Magnetorheological damper

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A magnetorheological damper or magnetorheological shock absorber is a damper filled with magnetorheological fluid, which is controlled by a magnetic field, usually using an electromagnet. [1] [2] [3] This allows the damping characteristics of the shock absorber to be continuously controlled by varying the power of the electromagnet. Fluid viscosity increases within the damper as electromagnet intensity increases. This type of shock absorber has several applications, most notably in semi-active vehicle suspensions which may adapt to road conditions, as they are monitored through sensors in the vehicle, and in prosthetic limbs. [4]

Contents

Types

Commercial applications

Many applications have been proposed using magnetorheological (MR) dampers. While vehicle applications are the most common use of MR dampers, useful medical applications have risen as well, including implants and rehabilitation methods. [6] Since MR dampers are not yet perfect, they are limited in terms of application. Disadvantages do exist when using a large scale MR damper, for example, particle settling within the carrier fluid may occur that inhibits some possible application.

History

The technology was originally developed by General Motors Delphi Automotive Division based in the USA and then developed further by BeijingWest Industries in China after BeijingWest Industries bought the technology from General Motors. BeijingWest Industries has subsequently introduced improvements including a redesigned ECU and the introduction of a dual coil system. The first car to use the technology was the 2002.5 Cadillac Seville STS, and the first sports car to use the technology was the 2003 C5 Corvette.

Automotive

These types of systems are available from OEMs for several vehicles, including the Acura MDX, Audi TT and R8, Buick Lucerne, Cadillac ATS, CTS-V, DTS, XLR, SRX, STS, Chevrolet Corvette, Camaro ZL1, Ferrari 458 Italia, 599GTB, F12 Berlinetta, Mustang Mach-E, Shelby GT 350, Holden HSV E-Series,and Lamborghini Huracán. [2] [7] These systems were produced by the Delphi Corporation and now by BWI Group under the proprietary name MagneRide. [8] [9]

MillenWorks has also included them in several military vehicles including the MillenWorks Light Utility Vehicle, and in retrofits to the US Army Stryker and HMMWV for testing by TARDEC. [10] [11]

Aviation

MRF-based dampers are excellent candidates for stability augmentation of the lead-lag (in-plane bending) mode of rotor blades in helicopters. [12] MRF-based squeeze film dampers are being designed for use in the rotary wing industry to isolate vibrations from the aircraft structure and crew. [13]

Control

A magnetorheological damper is controlled by algorithms specifically designed for the purpose. There are plenty of alternatives, such as skyhook or groundhook algorithms. [14] The idea of the algorithms is to control the yield point shear stress of the magnetorheological fluid with electric current. When the fluid is in the presence of an applied magnetic field, the suspended metal particles align according to the field lines. Viscosity of the fluid increases according to the intensity of the magnetic field. When this occurs at the right instant, the properties of the damper change helps in attenuating an undesired shock or vibration. The relative efficacy of magnetorheological dampers to active and passive control strategies is usually comparable. [15]

See also

Related Research Articles

<span class="mw-page-title-main">Shock absorber</span> Mechanical component

A shock absorber or damper is a mechanical or hydraulic device designed to absorb and damp shock impulses. It does this by converting the kinetic energy of the shock into another form of energy which is then dissipated. Most shock absorbers are a form of dashpot.

<span class="mw-page-title-main">Car suspension</span> Suspension system for a vehicle

Suspension is the system of tires, tire air, springs, shock absorbers and linkages that connects a vehicle to its wheels and allows relative motion between the two. Suspension systems must support both road holding/handling and ride quality, which are at odds with each other. The tuning of suspensions involves finding the right compromise. It is important for the suspension to keep the road wheel in contact with the road surface as much as possible, because all the road or ground forces acting on the vehicle do so through the contact patches of the tires. The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. The design of front and rear suspension of a car may be different.

<span class="mw-page-title-main">Magnetorheological fluid</span>

A magnetorheological fluid is a type of smart fluid in a carrier fluid, usually a type of oil. When subjected to a magnetic field, the fluid greatly increases its apparent viscosity, to the point of becoming a viscoelastic solid. Importantly, the yield stress of the fluid when in its active ("on") state can be controlled very accurately by varying the magnetic field intensity. The upshot is that the fluid's ability to transmit force can be controlled with an electromagnet, which gives rise to its many possible control-based applications.

