COMPARATIVE SURVEY OF VARIOUS STATIC AND DYNAMIC MODELS OF PNEUMATIC ARTIFICIAL MUSCLES

2017 ◽  
Vol 41 (5) ◽  
pp. 825-844 ◽  
Author(s):  
József Sárosi ◽  
Ján Piteľ ◽  
Mária Tóthová ◽  
Alexander Hošovský ◽  
István Bíró
Keyword(s):  
Dynamic Models ◽  
Geometric Model ◽  
Artificial Muscle ◽  
Artificial Muscles ◽  
Force Model ◽  
Static Force ◽  
Pneumatic Actuators ◽  
Model Based ◽  
Pneumatic Artificial Muscles ◽  
Comparative Survey

A lesser known type of pneumatic actuators is pneumatic artificial muscle (PAM) although these pneumatic actuators play an important role in industrial, medical and other applications. In this study a PAM model based on the assumption Euler’s law is developed, some static force models (geometric model-based static force model, static force model using maximum force of PAM and static force model using a polynomial function) are compared to Sárosi’s force model and two dynamic models based on Sárosi’s static force model and Hill’s muscle model are presented.

Model-Based Feedforward Control of a Robotic Manipulator With Pneumatic Artificial Muscles

2012 ◽  
Author(s):  
Ryan M. Robinson ◽  
Norman M. Wereley ◽  
Curt S. Kothera
Keyword(s):  
Control Algorithm ◽  
Controller Design ◽  
Feedforward Control ◽  
Artificial Muscles ◽  
Specific Work ◽  
Pneumatic Actuators ◽  
Precise Control ◽  
Model Based ◽  
Pneumatic Artificial Muscles ◽  
Dynamics Simulations

Pneumatic artificial muscles (PAMs) are lightweight, flexible actuators capable of higher specific work than comparably-sized hydraulic actuators at the same pressure and electric motors. PAMs are composed of an elastomeric bladder surrounded by a helically braided sleeve. Lightweight, compliant actuators are particularly desirable in portable, heavy-lift robotic systems intended for interaction with humans, such as those envisioned for patient assistance in hospitals and battlefield casualty extraction. However, smooth and precise control remains difficult because of nonlinearities in the dynamic response. The objective of this paper is to develop a control algorithm that satisfies accuracy and smooth motion requirements for a two degree-of-freedom manipulator actuated by pneumatic artificial muscles and intended for interaction with humans, such as lifting a human. This control strategy must be capable of responding to large, abrupt variations in payload weight over a high range of motion. In previous work, the authors detailed the design and construction of a proof-of-concept PAM-based manipulator. The present work investigates the feasibility of combining output feedback using proportional-integral-derivative control or fuzzy logic control with model-based feedforward compensation to achieve improved closed-loop performance. The model upon which the controller is based incorporates the internal airflow dynamics, the geometric parameters of the pneumatic actuators, and the arm dynamics. Simulations were performed in order to validate the control algorithm, guide controller design, and predict optimal gains. Using real-time interface software and hardware, the controller was implemented and experimentally tested on the manipulator. Performance was evaluated for several trajectories, and different payload weights. The effect of varying the feedforward gain was also analyzed. Model refinement further improved performance.

scholarly journals Mesterséges pneumatikus izomelemek modellezése és paramétereinek szimulációja MATLAB környezetben

2010 ◽  
Vol 5 (1-2) ◽  
pp. 273-277
Author(s):  
József Sárosi ◽  
János Gyeviki ◽  
Sándor Csikós
Keyword(s):  
Silicone Rubber ◽  
Geometric Model ◽  
Artificial Muscle ◽  
Common Type ◽  
Artificial Muscles ◽  
Pneumatic Artificial Muscles ◽  
Materials Used ◽  
Gas Tight

Pneumatic artificial muscles (PAMs) are becoming more commonly used as actuators in modern robotics. The most made and common type of these artificial muscles in use is the McKibben artificial muscle that was developed in 1950's. The braided muscle is composed of gas-tight elastic bladder, surrounded by braided sleeves. Typical materials used for the membrane constructions are latex and silicone rubber, while nylon is normally used in the fibres. This paper presents the geometric model of PAM and different MATLAB models for pneumatic artificial muscles. The aim of our models is to relate the pressure and length of the pneumatic artificial muscles to the force it exerts along its entire exists.

