Electronic safety applications make sure that you don't end up off the road

Sep 8, 2008

Taking a bend too fast or emergency braking to avoid a sudden, unexpected obstacle: ESC and ABS can help you to come through critical traffic situations like these unscathed. Parking and starting off on an incline hold no worries if an Electric Parking Brake (EPB) and Hill Start Assist (HSA) are fitted in the vehicle.

Berlin/Frankfurt am Main, Germany. Even the best driver can get into a skid. Perhaps the country road bend is just a bit tighter than he thinks, or a child darts into the road after a ball, or driving a touch too fast for the wet surface on the exit ramp. In situations like these, it's good if you don't have to rely solely on your own driving skills – but can be assured with electronic assistance to prevent the vehicle breaking away and to stop a small error from becoming a tragic accident with serious consequences.

ESC, or Electronic Stability Control, is the name of the technology which plays a significant part in drastically reducing the number of accidents and deaths on our roads.

In the USA, according to a study by the Insurance Institute for Highway Safety, more than 10,000 lives could be saved each year if all cars were equipped with ESC. The number of accidents, particularly those not involving other road users, could fall by more than half. This is why ESC will be mandatory as standard equipment in new vehicles from September 2011 in the USA; a step which European legislators have not yet taken.

Parking and starting off on an incline hold no worries if an Electric Parking Brake (EPB) and Hill Start Assist (HSA) are fitted in the vehicle. The ESC sensors capture a multitude of data, including speed, steering movements, the car's lateral and longitudinal acceleration and the so-called yawing motion, i.e. rotational movement about the vertical axis. If ESC detects that the car is moving in a different direction from that in which the driver has turned his steering wheel, then ESC will intervene. In this way ESC will prevent the car's front wheels from loosing lateral grip in the bend – a condition known as understeer. Or, even more difficult to control, if the vehicle rear end breaks away - the notorious oversteer skid. Engine power is lessened down and if this is not enough to stabilize the car, the technology can brake each wheel individually. ESC is, in effect, a braking system, which can operate four brake pedals either individually or jointly. And not even the best driver can do that.

Cars with a high center of gravity, i.e. the much-loved SUVs or typical family vehicles such as MPVs, can derive the most benefit from this technology; ESC will help prevent them from rolling over. In addition, ESC prevents consequential accidents caused by many drivers, especially those with little experience, when they overreact to inherently harmless driving errors and then conjure up genuinely dangerous situations by wild steering.

Anti-lock Brake System (ABS): keeping you safely in lane even when braking

An unexpected traffic hazard around a bend or a pedestrian stepping out into the road between two parked cars: the only thing here is to brake with maximum force. The possible consequences of one or more wheels locking up, especially if the road surface provides uneven grip because it is partly covered in mud, are that these wheels will transmit less braking force onto the road surface (dynamic friction instead of tire-to-road friction) and will lose their lateral stability. Inadequate braking force will be applied, the car will break away, will no longer react to the steering, and will slide out of control towards the obstacle.

In today's cars this is a task undertaken, as an integral part of ESC, by the anti-lock braking system, the ABS
and certainly far more effectively than by any driver. Because ABS not only prevents the wheels from locking up, it also keeps each wheel continuously in the so-called optimum slip range during braking. The ABS system's sensors do this by recording each wheel's rotational speed and analyzing the data in an electronic module. If electronic analysis of the sensor signals detects that one or more of the wheels are about to lock up, electro-hydraulic solenoid valves in the hydraulic system are briefly opened so that the pressure on the relevant wheel brake is appropriately reduced. Instead of being locked up, the wheel’s ability to turn freely again and transmit optimum longitudinal and lateral stability is restored. Brake pressure is then built up again. This brake pressure control, or modulation cycle, occurs many times each second, alerting the driver by means of noticeable feedback which drivers should not regard as irritations.

Hill Start Assist: taking the stress out of hill starts

The hill start: Many motorists shudder when they think back to that driving lesson. And one of the least enjoyable aspects of day-to-day driving is having to stop on the ramp leading up to the multi-story car park, perform contortions to take the parking ticket from the machine and then start off again as quickly as possible because the line of weekend traffic waiting for the car park is getting longer and longer. Juggling the hand brake and the clutch demands some practice if you don't want to stall the engine or provoke impatient honking of the horn. The Hill Start Assist (HSA) utilizes ABS and ESC sensors, converting these two safety assistants into a comfort feature although it must also be said that HSA is not merely a comfort feature but one which clearly contributes to more relaxed and therefore safer driving. These sensors allow the vehicle's movement to be monitored. If the driver stops on a hill, the electronics keep the brakes applied for a few seconds; the vehicle remains stationary and does not roll backwards. Only when the driver engages the clutch and presses the accelerator the electronics will release the brakes and allow the car to move forward it does not roll backwards when starting off and the engine most certainly does not stall.

Electric Parking Brake: the car is automatically secured when parking

Ever parked on a slight incline and forgotten to apply the hand brake? There's no need to worry about that any more if your car is fitted with the Electric Parking Brake. An electric motor clamps the brake pads firmly against the brake disk; when the driver switches off the ignition after parking. A locking mechanism engages, securing the vehicle without using any power. If the driver wants to engage or release the parking brake manually, a simple press of a button is sufficient – the traditional hand brake lever becomes unnecessary, giving vehicle designers extra space on the center console for more ergonomically situated stowage trays or controls, which the driver can reach more easily.

Press Release (MS-Word, 60 KB)

Press Image to the issue Electronic safety applications in the Continental Media Center.

Nicole Geissler

External Communications


Division Chassis & Safety

Guerickestraße 7

60488 Frankfurt am Main

Phone: +49 69 7603-8492

Fax: +49 69 7603-3945

E-Mail: nicole.geissler@continental-corporation.com