Pneumatic Muscle: Geometry of the Cylindrical Membrane and The Power Characteristic Prognostic

2018 ◽  
pp. 20-34 ◽  
Author(s):  
K. D. Efremova ◽  
V. N. Pilgunov
Keyword(s):  
Elastic Shell ◽  
Experimental Studies ◽  
Original Position ◽  
Internal Cavity ◽  
Internal Diameter ◽  
Numerical Representation ◽  
Pneumatic Muscle ◽  
Pneumatic Muscles ◽  
Shaped Cell ◽  
Force Characteristics

The pneumatic muscle is a pneumatic motor of the single-acting reciprocating motion. It is designed to create apullingforce. Return of the pneumatic muscle to its original position is provided by elastic deformation of its shell. A cylindrical membrane with the hard bottom and the lid provides the basis of the pneumatic muscle.The membrane cord is formed in the process of helically shaped CU-braid of the threads made from the super-hard synthetic fibres (for example, Kevlar). After the cord is filled with an elastomer, a strong, deformable and elastic shell is formed. An excessive pressure applied to the internal cavity of the membrane arises an extension of the tangent diagonal and a simultaneous shortening of the axial diagonal in the diamond-shaped cell, which is formed as a result of braid of cord threads. This results in pneumatic muscle’s retraction up to 25% of its original length, while creating a sufficiently large contraction force, which depends significantly on the contraction value.Using the cord structure of the MAS series pneumatic muscles of the company “FESTO” as an example, we have investigated a diamond-shaped cell deformation of the membrane and have defined a numerical dependence of its internal diameter and the volume of the internal cavity of the pneumatic muscle on the contraction value. This allowed us to develop a mathematical model of an idealized cylindrical membrane whose dynamics does not take into account a deformation force of the elastomer, filling a diamond-shaped cell.The experimental studies of industrial samples of the MAS 10 family of pneumatic muscles, carried out using a specially designed unit, allowed us to obtain their force characteristics. In the numerical representation, these characteristics turned out to be 2.5 ... 3 times less than the force characteristics of the pneumatic muscle with an idealized membrane, thereby allowing us to draw conclusions that the elastomer deformation forces have a significant influence. There is a proposal to take into account the elastomer deformation effect on the force characteristics of the pneumatic muscle by dint of the correction factor available from a comparative estimate of the force characteristics of the idealized membrane and the normalized force characteristics of the pneumatic muscles of the MAS family.The results of the performed studies allow us to predict the force characteristics of pneumatic muscles at the stage of their design and in-service.

Pneumatic Muscle: Heat and Mass Transfer in the Cylindrical Membrane

2018 ◽  
pp. 13-30
Author(s):  
K. D. Efremova ◽  
V. N. Pilgunov ◽  
A. S. Shablovskyi
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Elastic Shell ◽  
Thermodynamic System ◽  
Initial Position ◽  
Design Stage ◽  
Internal Cavity ◽  
Pneumatic Muscle ◽  
Muscle Dynamics ◽  
Shaped Cell

A pneumatic muscle is a one-way reciprocating air motor. It is designed to create apullingforce. The pneumatic muscle return to its initial position is ensured by a reversible strain of its shell. The pneumatic muscle is based on the cylindrical membrane with a rigid bottom and a cover. The membrane cord is formed during the process of cross-spiral weaving from the super-hard synthetic fibers (for example, Kevlar). After the cord has been filled with an elastomer, a strong, deformable and elastic shell is formed. When an overpressure is provided to the internal cavity of the membrane, in a diamond-shaped cell that is formed as a result of weaving cord threads, the tangential diagonal is lengthened and the axial diagonal is shortened simultaneously. Using the pneumatic muscle cord structure of the MAS series produced by FESTO company as an example, we studied a strain of the diamond-shaped cell of the membrane and found the numerical relationships between the value of the pneumatic muscle contraction, the inner diameter of the membrane and the volume of its internal cavity of the pneumatic muscle, which allowed us to develop a mathematical model of an idealized cylindrical membrane in the dynamics of which the strain force of the elastomer that fills the diamond-shaped cell was not taken into account. The paper shows that the cylindrical membrane used in the pneumatic muscle should be considered as a thermodynamic system with full or partial heat and mass transfer. Also discusses the special aspects of using pneumatic muscles in engineering systems as applied to the type of a thermodynamic process. The study of the air movement features in throttling openings of control and management devices, as well as the changes in the state of compressed air during heat and mass transfer allowed us to estimate a length of the transient process in the pneumatic muscle that works as part of the pneumatic load positioning system. The results of the performed studies expand opportunities for predicting the pneumatic muscle dynamics at the design stage of the pneumatic control system, as well as during its operation.

scholarly journals Extended-State-Observer-Based Super Twisting Control for Pneumatic Muscle Actuators

Actuators ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 35
Author(s):  
Yu Cao ◽  
Zhongzheng Fu ◽  
Mengshi Zhang ◽  
Jian Huang
Keyword(s):  
Control Method ◽  
Experimental Studies ◽  
State Observer ◽  
Extended State Observer ◽  
Extended State ◽  
Pneumatic Muscle ◽  
System States ◽  
The Stability ◽  
Twisting Control ◽  
Muscle Actuators

This paper presents a tracking control method for pneumatic muscle actuators (PMAs). Considering that the PMA platform only feedbacks position, and the velocity and disturbances cannot be observed directly, we use the extended-state-observer (ESO) for simultaneously estimating the system states and disturbances by using measurable variables. Integrated with the ESO, a super twisting controller (STC) is design based on estimated states to realize the high-precision tracking. According to the Lyapunov theorem, the stability of the closed-loop system is ensured. Simulation and experimental studies are conducted, and the results show the convergence of the ESO and the effectiveness of the proposed method.

