Ok, so this post is a translation from spanish of my post in LaF1.mx
Brake-by-Wire
Every year, the FIA provides certain technical parameters for the F1 teams. This year was no exception, but rather the opposite, as there were the greatest number of technical changes in the history of the category history. For 2014 , the most controversial is the new 1.6-liter V6 turbo charged engine (and the horrible sound it creates). Yet, another of the big news this year is the "Brake-by-Wire" (BBW) or electric brake control.
If you had the opportunity to see the Grand Prix of Australia (and did not fall asleep in the attempt to see a boring race in the morning), they have realized that many drivers blocked the wheels in some corners, or even went off track. This is largely due to the new brake system , and is the natural process of adaptation to new technology that drivers go through when they are not used to it.
The principle is very similar to the " fly-by-wire" aircraft , where the hydraulic system is replaced by a set of sensors and electronic actuators. In a traditional braking system , when we press the brake pedal, a master cylinder is activated, and this generates a hydraulic pressure in the brake lines. This pressure acts on the slave cylinder that is located on each wheel (on the calipers , to be precise) and pressing the pads against the discs and slowing the movement of the car.
In the new braking system, not only discs and pads brake the car, but also a set of motors that convert braking energy into electrical energy and stored it (the famous ERS- K , or Energy Recovery System). Now the brake pedal is connected to a computer that controls the brakes and ERS- K motors.
Then in BBW , the electronics calculates how much the pilot presses the brake pedal and combining information from the energy recovered in the ERS- K , determines how much pressure should be exerted on the rear brakes. The main reason for this is that the new rules state that F1 cars can only retrieve a certain amount of energy per lap, and this energy has a limit of storage in the batteries. When any of these limits is reached, the ERS- K fails to do its braking effect, and this task goes to 100% when normal braking system.
Right here is when it enters the BBW. If traditional brake system is used, the car would slow with different strength when the ERS- K is used and when it is off, leaving the pilot with not knowing how much pressure should be applied to stop at every turn. The system , or better said , the ECU (Electronic Control Unit) calculates how much will stop the ERS and therefore how much pressure should be sent to the brakes so the braking of the car always behave the same way.
In conclusion, the Brake-by-Wire is a brake control system through microprocessor, which makes the braking of the car is consistent and constant, and it maximizes power generation of ERS- K. It is clear that the BBW only works with the rear wheels, and the front ones have a traditional hydraulic braking system.
Everything sounds amazing, right? Well, the problem comes when developers make ECU mapping ( programming) for the computer decide how much brake the car with the ERS- K and how much with conventional brakes. This is really a headache for some engineers, and it is their responsibility that the system is reliable and that drivers have the right "feel".
In the words of James Key , Technical Director of Toro Rosso: "You take the hydraulic FIA guidelines specified, and work with the electronically controlled hydraulic caliper on the link, and also must have a redundancy, because if there is any fail, the brake system should revert to a manual brake circuit. We must take into account any type of failure that can be generated, mechanical and software , is a bit like a differential or a clutch, but the trick is to map it properly. "
But BBW also has its advantages. The reaction time is faster, resulting in shorter braking distances. The system is quieter and eliminates vibrations generated in the brake pedal ( sure some people do not like this, as you can go back to the Grand Prix of Australia and see for your self the offtrack of Felipinho). The space required for the system to eliminate the mechanical parts is reduced and hence reduces the weight.
Drivers and teams take their time to perfect this technology and used it to take advantage. Some teams are more advanced in the development of BBW like Mercedes, since they handle the Brake-by-Wire commercially in some models ( SL Class ) since 2001 , with its system Sensotronic Brake Control ( SBC) .
Hope you have more clear what is the BBW and its consequences in this year's Formula 1. If you have any questions can email me at agustin@ahl.com.mx and I will gladly try to answer them.
