WinCE-based embedded system for control of an industrial screw machine

Nowadays, industrial systems frequently require the control of some industrial process and monitoring of relevant data about the process, using a friendly visual environment. Normally, is used a PLC (Programmable Logical Controller) to control the process and assure that the timing requirements (deadlines) are satisfied and a PC to monitor the data. However, the implementation of such solution presents the following drawbacks to the system programmer: (1) he or she needs to know the communication protocol between the two platforms - PLC and the PC; (2) he or she needs to learn two different programming languages - the low level PLC language and a high level PC language. On the other hand, in some cases, the reserved space to control the systems is reduced, making the implementation of such solution very hard. This paper presents an approach based on an embedded PC with real-time processing capability and data monitoring facility. The proposed system runs the Windows CE operating system and allows all software development in C/C++, using the Microsoft Visual Studio environment. The system was tested on an industrial screw machine for PCBs

Combining Time-Triggered Plans with Priority Scheduled Task Sets

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-39083-3_13Time-triggered and concurrent priority-based scheduling are the two major approaches in use for real-time and embedded systems. Both approaches have their own advantages and drawbacks. On the one hand, priority-based systems facilitate separation of concerns between functional and timing requirements by relying on an underlying real- time operating system that takes all scheduling decisions at run time. But this is at the cost of indeterminism in the exact timing pattern of execution of activities, namely variable release jitter. On the other hand, time-triggered schedules are more intricate to design since all schedul- ing decisions must be taken beforehand in the design phase, but their advantage is determinism and more chances for minimisation of release jitter. In this paper we propose a software architecture that enables the combined and controlled execution of time-triggered plans and priority- scheduled tasks. We also describe the implementation of an Ada library supporting it. Our aim is to take advantage of the best of both ap- proaches by providing jitter-controlled execution of time-triggered tasks (e.g., control tasks), coexisting with a set of priority-scheduled tasks, with less demanding jitter requirements.This work has been partly supported by the Spanish Government’s project M2C2 (TIN2014-56158-C4-1-P-AR) and the European Commission’s project EMC2 (ARTEMIS-JU Call 2013 AIPP-5, Contract 621429).Real Sáez, JV.; Sáez Barona, S.; Crespo, A. (2016). Combining Time-Triggered Plans with Priority Scheduled Task Sets. En Reliable Software Technologies – Ada-Europe 2016. Springer. 195-212. https://doi.org/10.1007/978-3-319-39083-3_13S195212Liu, C., Layland, J.: Scheduling algorithms for multiprogramming in a hard real-time environment. J. ACM 20(1), 46–61 (1973)Martí, P., Fuertes, J., Fohler, G.: Jitter compensation for real-time control systems. In: Real-Time Systems Symposium (2001)Dobrin, R.: Combining off-line schedule construction and fixed priority scheduling in real-time computer systems. Ph.D. thesis. Mälardalen University (2005)Cervin, A.: Integrated control and real-time scheduling. Ph.D. thesis. Lund Institute of Technology, April 2003Balbastre, P., Ripoll, I., Vidal, J., Crespo, A.: A task model to reduce control delays. Real-Time Syst. 27(3), 215–236 (2004)Hong, S., Hu, X., Lemmon, M.: Reducing delay jitter of real-time control tasks through adaptive deadline adjustments. In: 22nd Euromicro Conference on Real-Time Systems - ECRTS, pp. 229–238. IEEE Computer Society (2010)ISO/IEC-JTC1-SC22-WG9: Ada Reference Manual ISO/IEC 8652:2012(E) (2012). http://www.ada-europe.org/manuals/LRM-2012.pdfBaker, T.P., Shaw, A.: The cyclic executive model and Ada. In: Proceedings IEEE Real Time Systems Symposium 1988, Huntsville, Alabama, pp. 120–129 (1988)Liu, J.W.S.: Real-Time Systems. Prentice-Hall Inc., Upper Saddle River (2000)Pont, M.J.: The Engineering of Reliable Embedded Systems: LPC1769. SafeTTy Systems Limited, Skelmersdale (2014). ISBN: 978-0-9930355-0-0Aldea Rivas, M., González Harbour, M.: MaRTE OS: an Ada kernel for real-time embedded applications. In: Strohmeier, A., Craeynest, D. (eds.) Ada-Europe 2001. LNCS, vol. 2043, pp. 305–316. Springer, Heidelberg (2001)Palencia, J., González-Harbour, M.: Schedulability analysis for tasks with static and dynamic offsets. In: 9th IEEE Real-Time Systems Symposium (1998)Wellings, A.J., Burns, A.: A framework for real-time utilities for Ada 2005. Ada Lett. XXVI XXVII(2), 41–47 (2007)Real, J., Crespo, A.: Incorporating operating modes to an Ada real-time framework. Ada Lett. 30(1), 73–85 (2010)Sáez, S., Terrasa, S., Crespo, A.: A real-time framework for multiprocessor platforms using Ada 2012. In: Romanovsky, A., Vardanega, T. (eds.) Ada-Europe 2011. LNCS, vol. 6652, pp. 46–60. Springer, Heidelberg (2011

Supporting Location Privacy Management through Feedback and Control

Participation in modern, socially-focused digital systems involves a large degree of privacy management, i.e. controlling who may access what information under what circumstances. Effective privacy management (control) requires that mobile systems’ users be able to make informed privacy decisions as their experience and knowledge of a system progresses. By informed, we mean users be aware of the actual information flow. Moreover, privacy preferences vary across the context and it is hard to define privacy policy that reflects the dynamic nature of our lives. This research explores the problem of supporting awareness of information flow and designing usable interfaces for maintaining privacy policies ad-hoc. We borrow from the world of Computer Supported Collaborative Work (CSCW) and propose to incorporate social translucence, a design approach that “supports coherent behaviour by making participants and their activities visible to one another”. We use the characteristics of social translucence, namely visibility, awareness and accountability in order to introduce social norms in spatially dispersed systems. Our research is driven by two questions: (1) how can artifacts from real world social interaction, such as responsibility, be embedded into mobile interaction; and (2) can systems be designed in which both privacy violations and the burden of privacy management is minimized. The contributions of our work are: (1) an implementation of Buddy Tracker, privacy-aware location-sharing application based on the social translucence; (2) the design and evaluation of the concept of real-time feedback as a means of incorporating social translucence in location-sharing scenarios; and finally (3) a novel interface for ad-hoc privacy management called Privacy-Shake. We explore the role of real-time feedback for privacy management in the context of Buddy Tracker. Informed by focus group discussions, interviews, surveys and two field trials of Buddy Tracker we found that when using a system that provided real-time feedback, people were more accountable for their actions and reduced the number of unreasonable location requests. From our observations we develop concrete design guidelines for incorporating real-time feedback into information sharing applications in a manner that ensures social acceptance of the technology