Evolution of Brake Controls to Motion Systems

Vehicles are currently being reconceived. Global megatrends are driving these efforts: Vehicle architecture is changing with the electrification of the powertrain and the growing capabilities of automated driving (AD). Digitalization and connectivity are fundamentally realigning the electrical and electronic architecture (E/E architecture) of vehicles, which is increasingly based on software – because it’s the software which, in future, will define the character of cars and the driving experience! Bytes take the place of horsepower. Apps and services are expanding the car into an immersive experience that’s steadily becoming safer and more comfortable.

What does this all mean for brakes? Changes – and, in part, radical changes in the long term!

As a more advanced development, it is even more compact, lighter and more cost-effective and, thanks to Multi-Logic, has performance characteristics superior to those of the MK C1. With Multi-Logic,the MK C2 features two printed circuit boards and two processors that can be used to uphold more functions in the event of a fault. This allows, for example, that the parking brake can be actuated redundantly. This makes it possible to dispense with a highly expensive mechanical transmission lock for immobilizing the vehicle. Owing to its benefits, the MK C2 evolutionary stage will form the basis for future Future Brake Systems (FBS).

However, the more E/E architecture and vehicle architecture evolve, the more attractive it becomes to eliminate this inflexible “one-box arrangement”. A first step, for example, could be to no longer actuate the brakes hydraulically on the rear axle, because hydraulics have a disadvantage: The fluid has to be changed and disposed of regularly – which is not environmentally sustainable. Moreover, if the brakes were actuated electromechanically, installation of the rear axle would be simplified because rigid hydraulic lines could be dispensed with. At the same time, the hydraulics on the front axle would still be available as a fallback system.

If the rear axle wheel brakes are operated electromechanically, i.e., “dry”, this could be utilized regeneratively, for example for systematic energy recuperation at the rear axle during each braking operation. Once the rear axle brakes become independent of the hydraulic system, they provide the ideal conditions for this. This would require a certain degree of “intelligence” in the brake system. This decentralization and “breaking-up” of the conventional architecture would further increase the degree of freedom for vehicle architectures.