Features of slopes overcoming by walking devices

2021 ◽  
Vol 9 (3) ◽  
pp. 234-240
Author(s):  
Vadim Chernyshev ◽  
Vladimir Arykantsev ◽  
Anton Goncharov ◽  
Nikolay Sharonov
Keyword(s):  
Mobile Robots ◽  
Experimental Studies ◽  
Field Tests ◽  
Soil Conditions ◽  
Adhesion Properties ◽  
Walking Machines ◽  
Volgograd Region ◽  
Propulsion Unit ◽  
Force Characteristics ◽  
Robot Body

For mobile robots designed to work in extreme conditions, an important characteristic is the value of the overcoming slope. For wheeled and tracked vehicles, the angle of the overcoming slope is limited by the adhesion properties of the soil. The walking device can provide overcoming of higher slopes, since the analogue of the adhesion coefficient for walking machines, with a large footprint track depth, can be significantly greater than 1. The paper discusses the results of experimental studies of the features of overcoming slopes by a walking device in weak soil conditions. When mobile robots overcoming inclines, they may overturn or slide downhill. It is shown that on soft soils the sliding of walking machines downhill is unlikely because of significant deformations of the soil under the support elements. On the other hand, the deformation of the soil worsens the resistance of the walking vehicle to overturning. A method of increasing resistance to overturning by controlling the position of the robot body by separately regulating the conditional clearance of walking mechanisms is considered. The possibility of adjusting the clearance in the propulsion unit on the basis of Umnov-Chebyshev cyclic walking mechanisms is shown. Climbing slopes requires a certain amount of traction. The values of the additional power and the force characteristics of the walking device’s drive necessary for successful overcoming of slopes have been determined. The results of the work can be demand in the development of walking machines and mobile robots. Key words Mobile robots, walking machines, interaction with the ground, traction and coupling properties, overcoming slopes, tipping resistance, mathematical modeling, field tests. Acknowledgements Research was partially supported by RFBR and the Administration of the Volgograd region, research projects no. 19-08-01180 a, 19-48-340007 p_a.

Control of a Pneumatic Muscle Actuated Rehabilitation System of the Lower Limb Bearing Joints

2015 ◽  
Vol 809-810 ◽  
pp. 706-711
Author(s):  
Tudor Deaconescu ◽  
Andrea Deaconescu
Keyword(s):  
Human Body ◽  
Lower Limb ◽  
Rehabilitation Medicine ◽  
Medical Systems ◽  
Pneumatic Muscle ◽  
Motion Graphs ◽  
Pneumatic Muscles ◽  
Rehabilitation System

The specific objectives of rehabilitation medicine are maintaining and recovering human body functions, as well as preventing dysfunctionalities by means of kinetic and orthotic techniques and a variety of equipment for support and adaptation. The latter are medical systems facilitating the exercise of muscles at constant or variable speeds according to professional recommendations. The paper presents and discusses the control of rehabilitation equipment designed for the passive mobilisation exercises of joints. The novelty of such equipment resides in its actuation by pneumatic muscles, as well as in its control by means of an SPC 200 controller and WinPISA software. The paper presents a number of examples of rehabilitation programmes and the corresponding motion graphs of the rehabilitation equipment sliding block.

A Novel Geometric Formula for Predicting Contractile Force in McKibben Pneumatic Muscles

2017 ◽  
Vol 11 (3) ◽  
pp. 368-377 ◽  
Author(s):  
Guido Belforte ◽  
◽  
Terenziano Raparelli ◽  
Silvia Alessandra Sirolli
Keyword(s):  
Analytical Formula ◽  
Experimental Models ◽  
Design Tool ◽  
Analytical Models ◽  
Pneumatic Muscle ◽  
Muscle Structure ◽  
Pneumatic Muscles ◽  
Muscle Geometry ◽  
Muscle Types ◽  
Specific Muscle

Several analytical models exist in the literature for predicting the behavior of braided pneumatic muscles (McKibben muscles). Such models take into consideration the various variables and parameters that are related to the muscle geometry, material properties, and the loads applied to the system, and propose various relationships between these variables. Owing to the complexity of the muscle structure, in several cases, instead of a physical model, empirical or experimental models are used, which generally have limited validity for specific muscle types, i.e., they are only valid for a restricted range of operating parameters. This study proposes a new analytical formula based on the geometry of a pneumatic muscle studied in the rest and work phases and a simple experimental method to obtain corrective factors useful to design muscles. A mathematical formula can thus be obtained that allows one to deduce the measurements of interest in the system as a function of the specific parameters and permits one to interpret in qualitative terms the behavior of the muscle at each moment for various values of pressure, contraction, and applied load and to identify any critical situations. This model can therefore be a very useful design tool because it allows one to adapt the muscle geometry based on the required forces and contractions for different applications that are compatible with the muscle structure on which the model is based. This paper also presents a method for evaluating the efficiency of the muscles, useful to better use them in different applications.

