A Magnetorheological Actuation System - Part II: Modeling

2007 ◽  
Author(s):  
Shaju John ◽  
Anirban Chaudhuri ◽  
Norman M. Wereley
Keyword(s):  
Active Vibration Control ◽  
Wheatstone Bridge ◽  
Bingham Plastic ◽  
Magnetic Circuits ◽  
Actuation System ◽  
System Part ◽  
Active Vibration ◽  
Hybrid Actuation ◽  
Actuation Systems ◽  
Moving Parts

There is a demand for hybrid actuation systems which combines actuation and valving systems in a compact package. Such self-contained actuation systems can be used in the field of rotorcraft as active pitch links and in the field of automotive engineering as active vibration control devices. MR fluids can be used in valves to control the motion of an output cylinder. Such a valving system will have no moving parts and thus can be used in applications where there is high centrifugal loading. In the current setup, MR valves are configured in the form of a Wheatstone bridge and bidirectional motion is produced in the output cylinder by alternate application of magnetic field in the arms of the wheatstone bridge. The actuation is performed using a compact Terfenol-D stack driven actuator. The frequency rectification of the stack motion is done using reed valves. This actuator and valve configuration form a compact hydraulic system with fluidic valves. The advantages of such systems are low parts count, absence of moving parts and the ability to control the motion of the output cylinder by controlling the fluid flow through the MR valves. By the application of different magnetic fields to the arms of the bridge (by applying different currents to the magnetic circuits), we can control the differential pressure seen by the output cylinder. This add the capability of designing controllers for the system. This work concentrates on the modeling of the entire actuation system performance. The results of the modeling effort is then compared with experimental results. The system is modeled by ordinary differential equations governing the motion of the active stack, fluid in the different sections and the output cylinder shaft. The rheological properties of the MR fluid is modeled using both Bingham plastic and bi-viscous models.

Bi-Directional Actuation of a Piston Using MR Valves and a Piezoelectric Pump

Aerospace ◽  
2005 ◽  
Author(s):  
Shaju John ◽  
Jin-Hyeong Yoo ◽  
Jayant Sirohi ◽  
Norman M. Wereley
Keyword(s):  
Mechanical Valve ◽  
Wheatstone Bridge ◽  
Piezoelectric Pump ◽  
Pump System ◽  
Mr Fluid ◽  
Bingham Plastic ◽  
Magnetic Circuits ◽  
Hybrid Actuation ◽  
Actuation Systems ◽  
Moving Parts

There is a demand for hybrid actuation systems which combine actuation and valving systems in a compact package. MR fluids can be used in valves to control the motion of an output cylinder. Such a valving system will have no moving parts and thus can be used in applications where there is high centrifugal loading. In the current setup, MR valves are configured in the form of a Wheatstone bridge where the two arms form the high and low pressure sides of the output cylinder. The actuation is performed using a compact piezoelectric stack driven actuator. The frequency rectification of the piezo stack motion is done using reed valves. This actuator and valve configuration form a compact hydraulic system with electro-mechanical valves. The advantages of such systems are that part count is low, fewer moving parts and the ability to control the motion of the output cylinder by controlling the fluid flow through the MR valves. By the application of different magnetic fields in the arms of the bridge (by applying different currents to the magnetic circuits), we can control the differential pressure seen by the output cylinder. This allows us to design different controllers for the system. The two systems in this configuration have been separately evaluated. The piezo pump system was first tested for its performance and efficiency with conventional hydraulic fluid and MR fluid. At this stage, the MR valve setup has not been added to isolate the actuating system from the valve system and the MR fluid acts merely as a transmission fluid. The Wheatstone bridge setup was then added and the efficiency of the MR valve was tested against a dummy mechanical valve. The modeling of the valve was done on the basis of standard rheological models like Bingham Plastic and bi-viscous models. Data for bi-directional actuation of the output cylinder is presented and assessed analytically.

A Magnetorheological Actuation System: Part I — Testing

2007 ◽  
Author(s):  
Shaju John ◽  
Jin-Hyeong Yoo ◽  
Norman M. Wereley
Keyword(s):  
Magnetic Field ◽  
Active Vibration Control ◽  
Active Material ◽  
Wheatstone Bridge ◽  
Mr Fluids ◽  
Actuation System ◽  
Hybrid Devices ◽  
Actuation Systems ◽  
Frequency Rectification ◽  
Moving Parts