<span class="mw-page-title-main">Ferrofluid</span> Special type of liquid which is attracted by poles of a magnet

Ferrofluid is a liquid that is attracted to the poles of a magnet. It is a colloidal liquid made of nanoscale ferromagnetic or ferrimagnetic particles suspended in a carrier fluid. Each magnetic particle is thoroughly coated with a surfactant to inhibit clumping. Large ferromagnetic particles can be ripped out of the homogeneous colloidal mixture, forming a separate clump of magnetic dust when exposed to strong magnetic fields. The magnetic attraction of tiny nanoparticles is weak enough that the surfactant's Van der Waals force is sufficient to prevent magnetic clumping or agglomeration. Ferrofluids usually do not retain magnetization in the absence of an externally applied field and thus are often classified as "superparamagnets" rather than ferromagnets.

<span class="mw-page-title-main">Smart fluid</span> Fluid whose properties can be changed by applying an electric or magnetic field

A smart fluid is a fluid whose properties can be changed by applying an electric field or a magnetic field.

<span class="mw-page-title-main">Mid-engine design</span> Automobile design in which the engine is placed between the front and rear axles

In automotive engineering, a mid-engine layout describes the placement of an automobile engine in front of the rear-wheel axles, but behind the front axle.

<span class="mw-page-title-main">Ferrari 599</span> Grand Tourer produced by Ferrari from 2006–2012 as a successor to the 575M

The Ferrari 599 GTB Fiorano is a grand tourer produced by Italian automobile manufacturer Ferrari. It was the brand's front engined, two-seat model that replaced the 575M Maranello in 2006 as a 2007 model, and was replaced for the 2013 model year by the F12berlinetta.

<span class="mw-page-title-main">Active vibration control</span>

Active vibration control is the active application of force in an equal and opposite fashion to the forces imposed by external vibration. With this application, a precision industrial process can be maintained on a platform essentially vibration-free.

<span class="mw-page-title-main">Electrorheological fluid</span>

Electrorheological (ER) fluids are suspensions of extremely fine non-conducting but electrically active particles in an electrically insulating fluid. The apparent viscosity of these fluids changes reversibly by an order of up to 100,000 in response to an electric field. For example, a typical ER fluid can go from the consistency of a liquid to that of a gel, and back, with response times on the order of milliseconds. The effect is sometimes called the Winslow effect after its discoverer, the American inventor Willis Winslow, who obtained a US patent on the effect in 1947 and wrote an article published in 1949.

In physical systems, damping is the loss of energy of an oscillating system by dissipation. Damping is an influence within or upon an oscillatory system that has the effect of reducing or preventing its oscillation. Examples of damping include viscous damping in a fluid, surface friction, radiation, resistance in electronic oscillators, and absorption and scattering of light in optical oscillators. Damping not based on energy loss can be important in other oscillating systems such as those that occur in biological systems and bikes. Damping is not to be confused with friction, which is a type of dissipative force acting on a system. Friction can cause or be a factor of damping.

Magnetorheological finishing (MRF) is a precision surface finishing technology. Optical surfaces are polished in a computer-controlled magnetorheological (MR) finishing slurry. Unlike conventional rigid lap polishing, the MR fluid's shape and stiffness can be magnetically manipulated and controlled in real time. The optic's final surface form and finishing results are predicted through the use of computer algorithms.

MagneRide is an automotive adaptive suspension with magnetorheological damper system developed by the Delphi Automotive corporation, during a period when the company was a subsidiary of General Motors (GM), that uses magnetically controlled dampers, or shock absorbers, for a highly adaptive ride. As opposed to traditional suspension systems, MagneRide has no mechanical valves or even small moving parts that can wear out. This system consists of four monotube dampers, one on each corner of the vehicle, a sensor set, and an ECU to maintain the system.

An active suspension is a type of automotive suspension that uses an onboard control system to control the vertical movement of the vehicle's wheels and axles relative to the chassis or vehicle frame, rather than the conventional passive suspension that relies solely on large springs to maintain static support and dampen the vertical wheel movements caused by the road surface. Active suspensions are divided into two classes: true active suspensions, and adaptive or semi-active suspensions. While semi-adaptive suspensions only vary shock absorber firmness to match changing road or dynamic conditions, active suspensions use some type of actuator to raise and lower the chassis independently at each wheel.

<span class="mw-page-title-main">MillenWorks</span>

MillenWorks, known as Rod Millen Motorsports until 2005, was an American automotive technology company started by Rod Millen in 1980. The company began by preparing Millen's rally cars, and evolved into designing and building them. The company developed vehicles, high performance auto parts, and technology for racing, concept cars, and the US military.

LORD Corporation is a diversified technology and manufacturing company that develops adhesives, coatings, motion management devices, and sensing technologies for industries such as aerospace, automotive, oil and gas, and industrial. With world headquarters in Cary, North Carolina, LORD has approximately 3,100 employees in 26 countries and operates 19 manufacturing facilities and 10 R&D centers worldwide. As of October 30, 2019, the company has been acquired by Parker Hannifin.

