Features and Benefits of Magnetic Suspension
Suspension and steering,  Car device

Features and Benefits of Magnetic Suspension

Any modern, even the most budgetary, car will be equipped with a suspension. This system is capable of providing a comfortable ride on roads with different types of surfaces. However, in addition to comfort, the purpose of this part of the machine is also to promote safe driving. For details on what a suspension is, read in a separate review.

Like any other auto system, the suspension is being upgraded. Thanks to the efforts of engineers from various auto concerns, in addition to classical mechanical modifications, a pneumatic design already exists (read about it in detail here), hydraulic and magnetic suspension and their varieties.

Let's consider how the magnetic type of pendants works, their modifications, and also the advantages over classical mechanical structures.

What is magnetic suspension

Despite the fact that the car's damping system is constantly being improved, and new elements appear in its design or the geometry of different parts changes, its operation remains basically the same. The shock absorber softens the shocks that are transmitted from the road through the wheel to the body (details about the device, modifications and faults of shock absorbers are described separately). The spring returns the wheel to its original position. Thanks to this scheme of work, the movement of the car is accompanied by constant adhesion of the wheels to the road surface.

Features and Benefits of Magnetic Suspension

You can radically change the suspension mode by installing an adaptive device on the machine platform that would adapt to the road situation and improve the vehicle's handling, no matter how good or bad the road is. An example of such structures is an adaptive suspension, which in different versions is already installed on serial models (for more details about this type of device, read here).

As one of the variants of adaptive mechanisms, an electromagnetic type of suspension was developed. If we compare this development with a hydraulic analogue, then in the second modification there is a special fluid in the actuators. The electronics change the pressure in the reservoirs, so that each damping element changes its stiffness. The principle is similar for the pneumatic type. The disadvantage of such systems is that the working circuit is not able to quickly adapt to the road situation, since it needs to be filled with an additional amount of working medium, which at best takes a couple of seconds.

The fastest way to cope with this work can be mechanisms that function on the basis of the electromagnetic interaction of the executive elements. They are more responsive to the command, since to change the damping mode, it is not necessary to pump or drain the working medium from the tank. The electronics in the magnetic suspension give the command, and the device instantly responds to these signals.

Increased ride comfort, safety at high speeds and unstable road surfaces, as well as ease of handling are the main reasons why developers are trying to implement magnetic suspension in production cars, since classic designs are not able to achieve ideal parameters in this regard.

The very idea of ​​creating a "hovering" vehicle is not new. She is often found on the pages of fantastic works with spectacular flights of gravikars. Until the first years of the 80s of the last century, this idea remained at the stage of fiction, and only some researchers considered it as possible, but in the distant future.

However, in 1982, the world's first development of a train moving on a magnetic suspension appeared. This vehicle was called a magnetoplane. Compared to classical analogs, this train developed an unprecedented speed at that time - more than 500 km / h, and in terms of its softness of "flight" and noiselessness of work, only birds could make real competition. The only drawback due to which the implementation of this development is slow is not only the high cost of the train itself. In order for him to be able to move, he needs a special track that provides the proper magnetic field.

Features and Benefits of Magnetic Suspension

Although this development has not yet been applied in the automotive industry, scientists do not leave this project "gathering dust on the shelf." The reason is that the electromagnetic principle of operation completely eliminates the friction of the driving wheels on the road surface, leaving only air resistance. Since it is impossible to completely transfer all wheeled vehicles to a similar type of chassis (it will be necessary to build corresponding roads around the world), engineers focused on introducing this development into the suspension of cars.

Thanks to the installation of electromagnetic elements on test samples, scientists were able to provide the concept cars with better dynamics and controllability. The design of the magnetic suspension is quite complex. It is a rack that is installed on all wheels according to the same principle as a MacPherson rack (read about it in detail in another article). These elements do not need a damper mechanism (shock absorber) or a spring.

Correction of the operation of this system is carried out through the electronic control unit (separate, since the microprocessor needs to process a lot of data and activate a large number of algorithms). Another feature of this suspension is that, unlike the classic versions, it does not need torsion bars, stabilizers and other parts to ensure the stability of the vehicle at bends and high speeds. Instead, a special magnetic fluid can be used, which combines the properties of a fluid and a magnetized material, or solenoid valves.

