scholarly journals Biomimetic Artificial Joints Based on Multi-Material Pneumatic Actuators Developed for Soft Robotic Finger Application

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1593
Author(s):  
Shumi Zhao ◽  
Yisong Lei ◽  
Ziwen Wang ◽  
Jie Zhang ◽  
Jianxun Liu ◽  
...  
Keyword(s):  
Structural Design ◽  
Air Pressure ◽  
Pneumatic Actuator ◽  
Artificial Joint ◽  
Artificial Joints ◽  
Pneumatic Actuators ◽  
Technical Parameters ◽  
Precise Control ◽  
Motion Range ◽  
Bending Mechanism

To precisely achieve a series of daily finger bending motions, a soft robotic finger corresponding to the anatomical range of each joint was designed in this study with multi-material pneumatic actuators. The actuator as a biomimetic artificial joint was developed on the basis of two composite materials of different shear modules, and the pneumatic bellows as expansion parts was restricted by frame that made from polydimethylsiloxane (PDMS). A simplified mathematical model was used for the bending mechanism description and provides guidance for the multi-material pneumatic actuator fabrication (e.g., stiffness and thickness) and structural design (e.g., cross length and chamber radius), as well as the control parameter optimization (e.g., the air pressure supply). An actuation pressure of over 70 kPa is required by the developed soft robotic finger to provide a full motion range (MCP = 36°, PIP = 114°, and DIP = 75°) for finger action mimicking. In conclusion, a multi-material pneumatic actuator was designed and developed for soft robotic finger application and theoretically and experimentally demonstrated its feasibility in finger action mimicking. This study explored the mechanical properties of the actuator and could provide evidence-based technical parameters for pneumatic robotic finger design and precise control of its dynamic air pressure dosages in mimicking actions. Thereby, the conclusion was supported by the results theoretically and experimentally, which also aligns with our aim to design and develop a multi-material pneumatic actuator as a biomimetic artificial joint for soft robotic finger application.

scholarly journals Nonlinear Mathematical Modeling in Pneumatic Servo Position Applications

2011 ◽  
Vol 2011 ◽  
pp. 1-16 ◽  
Author(s):  
Antonio Carlos Valdiero ◽  
Carla Silvane Ritter ◽  
Cláudio Fernando Rios ◽  
Marat Rafikov
Keyword(s):  
Mathematical Modeling ◽  
Low Cost ◽  
Dead Zone ◽  
Dynamic Performance ◽  
Nonlinear Dynamic System ◽  
Pneumatic Actuator ◽  
Pneumatic Actuators ◽  
Precise Control ◽  
Behavior Study ◽  
Fifth Order

This paper addresses a new methodology for servo pneumatic actuators mathematical modeling and selection from the dynamic behavior study in engineering applications. The pneumatic actuator is very common in industrial application because it has the following advantages: its maintenance is easy and simple, with relatively low cost, self-cooling properties, good power density (power/dimension rate), fast acting with high accelerations, and installation flexibility. The proposed fifth-order nonlinear mathematical model represents the main characteristics of this nonlinear dynamic system, as servo valve dead zone, air flow-pressure relationship through valve orifice, air compressibility, and friction effects between contact surfaces in actuator seals. Simulation results show the dynamic performance for different pneumatic cylinders in order to see which features contribute to a better behavior of the system. The knowledge of this behavior allows an appropriate choice of pneumatic actuator, mainly contributing to the success of their precise control in several applications.

scholarly journals Mechanical Failure of Artificial Joint Materials: Wear and Fatigue

2000 ◽  
Author(s):  
L. D. Timmie Topoleski
Keyword(s):  
Cyclic Loading ◽  
Bone Cement ◽  
Fatigue Failure ◽  
Relative Motion ◽  
Wear Mechanisms ◽  
Bone Cements ◽  
Artificial Joint ◽  
Artificial Joints ◽  
Cocrmo Alloy ◽  
Pmma Bone Cement

