Control Of Hydraulic Actuator Biology Essay

Abstractions: By using MR fluids as working fluid in power systems, direct interface can be realized between magnetic field and unstable power without the demand for mechanical traveling parts like bobbin in Directional control valves. In this survey, we got to cognize the engineering of fluid, its constituents, and the rule of work, and specifications. We got to cognize every bit good as the designs that make usage of this liquid. The of import thing is to plan valves, actuators and systems every bit good as covering with these valves. The new design of compact ( 4/3 ) Directional Control valve controlled proportionately with magnetic field ( variable current ) is possible. We think we can make the development work of the valves to work proportionately to command the hydraulic actuators. , Through a compact design and behavior experiments, and theoretical computations to make the optimum design. Reviews and has given us a clear thought of this engineering.

Cardinal words: Magnetorheological ( MR ) fluid, ( MR ) Valve design, ( MR ) Device, Hydraulic System.

INTODUCTION

Magnetorheological ( MR ) fluid consist of stable suspension of micro-sized, magnetic atoms dispersed in bearer medium like a hydrocarbon fluid, silicon oil or H2O. When an external magnetic field is applied, the polarisation induced in suspended atoms which consequences in Magnetorheological consequence of the MR fluid. The Magnetorheological consequence is direct influences on the mechanical belongingss of the MR fluid. The suspended atoms in the MR fluid become magnetized and align themselves, like ironss, with the way of the magnetic field. The preparation of these atom ironss restricts the motion of the MR fluid, thereby increasing the output emphasis of the fluids. The force of attractive force between the atoms in the ironss manifests as a opposition to shear distortion and accordingly, fluid flow. In an idealised MR fluid, the fluid does non get down fluxing till a peculiar value of shear emphasis, called the output emphasis, has been reached. Therefore, the viscousness of these fluids can be changed utilizing an external magnetic field.

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As anyone who has made MR fluid knows, it is non hard to do a strong MR fluid. Over 50 old ages ago both Rabinow and Winslow ( Carlson, 2001 ) described basic MR fluid preparations that were every spot every bit strong as fluids today. A typical MR fluid used by Rabinow consisted of 9 parts by weight of carbonyl Fe to one portion of silicone oil, crude oil oil or kerosine. To this suspension he would optionally add lubricating oil to better settling stableness. The strength of Rabinow ‘s MR fluid can be estimated from the consequence of a simple presentation that he performed.

Rabinow was able to suspend the weight of a immature adult female from a simple direct shear MR fluid device.

He described the device as holding a entire shear country of 8 square inches and the weight of the adult female as 117 lbs. For this presentation to be successful it was therefore necessary for the MR fluid to hold yield strength of at least 100 kPa. .

This alone belongings of MR fluids has been used in assorted commercial applications. MR fluids have been used in optical shining, ( Kordonski et al. ,1999 ) , unstable clasps, ( Lee et al. , 2000 ; Takesue et al.,2001 ) , vibration isolation systems and a assortment of aerospace, ( Kamath et al. , 1999 ) ; ( Marathe et al. , 1998 ) , civil ( Sodeyama et al. , 2001 ) ; ( Ribakov and Gluck, 2002 ) and automotive, ( Lam et al, 2003 ) ; ( Lindler et al. , 2003 ) muffling applications The of import rheological features of an MR fluid are its output force, viscousness and settling rate, ( Kordonski et al. 1998 ; Phule et Al 1998 ; Rosenfeld et Al. 2002 ) . The output force and viscousness of an MR fluid can be continuously varied utilizing appropriate magnetic Fieldss. Using this belongings, control strategies can be implemented in devices utilizing MR fluids.

Designs that take advantage of governable fluids are potentially simpler and more dependable than conventional electromechanical devices. In add-on, the MR fluid is one of the most efficient agencies to interface mechanical constituents with electronic controls ( Mechatronics ) , offering fast exchanging velocity, miniaturisation, and continuously variable control.

Controllable fluid has received a great trade of attending over the past decennary, because they offer the promise of valve with no traveling parts and low-priced way control valves, and illumination.

LITERATURE REVIEW

A literature study has been done to look into the past research associating to this work. The country of Magnetorheological fluids, devices of Magnetorheological, Magnetorheological valve design, trial & A ; Model for the Magnetorheological systems are of primary involvement.