Some modern cars use shock absorbers with a similar substance instead of oil. Since there is a high probability of failure of the system (after all, this is still a new development, which has not yet been fully thought out), springs may be present in its device.

Principle of operation

The principle of interaction of electromagnets is taken as the basis for the functioning of the magnetic suspension (in hydraulics it is fluid, in pneumatic air - air, and in mechanics - elastic parts or springs). The operation of this system has the following principle.

From the school course, everyone knows that the same poles of magnets mutually repel. To connect the magnetized elements, you will need to apply enough effort (this parameter depends on the size of the elements to be connected and the strength of the magnetic field). Permanent magnets with such a strong field to withstand the weight of a car are difficult to find, and the dimensions of such elements will not allow them to be used in cars, let alone adapt to the road situation.

Features and Benefits of Magnetic Suspension

You can also create a magnet with electricity. In this case, it will only work when the actuator is energized. The strength of the magnetic field in this case can be regulated by increasing the current on the interacting parts. Through this process, it is possible to increase or decrease the repulsive force, and with it the stiffness of the suspension.

Such characteristics of electromagnets make it possible to use them as springs and dampers. For this, the structure must necessarily have at least two electromagnets. The inability to compress parts has the same effect as a classic shock absorber, and the repulsive force of the magnets is comparable to that of a spring or spring. Due to the combination of these properties, the electromagnetic spring responds much faster than mechanical counterparts, and the response time to control signals is much shorter, as in the case of hydraulics or pneumatics.

In the arsenal of developers there is already a sufficient number of working electromagnets of various modifications. All that remains is to create an efficient suspension ECU that will receive signals from the chassis and body position sensors and fine-tune the suspension. In theory, this idea is quite realistic to implement, but practice shows that this development has several "pitfalls".

Firstly, the cost of such an installation will be too high for a motorist with an average material income. And not every rich person could afford to buy a car with a full-fledged magnetic suspension. Secondly, the maintenance of such a system would be associated with additional difficulties, for example, the complexity of the repair and a small number of specialists who understand the intricacies of the system.

A full-fledged magnetic suspension can be developed, but it will not be able to create worthy competition, since few people will want to shell out a fortune just for the sake of the response speed of the adaptive suspension. Much cheaper, and with good success, electrically controlled magnetic elements can be introduced into the design of classic shock absorbers.

Features and Benefits of Magnetic Suspension

And this technology already has two applications:

  1. Install an electromechanical valve in the shock absorber that changes the section of the channel through which the oil moves from one cavity to another. In this case, you can quickly change the stiffness of the suspension: the wider the bypass opening, the softer the shock absorber works and vice versa.
  2. Inject a magnetic rheological fluid into the shock absorber cavity, which changes its properties due to the effect of a magnetic field on it. The essence of such a modification is identical to the previous one - the working substance flows faster or slower from one chamber to another.

Both options are already used in some production vehicles. The first development is not so fast, but it is cheaper compared to shock absorbers filled with magnetic fluid.

Types of magnetic suspensions

Since a full-fledged magnetic suspension is still under development, automakers are partially implementing this scheme in their car models, following one of the two paths mentioned above.

Among all the developments of magnetic suspensions in the world, there are three varieties that deserve attention. Despite the difference in the principle of operation, design and use of different actuators, all these modifications have several similarities. The list includes:

  • Levers and other elements of the car walking, which determine the direction of movement of the wheels during the operation of the suspension;
  • Sensors for the position of the wheels relative to the body, their speed of rotation and the state of the road in front of the car. This list also includes general-purpose sensors - the forces of pressing the gas / brake pedal, engine load, engine speed, etc .;
  • A separate control unit in which signals from all sensors in the system are collected and processed. The microprocessor generates control pulses in accordance with the algorithms that have been stitched during production;
  • Electromagnets, in which, under the influence of electricity, a magnetic field with the corresponding polarity is formed;
  • A power plant that generates a current capable of activating powerful magnets.

Let's consider what is the peculiarity of each of them, and then we will discuss the advantages and disadvantages of the magnetic version of the damper system of the car. Before we get started, it's worth clarifying that none of the systems is the product of corporate espionage. Each of the developments is an individually developed concept that has the right to exist in the world of the automotive industry.

