Empirically-Sourced Mechanical Behaviors of Pneumatic Artificial Muscles for Compensation-Based Controls

2011 ◽  
Vol 186 ◽  
pp. 31-35 ◽  
Author(s):  
Fei Li ◽  
Yu Wang ◽  
He Ting Tong ◽  
Ray P.S. Han
Keyword(s):  
Mechanical Properties ◽  
Skeletal Muscle ◽  
High Power ◽  
Weight Ratio ◽  
Artificial Muscles ◽  
Mechanical Behaviors ◽  
Pneumatic Artificial Muscles ◽  
Powered Exoskeleton ◽  
And Control ◽  
Continuous Working

As a skeletal muscle-like actuator, PAM possesses many unique advantages. They include compliance and high power-to-weight ratio, which make it an ideal actuator for robotic and powered exoskeleton applications. But its flexible braided mesh shell and the compressibility of air make PAM much more difficult to model and control compared to traditional actuators. In this work, the mechanical properties of the McKibben PAM produced by Festo are examined, tested and discussed. The results demonstrate the muscle-like property of PAM and its strong non-linear and hysteresis behaviors. A simple law between the areas of the hysteresis and pressure is proposed, and the relationships of the areas of the hysteresis, external load and the continuous working time are studied. Further, changing the PAM length that is smaller than 0.4 mm may lead to the “crawl” phenomenon. Finally, the empirical results can be used in compensation-based controls of the hysteresis in the McKibben PAM.

Experimental Validation of Nominal Model Characteristics for Pneumatic Muscle Actuator

2013 ◽  
Vol 460 ◽  
pp. 1-12 ◽  
Author(s):  
Alexander Hošovský ◽  
Kamil Židek
Keyword(s):  
Control System ◽  
Nonlinear Differential Equations ◽  
Model Performance ◽  
Weight Ratio ◽  
Open Loop ◽  
Artificial Muscles ◽  
Pneumatic Actuators ◽  
Intelligent Control System ◽  
Pneumatic Artificial Muscles ◽  
The One

Pneumatic artificial muscles belong to a category of nonconventional pneumatic actuators that are distinctive for their high power/weight ratio, simple construction and low price and maintenance costs. As such, pneumatic artificial muscles represent an alternative type of pneumatic actuator that could replace the traditional ones in certain applications. Due to their specific construction, PAM-based systems have nonlinear characteristics which make it more difficult to design a control system with good performance. In the paper, a gray-box model (basically analytical but with certain experimental parts) of the one degree-of-freedom PAM-based actuator is derived. This model interconnects the description of pneumatic and mechanical part of the system through a set of several nonlinear differential equations and its main purpose is the design of intelligent control system in simulation environment. The model is validated in both open-loop and closed-loop mode using the measurements on real plant and the results confirm that model performance is in good agreement with the performance of real actuator.

Development of Semi-Crouching Assistive Device Using Pneumatic Artificial Muscle

2020 ◽  
Vol 32 (5) ◽  
pp. 885-893
Author(s):  
Naoki Saito ◽  
Daisuke Furukawa ◽  
Toshiyuki Satoh ◽  
Norihiko Saga ◽  
◽  
...  
Keyword(s):  
Weight Ratio ◽  
Artificial Muscle ◽  
Assistive Device ◽  
Artificial Muscles ◽  
Pneumatic Artificial Muscle ◽  
Contraction Force ◽  
Lower Back ◽  
Pneumatic Artificial Muscles ◽  
Compressive Pressure ◽  
Analytical Result

This paper describes a semi-crouching assistive device using pneumatic artificial muscles. The goal of this device is to reduce the load on the lower back when performing work in the semi-crouching position. The load on the lower back is reduced by decreasing the compressive pressure on the lumbar disk of the lower back. This compressive pressure increases as the contraction force of the erector spine increases. Therefore, it is important to reduce the muscle activity of the erector spine. Based on the analytical result of a worker’s position model, the proposed device adopts a scheme to push the chest of the user as an appropriate assistive method. Additionally, the analytical result shows that a reduction in weight of the device is also important for decreasing the load on the lower back. Based on these results, we prototyped a lightweight semi-crouching assistive device that can generate sufficient assistive force via a pneumatic artificial muscle, which has high power to weight ratio. This device was experimentally evaluated via electromyogram of the erector spine when the user maintains a semi-crouching position. The experimental results confirmed the usefulness of this device.

