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.

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.

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.

Modeling, Analysis, and Function Extension of the McKibben Hydraulic Artificial Muscles

2020 ◽  
Author(s):  
Siqing Chen ◽  
He Xu
Keyword(s):  
High Pressure ◽  
Theoretical Analysis ◽  
Artificial Muscle ◽  
Design Parameters ◽  
Artificial Muscles ◽  
Soft Robots ◽  
The Law ◽  
Soft Actuators ◽  
The Impact ◽  
The Relationship

Abstract Compared with rigid robots, flexible robots have soft and extensible bodies enforcing their abilities to absorb shock and vibration, hence reducing the impact of probable collisions. Due to their high adaptability and minimally invasive features, soft robots are used in various fields. The McKibben hydraulic artificial muscles are the most popular soft actuator because of the controllability of hydraulic actuator and high force to weight ratio. When its deformation reaches a certain level, the actuators can be stopped automatically without any other braking mechanism. The research of McKibben hydraulic artificial muscles is beneficial to the theoretical analysis of soft actuators in the mechanical system. The design of soft actuators with different deformations promotes the development of soft robots. In this paper, a static modeling of the McKibben hydraulic artificial muscles is established, and its correctness is verified by theoretical analysis and experiment. In this model, the deformation mechanism of the artificial muscle and the law of output force is put forward. The relationship between muscle pressure, load, deformation, and muscle design parameters is presented through the mechanical analysis of the braid, elastic tube, and sealed-end. The law of the muscle deformation with high pressure is predicted. The reason for the muscle’s tiny elongation with extremely high pressure is found through the analysis of the relationship between the angle of the braid, the length of single braided thread, and the pressure. With the increase of pressure, the angle of the braid tends to a fixed value. As the stress of braided thread increases, so does its length. The length changes obviously when the stress is extremely enormous. The angle of the braid and the length of the braided thread control the deformation of artificial muscles, resulting in a slight lengthening with extreme high pressure. Under normal pressure, the length of the braided wire is negligible, so that the entire muscle becomes shorter. According to the modeling and theoretical analysis, a new McKibben hydraulic artificial muscle that can elongate under normal rising pressure is designed. This artificial muscle can grow longer with pressure increases, eventually reaching its maximum length. During this time, its diameter barely changes. Its access pressure is higher than that of conventional elongated artificial muscles. Through experiments, the relationship between the muscle deformation, pressure, and load still conform to this theoretical model. This model can be used for the control of soft actuators and the design of new soft robots. This extensional McKibben hydraulic artificial muscles and the conventional McKibben hydraulic artificial muscles can be used in the bilateral control of soft robots.

scholarly journals Thermodynamic insight into the growth of nanoscale inclusion of Al-deoxidation in Fe–O–Al melt

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hong Lei ◽  
Yuanyou Xiao ◽  
Guocheng Wang ◽  
Hongwei Zhang ◽  
Wei Jin ◽  
...  
Keyword(s):  
Experimental Data ◽  
Free Energy ◽  
Gibbs Free Energy ◽  
Liquid Iron ◽  
Reaction Products ◽  
Straight Line ◽  
Nano Alumina ◽  
Increasing Temperature ◽  
The Relationship ◽  
Insight Into

Abstract Products of Al-deoxidation reaction in iron melt are the most common inclusions and play an important effect on steel performance. Understanding the thermodynamics on nano-alumina (or nano-hercynite) is very critical to explore the relationship between Al-deoxidation reaction and products growth in iron melt. In present study, a thermodynamic modeling of nano-alumina inclusions in Fe–O–Al melt has been developed. The thermodynamic results show that the Gibbs free energy changes for the formation of nano-Al2O3 and nano-FeAl2O4 decrease with the increasing size and increase with the increasing temperature. The Gibbs free energy changes for transformation of nano-Al2O3 into bulk-Al2O3 increase with the increasing size and temperature. The thermodynamic curve of nano-alumina (or nano-hercynite) and the equilibrium curve of bulk-alumina (or bulk-hercynite) obtained in this work are agree with the published experimental data of Al-deoxidation equilibria in liquid iron. In addition, the thermodynamic coexisting points about Al2O3 and FeAl2O4 in liquid iron are in a straight line and coincide with the various previous data. It suggested that these scattered experimental data maybe in the different thermodynamic state of Al-deoxidized liquid iron and the reaction products for most of the previous Al-deoxidation experiments are nano-alumina (or nano-hercynite).

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.

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.