SKF magnetic suspension

SKF is a Swedish manufacturer of auto parts for professional vehicle repairs. The design of the magnetic shock absorbers of this brand is as simple as possible. The device of these springy and damping parts includes the following elements:

  • Capsule;
  • Two electromagnets;
  • Damper stem;
  • Spring.

The principle of operation of such a system is as follows. When the car's electrical system is started, the electromagnets located in the capsule are activated. Due to the identical poles of the magnetic field, these elements are repelled from each other. In this mode, the device works like a spring - it does not allow the car body to lie on the wheels.

Features and Benefits of Magnetic Suspension

When the car is driving on the road, sensors on each wheel send signals to the ECU. Based on these data, the control unit changes the strength of the magnetic field, thereby increasing the travel of the strut, and the suspension becomes classic soft from a sporty one. The control unit also controls the vertical movement of the strut rod, which does not give the impression that the machine is running on springs alone.

The springing effect is provided not only by the repulsive properties of the magnets, but by the spring, which is installed on the rack in case of a power outage. Plus, this element allows you to turn off the magnets when the vehicle is parked with an inactive on-board system.

The disadvantage of this type of suspension is that it consumes a lot of energy, since the ECU constantly changes the voltage in the magnet coils so that the system quickly adapts to the situation on the road. But if we compare the "gluttony" of this suspension with some attachments (for example, with an air conditioner and a working interior heating), then it does not consume a critically large amount of electricity. The main thing is that a generator with a suitable power is installed in the machine (the function of this mechanism is described in here).

Delphi Suspension

New damping characteristics are offered by the suspension developed by the American company Delphi. Outwardly, it resembles the classic McPherson stance. The influence of electromagnets is carried out only on the properties of the magnetic rheological fluid in the cavities of the shock absorber. Despite this simple design, this type of suspension shows an excellent adaptation of the stiffness of the dampers depending on the signals from the control unit.

Compared to hydraulic counterparts with variable stiffness, this modification responds much faster. The work of the magnets only changes the viscosity of the working substance. As far as the spring element is concerned, its stiffness does not need to be changed. Its task is to return the wheel to the road as quickly as possible when driving fast on uneven surfaces. Depending on how the electronics work, the system is able to instantly make the fluid in the shock absorbers more fluid so that the damper rod moves faster.

Features and Benefits of Magnetic Suspension

These suspension properties are of little practicality for civilian transport. Fractions of a second play an important role in motorsport. The system itself does not require as much energy as in the case of the previous type of dampers. Such a system is also controlled on the basis of data coming from various sensors located on the wheels and suspension structure elements.

This development is already being actively used in adaptive suspension brands such as Audi and GM (some Cadillac and Chevrolet models).

Bose Electromagnetic Suspension

The Bose brand is known to many motorists for its premium speaker systems. But in addition to high-quality audio preparation, the company is also working on the development of one of the most spectacular types of magnetic suspension. By the end of the twentieth century, a professor who creates spectacular acoustics, also "infected" with the idea of ​​creating a full-fledged magnetic suspension.

The design of its development resembles the same rod shock absorber, and the electromagnets in the device are installed according to the principle, as in the SKF modification. Only they do not repel each other, as in the first version. The electromagnets themselves are located along the entire length of the rod and the body, inside which it moves, and the magnetic field is maximized and the number of pluses is increased.

The peculiarity of such an installation is that it does not require much more energy. It also simultaneously performs the function of both a damper and a spring, and it works both in a static (the car is standing) and in a dynamic (the car is moving along a bumpy road) mode.

Features and Benefits of Magnetic Suspension

The system itself provides control of a larger number of processes occurring while the car is driving. Damping of oscillations occurs due to a sharp change in the poles of the magnetic field. The Bose system is considered the benchmark of all such suspension designs. It is able to provide an effective stroke of the rod by as much as twenty centimeters, perfectly stabilize the body, eliminating even the slightest roll during high-speed cornering, as well as "pecking" during braking.

This magnetic suspension was tested on the flagship model of the Japanese automaker Lexus LS, which, by the way, was recently restyled (a test drive of one of the previous versions of the premium sedan was presented in another article). Despite the fact that this model already received a high-quality suspension, which is characterized by smooth operation, during the presentation of the magnetic system it was impossible not to notice the admiration of the auto journalists.

