Daimler Trucks North America (DTNA) is developing a scalable autonomous truck platform suitable for SAE Level 4 autonomous driving, including all of the redundancy systems needed to achieve safe and reliable operations.
The four key areas with a redundant architecture are the braking system, the steering system, the low voltage power net and the network communications. In case any of the primary systems encounter a fault, the vehicle will be able to monitor, assess and deploy its backup systems to control the truck safely.
Daimler Trucks’ L4 truck platform is based on Freightliner’s Cascadia model and the redundant chassis is being developed for Waymo Via based on its specifications. Daimler says that a first version of the truck has already been delivered for integration of the Waymo Driver, the autonomous driving system.
Dr Peter Vaughan Schmidt, head of the Autonomous Technology Group at Daimler Trucks, commented, “Every smart autonomous driving system needs a strong foundation: our Level 4 vehicle platform based on the Freightliner Cascadia is ideal for integration of autonomous software, hardware and compute. It can significantly contribute to enhancing safety in traffic thanks to its redundancy of systems and a multitude of sensors. It brings us much closer to our vision of accident-free driving.”
More than 1,500 new or unique requirements were identified by Waymo Via. The engineering team at Daimler Trucks North America is developing and implementing these requirements during the vehicle development process. For example, while current pneumatic braking systems have fail operational attributes, Daimler Trucks’ Level 4 vehicles have an additional layer of electronic redundancy, using two electronic control units (ECU) – a primary and a secondary system. Together, they ensure full brake performance, to safely execute a minimal risk maneuver in case one system is not operating properly.
The same logic applies to the steering system that has been enhanced by having two servo motors. In case of an electronic or hydraulic failure, the backup servo motor also receives the requested steering angle from the autonomous driving system and can react accordingly.
Daimler notes that constant communication between these key systems ensures that there is no loss of critical information flow among the controllers. It has also included a secondary communication network to key devices, which is also protected by cybersecurity requirements.
In combination with third party autonomous driving software, Daimler claims the redundant chassis offers customers full SAE Level 4 autonomous driving capabilities. As part of Daimler Trucks’ dual track strategy, the truck manufacturer is working together with two strong autonomous technology partners, Waymo Via and Torc Robotics, offering multiple routes to commercialization. Daimler adds that it has the capability to tailor and scale the Level 4 truck chassis to the autonomous driving specifications of both technology partners.