The SDV concept

The term “software-defined vehicle” implies that most of the functionalities available in a vehicle are implemented by software applications that run on dedicated microprocessors, equipped with an adequate availability of memory space and with various sensors.

This concept clashes with the architecture of traditional vehicles, characterized by a plethora of ECUs distributed throughout the vehicle. That architecture had not been designed to support a software-based approach, bearing in mind that current ECUs are heterogeneous and therefore difficult to update during the product life cycle.

Conversely, next-generation vehicles will require an architecture in which processing will be centralized rather than distributed. This centralized architecture will require a high level of compute power — high enough to support not only the workload required by the initial vehicle configuration but also any updates and features introduced later.

For convenience, software updates will need to be done wirelessly, that is, over the air (OTA). OTA software and firmware updates will involve the transfer of code and data to a central ECU, the brain or central processing unit of the system, which will also provide predictive diagnosis. Then there will be other ECUs, each one used to control specific parts of the vehicle.

Most current production vehicles have many ECUs with predetermined functions, often designed by different suppliers. This architecture is not very flexible and is complex to update. The next step is the transition to a domain-based architecture, in which multiple ECUs are aggregated to implement a single car-specific domain functionality. This requires the availability of powerful microprocessor-based heterogeneous computing systems.

Examples of domains available on some vehicles currently in production are the infotainment system, the ADAS and AD systems, the digital dashboard, the chassis, and the body. The domain-based architecture reduces the complexity of electrical connections by concentrating software and firmware applications at specific points in the vehicle.

The subsequent evolution leads to the zonal architecture, in which small and rugged servers will replace the domain controllers. The subdivision of the ECUs will no longer be by functionality, as in the traditional architecture, but by zone.