ZF brake-by-wire deletes yet another fluid from EV maintenance list

As we charge ever-forward into the future of electric vehicles, trends, like the software-defined-vehicle and by-wire controls have become increasingly popular, since they allow carmakers to adjust their vehicles' performance and even add features via a simple software update.

German automotive tech firm, ZF Friedrichshafen AG, imagines braking to be the next electrically-controlled frontier, thanks to brake-by-wire. The basic premise of the new tech is that it replaces the system of hydraulic hoses, cylinders, pistons, and booster pumps with a simple electric motor and a few circuit boards.

The simplification of the system means that EV service checks will not involve one less fluid, with brake pad maintenance being the only regular maintenance item involved in the system.

ZF claims that this new braking tech — apart from eliminating a complex series of components, thereby simplifying service checks and vehicle assembly — can help improve electric vehicle efficiency greatly by reducing drag between the brake discs and the pads. This reduction in drag also means less brake dust is generated.

Aside from mentioning a controller and motors controlling the actuation of the brake pads, ZF doesn't explain in its press release how exactly the technology works. That said, the company does say the system can make use of Integrated Braking Control, which enables features like ESC and ABS, meaning it's a feature-complete replacement for hydraulic systems.

What's more, at speeds to 100 km/h (62 mph), ZF's system touts shorter automatic emergency braking distances — up to nine metres (29.5 feet) less than conventional systems. ZF also claims the system's efficiency and cooperation between brake-by-wire and EV regenerative braking can increase electric vehicle range by up to 17% compared to conventional systems.

For those concerned about safety and redundancy, ZF has taken a page out of the aviation industry's books by duplicating almost everything, including motor power supply, data transmission, and processing. ZF also claims to be able to replicate the feedback of hydraulic braking.

It will be interesting to see these sorts of brake-by-wire systems installed in modern EVs and how the efficiency will compare with the current electrically-powered brake boosters found in most EVs. It's worth noting that Brembo released a similar brake-by-wire system in 2019, but that system still makes use of hydraulic fluid to actuate the brake pads, with electronics only connecting the pedal and the control unit.

ZF has not yet announced any partners for production vehicles, but it has been testing the system on a BYD Han EV