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.

scholarly journals Powered Upper Limb Orthosis Actuation System Based on Pneumatic Artificial Muscles

2018 ◽  
Vol 48 (1) ◽  
pp. 23-36 ◽  
Author(s):  
Dimitar Chakarov ◽  
Ivanka Veneva ◽  
Mihail Tsveov ◽  
Pavel Venev
Keyword(s):  
Upper Limb ◽  
Joint Stiffness ◽  
Artificial Muscles ◽  
Joint Motion ◽  
Robot Interaction ◽  
Pneumatic Actuators ◽  
Joint Torques ◽  
Actuation System ◽  
Pneumatic Muscles ◽  
Pneumatic Artificial Muscles

AbstractThe actuation system of a powered upper limb orthosis is studied in the work. To create natural safety in the mutual “man-robot” interaction, an actuation system based on pneumatic artificial muscles (PAM) is selected. Experimentally obtained force/contraction diagrams for bundles, consisting of different number of muscles are shown in the paper. The pooling force and the stiffness of the pneumatic actuators is assessed as a function of the number of muscles in the bundle and the supply pressure. Joint motion and torque is achieved by antagonistic actions through pulleys, driven by bundles of pneumatic muscles. Joint stiffness and joint torques are determined on condition of a power balance, as a function of the joint position, pressure, number of muscles and muscles

scholarly journals A Biomechatronic Device Actuated by Pneumatic Artificial Muscles for the Automatic Evaluation of Nociceptive Thresholds in Rheumatic Patients

Actuators ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 78
Author(s):  
Luigi Randazzini ◽  
Alessia Capace ◽  
Carlo Cosentino ◽  
Rosa Daniela Grembiale ◽  
Francesco Amato ◽  
...  
Keyword(s):  
Pain Sensitivity ◽  
Qualitative Evaluation ◽  
Control Unit ◽  
Automatic Measurement ◽  
Artificial Muscles ◽  
Embedded Control ◽  
Pneumatic Actuators ◽  
Diagnostic Protocol ◽  
Pneumatic Artificial Muscles ◽  
Rheumatic Patients

In the current clinical practice, the diagnosis of Rheumatoid Arthritis (RA) draws on the qualitative evaluation of pain sensitivity thresholds which is affected by several source of uncertainties, due to an operator-dependent diagnostic protocol. Taking our cue from the diagnostic shortcomings, we have explored the possibility of automating the measurement of mechanical nociceptive thresholds through the adoption of soft pneumatic actuators controlled by an embedded control unit. In this work, we want to show that a purpose-made biomechatronic device actuated by soft and pneumatic actuators is potentially a boon both for rheumatologists and biomedical researchers involved in nociception and physicophysical studies. In the full breadth and scope of the objective diagnosis of RA, the first prototype of a novel biomechatronic device for quantitative and automatic measurement of mechanical nociceptive thresholds has been designed and tested through nociception experiments on 10 subjects. The experimental results show that the designed device can reliably generate the controllable and repeatable nociceptive stimuli needed for the objective diagnosis of RA.

scholarly journals Design and Control of a 1-DOF Robotic Lower-Limb System Driven by Novel Single Pneumatic Artificial Muscle

2019 ◽  
Vol 10 (1) ◽  
pp. 43 ◽  
Author(s):  
Tsung-Chin Tsai ◽  
Mao-Hsiung Chiang
Keyword(s):  
Lower Limb ◽  
Artificial Muscle ◽  
Robotic System ◽  
Artificial Muscles ◽  
Prototype System ◽  
Pneumatic Artificial Muscle ◽  
Torsion Spring ◽  
Pneumatic Artificial Muscles ◽  
Control Response ◽  
Spring Mechanism

