Continental has further developed its pioneering electrohydraulic “brake-by-wire” system with the announcement of the MK C2 version.
Compared with its MK C1 predecessor, the MK C2 is lighter and more compact, so it is much easier to integrate into smaller vehicles and complete vehicle platforms with diverse powertrain concepts and varying installation spaces. Vehicle-specific system application has been simplified. The number of components was reduced, lowering costs. By moving to a multi-logic architecture with two independent partitions and a redundant fall-back level, system availability is increased, which is relevant particularly in view of automated driving. Even the base version of the new system offers the functional scope for highly automated valet parking.
Like its predecessor, the MK C2’s brake pedal is decoupled from the actual pressure generation, opening up benefits of rapidly increasing importance. During 80% or more of all deceleration events in an electric car, electric power can be generated through regenerative braking under “normal” driving styles. However, the brake-pedal feel is the same for the driver even though the wheel brakes are not used.
With the higher level of dynamics of MK C2, it can generate brake pressure within a mere 150 ms whenever the automated or driver assistance system requires pressure. This happens without unsettling the driver with a pedal reaction. So the new system is designed for automated driving according to SAE Level 3 or higher.
“Now that vehicle manufacturers are producing hybrid and electric cars on a large scale, we are offering the MK C2 at exactly the right time,” said Amit Kapoor, Head of R&D, Vehicle Dynamics business unit, Continental. “Future brake systems must continue to support safety, efficiency, comfort and, in the future, more and more additional functions. The MK C2 is perfectly suited for that. The new system generation is compact and lightweight, powerful, and still highly cost-optimized. With its modularity and scalability, it can be integrated in multi-vehicle platforms.”
Continental says that future brake systems must be capable of more than simply decelerating a car safely. They need to contribute to the efficiency of the vehicle and meet new requirements for automated driving. Part of that is to generate brake pressure very quickly when active driving safety requires it. In an electrified vehicle, the seamless blending of regenerative braking (recuperation) and wheel braking with the MK C2 can increase the recuperation efficiency by up to 30% on a hybrid braking system without a simulator pedal–making it possible to lower the CO2 emissions by up to 5 g/km.
MK C2 is the enabler for future brake systems and motion control solutions. It especially supports the first step forward towards brake systems of the future: the transition to genuine brake-by-wire systems. By fully decoupling pedal and pressure generation without a fallback level, an enormous integration benefit can be harvested; the brake system does not have to be mounted in a specific spot directly onto the bulkhead any longer to facilitate the mechanical fall-back level.
Instead, the new system with electronic pedal supports new vehicle concepts with innovative interior designs and cabin dimensions. As an enabler of future brake systems, MK C2 is modularized and scalable. Additionally, the application effort required to adapt it to different vehicle segments and models has been significantly reduced thanks to an intelligent modular system. Several system performance levels offer standardized function sets.
Depending on the customer requirements, the new system can be applied with a mechanical pedal (with hydraulic fall-back level) or with an electronic pedal (without hydraulic fall-back level, like the MK C2 EP variant). In the case of the MK C2 EP variant, the driver steps onto a decoupled electronic brake pedal. Sensors detect the driver’s brake force demand. The system’s electric motor subsequently generates hydraulic pressure.
Thanks to the multi-logic architecture and the redundant fall-back level, functions remain available even in the case of a fault, so the driver can get continuous support. Also, the parking brake can be redundantly controlled, making a mechanical transmission lock unnecessary to ensure a safe vehicle hold.