The manufacturer has equipped this system with several operating modes and a large number of different settings. For example, when the car is cornering at high speed, the suspension ECU records the speed of the vehicle, the beginning of body roll. Depending on the signals from the sensors, electricity is supplied to a greater extent to the rack of one of the more loaded wheels (more often it is the front one, located on the outer trajectory of the semicircle of rotation). Thanks to this, the outer rear wheel also becomes the support wheel, and the car maintains grip on the road surface.

Another feature of Bose's magnetic suspension is that it can also act as a secondary generator. When the shock absorber rod moves, the corresponding recuperation system collects the released energy into the accumulator. It is possible that this development will continue to be modernized. Despite the fact that this type of suspension is in theory the most efficient, by far the most difficult is to program the control unit so that the mechanism can realize the full potential of the system described in the drawings.

Prospects for the appearance of magnetic suspensions

Despite its obvious effectiveness, a full-fledged magnetic suspension has not yet entered mass production. At the moment, the key obstacle to this is the cost aspect and the complexity in programming. The revolutionary magnetic suspension is too expensive, and it has not yet been fully developed (it is difficult to create adequate software, since a large number of algorithms must be activated in the microprocessor to realize its full potential). But already now there is a positive trend towards the application of the idea in modern vehicles.

Any new technology needs funding. It is impossible to develop a novelty and immediately put it into production without preliminary tests, and in addition to the work of engineers and programmers, this process also requires huge investments. But as soon as the development is put on the conveyor, its design will gradually be simplified, making it quite possible to see such a device not only in premium cars, but also in models of the middle price segment.

Features and Benefits of Magnetic Suspension

It is possible that over time the systems will improve, which will make wheeled vehicles more comfortable and safe. Mechanisms based on the interaction of electromagnets can also be used in other vehicle designs. For example, to increase comfort while driving a truck, the driver's seat can be based not on pneumatic, but on a magnetic cushion.

As for the development of electromagnetic suspensions, today the following related systems need improvement:

  • Navigation system. The electronics must determine the condition of the road surface in advance. It is best to do this based on the data of the GPS navigator (read about the features of the device operation here). The adaptive suspension is prepared in advance for difficult road surfaces (some navigation systems provide information on the condition of the road surface) or for a large number of turns.
  • Vision system ahead of the vehicle. Based on infrared sensors and analysis of the graphic image that comes from the front video camera, the system must determine in advance the nature of changes in the road surface and adapt to the information received.

Some companies are already implementing similar systems in their models, so there is confidence in the imminent development of magnetic suspensions for cars.

Advantages and disadvantages

Like any other new mechanism that is planned to be introduced into the design of cars (or is already being used in motor vehicles), all types of electromagnetic suspension have advantages and disadvantages.

Let's talk about the pros first. This list includes such factors:

  • The damping properties of the system are unparalleled in terms of smooth operation;
  • By fine-tuning the damping modes, the car's handling becomes almost perfect without the rolls characteristic of simpler designs. The same effect ensures maximum grip on the road, whatever its quality;
  • During acceleration and hard braking, the car does not "bite" its nose and does not sit on the rear axle, which in ordinary cars seriously affects the grip;
  • Tire wear is more even. Of course, if the geometry of the levers and other elements of the suspension and chassis is properly tuned (for more details about the camber, read separately);
  • The aerodynamics of the car is improved, since its body is always parallel to the roadway;
  • Uneven wear of structural elements is eliminated by distributing forces between loaded / unloaded wheels.

In principle, all the positive points relate to the main purpose of any suspension. Every automaker strives to improve the existing types of damping systems in order to bring their products as close as possible to the mentioned ideal.

Features and Benefits of Magnetic Suspension

As for the disadvantages, the magnetic suspension has one. This is its value. If you install a full-fledged development from Bose, then even with the low quality of the interior and the minimum configuration of the electronic system, the car will still cost too much. Not a single automaker is yet ready to put such models into a series (even a limited one), hoping that the rich will immediately buy up the new product, and there is no point in investing a fortune in a car that will stand in warehouses. The only option is to manufacture such cars on an individual order, but in this case there are few companies that are ready to provide such a service.

In conclusion, we suggest watching a short video on how the Bose magnetic suspension works in comparison with classic counterparts:

The invention is NOT for ordinary mortals. EVERYONE WOULD LIKE to see this technology in their car

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