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.

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.

Flexible Sensor for McKibben Pneumatic Artificial Muscle Actuator

2009 ◽  
Vol 3 (6) ◽  
pp. 731-740 ◽  
Author(s):  
Shinji Kuriyama ◽  
◽  
Ming Ding ◽  
Yuichi Kurita ◽  
Jun Ueda ◽  
...  
Keyword(s):  
Artificial Muscle ◽  
The Elderly ◽  
Axial Displacement ◽  
Artificial Muscles ◽  
Pneumatic Artificial Muscle ◽  
Flexible Sensor ◽  
Pneumatic Artificial Muscles ◽  
Circumferential Displacement ◽  
Mckibben Actuators ◽  
Power Assistance

The demand for flexible, lightweight McKibben pneumatic artificial muscles (McKibben actuators) has been increasing for power assistance equipment used for assisting and rehabilitating the elderly. To accurately control this equipment, the length of the actuator should be measured. However, the equipment becomes heavier and less flexible when a rigid sensor, such as a potentiometer or an encoder, is used. The sensor should be flexible in order to take advantage of the favorable properties of the McKibben actuator. The aim of this study is to measure the length of the actuator without loss of its advantages. We propose a method of estimating the length from the circumferential displacement, which can be measured by a sensor made of electroconductive, flexible rubber. Higher accuracy is obtained by measuring the circumferential displacement than by measuring the axial displacement using this sensor. The sensor’s flexibility enables us to accurately control the actuator without any loss of flexibility or increase in weight. Furthermore, the sensor does not require the attachment of any rigid fixtures. The accuracy of the estimate is successfully evaluated and the usefulness of the proposed method is verified through its application to a multi-link arm driven by the McKibben actuator.

Operating Modes of Pneumatic Artificial Muscle Actuator

2013 ◽  
Vol 308 ◽  
pp. 39-44 ◽  
Author(s):  
Mária Tóthová ◽  
Ján Piteľ ◽  
Jana Boržíková
Keyword(s):  
Position Control ◽  
Artificial Muscle ◽  
Pneumatic Actuator ◽  
Variable Pressure ◽  
Artificial Muscles ◽  
Pneumatic Artificial Muscle ◽  
Operating Modes ◽  
Main Requirement ◽  
Pneumatic Artificial Muscles ◽  
Operation Characteristics

The paper describes operating modes of the PAM based actuator consisting of two pneumatic artificial muscles (PAMs) in antagonistic connection. The artificial muscles are acting against themselves and resultant position of the actuator is given by equilibrium of their forces according to different pressures in muscles. The main requirement for operation of such pneumatic actuator is uniform movement and accurate arm position control according to input desired variable. There are described in paper operation characteristics of the pneumatic artificial muscle in variable pressure and then operation characteristics of the pneumatic artificial muscle actuator consisting of two muscles in antagonistic connection.

Effects of Braid Angle on Pneumatic Artificial Muscle Actuator Performance

2008 ◽  
Author(s):  
Michael F. Gentry ◽  
Norman M. Wereley
Keyword(s):  
Empirical Data ◽  
Artificial Muscle ◽  
Analytical Models ◽  
Artificial Muscles ◽  
Pneumatic Artificial Muscle ◽  
Performance Limits ◽  
Equilibrium Equations ◽  
Model Predictions ◽  
Pneumatic Artificial Muscles ◽  
Force Equilibrium

Pneumatic artificial muscles (PAMs) provide numerous advantages for use as actuators in a wide variety of mechanical systems. Our study focused on determining the effects of braid angle on the performance of PAMs. This paper discusses how we constructed a set of PAMs with varying braid angle, predicted their performance using analytical models, gathered empirical data characterizing the PAMs, and compared the analytical predictions with the experimental results. We constructed six PAMs of different braid angles between 38° and 73°. To predict PAM performance, we used an analysis based on the force equilibrium equations for a pressurized actuator. We first quantified the performance limits of each actuator in a series of static characterization tests. Then we subjected each PAM to cyclical displacement testing. Finally, a series of cyclical tests were performed with a pre-strain applied to the PAMs, to better approximate their typical use. Our results showed variation of braid angle causes significant differences in performance among the six PAMs tested; PAMs with larger braid angle generated higher blocked force and exhibited greater contraction. The empirical data matched the model predictions based on our estimates for the braid angle of a given PAM.

