10:17. ABS: natural choice
| The sensor of speed of rotation of a wheel settles down in a nave. |
ABS is simple to formulate appointment – it interferes with blocking of wheels when braking. The brake pedal is too strongly pressed? It does not matter – electronics, comparing signals of sensors of speed of rotation on each of wheels, defines the moment of a sudden stop of a wheel and, opening the electromagnetic valve, dumps surplus of pressure from the brake highway in the special hydroaccumulator. Brake shoes are unclenched, rotation of a wheel is restored, the valve connects the highway again to pressure which by means of the vacuum amplifier of brakes is created by the right leg of the driver. And if this pressure is still too big, then the cycle is repeated again and again. In salon inclusion of ABS is shown by a crash during the operation of the executive block and pushes on a brake pedal, more or less noticeable depending on a system design. Actually, ABS imitates actions of the skilled driver who on the slippery road avoids blocking of wheels, using faltering braking. But ABS does it with a frequency inaccessible to the person and accuracy – to 15 times a second. As a result of ABS has to not only provide to the car the minimum brake way, but also force it to answer the helm – wheels slide and perceive the side force as far as coupling of tires with a covering allows. And it is the main advantage of ABS. In case of blocking of wheels the car it is uncontrollable slides directly, even when the steering-wheel is turned out against the stop.
Fears
It would seem, everything is already clear. Anti-blocking systems are recognized as all civilized auto world and already became the standard equipment on cars, since middle class. But often also voices of dissatisfied are distributed.
"No electronics will be compared to the skilled driver, – say one. – Give me the same car without ABS, and I will stop earlier!"
Others do not like the fact that ABS, interfering with braking process, absolutely excludes participation of the person. As press on a pedal, it with not palatable vibration will be back pushed out. The car pulls up itself, it is impossible to affect the delay course in any way, besides with ABS it is very difficult to calculate a brake way and to predict where the car will stop. It is necessary only to wait... Intolerably for the driver who got used to own a situation!
And the third nod on rally drivers. Like, not without reason those are afraid of ABS as plagues! And to them, athletes, more visible...
To disconnect not disconnected
To sort things out, we went to a technological crime. Found the plug which approaches the ABS executive block under a cowl, and pulled out it from a nest, having forced to light up a yellow kontrolka of ABS and it is disturbing to start blinking a red bulb of brakes in a combination of devices. So we deactivated not disconnected anti-blocking system. Tests took place according to such scheme. We chose four main exercises: braking on a straight line – on the uniform and mixed covering (miksta), in turn and during an obstacle detour (that is when performing maneuver a rerate). Passat equipped with the data-acquisition equipment which is precisely measuring the speed and a brake way. And driving there were our experts-testers. However, it was offered to make some of exercises also to ordinary drivers of the most different qualification – from the beginning motorist to the skilled professional. All could be trained before control arrivals, get used to the car and "adjust fire" to the next maneuver.
Each exercise was carried out in two series. At first did more than ten arrivals from the working ABS, then disconnected system, and the car hurried to the route of the next maneuver marked by bright landmarks again.
How to brake?
With anti-blocking system everything is simple: you want to receive the greatest possible delay – bogs, without thinking twice, a pedal in a floor. And how to brake without ABS?
At first we tried to do everything "according to the theory" - to brake on the verge of blocking of wheels. Does not leave! Too sensitive folksvagenovsky pedal does not allow to dose precisely brake force – and we are mistaken, and both in that, and in other party. And it in a quiet situation. And try to make it in an extreme situation when accident threatens!
Then we applied the tested way – faltering braking.
And for comparison tried, without philosophizing crafty, to brake "in a floor", with blocking of wheels. In what a difference? On a straight line the main difference – in course stability. Especially brightly it was shown when braking on a miksta. Under the left wheels there was a wet asphalt, and under right – a snow-covered roadside.
From the included ABS at first begins to take away the car towards a covering with the best coupling, but electronics works regularly: Passat is instantly leveled and further brakes on a straight line, practically without demanding podrulivaniye. During faltering braking without ABS the driver had to taxi up a little and the brake way appeared more.
But with full blocking of wheels the car braked almost also effectively, as with ABS. But at the same time sharply developed it to the left on a dangerous corner – to 40 °! ABS prize is obvious here.
Covering surprises
Ice happens smooth as a mirror, and rough as a sandpaper surface. Snow happens dense, rolled, friable, bound together, frozen together...
To what it we? And to the fact that each covering has the specifics, and after our tests to give definite answer to the question interesting all – in what conditions the brake way with ABS will be less, than without it – we cannot!
Options weight. For example, when at numerous stops on the same straight line of a wheel of our car knurled a track of the rough ice crumbed by thorns, the brake way with ABS and without it with the blocked wheels was almost identical. Not without reason our athletes say that the most "tenacious" covering – not asphalt, and ispolosovanny "nails" an ice track. And on snow – here so a surprise! – the car with ABS stopped a little later. All the matter is that on a snow covering the coefficient of coupling was lower, than rough ice – thorns use not so effectively here. For ABS, probably, it was unprofitable. But at "usual" faltering braking (pressed – released-pressed) during blocking of wheels before them the snow roller which helps the car to be slowed down more intensively is formed. Work of ABS interferes with blocking of a wheel – and the roller it is impossible.
Be not afraid to twist a wheel!
Imagine quite real situation: before you in slippery turn suddenly brings the truck, and develops it across the road. Or another: from side journey on rather narrow street directly before a nose the car jumps out and partitions off your strip, leaving free only counter.
On a wave of the adrenaline which rushed in blood the driver in panic, reflex, with all the might will press a brake. Wheels will be blocked. And with the blocked wheels the car in the first situation will take off outside of turn, and in the second – will crash into an obstacle. Because without ABS only faltering braking will help to avoid accident, and here from the driver not only outstanding composure and endurance, but also uncommon skill is required.
And here our example. The most experienced expert needed to call to the aid all the ability that, alternating strictly dosed pushes on pedals of a brake and exact work as a wheel, to repeat and even slightly to surpass results of the same maneuvers with ABS.
But what from that? Even the tester needed to make for this purpose more than ten ranging arrivals, and in a real situation the chance will be only one! And electronics will work reliably and for the good here.
When braking in turn the driver's task in general was the elementary: pressed a brake, turned a wheel – and the car, accurately tracing the set trajectory, it is intensively slowed down. It is available to any. It is only important to remember that during braking with ABS by car it is possible and it is necessary to operate. Did not freeze to squeeze a wheel, and safely to work with it!
At an obstacle detour (we braked when performing maneuver of a rerate familiar to our readers) the situation was such. When the speed of performance of maneuver came nearer to limit, after a detour of an obstacle the drift of a back axis began to develop. It was both with ABS, and without it. But using ABS, it was possible to reduce speed so that the drift was not so sharp and deep. And the brake way after a detour was 15 meters shorter. Significantly!
However, to keep on the road, at correction of a drift it was necessary to release a brake pedal even at the working anti-blocking system. Why? We do not argue, ABS leaves an opportunity to change a trajectory at emergency brake application, but not to slide on a straight line with the blocked wheels. But at fight against a drift work of ABS too reduces efficiency of the correcting actions by a wheel. And even those drivers whose cars are equipped with ABS, in similar situations need to be ready for a moment to release a brake pedal, having consciously refused services of electronics.
Avto-Revyu