It has been a long time coming but the mass adoption of alternative powered vehicles is really starting to gain momentum. According to a recent Strategy Analytics report, by 2025 around a third of all cars produced are expected to be electrified. With further rapid growth, it could mean that the majority of passenger vehicles are electrified as soon as 2030. There a several variables behind this prediction, one of these being legislation, where we have seen countries, including the UK, China and Norway, announcing additional legislation to make it harder, if not impossible, to sell new vehicles without electrification. However, despite this push towards electric vehicles, it’s important to remember that this does not mean the end of the internal combustion engine (ICE) just yet. Many of the electrified vehicles will still have some form of conventional engine power.
It’s important to fully understand the requirements of these different types of engines, whether it’s a conventional internal combustion engine, hybrid or fully electric powertrain. So, how is Arm powering these different types of vehicles today and how will we continue to power them in the future?
Recently, silicon manufacturers have announced devices incorporating Arm’s Cortex-R52 which meet a range of automotive application needs including that of advanced powertrain systems. STMicroelectronics have announced the Stellar family of products to address a broad range of automotive applications suitable for use in classic automotive applications, domain controllers and ADAS. NXP have announced their S32S family of processors for green vehicle control and autonomous driving. These products can deliver the real-time control needed for many applications coupled with functional safety features to support ASIL requirements. They also deliver more performance than ever before, solving the challenging requirements of ICE powertrain systems together with the needs of domain controllers, ADAS and autonomous systems. They offer flexible platforms from which to build a common architecture on and the availability of these types of products are set to enable the evolving automotive market and its rapid growth.
Vehicles must produce fewer tailpipe emissions and this continuing requirement is driving cleaner, more efficient engines and demanding better control of combustion and management of their exhausts. Even with trends such as engine downsizing, there remain challenges to control an efficient ICE engine. You need high-performance processing with real-time responsiveness and the ability to manage multi-core systems optimized for execution with non-volatile memory. All of this needs to be combined in a system with a mix of software including control tasks, Digital Signal Processing (DSP) and mixed levels of functional safety. The Arm Cortex-R52 provides the increased speed, performance and functional safety support necessary to meet these requirements.
With a hybrid vehicle you have the added complication of duplication. As well as having the internal combustion engine, you also have an electrified system and often a complex gearbox to integrate both drives. The challenge comes with the mechanics of building a hybrid vehicle, where the system may be distributed throughout the car. For example, the ICE control (normally located in the front of the vehicle), a separate electrified traction motor control system and a remote traction battery with charging port, will often each have their respective ECUs.
So how do these two systems operate efficiently and effectively together? As vehicle architectures become more integrated, it is possible to combine functions on fewer ECUs with flexible processors controlling multiple traction drive types and energy storage, whilst enabling simplified integration and maintaining separation through virtualization. This consolidation helps create a more efficient solution where there are common requirements shared between different functions. Not only is real-time responsiveness critical in these systems, but high levels of functional safety are needed, for example, ensuring neither powerplant causes unintended acceleration. A scalable platform improves flexibility, by enabling different levels of electrification and ICE control as engines are downsized in favour of higher power efficient electric drives, or battery management is enhanced as capacity and efficiency grows. The Cortex-R52 allows systems to address this flexibility as its real-time virtualization functionality helps to maintain separation between tasks. Whether it’s motor control, battery management or diagnostics tasks, these can be isolated helping to assure safe operation. Critically, Cortex-R52 provides a solution which is both scalable and flexible. It supports a hypervisor able to work in real time-systems which allows applications to be integrated together without the need for their complex customization and simplifying timing evaluation. It also prevents the need to specifically tag individual tasks to virtual machines and eliminates the limitation of a handful of virtual machines per core.
The workloads for powertrain control systems have also changed. ICE systems have increasingly been moving away from pure control loops and referencing look-up tables to algorithmic based control. Electric driver and battery management also demand DSP capabilities. The availability of DSP extensions in processors enables efficient execution of these types of workloads and complex motor control routines, which might otherwise require mixed controllers for both DSP and control elements of the application. These can now be combined into a single architecture simplifying the development process for user’s and enabling efficient distribution of tasks. Arm Architectures support these types of extensions. For example, the recent announcement of Arm's Helium Architecture for Cortex-M processors brings new vector processing capability to a new class of core. The Cortex-R52 implements enhanced DSP support and SIMD with the inclusion of the NEON extension.
Vehicle electrification and vehicle autonomy are two unrelated automotive trends, however there are synergies between these developments. The progress of higher levels of autonomy can be simplified by implementing autonomous systems into electric vehicles. Generally speaking, electric only powered vehicles are inherently simpler than an ICE system. For example, there are no complex gearboxes to control or exhaust aftertreatment to manage. An electrically actuated vehicle is simpler to control and can integrate better to the efficient planning of autonomous driving vehicles. This simplicity also provides benefits in lower maintenance and improved reliability.
Some vehicles are being developed with entirely new EE architecture either in response to the demands of automation or as ground up platforms for electric vehicles. This clean sheet approach to the architecture enables higher levels of integration than before. Instead of having multiple, discrete solutions, the encapsulation of the entire electrified drive can be combined into a single controller. In new architectures, there is the appearance of domain controllers. These are able to integrate a range of functions together. These may be the combination of different functions which are located in the same physical part of the vehicle, or previously separate parts of one system creating a single controller. As well as creating more efficient systems with fewer ECUs, domain controllers can provide higher level functions and enable a broader view of the wider vehicle demands, sharing information across different systems both within and beyond the car. In propulsion systems these can be used to more efficiently manage the motion helping improve efficiency and extending range. The Cortex-R processors profile with its multi-core capabilities, performance levels and determinism are ideal candidates to power many of these domain controller ECUs.
More established vehicle EE architectures tend to have distributed controllers, although even in a highly centralized system the need for local edge control and sensing nodes will persist. These typically perform a specific task such as inverter or generator, DCDC converter, in-car charger, or battery management. Their specific functionality means that the ECU is optimized to the requirements of that single function. Developers could use a Cortex-M7 with its scalar DSP extensions for the motor drive, or if a higher efficiency processor is needed, the Arm Cortex-M33 can be used for inverter and generator controls within simpler systems. In the case of Battery Management Systems, multiple Cortex-M processors such as a Cortex M0+, may be distributed within the cell monitors and connect with a centralized battery controller powered by a Cortex-M33 managing the overall battery condition.
In the coming years, we will definitely see more electrified vehicles on the road. As fully electric and hybrid powered vehicles start to dominate new car sales, the need for flexible, high-performance processing with multi-core, real-time and DSP capabilities will be critical to the successful mass market deployment. The emergence of new vehicle architecture with domain controllers will provide new ways of improving vehicle efficiency and will create controllers combining a range of different functions. In order to meet the demand for these new systems, our partners are creating solutions which are flexible, performant and able to scale the range of automotive needs for the vehicles of the future.
For more information on Arm’s automotive solutions, please visit our Automotive solutions page. If you would like to speak to our Automotive powertrain expert, please click on the below link.
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