This study determines the practicality and feasibility of the application of pneumatic artificial muscles (PAMs) in a pneumatic therapy robotic system. The novel mechanism consists of a single actuated pneumatic artificial muscle (single-PAM) robotic lower limb that is driven by only one PAM combined with a torsion spring. Unlike most of previous studies, which used dual-actuated pneumatic artificial muscles (dual-PAMs) to drive joints, this design aims to develop a novel single-PAM for a one degree-of-freedom (1-DOF) robotic lower-limb system with the advantage of a mechanism for developing a multi-axial therapy robotic system. The lower limb robotic assisting system uses the stretching/contraction characteristics of a single-PAM and the torsion spring designed by the mechanism to realize joint position control. The joint is driven by a single-PAM controlled by a proportional pressure valve, a designed 1-DOF lower-limb robotic system, and an experimental prototype system similar to human lower limbs are established. However, the non-linear behavior, high hysteresis, low damping and time-variant characteristics for a PAM with a torsion spring still limits its controllability. In order to control the system, a fuzzy sliding mode controller (FSMC) is used to control the path tracking for the PAM for the first time. This control method prevents approximation errors, disturbances, un-modeled dynamics and ensures positioning performance for the whole system. Consequently, from the various experimental results, the control response designed by the joint torsion spring mechanism can also obtain the control response like the design of the double-PAMs mechanism, which proves that the innovative single-PAM with torsion spring mechanism design in this study can reduce the size of the overall aid mechanism and reduce the manufacturing cost, can also improve the portability and convenience required for the wearable accessory, and is more suitable for the portable rehabilitation aid system architecture.

Contractile Pneumatic Artificial Muscle Configured to Generate Extension

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Benjamin K. S. Woods ◽  
Shane M. Boyer ◽  
Erica G. Hocking ◽  
Norman M. Wereley ◽  
Curt S. Kothera
Keyword(s):  
Compressive Loading ◽  
Compressive Force ◽  
Artificial Muscle ◽  
Specific Power ◽  
Artificial Muscles ◽  
Specific Work ◽  
Operational Characteristics ◽  
Pneumatic Artificial Muscles ◽  
High Specific Power ◽  
Internal Mechanism

Pneumatic artificial muscles (PAMs) are comprised of an elastomeric bladder surrounded by a braided mesh sleeve. When the bladder is inflated, the actuator may either contract or extend axially, with the direction of motion dependent on the orientation of the fibers in the braided sleeve. Contractile PAMs have excellent actuation characteristics, including high specific power, specific work, and power density. Unfortunately, extensile PAMs exhibit much reduced blocked force, and are prone to buckling under axial compressive loading. For applications in which extensile motion and compressive force are desired, the push-PAM actuator introduced here exploits the operational characteristics of a contractile PAM, but changes the direction of motion and force by employing a simple internal mechanism using no gears or pulleys. Quasi-static behavior of the push-PAM was compared to a contractile PAM for a range of operating pressures. Based on these data, the push-PAM actuator can achieve force and stroke comparable to a contractile PAM tested under the same conditions.

Theoretical Dynamic Modeling and Validation of Braided Pneumatic Artificial Muscles

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Jonathon E. Slightam ◽  
Mark L. Nagurka
Keyword(s):  
Theoretical Model ◽  
Dynamic Models ◽  
Empirical Method ◽  
System Model ◽  
Order System ◽  
Artificial Muscles ◽  
High Fidelity ◽  
Model Based ◽  
Human Scale ◽  
Curve Fit

Abstract The high force-to-weight ratios of braided fluidic artificial muscles (AMs) are ideal for human scale and mobile robot applications. Prior modeling efforts focus on the theoretical static characteristics or empirical dynamic models of these actuators when pressurized. This paper develops a comprehensive high fidelity theoretical dynamic model based on first principles for braided pneumatic AMs and presents experimental validation. A novel theoretical model for the nonlinear stiffness is derived to describe the pressure–displacement behavior. The stiffness model, together with friction, damping, and inertia models, forms an equation of motion (EOM) for braided pneumatic AMs. The EOM is coupled with first-order servopneumatic pressure dynamics, resulting in a third-order system model. System model simulations are compared to experimental results of prototypes with nine different geometries. On average, the system model is able to predict the quasi-static displacement within 7% and the dynamic response within 11%. The theoretical model is also benchmarked against a high fidelity curve fit method, with the empirical method showing a 2% improvement in only quasi-static scenarios. The model promises to be useful for mechanical system and model-based control designs.

