Adaptive Pneumatic Force Actuation and Position Control

1991 ◽  
Vol 113 (2) ◽  
pp. 267-272 ◽  
Author(s):  
J. E. Bobrow ◽  
F. Jabbari
Keyword(s):  
Position Control ◽  
Low Cost ◽  
Equations Of Motion ◽  
Pneumatic Actuator ◽  
Unit Weight ◽  
Force Output ◽  
Nonlinear Characteristics ◽  
Pneumatic Actuators ◽  
Highly Nonlinear ◽  
High Bandwidth

In this paper an implementation of an adaptive control law for a pneumatic actuator is presented. Pneumatic actuators are of particular interest for robotic applications because of their large force output per unit weight, and their low cost. Stabilization of a pneumatic actuator is difficult if a high bandwidth closed-loop system is desired. This is because of the compressibility of air, and of the nonlinear characteristics of air flowing through a variable area orifice. Further complications arise from the geometry of the mechanism because the equations of motion are highly nonlinear. The order of the dominant dynamics is shown to vary with the position of the mechanicsm.

Adaptive Tracking Control of an Air Powered Robot Actuator

1993 ◽  
Vol 115 (3) ◽  
pp. 427-433 ◽  
Author(s):  
B. W. McDonell ◽  
J. E. Bobrow
Keyword(s):  
Tracking Control ◽  
Position Control ◽  
Adaptive Controller ◽  
Pneumatic Actuator ◽  
Tracking Accuracy ◽  
Nonlinear Characteristics ◽  
Adaptive Tracking Control ◽  
Full State ◽  
Full State Feedback ◽  
High Bandwidth

An adaptive controller is presented for a one-degree-of-freedom pneumatic actuator. The control law uses full-state feedback for simultaneous parameter identification and tracking control. For position control, a pneumatic actuator with high bandwidth is difficult to obtain because of the compressibility of air and the nonlinear characteristics of air flowing through a variable area orifice. Most previous controllers for gas powered actuators were relatively limited fixed gain or on-off type controllers with low tracking accuracy. Experimental results demonstrate that tracking performance comparable to electric servomotors can be obtained using the algorithm presented despite the nonlinearities and compressibility of air.

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.

scholarly journals ARX, ARMAX, Box-Jenkins, Output-Error, and Hammerstein Models for Modeling Intelligent Pneumatic Actuator (IPA) System

2021 ◽  
Vol 1 (2) ◽  
pp. 81-88
Author(s):  
Mohamed Naji Muftah ◽  
Wong Liang Xuan ◽  
Ahmad ‘Athif Mohd Faudzi
Keyword(s):  
Position Control ◽  
Parametric Model ◽  
Black Box ◽  
Box Model ◽  
Pneumatic Actuator ◽  
Suitable Model ◽  
Model Structure ◽  
Output Error ◽  
Highly Nonlinear ◽  
Best Fit

A pneumatic actuator is highly nonlinear, which makes the precise position control of this actuator difficult to achieve. In order to achieve precise control, selecting a suitable model structure is a prerequisite before control estimation. This selection of the model structure is based upon an understanding of the physical systems. In this paper, the black-box model is chosen as a system identification model for modeling position control of an Intelligent Pneumatic Actuator (IPA) system and a variety of parametric model structures. The parametric model structure, such as ARX, ARMAX, Box-Jenkins, output-error structures, and Hammerstein available in the black-box model, is used to assist in modeling the IPA system. The results indicate that Hammerstein had the best performance for modeling position control of the IPA system with the best fit 94.95. Also, the results show that ARX, ARMAX, Box-Jenkins, and output-error structures had best fit more than 90%.

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.

Development of Wrist Rehabilitation Device Using Extension Type Flexible Pneumatic Actuators with Simple 3D Coordinate Measuring System

2021 ◽  
Vol 18 (4) ◽  
pp. 9158-9169
Author(s):  
Weihang Tian ◽  
Yoshio Suzuki ◽  
Tetsuya Akagi ◽  
Shujiro Dohta ◽  
Wataru Kobayashi ◽  
...  
Keyword(s):  
Exercise Training ◽  
Upper Limb ◽  
Position Control ◽  
Physical Disabilities ◽  
Low Cost ◽  
Measuring System ◽  
Pneumatic Actuators ◽  
Passive Exercise ◽  
Home Based ◽  
Passive Movements

