Lund University, Sweden
In design of resource-constrained embedded and networked control systems and cyber-physical systems it is necessary to be able to evaluate how the temporal non-determinism caused by the sharing of CPU and communication bandwidth effect control performance. In this presentation two tools are presented that allows for this. Jitterbug is a Matlab toolbox for analytical statistical evaluation of how latencies and jitter in a control loop effects control performance evaluated by a quadratic cost function. In Jitterbug it assumed that the latency distributions are known. If that is not the case or more general performance metrics are needed then the TrueTime toolbox can be used.
TrueTime supports co-simulation of the temporal effects caused by real-time kernels and networks together with the continuous-time dynamics of the physical system under control. In Truetime discrete-event models of kernels and networks are embedded within Simulink through the use of S-functions. Within the kernels controller code is modeled by tasks and/or interrupt handlers written in C/C++ code or .m functions. Currently TrueTime is also being ported to Modelica, jointly by Lund University and Vanderbilt University. This version currently under development is based on the open model exchange interface FMI (Flexible Mock-Up Interface), an open source alternative to Simulink's S-functions. During the talk demonstrations of both Jitterbug and TrueTime will be given.
Karl-Erik Arzen is professor in Automatic Control at Lund University, Lund, Sweden. He received his PhD in 1987 from the same university and since then has also worked for ABB Corporate Research. Arzen's research lies in the intersection of control engineering and embedded real-time systems, with a special emphasis on co-design of control and computing systems, and on feedback computing for embedded systems. Arzen has been strongly involved in the European Networks of Excellence Artist2 and ArtistDesign on embedded system design as well as participated in several EU STREP and IP projects. He is currently the co-director of the strategic ICT research area ELLIIT. Arzen is associate editor for Real-Time Systems Journal and area editor for Leibniz Transactions on Embedded Systems. He received the Dr Guido Carlo-Stella award in manufacturing automation from the World Batch Forum in 2006 for achievements in manufacturing automation and information structuring. He was the vice chair of the IFAC TC on Real-Time Computing & Control 2002 - 2004 and the chair of IEEE CSS TC on Real-Time Control, Computing and Signal Processing 1999 - 2002. He is a member of the Royal Swedish Academy of Engineering Sciences.