Software has been allowing vehicle components to communicate and coordinate with each other for almost five decades since the first electronic control units (ECUs) were installed in cars in the 1970s. Today, software is pervasive throughout vehicles, enabling new functionality and coordinating E/E architectures having as many as 100 ECUs.
The vehicle of the future will feature high levels of networking and automation defined by software, but a “software-defined car” is much more than a ”smartphone on wheels,” believes ZF. The difference is the quality and quantity of hardware systems that need to be intelligently connected by a software platform to help move people comfortably and safely.
Getting in the middle
In a preview of its activities at CES 2021 last month, ZF discussed its much bolder approach to software development. One of the elements of its strategy is getting into the business of creating middleware, the “mediator” between a vehicle computer’s operating system and its software applications. Key functions of the middleware are the abstraction of computing hardware from software applications and the communication between these applications.
In future vehicle platforms, the electric and electronic architecture (E/E architecture) will change dramatically. ZF and other industry experts believe that vehicle functionality will move away from decentralized controllers towards a centralized system with only a few dedicated domain control units (DCUs), e.g. for automated driving functions.
All these software applications benefit from a smoothly integrated middleware platform managing system integration, hence ZF’s interest in that piece of the mobility-software puzzle.
“The new ZF middleware underpins ZF’s claim to be one of the world’s leading system suppliers for the software-defined car of the future,” said Dr. Dirk Walliser, Senior Vice President Research & Development, Innovation & Technology at ZF. “Our customers benefit from accelerated development processes and significantly reduced complexity when integrating hardware and software. Throughout the vehicle’s lifetime, functions can be updated or additionally offered on-demand.”
As a comprehensive software platform, ZF’s middleware offering will be available in series production vehicles from 2024. Its development is closely connected to the development of application software for mobility domains like automated driving, integrated safety, vehicle motion control, and electric mobility.
Domain or zone architectures
One of the key E/E architecture trends happening in parallel with the move toward the software-defined car is a reduction in the number of ECUs from the typical 80 to 100 units. Vehicle functions will be managed increasingly by domain and zone-oriented controllers—or super ECUs.
The higher-performance computers simplify the overall E/E system, making for easier software updates and allowing for more easily additional functionality on the vehicle system level. While functionality will be consolidated into higher-level units, the trend will result in more but smaller smart actuators with less distributed intelligence.
Where the consolidation will end is an open question. Uwe Class, Vice President Advanced System Development at ZF, says that most OEMs could end up with about six domain controllers in a car plus or minus one, so around five to seven. Most have already been defined and given as input from the OEMs. They include controllers for the body, infotainment, chassis, drivetrain, and safety/ADAS domains.
Consolidation is also occurring on lower-level ECUs, with certain functions being combined. For example, the separate ECUs for electric and conventional parking brakes have been brought together into one ECU.
Ultimately, many functions will be added but the total number of ECUs will be reduced.
“My guess would be that we really probably stay in the 60 to 80 area, but with a much higher [number] of functions introduced into the vehicle,” said Class.
System solutions for the software-defined car
A well-developed approach to middleware linking to operating systems minimizes the number of interfaces, guarantees fast communication with all parts of the system, and helps to significantly reduce the complexity of system integration for the OEM.
The same principle applies to the development of hardware components; the middleware simplifies their flexible integration into vehicles providing communication in “one universal language.” It “translates” and standardizes the communication between a vehicle’s different hardware and software layers.
An open hardware/software architecture enables an accelerated and improved development process between ZF, vehicle manufacturers, and other partners—from development to end of vehicle life. As a result, vehicle manufacturers and end customers benefit from innovative vehicle functions that can always be state-of-the-art.
Depending on the OEM’s software architecture, ZF offers a modular approach with its middleware from a full platform solution to single modules that can be integrated into the OEM’s software platform.
Global software center
Beyond middleware, ZF is preparing for new mobility challenges in software, functions, and smart systems by establishing a Global Software Center at the turn of 2021 that will be headed by Dr. Nico Hartmann, Vice President, Software Solutions & Global Software Center.
“Our Global Software Center will be responsible for developing software systems for future architectures on a group-wide level and making them available to the entire company,” said Walliser.
This will allow ZF to coordinate and standardize new trends, technologies, methods, procedures, tools, and functions to make the resulting software available to all ZF divisions on a common development platform.
“Our approach represents a fresh and different look at software; we do not aim to ‘centralize’ software development,” said Hartmann. “The reason is simple: where experienced teams have long been developing interlinked hardware and software at the component level, we will not reduce competencies. Instead, we provide complimentary support and run joint software integration projects to create ideal overall conditions. This allows the expert teams to focus on their work but still have access to the latest resources via the Global Software Center. On the other hand, pure software products – such as our middleware – can be created centrally in the Global Software Center and then made available to everyone for further use.”
In the medium term, this will lead to uniform structures and a uniform development environment throughout the ZF Group. Software will be developed or adapted much faster to meet the needs of future software-defined vehicles through integrated cooperation with customers and partners.
Coordinating for systems solutions
A lot of the motivation behind the creation of the software group at ZF is meant to address the exponential increase in functionality and better anticipate market needs coming in within the next five to 10 years, according to Class. He is working closely with Hartmann because “it is important to look at challenges from a system/vehicle perspective because the big opportunities are in really integrating the complete portfolio we have on vehicle level.”
During the pre-CES 2021 presentation, execs said the company could provide the full software stack, but they expect most traditional customers will probably mix and match ZF’s offerings with others’. The full offering might more likely be requested from customers in the new automotive area that are relying completely on one system supplier.”
ZF would normally be a system integrator, “but you have to be flexible and scalable, especially with the middleware, also to include either OEM-specific modules as well as third-party modules,” said Class.
Class and other ZF execs stressed that they do not have plans to supply the underlying operating system, but would rely on partners or vendors for that.
With a more comprehensive approach, ZF is hoping to develop more solutions like its scalable ProAI supercomputing platform, developed with Nvidia and other comprehensive systems for traditional and new vehicle makers comprising software, computing, and sensors—as well as connected actuators.