Rehabilitation devices have been developed to assist patients recover from physical disabilities by using specific devices to do an exercise, training and therapy. The purpose of this study is to develop a home-based rehabilitation device which is safe to use and without requirement of person-in-charge. In this study, a simple home-based wrist rehabilitation device which can give passive exercise on spherical orbit while patients hold its handles is proposed and tested. The device has two moving handling stage driven by 6 extension type flexible pneumatic actuators (“EFPA” for short) on two hemispherical acrylic domes. The device can give passive exercise for the upper limb by changing the relative position of the patient’s hands. In this paper, the construction and operating principle of the tested device are described. A low-cost 3-dimentional coordinate measuring system using two wire-type linear potentiometers to control the position of the holding stages is also described. In addition, the tracking position control of the holding handles on sphere is carried out. As a result, it can be found that the handling stage of the tested device can trace the desired orbit based on the coordinates measured from 3-dimentional coordinate measuring system. It can be confirmed that the tested wrist rehabilitation device has a possibility to apply passive movements to the wrist along desired orbit while patients hold its handles.

An Analysis of a Pneumatic Servo System and Its Application to a Computer-Controlled Robot

1988 ◽  
Vol 110 (3) ◽  
pp. 228-235 ◽  
Author(s):  
S. Liu ◽  
J. E. Bobrow
Keyword(s):  
Position Control ◽  
Low Cost ◽  
Flow Characteristics ◽  
Open Loop ◽  
System Response ◽  
Direct Drive ◽  
Control Applications ◽  
Pneumatic Actuators ◽  
Loop Control ◽  
Pneumatic Servo System

Pneumatic actuators are capable of providing high power output levels at a relatively low cost. In addition, they are clean, lightweight, and can be easily serviced. The difficulty of achieving a high-bandwidth, stable, pneumatic control system has limited its use in robotic position control applications. For open-loop control applications, such as many robot grippers, pneumatic actuators are often used. In this paper, direct-drive pneumatic servo-actuators are examined for their potential use in robotic applications. A complete mathematical model of the actuator is derived, and several control algorithms are tested numerically and experimentally. Our analysis shows that pneumatic systems are practical for use in servo-control applications. The main limitation is that of the system response time, which is determined by the valve flow characteristics and supply pressure. Large output forces can be obtained and accurately controlled with the servo-valve and differential pressure transducer used in the experiments.

scholarly journals DESIGN, MANUFACTURING AND PROBLEM ANALYSIS OF AN ENTIRELY FDM 3D PRINTED LINEAR PNEUMATIC ACTUATOR

2020 ◽  
pp. 98-105
Author(s):  
Martin Varga ◽  
Filip Filakovský
Keyword(s):  
3D Printing ◽  
Low Cost ◽  
Pneumatic Actuator ◽  
Problem Analysis ◽  
Pneumatic Actuators ◽  
Manufacturing Plants ◽  
Custom Made ◽  
Machine Shops ◽  
3D Printed ◽  
Linear Actuators

Urgency of the research. Currently, manufacturing of pneumatic components is reserved only to well-equipped manufacturing plants and machine shops. The ability to reliably manufacture pneumatic components on a FDM 3D printer would enable the creation of low-cost custom-made pneumatic actuators with novel properties. This, in turn, could increase the speed and lower the cost of development of prototypes that use pressure air as their power source. Target setting. Today cost-effective 3D printers can be found both in manufacturing plants and small machine shops andhobbyist workshops. Hawing the possibility to make reliable pneumatic components like pneumatic actuators on such machines could be beneficial and lead to opening new applications for them. Actual scientific researches and issues analysis. Currently most research on using additive manufacturing to construct a pneumatic actuator focuses mainly on bellows type actuators. Research on 3d printing of classical pneumatic actuators is scarce and often presents a rough overview of the design process and immediately presenting a functional prototype without focusing and studying the design hurdles thoroughly. Uninvestigated parts of general matters defining. Parts for firm pneumatic actuators manufactured by FDM 3D printing exhibit properties that have detrimental effects on the optimal working of such actuators. The question is on the magnitude of these effects whether these effects can be tolerated and how to design such a firm pneumatic actuator without the need to postprocess all the components. The research objective. The aim of these research was to manufacture an early prototype of full plastic 3d printed not postprocessed linear actuators and make a preliminary analysis of encountered problems therefore pointing the way for further research in this field. The statement of basic materials. The analysis consists of an attempt to manufacture a simple prototype of full plastic 3d printed linear actuators without the use of postprocessing techniques and establishing a baseline for further research. Conclusions. In this paper the design of three iterations of FDM 3D printed pneumatic cylinders are presented. The problems arising from not using any postprocessing on either of the parts and using only 3d printed parts for the construction is also discussed. In the final chapter the design hurdles for the design and manufacturing of such an actuator are presented..

