Of Support ◽  
Snake Robots

Abstract Snakes can move through almost any terrain. Similarly, snake robots hold the promise as a versatile platform to traverse complex environments such as earthquake rubble. Unlike snake locomotion on flat surfaces which is inherently stable, when snakes traverse complex terrain by deforming their body out of plane, it becomes challenging to maintain stability. Here, we review our recent progress in understanding how snakes and snake robots traverse large, smooth obstacles such as boulders and felled trees that lack “anchor points” for gripping or bracing. First, we discovered that the generalist variable kingsnake combines lateral oscillation and cantilevering. Regardless of step height and surface friction, the overall gait is preserved. Next, to quantify static stability of the snake, we developed a method to interpolate continuous body in three dimensions (3D) (both position and orientation) between discrete tracked markers. By analyzing the base of support using the interpolated continuous body 3-D kinematics, we discovered that the snake maintained perfect stability during traversal, even on the most challenging low friction, high step. Finally, we applied this gait to a snake robot and systematically tested its performance traversing large steps with variable heights to further understand stability principles. The robot rapidly and stably traversed steps nearly as high as a third of its body length. As step height increased, the robot rolled more frequently to the extent of flipping over, reducing traversal probability. The absence of such failure in the snake with a compliant body inspired us to add body compliance to the robot. With better surface contact, the compliant body robot suffered less roll instability and traversed high steps at higher probability, without sacrificing traversal speed. Our robot traversed large step-like obstacles more rapidly than most previous snake robots, approaching that of the animal. 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.

Computer Aided Design and Realization of a Snake Robot with Two Sets of Three Revolute Joint Mechanism

2014 ◽  
Vol 592-594 ◽  
pp. 2272-2276 ◽  
Author(s):  
V.S. Rajashekhar ◽  
K. Thiruppathi ◽  
R. Senthil
Keyword(s):  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Rotating Disks ◽  
Revolute Joint ◽  
Snake Robot ◽  
Flat Surfaces ◽  
Joint Mechanism ◽  
Aided Design ◽  
Made In ◽  
Snake Robots

Snake robots have high degrees of freedom and can move on any kind of environment by suitably adjusting itself. In order to serve this purpose, a snake robot with two sets of three revolute joint mechanism was developed to exhibit concertina motion. There are rotating disks at the end of the segments which enables side winding motion. By the combination of these two motions, the snake robot can traverse on flat surfaces and even on slopes. The snake robot was first drafted and then modeled. Then the mechanism was simulated and stress analysis was done for it. Finally the design was implemented and the snake robot was made in reality.

scholarly journals Robotic modelling of snake traversing large, smooth obstacles reveals stability benefits of body compliance

2020 ◽  
Vol 7 (2) ◽  
pp. 191192 ◽  
Author(s):  
Qiyuan Fu ◽  
Chen Li
Keyword(s):  
Complex Terrain ◽  
Search And Rescue ◽  
Anisotropic Friction ◽  
Snake Robot ◽  
Flat Surfaces ◽  
Out Of Plane ◽  
Lateral Undulation ◽  
Anchor Points ◽  
Desert Dunes ◽  
Snake Robots

Snakes can move through almost any terrain. Although their locomotion on flat surfaces using planar gaits is inherently stable, when snakes deform their body out of plane to traverse complex terrain, maintaining stability becomes a challenge. On trees and desert dunes, snakes grip branches or brace against depressed sand for stability. However, how they stably surmount obstacles like boulders too large and smooth to gain such ‘anchor points’ is less understood. Similarly, snake robots are challenged to stably traverse large, smooth obstacles for search and rescue and building inspection. Our recent study discovered that snakes combine body lateral undulation and cantilevering to stably traverse large steps. Here, we developed a snake robot with this gait and snake-like anisotropic friction and used it as a physical model to understand stability principles. The robot traversed steps as high as a third of its body length rapidly and stably. However, on higher steps, it was more likely to fail due to more frequent rolling and flipping over, which was absent in the snake with a compliant body. Adding body compliance reduced the robot's roll instability by statistically improving surface contact, without reducing speed. Besides advancing understanding of snake locomotion, our robot achieved high traversal speed surpassing most previous snake robots and approaching snakes, while maintaining high traversal probability.