Actuation of untethered pneumatic artificial muscles and soft robots using magnetically induced liquid-to-gas phase transitions

2020 ◽  
Vol 5 (41) ◽  
pp. eaaz4239 ◽  
Author(s):  
Seyed M. Mirvakili ◽  
Douglas Sim ◽  
Ian W. Hunter ◽  
Robert Langer
Keyword(s):  
Phase Transition ◽  
Gas Phase ◽  
High Performance ◽  
Artificial Muscle ◽  
Artificial Muscles ◽  
Peak Strain ◽  
Soft Robots ◽  
Robotic Arms ◽  
Actuation Mechanism ◽  
Pneumatic Artificial Muscles

Pneumatic artificial muscles have been widely used in industry because of their simple and relatively high-performance design. The emerging field of soft robotics has also been using pneumatic actuation mechanisms since its formation. However, these actuators/soft robots often require bulky peripheral components to operate. Here, we report a simple mechanism and design for actuating pneumatic artificial muscles and soft robotic grippers without the use of compressors, valves, or pressurized gas tanks. The actuation mechanism involves a magnetically induced liquid-to-gas phase transition of a liquid that assists the formation of pressure inside the artificial muscle. The volumetric expansion in the liquid-to-gas phase transition develops sufficient pressure inside the muscle for mechanical operations. We integrated this actuation mechanism into a McKibben-type artificial muscle and soft robotic arms. The untethered McKibben artificial muscle generated actuation strains of up to 20% (in 10 seconds) with associated work density of 40 kilojoules/meter3, which favorably compares with the peak strain and peak energy density of skeletal muscle. The untethered soft robotic arms demonstrated lifting objects with an input energy supply from only two Li-ion batteries.

Development of a new system for reducing the temperature increase during the positioning of spoilers using pneumatic artificial muscle (PAM)

2020 ◽  
Vol 92 (8) ◽  
pp. 1257-1261
Author(s):  
Mustafa Soylak ◽  
Mustafa Bakır
Keyword(s):  
Temperature Increase ◽  
Low Cost ◽  
Artificial Muscle ◽  
Artificial Muscles ◽  
Content Type ◽  
Air Inlet ◽  
Thermal Changes ◽  
Pneumatic Artificial Muscles ◽  
Regional Temperature ◽  
Control Surfaces

Purpose The usage of pneumatic artificial muscles (PAMs) is becoming increasingly widespread across a variety of industries because of its advantages such as its lightness and its ability to generate a huge amount of force using the fewest components. The purpose of this paper is to develop a piece of hardware to minimize and equally distribute the thermal changes on the surface of a PAM when positioning using PAMs. A classic PAM and a PAM that contains the hardware suggested for tasks, such as the positioning of spoilers decelerating control surfaces for aircrafts, were compared experimentally. Design/methodology/approach Rapid thermal changes were detected in the classic PAM, especially at the tip of the PAM. These thermal changes decrease the positioning sensitivity and reliability, thus shortening life span of the PAMs. A component was developed that could create a circulation of air around the tip of the PAM, preventing the temperature increase caused by still air. It is installed inside the PAM and makes it possible to control the pressurized air volume in crucial areas. Shaped as a perforated metal pipe, the component was embedded inside the PAM and effects of this component were investigated. Findings The experiment results have shown that, thanks to the system that was developed, cool air that comes from outside is able to reach the tip of the PAM every time, thus keeping regional temperature increase to a minimum. The temperature increase in the pressurized air inlet was minimized by creating a circulation of air in the area. Originality/value With this study, the distribution of heat in different areas on PAM was homogenized at a low cost using the component that was developed.

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