Magnetorheoological fluids

It is indispensable to cognize the work done by research workers in the survey MR fluids, and for the intent of cognition of the belongingss and specifications of this MR fluid and their possible usage.

( Bossis, et Al. 2002 ) have presented the basic phenomena related to the interplay between inter atom magnetic forces which are responsible for the gelation of the suspension and hydrodynamic forces which will interrupt this gel and will let the suspension to flux. They had given some analytical anticipations for the output emphasis and stress how the combination of field and flow can give rise to a really rich rheology with hysteresis and shear-induced stage separation.

( Zipser, et Al. 2001 ) have described the flow behaviour of Magnetorheologic fluids in narrow channels, influenced by variable magnetic Fieldss and temperature. Furthermore, they had studied possibilities and bounds of using Magnetorheologic fluids in smart actuators.

( Olabi, and Grunwald, 2007 ) have presented the province of the art of an actuator with a control agreement based on MR fluid engineering. They had showed the first-class characteristics like fast response, simple interface between electrical power input and the mechanical power end product, and controllability make MR fluid the following engineering of pick for many applications.

( Laun, et Al. 2008 ) have done the measurings of the first and 2nd normal emphasis difference in steady shear of a 50 vol. % MR fluid. The analysis was based on a comparing of plate-plate and cone-plate consequences. Since the radial profiles of true magnetic flux denseness in the sample could non be expected to be indistinguishable for both geometries, they have carefully analyzed the flux denseness profiles both by Hall investigation measurings and Maxwell 2D FEM simulations. In add-on, they had addressed the normal emphasiss consequence on the concentricity in coaxal cylinder geometry.

( Brigadnov, and Dorfmann, 2005 ) have presented the stuff constituent dealingss for a non-Newtonian incompressible MR fluid. They had considered the full system of equations every bit good as the Clausius-Duhem inequality for traveling isotropic MR fluids in an electro-magnetic field. To exemplify the cogency of the constituent dealingss, the flow of a MR fluid between two analogues fixed home bases under the influence of a changeless magnetic field perpendicular to the flow way was considered.

Literatures above, were identified on the MR fluid, composing, mechanical specifications, and Magnetic specifications. Equally good as, how make to be intervention with its. Besides been identified on the dealingss between the specifications alteration, with the magnetic field of its. It has besides been identified on the mathematical method of ciphering the variables, and the usage of appropriate package.

Devicess of Magnetorheological

In this subdivision we will look at some researches for devices, working with the MR fluid. MR unstable damper and Brake are devices to give its map by the shear emphasis of MR fluid.

( Hitchcock, et Al. 2007 ) have presented theoretical and experimental probes of a fresh external beltway, fail-safe, Magnetorheological ( MR ) fluid damper. A fail-safe ( MR ) fluid damper was referred to as a device that retains a lower limit needed damping capacity in the event of a power supply or electronic system failure. They had developed theoretical preparation based on the Herschel-Bulkley constituent theoretical account for an annulate flow. Experimental consequences had obtained to show the cogency of the theoretical analysis.

( Kelso, 2001 ) has illustrated the development of a fast-response for MR damper, low-power, cost-efficient solution. Basically, a competitory ‘whole attack ‘ active or semi-active MR solution can be viewed as system of separate constituents: parametric quantity detection, intelligent control, power bringing, and MR hardware engineering. He had presented that is MR engineering, consisting simple, commercial-off-the-shelf ( COTS ) constituents where possible, presents an attractive, practical and cost effectual constituent of the ‘whole attack ‘ MR solution.

( Yang, et Al. 2005 ) have investigated theoretically the cardinal design method of the MR damper. They had developed theoretical method to analyse the shear emphasis by the MR fluid within the damper. An technology look for the shear emphasis was derived to supply the theoretical foundations in the design of the damper. Based on this equation, be algebraically manipulated, the volume and thickness of the annulate MR fluid within the damper was yielded.

( Milecki, 2001 ) described and studied a semi-active governable fluid damper. He had proposed a simulation theoretical account of a damper and made some control analysis. He had presented the experimental consequences in a damper whose features may by adapted in existent clip to the user ‘s demands. Such dampers could used to extinguish oscillations in different servo thrust machine tools systems.

