Swedish braking technology company, Haldex, is set to lead a development contract of its ‘Scalable Brake System’ by the end of this year.
With the advent of autonomous driving, vehicle system architecture is about to be re-written. Currently, the vehicle operator manages the integration of propulsion, braking and steering. To reach full autonomy, Haldex is adamant that the subsystems need to be able to accurately control and communicate for the system to be able to analyse the data and make correct decisions.
System integration, according to Haldex, is the key for autonomous driving to become successful.
System integration requires open communication, according to Andreas Jähnke, SVP R&D at Haldex.
“Today, only selected data of the wheel end performance is shared in the system, even though most of a vehicle’s behavior is determined by the wheel end performance,” he says.
“Haldex wants to change that. We fully believe in open systems where the OEM gets full access to the data from the wheel end.
“By developing the brake systems jointly with OEMs, we re-shape the principles for the vehicle system architecture. We know that new and old technology will live side by side for many years. By separating the software from the hardware, you can use the same software functionality to execute different mechanical tasks, hence you can have a vehicle structure which can run both pneumatic and electromechanical brakes.
“We also want to move away from the principle of the [Electronic Braking System – EBS] being a black box that is the central hub for the intelligence in the brake system. To build a scalable system with maximum control and predictability, more technology and intelligence should be placed at the wheel end.”
One of the new products from Haldex that is based on this concept is the Fast Acting Brake Valve (FABV) – it is a high-performance valve, placed at the wheel end together with an Electronic Control Unit (ECU), that is reported to act ten times faster than conventional modular based systems.
The result, according to Haldex, is 15 per cent less stopping distance, but also the ability to ensure that the vehicle runs in the path it is intended to, with a stability and predictability not seen with other technology that is available today.
“When replacing the driver, you need redundancy on different levels,” Jähnke says. “We are not unique to provide steering by braking, but our wheel end accuracy with the FABV is unique.”
System integration is not limited to the truck and furthermore the performance of the combination of truck and trailer will be directly affected by how the subsystems are working as part of the full vehicle system which includes trucks and trailers, according to Jähnke. “At Haldex we are developing the Scalable Brake System to make it feasible for our partners to optimise the safety and performance of the buses, trucks, trailers and ‘movers’ of tomorrow.”
Another Haldex product in development that also provides a 15 per cent improvement in commercial vehicle stopping distance, compared to air disc brakes, is the Electromechanical Disc Brake EMB. It’s currently being tested on electric buses with positive results. The benefit of the electromechanical brake is not only its improved performance compared to today’s air disc brakes, but the energy gains from replacing the pneumatic brake system with a full electrical brake system. Today’s electrical heavy vehicles still have a pneumatic brake system installed. It needs about 2.5 times more energy than an electrical brake system.