Design and Control of a Frog-Inspired Swimming Leg Powered by Pneumatic Muscle

2016 ◽  
Author(s):  
Jizhuang Fan ◽  
Gangfeng Liu ◽  
Huan Wang ◽  
Wei Zhang ◽  
Yanhe Zhu
Keyword(s):  
Dynamic Model ◽  
Step Response ◽  
Joint Control ◽  
Pneumatic Muscle ◽  
Experiment Platform ◽  
Pneumatic Muscles ◽  
Ankle Joints ◽  
Self Tuning ◽  
And Control ◽  
Swimming Leg

According to the shortages of previous generation of frog inspired robot, antagonistic joint based frog inspired leg was designed. With the multi-DOFs of hip, knee and ankle, the designed leg was able to perform various frog swimming modes. The dynamic model of antagonistic joint based on advanced pneumatic muscle model was established in MATLAB/Simulink environment. Besides, the servo control strategy of joint angle was studied based on the dynamic model of antagonistic joint. The PID and self-tuning fuzzy control were utilized to control the antagonistic joint. According to different swimming modes, joint trajectories of hip, knee and ankle were created by inverse kinematics based on the frog swimming mechanism. Therefore, the leg was controlled by the separated controls of hip, knee and ankle joints. Feasibility of pneumatic antagonistic joint control was validated via step response experiments with different loads. Finally, the experiment platform was established to carry swimming experiments with the developed frog-inspired swimming leg. The feasibility of antagonistic frog inspired swimming leg driven by pneumatic muscles was validated.

Experimental Studies of Pulsatile Flow and Endothelial Cell Adaptation in Ventricle Shaped Cell Culture Chambers

ASAIO Journal ◽  
1992 ◽  
Vol 38 (3) ◽  
pp. M501-M506 ◽  
Author(s):  
C. W. CHRISTENSEN ◽  
M. M. SAMET ◽  
D. M. CHICK ◽  
P. I. LELKES
Keyword(s):  
Cell Culture ◽  
Endothelial Cell ◽  
Pulsatile Flow ◽  
Experimental Studies ◽  
Cell Adaptation ◽  
Shaped Cell

Actuation by Pneumatic Muscles of a Parallel Asymmetric Gripper System

2014 ◽  
Vol 548-549 ◽  
pp. 943-947 ◽  
Author(s):  
Doina Negrea ◽  
Andrea Deaconescu ◽  
Tudor Deaconescu
Keyword(s):  
Pneumatic Muscle ◽  
Natural Systems ◽  
Structural Rigidity ◽  
Pneumatic Muscles ◽  
Gripper Systems

Deployment of pneumatic muscles for the actuation of gripper systems is a solution with numerous benefits, related mostly to the developed force, structural rigidity, compliance and dexterity. The paper discusses a gripper variant with parallel jaws, actuated by a pneumatic muscle. The structure of the mechanism is presented, and the transmission functions of speeds and forces are determined. Due to its construction, the gripper system can be used for precision applications, similar to natural systems.

scholarly journals A Procedure for the Fatigue Life Prediction of Straight Fibers Pneumatic Muscles

Actuators ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 300
Author(s):  
Francesco Durante ◽  
Michele Gabrio Antonelli ◽  
Pierluigi Beomonte Zobel ◽  
Terenziano Raparelli
Keyword(s):  
Fatigue Life ◽  
Silicone Rubber ◽  
Life Prediction ◽  
Experimental Tests ◽  
Fatigue Life Prediction ◽  
Pneumatic Actuators ◽  
Pneumatic Muscle ◽  
Duration Data ◽  
Life Duration ◽  
Pneumatic Muscles

Different from the McKibben pneumatic muscle actuator, the straight fibers one is made of an elastomeric tube closed at the two ends by two heads that ensure a mechanical and pneumatic seal. High stiffness threads are placed longitudinally into the wall of the tube while external rings are placed at some sections of it to limit the radial expansion of the tube. The inner pressure in the tube causes shortening of the actuator. The working mode of the muscle actuator requires a series of critical repeated contractions and extensions that cause it to rupture. The fatigue life duration of a pneumatic muscle is often lower than traditional pneumatic actuators. The paper presents a procedure for the fatigue life prediction of a straight-fibers muscle based on experimental tests directly carried out with the muscles instead of with specimens of the silicone rubber material which the muscle is made of. The proposed procedure was experimentally validated. Although the procedure is based on fatigue life duration data for silicone rubber, it can be extended to all straight-fibers muscles once the fatigue life duration data of any material considered for the muscles is known.

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