Bosch’s development team has completed testing its new hydraulic brake-by-wire system on public roads. Over six days, 3,300 kilometers have been covered through different climate zones to the Arctic Circle.
The new solution completely eliminates the mechanical connection between the brake pedal and the brake system. The driver’s brake request is transmitted to the brake-by-wire system as an electrical signal via redundant signal lines. With this approach, Bosch offers an efficient solution with two independent hydraulic brake actuators – a by-wire brake actuator and an ESP.
The hydraulic brake-by-wire system is planned to be launched on the market from autumn 2025. In addition, Bosch is also developing a purely electromechanical system. The company has already received orders from various vehicle manufacturers and expects that by 2030, more than 5.5 million vehicles worldwide will be equipped with its new brake-by-wire system.
The elimination of any mechanical connection means there is no longer a need to mount the brake system components on the firewall. Instead, the components can now be installed where optimal in terms of crash safety, NVH and manufacturing. This flexibility helps avoid the need for different variants for right-hand and left-hand drive markets.
By-wire technology also enables new pedal concepts with significantly shorter brake pedal travel to create space for new interior designs. Its slim design saves installation space and reduces the weight of the brake system. Since both the by-wire brake actuator and the ESP are assigned to different channels of the electrical system, they can each independently build up the required brake pressure on all four-wheel brakes in the event of a fault. This makes it suitable for automated vehicles.
The brake-by-wire system was developed at the Bosch development center in Abstatt near Heilbronn. The development team traveled from the southwest of Germany via Hamburg, Copenhagen and Stockholm, with a short detour to the Arctic Circle to the finish at the Bosch winter test center in Vaitoudden in Arjeplog, northern Sweden.
Bosch has obtained approval for public roadway use for the test vehicle in several countries, based on a safety concept. “Our hydraulic brake-by-wire system has worked perfectly on the journey. With our first long-distance test, we impressively demonstrated that we can bring a real brake-by-wire system safely and successfully from the test track to the road”, explained Hagen Kuckert, project manager for the by-wire brake actuator at Bosch in Abstatt.