There is a demand for compact hybrid actuation systems which combines actuation and valving systems in a compact package. Such self-contained actuation systems have potential applications in the field of rotorcraft (as active pitch links) and automotive engineering (as active vibration control devices). Hybrid hydraulic actuation systems, based on frequency rectification of the high frequency motion of an active material, can be used to exploit the high bandwidth of smart material to design devices with high force and stroke. Magnetorheological (MR) fluids are active fluids whose viscosity can be changed through the application of a magnetic field. By using MR fluids as the hydraulic fluid in such hybrid devices, a valving system with no moving parts can be implemented. Such a system will be attractive in rotorcraft applications with large centrifugal force loading. Thus, MR fluids can be used to control the motion of an output cylinder. The MR fluid based valves can be configured in the form of a Wheatstone bridge to produce bi-directional motion in an output cylinder by alternately applying a magnetic field in the two arms of the bridge. In this study, the actuation is performed using a compact Terfenol-D stack driven actuator. The frequency rectification of the stack motion is done using reed valves. This actuator and valve configuration form a compact hydraulic system with fluidic valves. The advantages of such systems are that part count is low, absence of moving parts and the possibility of continuous controllability of the output cylinder. By applying varying magnetic fields in the arms of the bridge (by applying different currents to the coils), the differential pressure acting on the output cylinder can be controlled. The description of the experimental setup, the tests performed and the experimental results are presented in this paper.

Theoretical Modeling for Electroactive Polymer-Ceramic Hybrid Actuation Systems

Aerospace ◽  
2004 ◽  
Author(s):  
Tian-Bing Xu ◽  
Ji Su
Keyword(s):  
Performance Optimization ◽  
High Performance ◽  
Electroactive Polymer ◽  
Actuation System ◽  
Electromechanical Responses ◽  
Electromechanical Performance ◽  
New Type ◽  
Hybrid Actuation ◽  
Actuation Systems ◽  
Further Development

An electroactive polymer-ceramic hybrid actuation system (HYBAS) was recently developed. The HYBAS demonstrates significantly-enhanced electromechanical performance by utilizing advantages of cooperative contributions of the electromechanical responses of an electrostrictive copolymer and an electroactive single crystal. The hybrid actuation system provides not only a new type of device but also a concept to utilize different electroactive materials in a cooperative and efficient method for optimized electromechanical performance. In order to develop an effective procedure to optimize the performance of a hybrid actuation system (HYBAS), a theoretical model has been developed, based on the elastic and electromechanical properties of the materials utilized in the system and on the configuration of the device. The model also evaluates performance optimization as a function of geometric parameters, including the length of the HYBAS and the thickness ratios of the constituent components. The comparison between the model and the experimental results shows a good agreement and validates the model as an effective method for the further development of high performance actuating devices or systems for various applications.

A Novel Approach to Active Vibration Isolation With Electrohydraulic Actuators

2001 ◽  
Author(s):  
Yisheng Zhang ◽  
Andrew Alleyne
Keyword(s):  
Control Problem ◽  
Vibration Control ◽  
Vibration Isolation ◽  
Controller Design ◽  
Active Vibration Control ◽  
Actuation System ◽  
Novel Approach ◽  
Active Vibration ◽  
Natural Dynamics ◽  
Velocity Tracking

Abstract This paper presents a novel reformulation of the standard active vibration control problem for large systems to take advantage of the natural dynamics of a particular type of actuator: the electrohydraulic actuator. The standard linear vibration control problem set-up is followed by details of the limitations to this standard approach for electrohydraulic systems. This root of the problems lies in the attempt to utilize the electrohydraulic actuation system to provide a particular force. Previous work (Alleyne & Liu, 1999) has shown the inherent limitations to force tracking for these systems. To circumvent the limitations, the problem is reformulated as a velocity tracking one, which lends itself naturally to the dynamics of electrohydraulic systems. Subsequently, a SISO controller can be readily designed for the velocity tracking problem using standard controller design tools. Although the controller design is relatively standard, experimental results are given which demonstrate the efficacy of the problem reformulation.

scholarly journals A Systematic Literature Review of Various Control Techniques for Active Seat Suspension Systems

2020 ◽  
Vol 10 (3) ◽  
pp. 1148 ◽  
Author(s):  
Mohammed Al-Ashmori ◽  
Xu Wang
Keyword(s):  
Literature Review ◽  
Vibration Control ◽  
Systematic Literature Review ◽  
Active Vibration Control ◽  
Specific Area ◽  
Future Research ◽  
Control Techniques ◽  
Suspension Systems ◽  
Actuation System ◽  
Active Vibration

Drivers of heavy trucks are exposed to large amounts of vibration which can lead to serious health risks. Many suspension systems/methods can be used to isolate these transmitted vibrations, such as vehicle suspension systems, cabin suspension systems and seating suspension systems. The central idea of the work is to identify the research gaps and raise our future research questions in this specific area. The novelty of this paper is proposing a model predictive controller for active vibration control of seating suspension systems. A systematic literature review of the existing work of the vibration control of seating suspension systems has been conducted. Various control techniques that are used in the seating suspension systems have been summarized and evaluated. This paper focusses on the biodynamic model of the driver and seat for the first step needed in the design of the seating suspension system. Then, it illustrates the different types of the system vibration controls and their performance evaluation methods. At the end, the paper details several active seating suspension systems including their actuation system structures and control algorithms which are used in the heavy vehicle trucks.