Identifying Physico-Chemical Laws from the Robotically Collected Data

2019 ◽  
Author(s):  
Liwei Cao ◽  
Danilo Russo ◽  
Vassilios S. Vassiliadis ◽  
Alexei Lapkin
Keyword(s):  
Experimental Data ◽  
Numerical Models ◽  
Predictor Variable ◽  
Physical Models ◽  
Training Data ◽  
Mixed Integer ◽  
Physico Chemical ◽  
Data Points ◽  
Future Work ◽  
The Relationship

<p>A mixed-integer nonlinear programming (MINLP) formulation for symbolic regression was proposed to identify physical models from noisy experimental data. The formulation was tested using numerical models and was found to be more efficient than the previous literature example with respect to the number of predictor variables and training data points. The globally optimal search was extended to identify physical models and to cope with noise in the experimental data predictor variable. The methodology was coupled with the collection of experimental data in an automated fashion, and was proven to be successful in identifying the correct physical models describing the relationship between the shear stress and shear rate for both Newtonian and non-Newtonian fluids, and simple kinetic laws of reactions. Future work will focus on addressing the limitations of the formulation presented in this work, by extending it to be able to address larger complex physical models.</p><p><br></p>

Diagnostics of metal samples using the results of experimental and theoretical study of positively charged microparticles formed upon sample destruction

2018 ◽  
Vol 84 (10) ◽  
pp. 23-28
Author(s):  
D. A. Golentsov ◽  
A. G. Gulin ◽  
Vladimir A. Likhter ◽  
K. E. Ulybyshev
Keyword(s):  
Experimental Data ◽  
Early Stage ◽  
Experimental Studies ◽  
Material Model ◽  
Total Charge ◽  
Cross Sectional ◽  
Practical Applications ◽  
Mechanical And Electrical Properties ◽  
Order Of Magnitude ◽  
Using Data

Destruction of bodies is accompanied by formation of both large and microscopic fragments. Numerous experiments on the rupture of different samples show that those fragments carry a positive electric charge. his phenomenon is of interest from the viewpoint of its potential application to contactless diagnostics of the early stage of destruction of the elements in various technical devices. However, the lack of understanding the nature of this phenomenon restricts the possibility of its practical applications. Experimental studies were carried out using an apparatus that allowed direct measurements of the total charge of the microparticles formed upon sample rupture and determination of their size and quantity. The results of rupture tests of duralumin and electrical steel showed that the size of microparticles is several tens of microns, the particle charge per particle is on the order of 10–14 C, and their amount can be estimated as the ratio of the cross-sectional area of the sample at the point of discontinuity to the square of the microparticle size. A model of charge formation on the microparticles is developed proceeding from the experimental data and current concept of the electron gas in metals. The model makes it possible to determine the charge of the microparticle using data on the particle size and mechanical and electrical properties of the material. Model estimates of the total charge of particles show order-of-magnitude agreement with the experimental data.

Potential Role of Inflammation in Associations between Particulate Matter and Heart Failure

2018 ◽  
Vol 24 (3) ◽  
pp. 341-358 ◽  
Author(s):  
Xiaotong Ji ◽  
Yingying Zhang ◽  
Guangke Li ◽  
Nan Sang
Keyword(s):  
Heart Failure ◽  
Particulate Matter ◽  
Inflammatory Response ◽  
Heart Diseases ◽  
Experimental Studies ◽  
Epidemiological Studies ◽  
Inflammatory Mechanism ◽  
High Concentrations ◽  
Future Work ◽  
The Relationship

Recently, numerous studies have found that particulate matter (PM) exposure is correlated with increased hospitalization and mortality from heart failure (HF). In addition to problems with circulation, HF patients often display high expression of cytokines in the failing heart. Thus, as a recurring heart problem, HF is thought to be a disorder characterized in part by the inflammatory response. In this review, we intend to discuss the relationship between PM exposure and HF that is based on inflammatory mechanism and to provide a comprehensive, updated evaluation of the related studies. Epidemiological studies on PM-induced heart diseases are focused on high concentrations of PM, high pollutant load exposure in winter, or susceptible groups with heart diseases, etc. Furthermore, it appears that the relationship between fine or ultrafine PM and HF is stronger than that between HF and coarse PM. However, fewer studies paid attention to PM components. As for experimental studies, it is worth noting that coarse PM may indirectly promote the inflammatory response in the heart through systematic circulation of cytokines produced primarily in the lungs, while ultrafine PM and its components can enter circulation and further induce inflammation directly in the heart. In terms of PM exposure and enhanced inflammation during the pathogenesis of HF, this article reviews the following mechanisms: hemodynamics, oxidative stress, Toll-like receptors (TLRs) and epigenetic regulation. However, many problems are still unsolved, and future work will be needed to clarify the complex biologic mechanisms and to identify the specific components of PM responsible for adverse effects on heart health.

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