( Gravatt, 2003 ) has focused in his MSc. thesis on another application of MR dampers, affecting super-sport bikes. He had discussed the method of planing and fabricating MR dampers. The research lab testing has been covered, including the trial equipment, trial process, and the laboratory trial consequences. The consequences of field trials with stock dampers and MR dampers with a assortment of control systems were discussed.

( Sukhwani and Hirani, 2008 ) have described the design process of MR brake and discourse the consequence of MR spread on its braking torsion. They have performed the theoretical design and its findings, prototyping, and experimental survey of MR brake. An experimental trial apparatus has been developed to mensurate the braking torsion under assorted runing velocities ( 200 to 1200 r/min ) and control currents ( 0.0 to 1.2 A ) . The effects of cardinal and side electromagnets on braking torsion have been examined.

( Karakoc, et Al. 2008 ) have discussed the design considerations for constructing an automotive Magnetorheological ( MR ) brake. They were considered practical design standards such as stuff choice, sealing, working surface country, syrupy torsion coevals, applied current denseness, and MR fluid choice to choose a basic automotive MR brake constellation. Then, a finite component analysis was performed to analyse the resulting magnetic circuit and heat distribution within the MR brake constellation. They had followed by a multidisciplinary design optimisation ( MDO ) process to obtain optimum design parametric quantities that can bring forth the maximal braking torsion in the brake.

( Park, et Al. 2006 ; 2008 ) developed and studied a Magnetorheological brake system for the automotive which has been performed advantages over the conventional hydraulic brake system.

( Zhang et al. 2006 ) have proposed the magnetic design of an MR damper, and have discussed a finite component analysis ( FEA ) on the magnetic impregnation for the extreme betterment of the high force. Through experimental confirmation, the damper force was efficaciously scaled by the magnetic design.

Literatures above have been identified on devices which used MR fluid, Types and design of its. We got to cognize besides the method of ciphering the variables, by experimentation design and theoretical. Equally good as utilizing the package.

Magnetorheological valve design

In this subdivision we will look at some research for valves, working with the MR fluid. Including force per unit area control valve and flux control valve. These valves are really of import in control system, for this ground the research workers focused on develop it.

( Yokota, et Al. 1999 ) proposed and fabricated a force per unit area control valve utilizing MR fluid. The valve consists of a flow channel between a brace of magnetic poles and the differential force per unit area was controlled by the applied magnetic field strength. It features simple, compact and dependable construction without traveling parts. The inactive features experiments found that the differential force per unit area was controlled by the applied magnetic field strength under small influence of the flow rate, which corresponds to coerce control valve. The differential force per unit area and end product power alteration of 0.68MPa and 20W were obtained with the input current and power alteration 710A.turns and 1.9W at the flow rate of 30cm3/s ( 1.8L/min ) .

( Songjing, et Al. 2002 ) have developed a new type MR fluid alleviation valve. The building and working of new type valve were introduced. Its steady-state public presentation was simulated and experimented.

( Yoo and Wereley 2002 ) have designed the illumination MR valve with the maximal public presentation of the MR consequence in fluid mechanics. The public presentation of the MR valve was limited by impregnation phenomenon in magnetic circuit and by the finite output emphasis of MR fluid. Design parametric quantities of the MR valve were studied and an optimum public presentation was designed utilizing steel ( Permalloy ) stuff in the magnetic circuit. A maximal magnetic flux denseness at the spread was achieved in the optimized valve design based on a restraint on the outer diameter restriction. Valve public presentation was verified with simulation. A flow manner beltway damper system was fabricated and used by experimentation and validated valve public presentation.

( Li, et Al. 2003 ) have optimized the design of a high-efficiency Magnetorheological ( MR ) valve utilizing finite component analysis. The MR valve was composed of a nucleus, a lesion spiral, and a cylinder-shaped flux return. The nucleus and flux return form the ring through which the MR fluid flows. The effects of magnetic field formation mechanism and MR consequence formation mechanism on the MR valve public presentation were investigated. Analytic consequences of the magnetic flux denseness in the valve indicate that the impregnation in the magnetic flux may be in the nucleus, the flux return, or the valve length. To forestall the impregnation every bit good as to minimise the valve weight, the dimensions of the valve were optimally determined utilizing finite component analysis. In add-on, this analysis was coupled with the typical Bingham plastic analysis to foretell the MR valve public presentation.

