The Software-defined vehicle is coming closer to reality

Jutta Schneider from Mercedes-Benz explained how automated driving in permanent online mode and the dovetailing of vehicle and cloud will determine the fundamental architecture of future software-defined vehicles (SDVs). The anchoring of these functions in the vehicle software is organized by the Mercedes operating system MB.OS. When designing and implementing this software, it was crucial for Mercedes engineers to keep the user interface itself in hand - because it determines the user experience and thus the brand identity. For the same reason, it is important for the company to have access to and control over all the data it generates - a viewpoint shared by a majority in the German auto industry. More about this below.

MB.OS is divided into four domains: “Infotainment”, “Automated Driving”, "Body & Comfort," and "Driving & Charging." These domains are held together by a cross-functional layer in both software and hardware. The functional requirements for the software are reflected in the performance specifications for the high-performance on-board computers (HPC) and sensor systems. At the heart of these systems are the driver assistance functions up to and including automated driving. These domains, including their connections to the backend and the cloud, are implemented in both hardware and software, Schneider emphasized.

With regard to the E/E architecture - i.e. the distribution of computing power across the vehicle - Mercedes has opted for a zonal approach. This allows the complexity of software and hardware to be significantly reduced; the inclusion of the cross-functional layer ("horizontal functions") also simplifies the development and integration processes.

Against the backdrop of the current competitive situation, it is of course not only a question of what the blueprints for future vehicle electronics look like on paper, but also how they are implemented in products. Here, Mercedes has recognized that there is no time to lose. "We see an awful lot of challenges," Schneider said. "But we have to act much faster and more flexibly."

Audi also presented the latest generation of its electronics and software. Ulrich Herfeld, responsible for overall vehicle development, showed in his presentation where the Ingolstadt company is headed. He did this using the example of the brand-new Q6 e-tron electric SUV, which is currently in the starting blocks for market launch. For it and future successor models, Audi has designed a new "end-to-end electric" architecture and also immediately given it the snappy acronym e³ architecture. Five high-performance zone computers provide more than 600 new functions. These computers are dimensioned in such a way that they can also take on additional tasks in the future. "The hardware deployed will be sufficient for many years," Herfeld explained. "We have numerous new features in the pipeline."

At Audi, one HPC is responsible for each of the powertrain, driver assistance systems, infotainment and body and comfort functions; the fifth computer manages common basic functions as well as connectivity and cybersecurity. Owners of the vehicle will be able to expand the software's range of functions by means of apps that Audi provides for download in its own store. The Audi developers have placed great emphasis on the software's update capability - Herfeld promises that an update of the vehicle software can be downloaded and re-flashed within 40 minutes.

In the presentation by Christoph Grote, head of electronics and software development at BMW, the software-defined car with continuous online data connection was also the starting point of the considerations. According to his conception, the SDV is able to break the shortcomings of today's "hardware-limited" vehicles. This becomes particularly clear in the factor of updateability and expandability – not only with in-house software, but also via third-party apps, especially in the areas of infotainment and digital content.

To achieve all this, it is necessary to introduce a professional tooling system and development processes. For further development as well as for the ability to retrofit, Grote believes it is imperative to establish industry-wide standards. In this respect, the BMW mastermind sees a role model in the telecommunications industry, which already lives by these standards. Grote cited numerous initiatives and approaches in the automotive industry for establishing a corresponding standards-based ecosystem - examples include Eclipse, Covesa and the SOAEE project. "I am a fan of ecosystems," Grote confessed.

Not all software needs to be developed in-house, according to Grote. "A fully equipped 7 Series car is not far from 500 million lines of code," Christoph Grote reports from his practice. In view of such software scopes, a complete in-house development of the software would not be realistic at all. Grote says that it's possible to buy in everywhere where the vehicle user doesn't see anything - in other words, everywhere beyond user interaction and brand identity. And when you consider that, according to Grote, "80% of the work in software is below the application level," then it becomes clear that there is immense potential for buying in software.

These signals have obviously been understood at the Google subsidiary Geo Automotive. As Geo Automotive General Manager Jørgen Behrens explained, Google wants to give vehicle manufacturers the opportunity to use its numerous APIs as well as map and cloud services without pushing themselves to the fore. Platforms and products such as Android Automotive OS, Google Automotive Services or Google Maps Platforms could be discreetly integrated into the deeper functionalities of navigation or driver assistance systems without being visible to the outside world. In addition, Google also has no ambitions to implement its well-known ad-driven business model when used in cars, he said. "And we have no plans to do that," Behrens clarified later in a panel discussion.

Google's offerings for cars now range from voice controls and text-to-speech functions to navigation maps and specific geographic information for driver assistance systems. For example, these can ensure that the vehicle brakes automatically before a road bend. Via Google Cloud Conversational, vehicle OEMs can even bring Google's AI into the car. The company seems to be quite successful with this strategy: Behrens listed a whole slew of customers - from Audi to BMW and Mercedes to Volvo and Tesla.

Stephan Stass from Bosch highlighted a special aspect of the software-defined vehicle (SDV): In his presentation, he drew the connecting line between the electronic control of brakes, steering and similar units (X-by-Wire) to the software-defined vehicle. To be sure, this technology has already been introduced in part. However, Stass sees a paradigm shift coming with the move to the SDV; the focus on software in vehicle development will give X-by-Wire techniques an unprecedented boost, he said. "These trigger points are being reached right now," Stass said.

"We can save up to 70 mm of space with brake-by-wire," Stephan Stass points out, and a combination of steer and brake-by-wire could achieve a "15% shorter braking distance," which he quantifies as over 2 m at 80 km/h in a split-µ situation.

According to the Bosch expert, X-by-Wire will enable numerous functions in the vehicle, such as novel elements of user interaction and more design freedom in general. More importantly, X-by-Wire makes previously conventionally designed assemblies such as steering and brakes accessible for continuous software updates and thus for functional enhancements even after the sale of the vehicle.

He addresses a particularly important aspect around x-by-wire at the very end: "The TCO equation is solved; VMM is a pure software product." With TCO, he abbreviated the common term Total Cost of Ownership, while with VMM for Vehicle Motion Management, he introduced an abbreviation that was new to many in attendance.

In the medium term, Stass sees x-by-wire components moving to the vehicle's central or zone computers. This development will shape a new era of mobility, Stass promised. Bosch has already begun to reorganize its development processes accordingly, he said.