Abstract Total artificial joint replacements are one of the most effective treatments for arthritis. Artificial joints are used to replace damaged cartilage and act as low-friction articulating materials in joints. During normal human walking, some of the materials used for artificial knee and hip replacements are subjected to both sliding articulation (relative motion) and cyclic loading. A common example is the CoCrMo alloy femoral surface of an artificial knee that articulates against an ultra-high-molecular-weight-polyethylene (UHMWPE) component. Other materials do not experience relative motion (at least not intentionally) and are subjected to only cyclic loading. An example is the poly(methyl methacrylate) or PMMA bone cement used to fix components of artificial joints into bones. In the case of articulating materials, both surfaces are susceptible to wear, from both second-body and third body (in the presence of abrasive particles) mechanisms. Wear of the UHMWPE has received considerable attention recently, since the polymer wear is far more obvious than the metal wear. The Biomaterials field is developing an understanding of the wear mechanisms and how to enhance the wear resistance of UHMWPE. The wear of the metal components has not received as much attention, yet materials wear as a couple; both surfaces play a role in the overall wear. In the UMBC Laboratory for Implantable Materials, we are investigating the mechanisms of CoCrMo alloy wear, and the effect of worn metal components on the wear of UHMWPE. Understanding the wear mechanisms of metal components may help to extend the life of artificial joints by allowing new articulating material combinations and joint designs. For non-articulating materials, fatigue failure is a primary concern. Fatigue of metal components is relatively rare. In the distal portion of an artificial hip, the metal hip stem is fixed into the bone by a layer of PMMA bone cement. The PMMA bone cement is far weaker and less resistant to fracture and fatigue than either the bone or the metal, and thus may be considered the mechanical “weak link” in cemented total joints. We are investigating the fatigue properties of PMMA bone cements, and studying the mechanisms of fatigue crack initiation. If we can determine how fatigue cracks start in bone cement, we may be able to develop, for example, new surgical procedures (e.g., bone preparation) that will reduce the likelihood of fatigue failure. New formulations of bone cement have been developed for both joint fixation, and also for bone repair or replacement. Understanding the failure mechanisms of bone cements may enable safe and effective new uses for new bone cements, and extend the lives of cemented artificial joints.

Development of Low-Cost Wearable Servo Valve Using Buckled Tube Driven by Servo Motor

2013 ◽  
Vol 393 ◽  
pp. 532-537 ◽  
Author(s):  
Abdul Nasir ◽  
Tetsuya Akagi ◽  
Shujiro Dohta ◽  
Ayumu Ono ◽  
Yusuke Masago
Keyword(s):  
Control System ◽  
Flow Rate ◽  
Position Control ◽  
Low Cost ◽  
Control Valve ◽  
Artificial Muscle ◽  
Pneumatic Actuators ◽  
Servo Valve ◽  
Precise Control ◽  
Care Systems

Recently, power assisted nursing care systems have received much attention and those researches have been done actively. In such a control system, an actuator and a control valve are mounted on the human body. Designing the system, the size and weight of the valve become serious concerns. The purpose of our study is to develop a small-sized, lightweight and low-cost servo valve for precise control using wearable pneumatic actuators. In this study, a low-cost wearable servo valve that can control the output flow rate by changing the twisted angle of the buckled tube in the servo valve is proposed and tested. The position control system of McKibben rubber artificial muscle using tested valve and embedded controller is also proposed and tested. As a result, we confirmed that the tested servo valve can control the flow rate in both supply and exhaust in an analog way. In addition, the estimated cost of the proposed valve can be reduced about 100 times cheaper (10 US Dollar) compared with the typical servo valve.

Bionic Lubrication System of Artificial Joints: System Design and Mechanics Simulation

2005 ◽  
Author(s):  
S. H. Su ◽  
J. H. Zhang ◽  
D. H. Tao
Keyword(s):  
Three Dimensional ◽  
Joint Capsule ◽  
The Body ◽  
Artificial Joint ◽  
Lubrication System ◽  
Wear Particles ◽  
Element Analysis ◽  
Artificial Joints ◽  
Fea Model ◽  
Capsule Thickness

A new structure of artificial joints with bionic joint capsule was proposed and designed to overcome the feedback of current prostheses that omitted many functions of lubricant and joint capsule. The new structure was composed of three components: therapeutic lubricant, artificial joints and artificial joint capsule. The lubricant sealed by capsule not only can reduce the wear of artificial joints but also can prohibit the wear particles leaking to the body liquid. So the unwilling reactions between the wear particles and liquid may be avoided completely. Meanwhile, a three-dimensional (3-D) finite element analysis (FEA) model was created for the bionic artificial joints with joint capsule. The effects of capsule thickness and the flexion angels on the stress values and distributions were discussed in detail.