scholarly journals A Review of Microrobot’s System: Towards System Integration for Autonomous Actuation In Vivo

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1249
Author(s):  
Zhongyi Li ◽  
Chunyang Li ◽  
Lixin Dong ◽  
Jing Zhao
Keyword(s):  
Medical Imaging ◽  
System Integration ◽  
Working Environment ◽  
Delivery Methods ◽  
Actuation System ◽  
Imaging Algorithms ◽  
Hybrid Actuation ◽  
Actuation Systems ◽  
And Control

Microrobots have received great attention due to their great potential in the biomedical field, and there has been extraordinary progress on them in many respects, making it possible to use them in vivo clinically. However, the most important question is how to get microrobots to a given position accurately. Therefore, autonomous actuation technology based on medical imaging has become the solution receiving the most attention considering its low precision and efficiency of manual control. This paper investigates key components of microrobot’s autonomous actuation systems, including actuation systems, medical imaging systems, and control systems, hoping to help realize system integration of them. The hardware integration has two situations according to sharing the transmitting equipment or not, with the consideration of interference, efficiency, microrobot’s material and structure. Furthermore, system integration of hybrid actuation and multimodal imaging can improve the navigation effect of the microrobot. The software integration needs to consider the characteristics and deficiencies of the existing actuation algorithms, imaging algorithms, and the complex 3D working environment in vivo. Additionally, considering the moving distance in the human body, the autonomous actuation system combined with rapid delivery methods can deliver microrobots to specify position rapidly and precisely.

Mathematical Modelling and Design and of MR Dampers

Volume 2 ◽  
2004 ◽  
Author(s):  
Weng W. Chooi ◽  
S. Olutunde Oyadiji
Keyword(s):  
Magnetic Field ◽  
Yield Stress ◽  
Active Vibration Control ◽  
Mr Fluid ◽  
Bingham Plastic ◽  
Mr Dampers ◽  
Mr Fluids ◽  
Annular Gap ◽  
Active Valve ◽  
Active Vibration

Most magnetorheological (MR) fluid devices are fixed-pole valve mode devices where the fluid flows through a magnetically active valve. Controlling the strength of the magnetic field inside the valve allows the rheological properties of the MR fluid to be varied. Upon the application of a magnetic field, MR fluids develop a yield stress, which must be overcome before any flow is possible. This behavior can be represented mathematically by models of fluid with a yield stress like the Bingham plastic model. MR dampers have utilized this property of the MR fluids to provide controllable, semi-active vibration control. The most effective and widely used configuration of MR dampers incorporates an annular gap through which the MR fluid is force to flow. This paper presents a solution for annulus flows, derived from fundamental equations of fluid mechanics, of any general model of fluid with a yield stress. An example of the application of the general analytical expressions using the Herschel-Buckley model is given, and the limitations of the parallel plate approximation is illustrated for configurations whereby the size of the annular gap relative to the mean radius is large. Finally, the flow solution is incorporated into the mathematical model of an MR damper designed at the University of Manchester, and simulation results incorporating the effects of compressibility in the modeling procedure are presented. It was shown that this model can describe the major characteristics of such a device — nonlinear, asymmetric and hysteretic behaviors — successfully.

Research on Performances of Hybrid Actuation System with Dissimilar Redundancies

2012 ◽  
Vol 430-432 ◽  
pp. 1559-1563 ◽  
Author(s):  
Li Ming Yu ◽  
Zi Qing Ye
Keyword(s):  
Operating Mode ◽  
Development Trend ◽  
Hydraulic Actuator ◽  
Actuation System ◽  
Electric Aircraft ◽  
Hybrid Actuation ◽  
Actuation Systems ◽  
The Development Trend ◽  
More Electric Aircraft ◽  
Mode A

Hybrid actuation system (HAS) with dissimilar redundancies conforms to the development trend of future actuation systems in more electric aircraft (MEA). Hybrid Actuation system is composed of a traditional servo valve controlled hydraulic actuator (SHA) and an electro-hydraulic actuator (EHA). It has two operating models, active/passive mode (A/P) and active/active mode (A/A). In A/A model both actuators are actively controlled. Corresponding to A/A model, SHA is actively controlled and EHA is passively controlled in A/P model. The hybrid actuation system is built in the AMESim simulation environment, comparative analysis is performed when system operates in these two modes, such as signal response and force fighting. The simulation results provide a guideline to determine the specific operating mode of the system in different circumstances.

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