( Ai, et Al. 2006 ) have designed of an MR valve possessing at the same time annulate fluid opposition channels and radial flow opposition channels. They have described the construction and working of it, and a mathematical had developed. The simulation consequences show that the efficiency of the MR valve could be improved significantly with two types of fluid flow opposition spreads.

( Nguyen, et Al. 2007 ) have presented the geometric optimum design of MR valves in order to better valve public presentation, such as force per unit area bead. They had investigated the force per unit area drops on the footing of the Bingham theoretical account of an MR fluid. Then, the valve ratio, which was an nonsubjective map, was derived by sing the field-dependent ( governable ) and syrupy ( unmanageable ) force per unit area beads of the MR valves.

( Nguyen, et Al. 2008 ) have presented an optimum design for MR valves for minimising the control energy to be applied to gyrate to command the force per unit area bead of the valves. The optimisation job identifies parametric quantities such as applied current, spiral wire size and geometric dimensions of the valves which satisfy the specified force per unit area bead and inductive clip changeless demands.

Literatures above have been identified on sorts of valves used in MR fluid engineering and its design, every bit good as its applications. It besides identified the valve design by experimentation and theoretical, in add-on to the package used in the design.

Test & A ; Model for the Magnetorheological systems

In this subdivision we will look at some research for systems which are utilizing MR fluid. These systems are controlled by MR valves every bit good as in Hydraulic systems.

( Yoo and wereley, 2004 ) have implemented four MR valves as Wheatstone span hydraulic power circuits to drive a hydraulic actuator utilizing a gear pump for driving a conventional hydraulic actuator. If a alteration in way is required, the flow through each of the valves in the Wheatstone span could be controlled swimmingly via altering the applied magnetic field. They had studied the behaviour and public presentation of the MR valve in footings of nondimensional parametric quantities. The public presentation of the hydraulic actuator system with a Wheatstone span web of MR valves was derived utilizing three different constituent theoretical accounts of the MR fluid: an idealised theoretical account ( infinite output emphasis ) , a Bingham plastic theoretical account, and a biviscous theoretical account. The analytical system efficiency in each instance was compared to experiment.

( Yoo, et Al. 2005 ) have described a paradigm MR-piezo loanblend actuator that combines the piezo pump and MR valve actuator constructs, ensuing in a self-contained hydraulic propulsion device without active electromechanical valves. They had designed and constructed of a paradigm MR-piezo intercrossed actuator. They had tested and described the public presentation and efficiency of the system by experimentation.

( John, et Al. 2008 ) have configured the MR valves in the signifier of an H-bridge to bring forth di-direction gesture in an end product cylinder by alternately using magnetic field in two opposite weaponries of the span. The primary propulsion was performed utilizing a compact terfenol-D rod driven pump and frequence rectification of the rod gesture was done utilizing inactive reed valves. The pump and reed valve constellation along with MR valves form a compact hydraulic propulsion system. Actuator design, analysis and experimental consequences were presented. A clip sphere theoretical account of the actuator was developed and validated utilizing experimental informations.

Literature above gave us an thought of the systems and hydraulic actuators utilizing MR fluid engineering. It is clear that the research workers began to develop thoughts and the development of systems to make the optimum design.

Decision

After researching the literature and studied in deepness. We conclude the thought of the work of the MR fluid. We got to cognize every bit good as the types and designs that work with MR fluid engineering. The thing that concerns us is to plan the valve, which works with MR fluid engineering, in add-on to the systems and hydraulic actuators.

We conclude that the literature does non advert one of the research workers to develop a compact directional hydraulic valve works proportionately to command the hydraulic actuator, utilizing the MR fluid engineering. That is why we are developing a design that the valve, doing the thought of relative directional control valve utilizing MR fluid.

The new design of compact ( 4/3 ) Directional Control valve controlled proportionately with magnetic field ( variable current ) is possible. We think we can make the development work of the valves to work proportionately to command the hydraulic actuators. , Through a compact design and behavior experiments, and theoretical computations to make the optimum design. Reviews and has given us a clear thought of this engineering. This is our research.

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