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.

720 Development of an Artificial Joint Mechanism Controlled by Air Pressure

2000 ◽  
Vol 005.1 (0) ◽  
pp. 257-258
Author(s):  
Yutaka TANAKA ◽  
Akio GOFUKU ◽  
Mitsuhiro KISHIMOTO
Keyword(s):  
Air Pressure ◽  
Artificial Joint ◽  
Joint Mechanism

Super Multi-Joint Manipulator by Using Creased Plate and Pneumatic Actuators Arranged Antagonistically

2015 ◽  
Vol 27 (3) ◽  
pp. 276-285 ◽  
Author(s):  
Shunon Kikuchi ◽  
◽  
Yasuyuki Yamada ◽  
Ryoichi Higashi ◽  
Toshio Morita ◽  
...  
Keyword(s):  
Flow Rate ◽  
Power Transmission ◽  
Vertical Plane ◽  
Transmission Mechanism ◽  
Pneumatic Actuator ◽  
Pneumatic Actuators ◽  
Rate Adjustment

<div class=""abs_img""> <img src=""[disp_template_path]/JRM/abst-image/00270003/07.jpg"" width=""340"" />The manipulator when air flowed in</div> The new super multi-joint manipulator mechanism we introduce in this paper is constructed from a long flexible resinous plate in the center of the manipulator and a pneumatic actuator the same length as the arm arranged antagonistically. The number of power transmission mechanism is fewer than that of joints. Specialized in a winding grip, the mechanism is light and simple. From the effect of this property, the manipulator could be easily extended in the length. The experimental mechanism mode was developed and several experiments were conducted, such as driving on the vertical plane, grasping some objects and moving with flow rate adjustment. As a result, the manipulator could drive on the vertical plane, winds cylinders of 50–200 mm in diameter and controls winding behavior.

Evaluation of UHMWPE Component under Various Positions for UKA

2008 ◽  
Vol 594 ◽  
pp. 72-77 ◽  
Author(s):  
Chien Wei Liu ◽  
Wen Lung Li ◽  
Chen Tung Yu ◽  
Chia Chi Lo
Keyword(s):  
Finite Element Analysis ◽  
Tibial Component ◽  
Tibial Plateau ◽  
Positional Error ◽  
Artificial Joint ◽  
Positioning Error ◽  
Knee Prostheses ◽  
Element Analysis ◽  
Artificial Joints ◽  
Unicompartmental Knee

The development of artificial joints is now considered quite mature, and the main treatment for osteoarthritis. However, in recent unicompartmental knee arthroplasty (UKA) clinical follow-ups, complications due to wear of polyethylene (PE) tibial components still exist. Therefore, this study focused on the possibility of avoiding and minimizing damage to the PE tibial component. Currently, the most common problem in the application of UKA is the malresection of the tibial plateau, often resulting in malpositioning of the tibial implant. This positioning problem may be the main reason for advanced wear and dislocation of a PE tibial component. In this study, finite element analysis (FEA) was used to study the stress change of malpositioned PE tibial components in order to better understand the damaging mechanism on PE tibial components. It was found that anatomically designed unicompartmental knee prostheses (UKP) allowed more positioning error in varus tilt than symmetrically designed ones. And both should avoid any positional error greater than 10° valgus tilt. Otherwise, increased wear of PE tibial components would result in shortened lifetime of the artificial joint.

scholarly journals Comparison of PWM control of pneumatic actuator based on energy efficiency

2012 ◽  
Vol 25 (2) ◽  
pp. 93-101 ◽  
Author(s):  
Stanimir Cajetinac ◽  
Dragan Seslija ◽  
Vlastimir Nikolic ◽  
Milica Todorovic
Keyword(s):  
Energy Efficiency ◽  
Pneumatic Actuator ◽  
Pwm Control ◽  
Pneumatic Actuators

In this paper different realizations of PWM control of pneumatic actuators are compared. The actuators are controlled by PLC and two 3/2 valves. Quality of tracking and air consumptions for different realizations of control are compared.

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