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 Position/force control of master–slave antagonistic joint actuated by water hydraulic artificial muscles

2019 ◽  
Vol 16 (3) ◽  
pp. 172988141985398
Author(s):  
Dayong Ning ◽  
Jinkai Che ◽  
Zengmeng Zhang ◽  
Hao Tian ◽  
Jiaoyi Hou ◽  
...  
Keyword(s):  
Rotation Angle ◽  
Weight Ratio ◽  
Artificial Muscle ◽  
Force Transducer ◽  
Torque Control ◽  
Artificial Muscles ◽  
Pneumatic Artificial Muscle ◽  
Proportional Integral Derivative ◽  
Proportional Integral ◽  
Water Hydraulic

Because of the high force–weight ratio of water hydraulic artificial muscle and its high compatibility with an underwater environment, the water hydraulic artificial muscle has received increasing attention due to its potential uses in marine engineering applications. The master–slave anthropopathic joint actuated by water hydraulic artificial muscles is light and small, and it has good maneuverability for underwater manipulators. However, the control methodologies for water hydraulic artificial muscle joint have not been thoroughly explored to date. This article introduces a master–slave control system of isomorphic artificial muscle joints. The water hydraulic artificial muscle joint acts as a slave joint working under the sea, and the pneumatic artificial muscle joint acts as a master joint that is operated by people. The rotation angle signal of the pneumatic artificial muscle joint is fed back as the input to regulate the rotation angle of the water hydraulic artificial muscle joint through a proportional–integral–derivative control. Meanwhile, the torque of the pneumatic artificial muscle joint is controlled by a proportional–integral–derivative controller based on the feedback of a two-force-transducer system in the water hydraulic artificial muscle joint as input. Therefore, the operator can control the movement and feel the load of the water hydraulic artificial muscle slave joint. Master–slave control experiments were performed, and the position/torque control results were analyzed using various loads and torque gains. This study contributes to the design and control of an anthropopathic underwater manipulator.

Pneumatic Artificial Muscle as Actuator in Mechatronic System

2013 ◽  
Vol 460 ◽  
pp. 81-90 ◽  
Author(s):  
Jana Mižáková ◽  
Ján Piteľ ◽  
Mária Tóthová
Keyword(s):  
Time Delay ◽  
Artificial Muscle ◽  
Artificial Muscles ◽  
Pneumatic Artificial Muscle ◽  
Mechatronic System ◽  
Mechatronic Systems ◽  
Static And Dynamic Characteristics ◽  
Pneumatic Artificial Muscles ◽  
Basic Characteristics ◽  
System With Time Delay

The paper describes basic characteristics of pneumatic artificial muscles (PAM) for using as actuator in mechatronic system. The previous parameters research of individually connected artificial muscles shows, that it is significantly nonlinear system with time delay. Availing these results, problem of using of static and dynamic characteristics of PAMs for control and modeling electropneumatic mechatronic systems based on the artificial muscles occurs. To solve this problems, the paper also deals with design of some models.

scholarly journals Pneumatic Artificial Muscles Based on Biomechanical Characteristics of Human Muscles

2006 ◽  
Vol 3 (3) ◽  
pp. 191-197 ◽  
Author(s):  
N. Saga ◽  
J. Nagase ◽  
T. Saikawa
Keyword(s):  
Weight Ratio ◽  
Artificial Muscle ◽  
Human Muscle ◽  
Wearable Device ◽  
Artificial Muscles ◽  
Rehabilitation Robot ◽  
Contraction Rate ◽  
Highly Nonlinear ◽  
Pneumatic Artificial Muscles ◽  
Human Muscles

