Autonomous vehicles (AVs) represent one of the greatest challenges yet to system engineering. Not only are AVs complex systems in their own right, they are potentially part of a larger connected infrastructure of smart roads. Model-based approaches, including SysML modeling, represent a game-changing opportunity to meet that challenge. In this blog series, we shall look at one aspect of that challenge, mapping functional architecture to requirements, and how Syndeia, the MBSE platform from Intercax, can support that task. Figure 1 shows a SysML block definition diagram of an ADS (Automated Driving System) operations domain, which includes

  • One to many Vehicles of varying levels of autonomy
  • One to many Driver/Passengers, with the distinction becoming unclear as the autonomy level changes
  • The Operational Design Domain (ODD), the general environment in which the Vehicle is designed to operate. Variable factors include road type, weather and time of day. The ODD also includes the connected infrastructure (road signs, traffic signals, etc.) that communicate electronically with the Vehicles and each other.
  • Obstacles, the random factors in the local environment (e.g. pedestrians) that the Vehicle and/or Driver must recognize and respond to appropriately.
  • Operations Center, a central authority for communication and control

Preparing such a domain diagram, specifying the elements with which the system-of-interest, the Vehicle, must interact, is generally an early part of any Model-Based Systems Engineering (MBSE) effort. Note that this only concerns the vehicles’ operating environment. Additional modeling could include manufacturing, distribution, maintenance and other factors, depending on the purpose of the model. sysml-autonomous-vehicles-mbse

Figure 1 SysML Block Definition Diagram of ADS Operations Domain

The focus of this blog series, however, is not the overall design of the AV or the ADS domain, but a specific part of the development process, the modeling of requirements and functions.  This is an early stage task and particularly important for the software development. We will look at multiple parts of this task, including

  • Modeling of Requirements in a requirements management tool and/or a SysML model
  • Modeling of Functions in the SysML tool
  • Connection of Requirements to Functions and Project Management
  • Connection of Functions to Software Configuration and Project Management
  • Visualization and Traceability through the Total System Model

Figure 2 shows the architecture of our MBSE structure. Syndeia, the Model-Based Engineering platform from Intercax, is used to create, maintain and visualize the Total System Model (TSM). Our toolset for this example includes Jama, MagicDraw, GitHub, and JIRA, but other software tools, e.g. IBM Rational Rhapsody and DOORS NG, could be used in a similar fashion. tsm-syndeia

Figure 2 Total System Model architecture supported by Syndeia

In Part 2 of this series, we will look at options for connecting requirements in Jama to SysML and JIRA.  Part 3 will introduce functional architecture modeling with connection to requirements, project management and software configuration repositories. Visualization and search of the resulting connection network or graph is considered in Part 4.  The SysML model, in MagicDraw and IBM Rational Rhapsody, will be made available for download with Part 4. Related Posts:

Dirk Zwemer

Dr. Dirk Zwemer (dirk.zwemer@intercax.com) is President of Intercax LLC (Atlanta, GA), a supplier of MBE engineering software platforms like Syndeia and ParaMagic. He is an active teacher and consultant in the field and holds Level 4 Model Builder-Advanced certification as an OMG System Modeling Professional.