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.

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.

Modeling and compensation control of asymmetric hysteresis in a pneumatic artificial muscle

2017 ◽  
Vol 28 (19) ◽  
pp. 2769-2780 ◽  
Author(s):  
Lina Hao ◽  
Hui Yang ◽  
Zhiyong Sun ◽  
Chaoqun Xiang ◽  
Bangcan Xue
Keyword(s):  
Dynamic Performance ◽  
Artificial Muscle ◽  
Least Square Method ◽  
Least Square ◽  
Model Parameters ◽  
Pneumatic Artificial Muscle ◽  
Proportional Integral Derivative ◽  
Proportional Integral Derivative Controller ◽  
Proportional Integral ◽  
Control Precision

Pneumatic artificial muscle is a novel compliance actuator, and it has many excellent actuator characteristics, such as high power density, safety, and compliance. However, it also has strong nonlinear and asymmetric hysteresis, which makes the accurate trajectory control for a pneumatic artificial muscle very difficult. In this article, the pressure/length hysteresis of a pneumatic artificial muscle was analyzed via an isotonic test. And then, it was described using extended unparallel Prandtl–Ishlinskii model, and the model parameters were identified by an adaptive weight particle swarm optimization with a mutation portion algorithm. For the comparison, the classical Prandtl–Ishlinskii was also considered, and its parameters were identified by least square method. Based on the hysteresis model built by extended unparallel Prandtl–Ishlinskii model, an integral inverse compensator was proposed, and then a proportional–integral–derivative controller with the integral inverse compensator (integral inverse-proportional–integral–derivative) was designed. The simulations and experiments validated that the integral inverse-proportional–integral–derivative controller has good dynamic performance. Compared with conventional proportional–integral–derivative controller without a hysteresis compensator, the control precision of integral inverse-proportional–integral–derivative controller is improved by 43.86%.

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.

Developing a Novel Robotic Fish With Antagonistic Artificial Muscle Actuators

2017 ◽  
Author(s):  
Sunil Kumar Rajendran ◽  
Feitian Zhang
Keyword(s):  
Heat Dissipation ◽  
Weight Ratio ◽  
Artificial Muscle ◽  
Robotic Fish ◽  
Artificial Muscles ◽  
Underwater Robotics ◽  
Closed Loop System ◽  
Underwater Robots ◽  
Muscle Actuators ◽  
Novel Design

Super-coiled polymer (SCP), one of the newly-developed artificial muscles, has various advantages over traditional artificial muscles in terms of cost, flexibility and power-to-weight ratio. This paper investigates the performance of super-coiled polymer-based actuation in underwater robotics, and presents a novel design of robotic fish using antagonistic SCP actuators. Dynamic model of the robot is derived. An example robotic fish prototype is developed and used in experiments to study SCP actuation for underwater robots. Furthermore, experimental results show that using SCP actuators in robotic fish solves the challenging heat-dissipation problem at ease, thus improving the dynamic response of SCP actuation significantly. A PID controller is designed to regulate the tail flap angle of the designed robotic fish. Simulation results of the closed-loop system are presented to validate the proposed robot design and actuation approach.

Theoretical Modeling, Analysis, and Experimental Results of a Hydraulic Artificial Muscle Prototype

2019 ◽  
Author(s):  
Jonathon E. Slightam ◽  
Mark L. Nagurka
Keyword(s):  
Muscle Mechanics ◽  
Weight Ratio ◽  
Artificial Muscle ◽  
Theoretical Modeling ◽  
Experimental Results ◽  
Artificial Muscles ◽  
Mobile Manipulation ◽  
Modeling Analysis ◽  
Potential Applications ◽  
High Internal Pressure

Abstract Fluidic braided artificial muscles have been studied for close to seventy years. Their high power-to-weight ratio and force-to-weight ratio make them a desirable actuation technology for compact and lightweight mobile manipulation. Use of hydraulics with fluidic artificial muscles has helped realize high actuation forces with new potential applications. To achieve large actuation forces produced from high internal pressure, artificial muscles operate near the limitations of their mechanical strength. Design improvements and future applications in mechanical systems will benefit from detailed theoretical analysis of the fluidic artificial muscle mechanics. This paper presents the theoretical modeling of a hydraulic artificial muscle, analysis of its mechanics, and experimental results that validate the model. A prototype is analyzed that operates at 14 MPa and can generate up to 6.3 kN of force and a displacement of 21.5 mm. This model promises to be useful for mechanical system design and model-based control.

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.

A Pneumatic Artificial Muscle Actuated Above-Knee Prosthesis

2010 ◽  
Author(s):  
Garrett Waycaster ◽  
Sai-Kit Wu ◽  
Xiangrong Shen
Keyword(s):  
Sliding Mode ◽  
Mechanical Design ◽  
Knee Prosthesis ◽  
Artificial Muscle ◽  
Torque Control ◽  
Stair Climbing ◽  
Pneumatic Artificial Muscle ◽  
Control Approach ◽  
Energy Consuming ◽  
And Control

This paper describes the mechanical design and control approach for an above-knee (AK) prosthesis actuated by pneumatic artificial muscle. Pneumatic artificial muscle (PAM) affords great potential in prosthetics, since this type of actuator features a high power density, and similar characteristics to human muscles. However, there is no application of PAM in AK prosthetics in existing literature to the best knowledge of the authors. In this paper, a design of the prosthesis is presented, which provides sufficient actuation torque for the knee joint in energy consuming locomotive functions such as fast walking and stair climbing. The corresponding control approach is also presented, which combines an impedance-based locomotive controller with a lower-level sliding-mode torque control approach. Experiments on the proposed AK prosthesis have also been conducted to demonstrate the ability to mimic normal gait characteristics.

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