Pneumatic Artificial Mini-Muscles Conception: Medical Robotics Applications

2009 ◽  
Vol 15 ◽  
pp. 49-54
Author(s):  
S. Díaz-Zagal ◽  
C. Gutiérrez-Estrada ◽  
E. Rendón-Lara ◽  
I. Abundez-Barrera ◽  
J.H. Pacheco-Sánchez
Keyword(s):  
Skeletal Muscle ◽  
Force Control ◽  
Artificial Muscle ◽  
Medical Robotics ◽  
Artificial Muscles ◽  
Pneumatic Artificial Muscle ◽  
Organic System ◽  
Pneumatic Artificial Muscles ◽  
The Hill

Actually, the pneumatic artificial muscles of McKibben type [1] show a great functional similarity with the skeletal muscle. A detailed analysis of the system has been performed to better characterize this similarity with the analogous dynamic behavior of the organic system. Such analysis has shown that the McKibben-type artificial muscle can be adapted to the Hill fundamental model [2]. Research regarding pneumatic artificial muscle with application to robotics has recently focused on mini-actuators for miniaturized robotics systems. This is specially true in the area of medical robotics, but an extension of miniactuator technology to other applications may be feasible, such as the development of artificial fine-motion limbs (hands and/or fingers). The present work details the artificial muscle miniaturization process developed in the LESIA laboratory, their behavior, their position and force control characteristics, as well as the possible applications of this technology to medical robotics.

scholarly journals Reverse pneumatic artificial muscles (rPAMs): Modeling, integration, and control

PLoS ONE ◽  
2018 ◽  
Vol 13 (10) ◽  
pp. e0204637 ◽  
Author(s):  
Erik H. Skorina ◽  
Ming Luo ◽  
Wut Yee Oo ◽  
Weijia Tao ◽  
Fuchen Chen ◽  
...  
Keyword(s):  
Artificial Muscles ◽  
Pneumatic Artificial Muscles ◽  
And Control

Artificial muscles based on conducting polymers

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
María Teresa Cortés ◽  
Juan Carlos Moreno
Keyword(s):  
Conducting Polymers ◽  
Response Time ◽  
High Power ◽  
High Efficiency ◽  
Large Strain ◽  
Weight Ratio ◽  
Fast Response ◽  
Artificial Muscles ◽  
Power Weight ◽  
C 50

Abstract Natural muscles have mechanical properties that conventional actuators do not possess. These natural machines show large strain, moderate stress, high efficiency and stability, fast response time, high power/weight ratio, long lifetime, etc. In the last years a great interest has arisen to develop materials that mimic natural mechanisms. Conducting polymers have an array of potential applications as artificial muscles since they are capable to produce a moderate displacement when submitted to an electrochemical reaction. This property has been used to fabricate actuator devices that imitate and even improve the performance of natural muscles. For example, conducting polymers show stresses 15 times higher than those generated by mammalian muscles, a high power/weight ratio and a high degree of compliance. However, there are also several responses that need improvement in the actuators based on conducting polymers. Strains are still c. 50% lower than in natural muscles. Most of this kind of actuators only work in liquid media. It is necessary to increase the response time and obtain more durable actuators with longer lifetime and higher stability. In spite of these disadvantages, the first actuators based on conducting polymers are being commercialized. This paper presents a brief summary of some of the actuators based on these polymers, focusing on their design, performance and actuation mechanism.

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