Brembo wants brake-by-wire to feel less alien
Car makers are striding toward the full digital operation of brake, clutch, throttle, and shifter control systems. Soon, mechanical levers, links, and hydraulic piping will be replaced by software and wires linking the driver to all of their vehicle’s powertrain and braking equipment.
Italian brake specialist Brembo recently announced a new by-wire system called Sensify, a combination of the words sense and simplify based on a forward-looking approach: to integrate human perceptions more efficiently with vehicle design. While Brembo won’t say exactly which brands will use Sensify, it promises this system will reach production in less than two years. (The fact that Brembo demonstrated its technology on Tesla Model S sedans suggests that Elon Musk is first in line for public introduction.)
Founded just over 60 years ago as a repair parts producer, Brembo has expanded its reach into 15 countries and three continents to specialize in state-of-the-art braking systems for car, motorcycle, and motorsports use. Brembo also manufactures clutch systems and cast-magnesium wheels for racing bikes.
Brake-by-wire is not a new technology. It initially gained popularity in the late 1990s among OEMs developing electric and hybrid vehicles that rely on regenerative braking, such as the GM EV1 and Toyota Prius. In place of a conventional hydraulic braking system (in which the driver’s force on the brake pedal has a mechanical link to brake actuation), a brake-by-wire system functions with sensors and computers to calculate braking force, with electric motors that apply the braking force to the hydraulic system.
Given the lack of physical connection to the driver, tuning brake pedal feel and response to seem natural can be challenging.
The C8 Chevy Corvette is so equipped and Formula 1 racers have used such an approach to decelerate their rear wheels since 2014. Other models that have offered brake-by-wire include the Toyota Prius, Lexus RX400h, Mercedes-Benz E-Class and CLS-Class, and the Alfa Romeo Giulia. A competing system offered by Continental Automotive called MK C1 is specifically aimed at enabling full autonomous driving. This design combines the brake master cylinder, power booster, ABS system, and electronic stability control into one compact package.
Under development for a decade, Brembo’s Sensify offers the flexibility to suit needs ranging from sub-compact city cars to large commercial vehicles as well as top-flight racing applications. Every arrangement has a brake pedal “simulator” to accept driver commands while providing intelligently programmed feel and feedback. Wires dispatch signals from the pedal to two brake control units, one per axle. Then a choice exists: Each brake control unit can send either an electric signal to calipers equipped with an integral electro-mechanical actuator (essentially an electric motor) to squeeze the brake pads into contact with their rotor or hydraulic fluid under pressure to activate a conventional brake caliper. In other words, the vehicle maker can choose between full by-wire operation, thereby eliminating brake fluid entirely, or a mix of hydraulic operation of the front brakes with electric actuation at the rear.
Brembo claims multiple benefits, including faster ABS and traction control response, shorter stopping distances, more programmable driver feedback, reduced maintenance, and elimination of friction caused by unnecessary pad-to-rotor contact. While Brembo doesn’t claim that Sensify is less expensive to produce than today’s brake systems, the possibility of lower cost to the vehicle manufacturer definitely exists.
Francesco Mosti, a Brembo North America engineering manager, adds, “Providing a separate actuator at each wheel enables better control at all four corners. That results in smoother, more linear response and safer braking over wide-ranging road conditions.”
By-wire technology isn’t going anywhere. But if faster, more efficient, and more reliable braking is the result, and driver feedback can be carefully tuned for maximum confidence, we’re excited to try out Sensify when Brembo’s first examples hit streets.