As Moore’s Law continues to perpetuate, so too does the complexity of vehicular electronics systems. While not necessarily matching the law (the number of transistors in an integrated circuit doubles approximately every two years), the increased complexity has produced well-recognized and growing problems.
With this in mind, automaker BMW, which perhaps incorporates the highest percentage of electronics in its vehicles, recently chose Dassault Systèmes V6 PLM (Product Lifecycle Management) solutions to develop the future electrical, electronics, and embedded software—the complete electrical/electronic (E/E) architecture—of its cars.
BMW’s Requirements
By using a full systems approach, BMW addresses wiring harness variations, electronic interfacing software, communication between systems, and more.
“They had a pretty good idea on how they wanted to fundamentally breakdown their architecture in the vehicle, how they wanted to represent software objects and electrical objects, and so on,” says Kevin Baughey, director of Brand and Market strategy for ENOVIA at Dassault Systèmes.
With the V6 PLM, Dassault could provide an out-of-the-box solution that met BMW’s view of how it wanted to design and decompose its vehicles.
According to Baughey, transforming BMW’s development activity into a true systems engineering approach requires major changes. “[It involves] looking at fundamentally architecting their platforms from the highest level down to the lowest level—doing the requirements, the features/functions partitioning to logical decomposition, and managing everything from the software objects that implement those functions to modeling the electronics pieces, as well as showing the network architecture,” he says.
Fully embracing the systems approach includes understanding and analyzing how the electronic control units (ECUs) in all systems communicate on the network. Obviously, the hardware is a part of linkage, too. “It’s in the scope of this project about electrical and electronic systems architecture,” explains Baughey.
In its “Architecture, Integration and Design for Automotive (AIDA) Project,” BMW will implement a seamless collaborative process to connect the various components and subsystems, as well as the engineering and management of the E/E process.
The existing V6 implementation, already in operation today, is the first step in a 10-year partnership between BMW and Dassault Systèmes. The joint effort focuses on building the best infrastructure and applications for BMW’s E/E domain.
V6 Capabilities
Addressing the needs of extended enterprise and complex engineering processes, Dassault Systèmes’ ENOVIA PLM solution is based on flexibility, open standards, scalability, and industry-specific product-development business processes. The latest V6 release, V6R2011x, includes 479 new functions and eight new solutions to support customer collaborative design processes using Dassault Systèmes’ CATIA, DELMIA, and SIMULIA brands.
The PLM approach also features an online platform, with the newest version providing seven new products and 359 cross-industry and industry-specific functions. This portion enables cloud-computing-based life-cycle and collaboration management.
Dassault Systèmes uses a process model called RFLP (Requirements/Functional/Logical/Physical), an enhanced model-based approach to applying the systems engineering methodology for virtual design and validation (Fig. 1). Based on the well-known V-cycle design process, RFLP allows concurrent engineering to coordinate the separate activities of distributed design teams.
Thanks to the coordinated creation, sharing, and managing, program managers can reduce cycle times (Fig. 2). Project tasks are accessed directly from CATIA or DELMIA V6; completed tasks become seamless drag-and-drop deliverables into a designer’s project space. This makes real-time, cross-discipline project management possible.
Geensoft Connectivity
Baughey credits Dassault’s relationship with, and subsequent acquisition of, Geensoft as another compelling factor in BMW’s selection of the V6 to meet systems integration and PLM requirements. Geensoft capabilities added the capacity to model and generate the entire vehicle-control software system in the V6, allowing a validation loop by connecting the physical equipment with the digital mockup.
The integration of Geensoft software into the V6 demonstrates the openness of the PLM solution. “BMW saw the value of the openness of our platform to be able to connect in other value-added processes and solutions to enhance this particular architecture,” says Baughey.
Geensoft’s AUTOSAR (Automotive Open System Architecture) capabilities were clearly recognized by BMW. “They [BMW] had an approach using AUTOSAR for architecting their software,” says Baughey. “Geensoft has very comprehensive tools for supporting AUTOSAR.” Geensoft’s capabilities include the automation of AUTOSAR and ISO 26262 development processes.
AUTOSAR, an open and standardized automotive software architecture, is the product of a joint venture among automobile manufacturers, suppliers, and tool developers. It was developed specifically to address the growing complexity of automotive software. BMW was one of the initial partners of AUTOSAR.
