Often, directing the car into a turn, we can not imagine at what speed it is safe to go through a bend under specific road conditions. Having sensed something was amiss, the "racer" discharges gas, or even starts to slow down - and often only exacerbates the situation.
The strange electronic device FDR (FahrDyna-mikRegelung - driving dynamics control), which appeared exactly ten years ago at the Mercedes S-class, marked a new and very important stage in the development of the car.
WHAT IS HER NAME?
The initial German abbreviation FDR did not last long and gave way to a universal philological ESP (Electronic Stability Program, Elektronische Stabilita..tspro-gramm - electronic stabilization program), hinting that we are talking about a program for a computer. This is partly true. The anti-lock braking system already includes the main components for the ESP. Wheel brakes can be controlled individually, the pump creates pressure in the system. What is missing is just the sensors of angular and lateral accelerations and the sensor of the steering angle. But the “anti-block” controller does not know what to do with additional information - a completely new program is needed.
Why did it take as long as 15 years for its implementation? The problem, first of all, is the reliability of all elements. The fundamental difference between ESP and ABS is that it continuously monitors the compliance of the vehicle’s accelerations with the driver’s desire, expressed in the steering angle. While the ABS is turned on only when braking, while quite energetic. If the ESP understands that the acceleration of the car has reached critical (skidding begins), the system has the right (and is obliged!) To start braking the wheels, dumping or adding gas. Agree, the failure of a device with such powers is fraught with grave consequences. Over time, difficulties have been successfully overcome, and now almost two-thirds of new cars in Germany are equipped with this active safety system.
The Bosch monopoly has long been broken: Continental Tevez, Lucas, TRW make similar devices. They do not have the right to use the ESP reduction, and they have no desire - after all, I want to show my uniqueness. The letters of the Latin alphabet are combined in the most bizarre combinations (see table).
Original names are not always a whim of manufacturers. After all, firms set up programs differently, taking into account the characteristics of specific cars. For example, in adolescence, the A-Class-prone Mercedes-Benz A-class coup is calming much earlier than the SLK coupe. In the BMW X5, the system takes into account the influence of the trailer. Cargo and bus devices work with pneumatic brakes, moreover, on a larger number of wheels, and even take into account the height of the center of mass of the machine.
HOW DOES IT WORK?
If the car stubbornly does not want to go into a turn and slides the front wheels out (understeer), ESP brakes the inner rear wheel. If, as a result of skidding of the rear part, the machine tries to turn steeper than necessary (oversteer), the device corrects the error by braking the outer front wheel. And to prevent the rear-wheel drive car from skidding, the system will “strangle” the motor a little.
This is the work of ESP in its classic form. Today, more sophisticated devices have appeared that allow you to return the car (and even with a trailer) to the true path in more complex situations. For example, the latest TRW development, used, in particular, on the Peugeot 407, can brake up to three wheels simultaneously, each with a different force. And if the computer reveals the driver’s inclination towards racing style, the electronics will lower the sensitivity threshold of the system, making it possible, if not to go through the turn with a “fan, ” then at least a little frolic. By the way, the flip side of the ESP is the accelerated brake wear of those who make it constantly work.
Is driving an “active-safe” car boring? No screeching tires, no police U-turns, no wheel slipping! Most drivers, however, do not strive for this, and those who still want to "drag themselves out" can, at their own risk and risk, turn off the stabilization system with a button. True, on some models it needs to be pressed up to … five (!) Times in a row, and after turning off the ignition, the ESP is activated again.
WHO HELPS HER?
Today, ESP strives to control not only the pedals, but also the steering wheel. The car begins to correct the trajectory by a small turn of the steered wheels towards the skid - remember the lectures in the driving school? Often this is enough. If the matter has gone too far, the device additionally begins the stabilization procedure using brakes.
Automatic steering is useful even when the car just slows down on the surface with a different coefficient of adhesion (for example, left wheels on snow, right wheels on asphalt). To prevent the car from turning around, it was necessary to reduce the braking force on the side of the asphalt, increasing the braking distance. Exit: automatically fend off the steering turn.
But the behavior of the machine in critical conditions also depends on the suspension settings - the characteristics of shock absorbers. Stabilization systems have taught how to manage them, which is reflected in the abbreviations - ICCS, ICM.
WHERE DOES IT WORTH?
Often ESP (especially on mass models) is offered as an option, so its distribution in different countries is influenced by the mentality of drivers and features of roads (see table). In Germany, as you know, there is no speed limit on autobahns. In Japan, on the contrary, there is nowhere to disperse. In the USA, on wide, even highways, turns are rare …
But statistics “insist” on the effectiveness of stabilization devices. For example, Daimler-Chrysler states that the number of accidents due to loss of driver control of a car has decreased since the introduction of ESP in the series by 42%. The NHTSA, the US National Traffic Safety Authority, has a close 35%. The number of deaths in such accidents decreased in the United States by 30%. Especially indicative of the effectiveness of ESP on high, heavy off-road vehicles: the number of accidents decreased by 67%, fatalities in them - by 63%! It is no coincidence that in the USA since 2006 all Ford, GM and Chrysler all-terrain vehicles will be equipped with ESP.
The EU Transport Commission has even declared 2005 the year of ESP under the slogan “Save 25, 000 lives.” You can do it by reducing the number of victims by half (!) No later than 2010. Germany has remained a relatively small part of the way: already 90% of cars of middle and higher classes complete the ESP.
How about in Russia? Do we need sophisticated electronics in our conditions? The choice of foreign cars without ESP is gradually narrowing. However, for most inexpensive cars this device is still an option. Pay extra or save? Of course, you decide. But we are already used to buying insurance against damage in road accidents. Or is it better to pay to avoid an accident?
Expert Opinion ZR
Today, ESPs are little like the ugly ducklings that they managed to get to know nearly a dozen years ago. And the point is not only that their programs are more perfect, sensors are more accurate, and processors are faster. Stabilization systems have become an integral part of automobiles, and the difficulty of controlling a powerful rear-wheel drive car on a slippery road is a concept from the past.
The main advantage of the stabilization system is that in a critical situation, it allows you to maintain control of the machine. This is especially important in Russian conditions, where the length of routes dictates high speeds. However, the roads - far from ideal, very often without dividing barriers between oncoming lanes - do not exclude the danger of head-on collisions.
Although the ZR measurements showed that in many cases a well-trained driver will be able to “replay” the electronics, you should not rely on the seconds achieved on “snakes” and “rearrangements”. Real, on the road, maneuvers, even the most sensible driver (they don’t give others rights, for example) are always very far from those that professionals practice at training grounds.