A Model-Based Design Approach for Wireless Sensor-Actuator Networks

In this paper, we propose a model-based design approach for developing wireless sensor-actuator networks that can map multiple sets of application-level interactions onto a single networking substrate while still enforcing individual requirements. We use a top-down design approach where the functional requirements for each application are graphically modeled using a tool called SysWeaver. Sensor networking applications add unique challenges for model-based design frameworks because the system deployment view is tightly coupled to an installation-specific network topology and link characteristics. Wireless devices can also be mobile and hence may not easily map to standard deployment views. We introduce a SysWeaver plugin called SenseWeaver that is able to capture live toplogy data from an instrumentation deployment and feed the topology and link characteristic information to the system model. A developer can then use SenseWeaver specify the functional requirements of multiple applications, analyze communication and task scheduling requirements based on actual topology data, and automatically generate customized code for each sensor network node.</p

Analysis and Verification Challenges for Cyber-Physical Transportation Systems

Substantial technological and engineering advances in various disciplines make it possible more than ever before to provide autonomous control choices for cars, trains, and aircraft. Correct automatic control can improve overall safety tremendously. Yet, ensuring a safe operation of those control assistants under all circumstances requires analysis techniques that are prepared for the rising complexity resulting from combinations of several computerized safety measures. We identify cases where cyber-physical transportation systems pose particularly demanding challenges for future research in formal analysis techniques

Bounding Memory Interference Delay in COTS-based Multi-Core Systems

<p>In commercial-off-the-shelf (COTS) multi-core systems, a task running on one core can be delayed by other tasks running simultaneously on other cores due to interference in the shared DRAM mainmemory. Such memory interference delay can be large and highly variable, thereby posing a significant challenge for the design of predictable real-time systems. In this paper, we present techniques to provide a tight upper bound on the worst-case memory interference in a COTS-based multi-coresystem. We explicitly model the major resources in the DRAM system, including banks, buses and thememory controller. By considering their timing characteristics, we analyze the worst-case memoryinterference delay imposed on a task by other tasks running in parallel. To the best of our knowledge, this is the first work bounding the request re-ordering effect of COTS memory controllers. Our work also enables the quantification of the extent by which memory interference can be reduced by partitioning DRAM banks. We evaluate our approach on a commodity multi-core platform running Linux/RK. Experimental results show that our approach provides an upper bound very close to our measured worst-case interference.</p

Tartan Racing: A Multi-Modal Approach to the DARPA Urban Challenge

The Urban Challenge represents a technological leap beyond the previous Grand Challenges. The challenge encompasses three primary behaviors: driving on roads, handling intersections and maneuvering in zones. In implementing urban driving we have decomposed the problem into five components. Mission Planning determines an efficient route through an urban network of roads. A behavioral layer executes the route through the environment, adapting to local traffic and exceptional situations as necessary. A motion planning layer safeguards the robot by considering the feasible trajectories available, and selecting the best option. Perception combines data from lidar, radar and vision systems to estimate the location of other vehicles, static obstacles and the shape of the road. Finally, the robot is a mechatronic system engineered to provide the power, sensing and mobility necessary to navigate an urban course. Rigorous component and system testing evaluates progress using standardized tests. Observations from these experiments shape the design of subsequent development spirals and enable the rapid detection and correction of bugs. The system described in the paper exhibits a majority of the basic navigation and traffic skills required for the Urban Challenge. From these building blocks more advanced capabilities will quickly develop.</p

Results of SEI Independent Research and Development Projects

The Software Engineering Institute (SEI) annually undertakes several independent research and development (IRAD) projects. These projects serve to (1) support feasibility studies investigating whether further work by the SEI would be of potential benefit and (2) support further exploratory work to determine whether there is sufficient value in eventually funding the feasibility study work as an SEI initiative. Projects are chosen based on their potential to mature and/or transition software engineering practices, develop information that will help in deciding whether further work is worth funding, and set new directions for SEI work. This report describes the IRAD projects that were conducted during fiscal year 2009 (October 2008 through September 2009)

Results of SEI Independent Research and Development Projects (FY 2010)

The Software Engineering Institute (SEI) annually undertakes several independent research and development (IRAD) projects. These projects serve to (1) support feasibility studies investigating whether further work by the SEI would be of potential benefit and (2) support further exploratory work to determine whether there is sufficient value in eventually funding the feasibility study work as an SEI initiative. Projects are chosen based on their potential to mature and/or transition software engineering practices, develop information that will help in deciding whether further work is worth funding, and set new directions for SEI work. This report describes the IRAD projects that were conducted during fiscal year 2010 (October 2009 through September 2010).</p