Everybody hates TLA's (Three Letter Acronyms), so we take the mystery out of braking system jargon.
The most common is ABS (Anti-Lock Brake System). When the brakes are applied very hard, such as an emergency stop and the wheel locks (stops rolling) your ability to steer and slow the car is diminished. The tyre’s greatest grip for steering and braking is obtained when the brakes keep the wheel rolling, close to the point of locking, but not actually locking. ABS has sensors in the wheels that detect when an individual wheel locks and the ABS then momentarily releases the brakes on that wheel to get it rolling, then it instantly re-applies the brakes to keep the wheel on the threshold of locking. It does this around 15 times a second.
Although ABS is a braking system it also improves the steering in an emergency as the rolling wheels allow the car to be steered away from an obstacle and trouble. ABS is particularly good on wet slippery roads as it optimises braking and reduces the braking distances.
The downside to this technology is that when it does operate the system sends a pressure pulse up the brake pedal that can be felt by the driver and although it can be disconcerting it is totally normal. You must keep pushing the brake pedal as hard as you can until you have steered out of trouble.
ESC (Electronic Stability Control) which is also known by many other names that vehicle manufacturers call their systems. These names include VSC (Vehicle Stability Control), DSC (Dynamic Stability Control), ESP (Electronic Stability Program), VSA (Vehicle Stability Assist) but they are all substantially the same technology. It piggy backs on the ABS system, using the ABS’s sensors, plus other components to detect when the vehicle is starting to slide, then it de-powers the engine and applies the brakes to individual wheels to bring the vehicle back under control.
With computer power at a substantial level nowadays, and the quality of the actuating process that makes it all work, ESC can process and correct in milliseconds, faster than human intervention and with accuracy that is quite astounding. ESC represents the first substantial steps towards intelligent crash avoidance technology and can be found accompanied by the suite of other safety technologies including air bags, pre-tensioning seat belts, active headrests, roll over detection, lane change detection and there's even more on the horizon! Our local manufacturers now include ESC on most models too so it's great to see the technology on the local products allowing them to achieve 5 star crash ratings.
BA (Brake Assist) monitors how quickly the brake pedal is pressed, to determine if the driver is panic braking. When it detects this it instantly boosts the brake pressure to the maximum and holds it there as long as the driver has their foot on the brake pedal to give the shortest braking distance. This system also over comes the problem of increased braking distance caused where vibrations from the activation of the ABS unsettles the driver and cause them to lessen their foot’s pressure on the brake pedal.
EBD (Electronic Brake Distribution) manages the front to rear brake pressure balance so that conditions such as cornering with an uneven load or rough road surfaces does not cause the brakes to lock and require the ABS to manage the locked wheel.
The stability of a vehicle is affected by anything that causes the tyre to lose grip with the road and this can happen when too much power is applied. Although not a braking system it works with the brakes on some occasions as the TCS (Traction Control System) monitors when one wheel is spinning faster than the other wheels under acceleration and then it depowers the engine or uses the brakes to grab the spinning wheel or a combination of both to restore tyre grip and traction.
RSC (Roll Stability Control) uses roll sensors to measure the angle of the body and when it tilts beyond a critical angle and is likely to roll it depowers the engine while at the same time severely applying the brakes to one side of the car to induce understeer to pull that side of car back around and allow it to come back on all 4 wheels.