FBS 2 will be ‘semi-dry’ or ‘dry on one axle’, meaning the front brake calipers will still be actuated by hydraulics while the rears become electromechanical. Continental says its customers are interested in this as a first step.
The full monty will be FBS 3, where hydraulics are gone, with a fully ‘dry’ system being electronically controlled and electrically actuated. Continental says that will decentralise the braking system, enabling vehicle architectures to use space more effectively.
FBS 2 is already a reality. It will enter production with an American maker in 2025.
Advantages of brake-by-wire
Brake-by-wire systems are intuitive and there are several benefits over a mechanical braking system.
Aside from the packaging and weight, pedal feel can be tuned by engineers using driving simulators to give a more aggressive response on track and a more relaxed response in traffic.
Another advantage is that pedal travel doesn’t increase when the brakes take a beating and get hot. What the driver actually feels is a simulator built into the MKC1 that generates the sensation normally fed back through the hydraulics, only it remains consistent however hard the brakes are working.
Full drive-by-wire wire brakes would also allow manufacturers to dispense with that nasty, inflammable, corrosive material that is hydraulic brake fluid, giving them dry chassis and production lines that have no need for the messy liquid.
Complete corners consisting of suspension, wheel hubs, discs and brakes could be preassembled ready to bolt on the car. A further advantage of doing away with hydraulic brake fluid is that it’s hygroscopic (it absorbs atmospheric moisture) so needs changing at intervals.
It will also mean that brake systems, like the modern vehicle architectures to which they are fitted, can become modular and distributed throughout the car.
Steer-by-wire systems
What about steer-by-wire? Although electric power-assisted steering (EPAS) is common now, mainly because it’s far less energy-hungry than a hydraulic steering pump, it still maintains a mechanical connection between driver and steering; it just takes away some of the steering effort from the driver by using a motor.