SDVs require new zonal architecture ecosystems

During The Autonomous 2023, industry stakeholders concluded that fostering a culture of safety would help finally take autonomous vehicles (AVs) beyond the hype. At the 2024 event, held on 23-24 September, discussion homed in on the technological concept upon which that culture will flourish: software-defined vehicles (SDVs).

Dirk Linzmeier, Chief Executive at event initiator TTTech Auto, called the shift to SDVs and AVs the “biggest transformation” in automotive history. The transition, he believes, is inevitable, far-reaching, and happening fast. By 2028, Goldman Sachs estimates that 28% of all vehicles will incorporate SAE Level 2+/2++ advanced driver assistance systems (ADAS). Two years later, 90% of new cars could be software-defined in some way.

Investment will be substantial: as companies compete to grab a slice of the pie, Linzmeier anticipates the SDV market initially splintering into East and West, exacerbated by Western OEMs losing opportunities in China to domestic companies. Despite these divergences, he emphasised that “safety is neither competition nor compromise; it’s about getting it right.” But how can players in the SDV value chain come together to deliver on that creed?

From domain to zonal

For vehicle autonomy to satisfy investors and customers, systems must be safer than human drivers. The test metrics to validate progress will need to be intense, and the miles covered by systems in development today represent a mere fraction of what will ultimately be required. “Successfully implementing an SDV means no corner cutting,” stated Ricky Hudi, Chairman of The Autonomous. “But it’s also more than just software. An SDV is not an end unto itself.” Instead, it should aim to combine a constantly up-to-date portfolio of desirable functions cohesively.

However, automakers must harmonise several complex tech vectors—including sensor hardware, vehicle connectivity, and proprietary machine learning algorithms—with safety and scalability considerations. This makes the evolution of vehicle architectures essential. A domain-oriented approach, where potentially hundreds of electronic control units (ECUs) govern specific vehicle functions, is common. As SDVs become more complex, this could result in convoluted wiring and undesirable performance. As such, the idea of simplifying proximate functions into more reliable and easily scalable units controlled by a central computer—a zonal architecture—is gaining popularity.

According to Lars Reger, Chief Technology Officer at NXP Semiconductors, the problem is that some OEMs are not managing the transition comfortably. “They’re under such pressure that they’ve become stuck in the transition and created ‘zomain’ architectures.” These are overly complex and dissonant collections of legacy hardware and software assembled without a clear, holistic vision. It is from this, he added, that many automakers’ well-publicised struggles to incorporate software originate. “Frankensteining will not get us where we want to be.”

Decoupling hardware and software

In Reger’s view, reducing the complexity of SDV architectures should be the industry’s primary goal. With companies in different global markets inevitably working towards different targets in step with varied legislation, this is easier said than done. “The answer is a simple one academically but tough technically.” He put forward NXP’s S32 CoreRide platform as an example solution that can address the industry’s challenges: a layered “building block” approach that entails close collaboration throughout the value chain.

First, semiconductor manufacturers provide chips with the drivers, processing, networking, and power management capabilities necessary for advanced SDV functions. Next, software providers contribute certified middleware and an operating system (OS) for pre-integration with this hardware. Finally, OEMs and Tier 1s can add their vehicle app functionality on top. The result, Reger claimed, is a coherent and streamlined architecture built to an automaker’s exact specification.

Crucially, this methodology breaks SDV architectures down into more manageable chunks. There was consensus at The Autonomous that the development of hardware and software must be decoupled from each other. Prashant Gulati, Chief Executive of SDVerse, recalled Stellantis’ Carlos Tavares dubbing industry conditions ‘Darwinian’. In this milieu, allocating resources effectively will be key, and automakers must embrace consolidation rather than multiplicity. “The promise of SDVs—a multi-trillion-dollar opportunity—can only be unlocked by moving over to zonal architectures,” stated Gulati.

However, this isn’t to say that opportunities for competition and growth disappear. SDVerse is creating a B2B marketplace that links OEMs with software developers to boost the discovery and commercialisation of compatible solutions. At the time of writing, Renault and General Motors are confirmed partners. “We need to leverage ecosystems and reconsider how hardware and software can evolve together,” added Ethan Sorrelgreen, Global Head of Product at Woven by Toyota, software subsidiary for the automaker’s vehicle OS. “If we can develop a braking system application that applies to lots of models because they have the same hardware, the software becomes safer, and the development cost can be amortised more easily.”

Software is a must

Although the benefits of the SDV transformation seem clear, there is still a fundamental cultural challenge for automakers: “Software is never done,” commented Michael Fait, Head of SDVs, Europe, at Thoughtworks. “It used to be ‘get it right the first time’, but now it’s almost the opposite.” Application development needs to be far more fluid to account for the continuous updateability from which SDVs will derive their value.

[Software] isn’t just an opportunity or a must; it’s a matter of survival

At the same time, Sorrelgreen added that scalability must always be front of mind. “Bringing a Toyota-like production system to software will be critical. Standardisation reduces costs, improves quality, and increases safety. We can use ‘tried and true’ manufacturing precedents to get us there.” While the cultural transformation required won’t happen overnight, it is nonetheless essential for realising the full safety potential of a software-defined industry.

In the US, there are currently 1.26 road fatalities per 100 million miles driven, according to the National Highway Traffic Safety Administration. Stefan Poledna, Chief Technology Officer at TTTech Auto, proposed that software has a much larger role to play in enabling automated driving functions to exceed that standard. “A single system-on-a-chip system is not up to that level. For crucial features, we need to provision diversity and redundancy throughout the architecture.” He told Automotive World that “those who master integration will be the winners, and that means a platform approach and system architecture capabilities.”

Regarding the overall value of software, Gulati declared: “It isn’t just an opportunity or a must; it’s a matter of survival.” Indeed, the global auto software market’s growth is impossible to ignore— McKinsey & Co forecasts it will reach US$84bn in 2030, more than double its 2020 value. However, Nikolai Setzer, Chief Executive of Continental, concluded by emphasising that SDVs can only flourish if everyone treats the challenges as collaborative instead of competitive. “We all need to accept that there are different hierarchical levels. Creating an open and transparent ecosystem is our greatest challenge, but it’s also our greatest opportunity.”