This article reports the pneumatic artificial muscles based on biomechanical characteristics of human muscles. A wearable device and a rehabilitation robot that assist a human muscle should have characteristics similar to those of human muscle. In addition, since the wearable device and the rehabilitation robot should be light, an actuator with a high power to weight ratio is needed. At present, the McKibben type is widely used as an artificial muscle, but in fact its physical model is highly nonlinear. Therefore, an artificial muscle actuator has been developed in which high-strength carbon fibres have been built into the silicone tube. However, its contraction rate is smaller than the actual biological muscles. On the other hand, if an artificial muscle that contracts axially is installed in a robot as compactly as the robot hand, big installing space is required. Therefore, an artificial muscle with a high contraction rate and a tendon-driven system as a compact actuator were developed, respectively. In this study, we report on the basic structure and basic characteristics of two types of actuators.

scholarly journals Analysis and control of a parallel lower limb based on pneumatic artificial muscles

2017 ◽  
Vol 9 (1) ◽  
pp. 168781401668500 ◽  
Author(s):  
Feilong Jiang ◽  
Guoliang Tao ◽  
Qingwei Li
Keyword(s):  
Lower Limb ◽  
Artificial Muscle ◽  
Artificial Muscles ◽  
Pneumatic Artificial Muscle ◽  
Joint Movement ◽  
Obturator Internus ◽  
Pneumatic Artificial Muscles ◽  
Human Limb ◽  
Adaptive Control Algorithm ◽  
And Control

Most robots that are actuated by antagonistic pneumatic artificial muscles are controlled by various control algorithms that cannot adequately imitate the actual muscle distribution of human limbs. Other robots in which the distribution of pneumatic artificial muscle is similar to that of human limbs can only analyze the position of the robot using perceptual data instead of rational knowledge. In order to better imitate the movement of a human limb, the article proposes a humanoid lower limb in the form of a parallel mechanism where muscle is unevenly distributed. Next, the kinematic and dynamic movements of bionic hip joint are analyzed, where the joint movement is controlled by an observer-based fuzzy adaptive control algorithm as a whole rather than each individual pneumatic artificial muscle and parameters that are optimized by a neural network. Finally, experimental results are provided to confirm the effectiveness of the proposed method. We also document the role of muscle in trajectory tracking for the piriformis and musculi obturator internus in isobaric processes.

scholarly journals Pulse width modulation modeling for efficient pneumatic artificial muscle control

2019 ◽  
Vol 11 (12) ◽  
pp. 168781401989543
Author(s):  
Miroslav Rimar ◽  
Marcel Fedak ◽  
Ivan Corny ◽  
Andrii Kulikov ◽  
Stefan Kuna ◽  
...  
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Dynamic Properties ◽  
Artificial Muscle ◽  
Artificial Muscles ◽  
Pneumatic Artificial Muscle ◽  
Muscle System ◽  
Nonlinear Structure ◽  
Positioning Control ◽  
Pneumatic Artificial Muscles

The aim of the article is to analyze the properties of artificial muscle system and effectiveness evaluation of the application of pulse width modulation in terms of improving the dynamic properties. In terms of dynamic properties, pneumatic artificial muscles represent a very complicated nonlinear structure. For this reason, the design of a robust positioning control system for pneumatic artificial muscle devices is demanding because, apart from the above-mentioned nonlinearity (because of air compressibility, air flow variability through valves, etc.), this is a time-and-parameter invariant system. The aim of the article is to evaluate the influence of pulse width modulation in pneumatic artificial muscle systems with regard to the accuracy and stability of the position achieved in the repeat mode, as well as the elimination of the adverse effect of the oscillation. The efficiency of the proposed control algorithm is demonstrated by experiments with external workload and no load.

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