The further progression with AUTOSAR was a key part of BMW’s V6 decision. As a leader in implementing AUTOSAR’s capabilities, BMW is well-informed on its perspective, architecture, and how it wants to develop it. “It’s really finding a platform that supports that type of mentality, that type of thinking, that type of leading-edge architecture development,” says Baughey.
The V6 Link to AUTOSAR Capability
Geensoft’s AUTOSAR Builder tool is based on Artop (www.artop.org), an open AUTOSAR tool environment that’s available free of charge. With AUTOSAR Builder, users can import a Model-Based Design legacy description and generate AUTOSAR-compliant C code for direct embedding on target ECUs. The AUTOSAR Builder tool suite (Fig. 3) includes:
- AUTOSAR Authoring Tool (AAT) with an ECU extract (EEX) capability and a SWC Conformance Validator
- Generic ECU Configuration Editor (GCE) with a Configuration Code Generator
- Runtime Environment (RTE) Generator (RTEG), an automated generation tool for the AUTOSAR specification
- AUTOSAR Simulation (ASIM) that covers the VFB (virtual function bus) level (the sum of all communication mechanisms and essential interfaces to the basic software provided by AUTOSAR), the ECU level, and soon the Network level
- AUTOSAR Re-targeting Tool (ART) allows code migration of a Model-Based Design description from Simulink to AUTOSAR.
Software engineers will be able to take full advantage of AUTOSAR when linked into the V6 PLM. For example, it can be used to move a feature or function from one ECU to another ECU. Still, one key question must be answered: How does this impact the system? More specifically, beyond the logical implications, what specific functions and features are affected and what requirements drive those features and functions? These concerns can be remedied using V6 PLM, which preemptively corrects a problem before it’s observed in the vehicle.
Less Complexity, No Problem
BWM’s application of the V6 is aggressive in nature, but the V6 is scalable to different E/E system integrator’s needs. For example, it can be used to simplify the design process for a maker of midrange vehicles.
“Regardless of what type of vehicle you are developing or how sophisticated the systems are, the bottom line is we’ve reached a level of electrical/electronic sophistication in the vehicle that you need to capture and take advantage of these types of system approaches to be able to maintain your quality level and your time to market and your cost,” says Baughey. Many studies reveal what this can mean for a bottom-line benefit.
“If manufacturing issues dictate how a company architects its products, those criteria can be incorporated into the decision-making process,” says Baughey. “We use this type of logical process if it is this type of manufacturing scenario.”
The same framework can be used to address the thermal and mechanical problems if the focus is in a single system, such as powertrain. “The benefit is, once they solve that problem and they realize that E/E is their next problem, they don’t have to go to a different solution, a different provider, or anything; they just start using their building block to cover the E/E space,” says Baughey.
Figure 4 shows a powertrain logical diagram using standard Modelica systems modeling language, which is accessible in the V6.
Perhaps the plethora of powertrain options that the industry, and specifically BMW, plans to address compelled BMW to choose the V6 (or, at the least, is one more aspect). Certainly, the powertrain is a major component of the rising complexity facing all carmakers.
“You can start to see the benefits when you are doing hardware in the loop, software in the loop strategies as well, even for the testing of mechanical systems,” says Baughey. The V6 can tie the pieces together.
By bringing all of the complex pieces together, users can address solutions to problems that they don’t know they have—yet.
“The biggest problems can occur when one group doesn’t know what another group is doing, especially in a timely manner,” says Baughey. “Having them all work in the same environment, using the same types of methodologies for development, and having them follow the exact same approach, allows them to communicate and collaborate a lot more effectively.”
In fact, inter-project communication is an essential aspect of the V6 platform. System engineers can quickly find out who’s responsible for what subsystems and take the critical next step: Connect with these people and start to collaborate and ask questions. Rather than wait for the next design review, they can ping them in real time, says Baughey. The real-time collaboration between design teams is a major value proposition of the V6.
Managing from Engineering to Manufacturing
Leveraging, reusing functions, and avoiding duplication in engineering and manufacturing gets a final boost when integrating these processes with business practices. “By using a mainstream PLM solution, we are also able to leverage those common PLM business processes like change management, configuration, and so on,” says Baughey.
Merging the business processes with mainstream development avoids standalone, work-intensive processes to handle change management in a separate, isolated methodology.
“It’s in the same environment that you are leveraging your configuration information and you are configuring your product structure,” says Baughey. “You don’t have to duplicate that either manually or in some back office process. It’s all right there.”