PID Sliding Mode Control of Prolate Flexible Pneumatic Actuators

2016 ◽  
Author(s):  
Jonathon E. Slightam ◽  
Mark L. Nagurka
Keyword(s):  
Sliding Mode Control ◽  
Position Control ◽  
Sliding Mode ◽  
Low Cost ◽  
Tracking Error ◽  
Pneumatic Actuators ◽  
Model Based ◽  
Mode Control ◽  
Significant Performance ◽  
Soft Actuators

The inherent compliance, high power-density, and musclelike properties of soft actuators are especially attractive and useful in many applications, including robotics. In comparison to classical/modern control approaches, model-based control techniques, e.g., sliding mode control (SMC), applied to flexible fluidic actuators (FFAs) offer significant performance advantages and are considered to be state-of-the-art. Improvements in position tracking are possible using nonlinear control approaches that offer enhanced performance for common applications such as tracking of sinusoidal trajectories at high frequencies. This paper introduces a SMC approach that increases the tracking capabilities of prolate flexible pneumatic actuators (PF-PAs). A model-based proportional, integral, derivative sliding mode control (PIDSMC) approach designed for position control of PFPAs is proposed. SMC and PIDSMC systems are implemented on low-cost open-source controls hardware and tested for tracking sinusoidal trajectories at frequencies of 0.5 Hz and 1.0 Hz with an amplitude of 8.255 mm and an offset of 12.7 mm. The PIDSMC approach reduced the maximum tracking error by 20.0%, mean error by 18.6%, and root-mean-square error by 10.5% for a 1 Hz sinusoidal trajectory and by 8.7%, 14.7%, and 3.8%, respectively, for a 0.5 Hz sinusoidal trajectory. These reductions in tracking errors demonstrate performance advantages of the PIDSMC over conventional sliding mode position controllers.

Modeling of Pneumatic Actuator System for High Performance Nonlinear Controller Design

2004 ◽  
Author(s):  
Meihua Tai ◽  
Ke Xu
Keyword(s):  
Force Control ◽  
High Performance ◽  
Controller Design ◽  
Pneumatic Actuator ◽  
Nonlinear Controller ◽  
Detailed Model ◽  
Pneumatic Actuators ◽  
High Bandwidth ◽  
Actuator System ◽  
Electrical Motors

Modern applications in robotics such as teleoperations and haptics require high performance force actuators. Pneumatic actuators have significant advantages over electrical motors in terms of force-to-mass ratio. However, position and force control of these actuators in applications that require high bandwidth is not trivial because of the compressibility of air and highly non-linear flow through pneumatic system components. In this paper, we develop a detailed model of a pneumatic actuator system comprised of a double acting cylinder and a proportional servo valve to be used in position, force or hybrid position and force control.

Comparison Between an Intelligent Controller and a Sliding Mode Controller to Positioning Pneumatic Actuators

2014 ◽  
Author(s):  
Naghmeh Garmsiri ◽  
Nariman Sepehri
Keyword(s):  
Sliding Mode ◽  
Low Cost ◽  
Static Friction ◽  
Good Choice ◽  
Pneumatic Actuator ◽  
Pneumatic Actuators ◽  
Intelligent Controller ◽  
Model Free ◽  
Consistent Performance ◽  
Model Free Controller

Sliding Mode Control (SMC) technique is a well-established method in positioning pneumatic actuators due to its consistent performance in the presence of model uncertainties. Brain Emotional Learning Based Intelligent Controller (BELBIC) is a new model free controller with flexible structure and low computational load. It has been successfully applied to many control problems. In this work we study, for the first time, how well a BELBIC performs in comparison with SMC approach in positioning a pneumatic actuator. Different position tracking tasks are evaluated on a low-cost pneumatic actuator and in presence of significant friction. Comparison is done based on positioning accuracy, non-oscillatory motion and robustness to external load. The results show that while both controllers successfully track different trajectories, SMC is generally more accurate. BELBIC maintains its performance in the presence of large static friction. Furthermore, it produces less oscillatory control action. This work concludes that BELBIC can be a good choice for positioning of pneumatic actuators.

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