AUTOSAR proof-tests vehicle electrical design at every level

It’s no secret: the methodology known as “simulation” is a cornerstone of many engineering disciplines these days. Simulation is a tool that enables designers to meet the time, cost and complexity challenges common in today’s development projects, from passenger jets to paint sprayers… and, of course, automobiles. It is also a means to detect emerging design flaws or avoid them altogether.

Simulation is applied at diverse levels: systems, circuits, multi-body, or Finite Element (FEM) simulation. It works with software-based models that enable emerging designs to be verified independently of tangible hardware prototypes. Test vectors or parameters can be changed easily within a simulation model, and the same model provides easy access to internal variables that would be difficult or impossible to extract in hardware tests.

It all adds up to a natural fit for automotive design applications. Especially in the development of electronic control units (ECUs), model-based development practices are now widespread, and becoming more so.

Of course, what “works” can always be improved, and what is good can always be made better. Openness and standardization have the potential to take productivity to a new level, and industry thought leaders are responding. The emerging automotive design software standard known as AUTOSAR (Automotive Open System Architecture) began as the product of a standardization effort among European auto makers and their suppliers. Its objectives are to bring structure, clean interfaces and implicit methodologies to a process—in this case, the design of distributed systems within automobiles.

AUTOSAR is a set of standards encompassing interfaces and software module definitions. It establishes a structure for the embedded software within a vehicle’s complex network-based distributed system. AUTOSAR frees designers to focus on unique, innovative functions while insulating them from implementation details of integration.

In an AUTOSAR-compliant system, automotive functions ranging from door locks to engine controls are built up from one or more software components (SWCs) that can be executed on AUTOSAR-compliant ECUs. SWCs are the means to deliver differentiated features in an end product.

A continuum of verification scenarios

AUTOSAR places a host of new demands on simulation and verification processes as the design evolves. To reap the benefits of AUTOSAR standards, OEMs and suppliers must communicate accurately and interact efficiently.

The AUTOSAR flow includes the software component and behavior design, the software architecture design, the ECU and topology definition, and the function distribution. Figure 1 depicts the progression of these steps, with the chronology going essentially from left to right. Depending on agreements between OEMs and suppliers, diverse scenarios, work divisions, and packages for the individual participant affect the nature of the development process. Innate in the process is the series of consistency checks symbolized by the check marks in Figure 1. The simulation levels, too, progress from single-function SWCs to top-level architectural models as follows:

Figure 1: Consistency checks and simulations along the design flow