<span class="mw-page-title-main">Ferrari California</span> Motor vehicle

The Ferrari California is a grand touring, high performance sports car created by the Italian automobile manufacturer Ferrari. It is a two-door 2+2 hard top convertible. When originally unveiled in 2008, the California was powered by a front-mid mounted, rear wheel drive, naturally aspirated 4.3-litre V8. In 2012 a lighter, slightly more powerful variant, the California 30 was introduced. In 2014, Ferrari announced the second generation of the model, named California T powered by a new twin-turbo 3.9-litre V8.

A regenerative shock absorber is a type of shock absorber that converts parasitic intermittent linear motion and vibration into useful energy, such as electricity. Conventional shock absorbers simply dissipate this energy as heat.

Magnetic field-assisted finishing, sometimes called magnetic abrasive finishing, is a surface finishing technique in which a magnetic field is used to force abrasive particles against the target surface. As such, finishing of conventionally inaccessible surfaces is possible. Magnetic field-assisted finishing (MAF) processes have been developed for a wide variety of applications including the manufacturing of medical components, fluid systems, optics, dies and molds, electronic components, microelectromechanical systems, and mechanical components.

<span class="mw-page-title-main">Ferrari F12</span> Grand Tourer produced by Ferrari as the successor to the 599 GTB

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Magnetorheological elastomers (MREs) are a class of solids that consist of polymeric matrix with embedded micro- or nano-sized ferromagnetic particles such as carbonyl iron. As a result of this composite microstructure, the mechanical properties of these materials can be controlled by the application of magnetic field.

References

  1. 1 2 "Innovative Designs for Magneto-Rheological Dampers" (PDF). Retrieved 2013-12-08.
  2. 1 2 Primary Suspension Archived October 14, 2007, at the Wayback Machine
  3. ↑ http://www.lord.com/Home/MagnetoRheologicalMRFluid/MRFluidTechnology/tabid/3318/Default.aspx MR Fluid Technology Archived October 13, 2007, at the Wayback Machine
  4. ↑ Technology Compared Archived October 17, 2007, at the Wayback Machine
  5. ↑ Unuh, Mohd Hishamuddin; Muhamad, Pauziah; Mohd Yakub, Mohd Fitri; Ismail, Mohamad Amiruddin; Tanasta, Zaimi (2019). "Experimental Validation to a Prototype Magnetorheological (MR) Semi-Active Damper for C-Class Vehicle". International Journal of Automotive and Mechanical Engineering. 16 (3): 7034–7047. doi: 10.15282/ijame.16.3.2019.15.0527 . ISSN   2229-8649.
  6. ↑ Carlson, J.D.; Matthis, W.; Toscano, J.R. (March 2001). "Smart Prosthetics Based on MR Fluids". Proc. 8th Annual Symposium on Smart Structure and Material SPIE.
  7. ↑ "Ready For A Track Near You: Mustang Mach-E Gt And Gt Performance Edition Ready For Customer Orders". Ford Media center. Ford.com. 26 Apr 2021. Retrieved 21 May 2021.
  8. ↑ "Press Release: Audi R8 Features Delphi's Revolutionary MagneRide Semi-Active Suspension". Delphi.com. Archived from the original on 2013-11-11. Retrieved 2013-12-08.
  9. ↑ "Ferrari F12 Berlinetta news and pictures new Ferrari supercar". evo. 2012-02-29. Retrieved 2012-03-05.
  10. ↑ http://www.millenworks.com/html/aboutus/news/Stryker_Test.pdf MillenWorks Active Damper Suspension System Archived November 29, 2007, at the Wayback Machine
  11. ↑ "A New Generation of Magneto-Rheological Fluid Dampers" (PDF). Archived (PDF) from the original on June 4, 2011. Retrieved 2013-12-08.
  12. ↑ Kamath, Gopalakrishna M.; Wereley, Norman M.; Jolly, Mark R. (1999). "Characterization of Magnetorheological Helicopter Lag Dampers". Journal of the American Helicopter Society. 44 (3): 234–248. doi:10.4050/JAHS.44.234.
  13. ↑ Forte, P.; Paternò, M.; Rustighi, E. (2004). "A Magnetorheological Fluid Damper for Rotor Applications". International Journal of Rotating Machinery. 10 (3): 175–182. doi: 10.1155/S1023621X04000181 .
  14. ↑ Magnetorheological Damper Laboratory Archived 2012-04-25 at the Wayback Machine
  15. ↑ ALY, Aly Mousaad; Richard Christenson (2008). "On the evaluation of the efficacy of a smart damper: a new equivalent energy-based probabilistic approach". Smart Materials and Structures. 17 (4): 045008. Bibcode:2008SMaS...17d5008A. doi:10.1088/0964-1726/17/4/045008. S2CID   110065009.
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