scholarly journals A Muscle-Driven Mechanism for Locomotion of Snake-Robots

Automation ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 1-26
Author(s):  
Marcela Lopez ◽  
Mahdi Haghshenas-Jaryani
Keyword(s):  
Experimental Data ◽  
Experimental Studies ◽  
Artificial Muscle ◽  
Linkage Mechanism ◽  
Snake Robot ◽  
Robot Locomotion ◽  
Straight Line ◽  
Soft Actuators ◽  
The Relationship ◽  
Snake Robots

This paper presents the concept of muscle-driven locomotion for planar snake robots, which combines the advantages of both rigid and soft robotic approaches to enhance the performance of snake robot locomotion. For this purpose, two adjacent links are connected by a pair of pneumatic artificial muscles wherein an alternate actuation of these soft actuators causes a rotational motion at the connecting joints. The muscle-based actuated linkage mechanism, as a closed six-linkage mechanism, was designed and prototyped. The linear motion and force generation of the pneumatic artificial muscle was experimentally characterized using isotonic and isometric contraction experiments. A predictive model was developed based on the experimental data to describe the relationship between the force–length–pressure of the PAMs. Additionally, the muscle-driven mechanism was kinematically and dynamically characterized based on both theoretical and experimental studies. The experimental data generally agreed with our model’s results and the generated joint angle and torque were comparable to the current snake-like robots. A skx-link planar snake robot with five joints, five pairs of antagonistic muscles, and an associated pneumatic controller was prototyped and examined for simple movements on a straight-line. We demonstrated the muscle-driven locomotion of the six-link snake robot, and the results show the feasibility of using the proposed mechanism for future explorations of snake robot locomotion.

scholarly journals Two new design concepts for snake robot locomotion in unstructured environments

2010 ◽  
Vol 1 (3) ◽  
Author(s):  
Pål Liljebäck ◽  
Øyvind Stavdahl ◽  
Kristin Y. Pettersen ◽  
Jan Tommy Gravdahl
Keyword(s):  
Motion Control ◽  
Contact Forces ◽  
Design Concept ◽  
Constraint Forces ◽  
Snake Robot ◽  
Design Concepts ◽  
Robot Locomotion ◽  
Unstructured Environments ◽  
The Subject ◽  
Snake Robots

AbstractThis communication presents and justifies ideas related to motion control of snake robots that are currently the subject of ongoing investigations by the authors. In particular, we highlight requirements for intelligent and effcient snake robot locomotion in unstructured environments, and subsequently we present two new design concepts for snake robots that comply with these requirements. The first design concept is an approach for sensing environment contact forces, which is based on measuring the joint constraint forces at the connection between the links of the snake robot. The second design concept involves allowing the cylindrical surface of each link of a snake robot to rotate by a motor inside the link in order to induce propulsive forces on the robot from its environments. The paper details the advantages of the proposed design concepts over previous snake robot designs.

The Third Phase: Trial and Error with LBOs

2011 ◽  
pp. 108-158
Author(s):  
Paul Jowett ◽  
Francoise Jowett
Keyword(s):  
Trial And Error ◽  
The Third ◽  
Third Phase ◽  
Phase Trial

Modeling and Mechanical Analysis of Snake Robots on Cylinders

2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Chaoquan Tang ◽  
Peng Li ◽  
Gongbo Zhou ◽  
Deyuan Meng ◽  
Xin Shu ◽  
...  
Keyword(s):  
Mechanical Analysis ◽  
Point Of View ◽  
The Body ◽  
Optimal Method ◽  
Tree Structures ◽  
Snake Robot ◽  
Mechanical Models ◽  
And Performance ◽  
The Relationship ◽  
Snake Robots

The narrow and redundant body of the snake robot makes it suitable for the inspection of complex bar structures, such as truss or tree structures. One of the key issues affecting the efficient motion of snake robots in complex bar structures is the development of mechanical models of snake robots on cylinders. In other words, the relationship between the payload and structural and performance parameters of the snake robot is still difficult to clarify. In this paper, the problem is approached with the Newton–Euler equations and the convex optimal method. Firstly, from the kinematic point of view, the optimal attitude of the snake robot wrapped around the cylinder is found. Next, the snake robot is modeled on the cylinder and transformed into a convex optimization problem. Then, the relationship between the payload of the snake robot on the cylinder and the geometric and attitude parameters of the body of snake robots is analyzed. Finally, the discussion for the optimal winding attitude and some advices for the design of the snake robot are proposed. This study is helpful toward the optimal design of snake robots, including geometry parameters and motor determination.

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