@inproceedings{SteindlMottokMeieretal., author = {Steindl, Michael and Mottok, J{\"u}rgen and Meier, Hans and Schiller, Frank and Fr{\"u}chtl, M.}, title = {Safeguarded Processing of Sensor Data}, series = {IT-SecurityArea (IT-SA 2009) vom 13.-15. Oktober 2009, N{\"u}rnberg}, booktitle = {IT-SecurityArea (IT-SA 2009) vom 13.-15. Oktober 2009, N{\"u}rnberg}, pages = {8}, abstract = {The spectrum of software tasks no longer includes only rare function controlling tasks for sensor actuator chains in reactive embedded systems. However, more and more responsible challenges like safety-critical scenarios are tackled. Therefore sensor data have to be safeguarded by several mechanism. An obvious and widely used approach is the use of two redundant hardware controllers, but this comes along with an additional cost, space and energy factor. Another way to fulfill certain safety properties is to implement a second diverse software channel in a single micro-controller architecture according the Safely Embedded Software (SES) approach. However, a lack of performance occurs by implementing this diverse channel for complex computations e.g. floating-point operations. This paper gives an approach for transferring the SES into a coprocessor and to migrate SES to a flexible and powerful FPGA architecture.}, language = {en} } @inproceedings{SteindlMottokMeieretal., author = {Steindl, Michael and Mottok, J{\"u}rgen and Meier, Hans and Schiller, Frank and Fr{\"u}chtl, M.}, title = {Migration of SES to FPGA Based Architectural Concepts}, series = {Proceedings of the Workshop 'Safely embedded software'}, booktitle = {Proceedings of the Workshop 'Safely embedded software'}, language = {en} } @article{RaabMottokMeier, author = {Raab, Peter and Mottok, J{\"u}rgen and Meier, Hans}, title = {OSEK-RTOS f{\"u}r Jedermann (Teil 2)}, series = {Embedded Software Engineering Report}, volume = {53}, journal = {Embedded Software Engineering Report}, pages = {10 -- 12}, language = {de} } @article{RaabMottokMeier, author = {Raab, Peter and Mottok, J{\"u}rgen and Meier, Hans}, title = {OSEK-RTOS f{\"u}r Jedermann (Teil 1)}, series = {Embedded Software Engineering Report}, volume = {53}, journal = {Embedded Software Engineering Report}, number = {September}, pages = {14 -- 15}, language = {de} } @inproceedings{SteindlMottokMeier, author = {Steindl, Michael and Mottok, J{\"u}rgen and Meier, Hans}, title = {SES-based Framework for Fault-tolerant Systems}, series = {8th IEEE Workshop on Intelligent Solutions in Embedded Systems, Heraklion, Greece, July 2010}, booktitle = {8th IEEE Workshop on Intelligent Solutions in Embedded Systems, Heraklion, Greece, July 2010}, doi = {10.1109/WISES.2010.5548427}, pages = {12 -- 16}, abstract = {Embedded real-time systems are often used in harsh environments, for example engine control systems in automotive vehicles. In such ECUs (Engine Control Unit) faults can lead to serious accidents. In this paper we propose a safety embedded architecture based on coded processing. This framework only needs two channels to provide fault tolerance and allows the detection and identification of permanent and transient faults. Once a fault is detected by an observer unit the SES guard makes it visible and initiates a suitable failure reaction.}, language = {en} } @inproceedings{KraemerMottokMeier, author = {Kr{\"a}mer, Stefan and Mottok, J{\"u}rgen and Meier, Hans}, title = {Osek-basierende Implementierung des LLREF-Scheduling-Algorithmus f{\"u}r eine Dual-Core-Architektur}, series = {2. Landshuter Symposium Mikrosystemtechnik, Tagungsband, 24. une 25. Februar 2010, Hochschule Landshut}, booktitle = {2. Landshuter Symposium Mikrosystemtechnik, Tagungsband, 24. une 25. Februar 2010, Hochschule Landshut}, pages = {343 -- 349}, language = {de} } @inproceedings{SteindlMottokMeieretal., author = {Steindl, Michael and Mottok, J{\"u}rgen and Meier, Hans and Schiller, Frank and Fr{\"u}chtl, M.}, title = {Safeguarded Processing of Sensor Data}, series = {5th Embedded Real Time Software and Systems Conference (ERTS2 2010), May 2010, Toulouse, France}, booktitle = {5th Embedded Real Time Software and Systems Conference (ERTS2 2010), May 2010, Toulouse, France}, language = {en} } @article{KraemerMottokMeier, author = {Kr{\"a}mer, Stefan and Mottok, J{\"u}rgen and Meier, Hans}, title = {Multi-Core Scheduling in Embedded Systemen, Teil 1}, series = {Hanser Automotive}, journal = {Hanser Automotive}, number = {1-2}, pages = {18 -- 22}, language = {en} } @article{KraemerMottokMeier, author = {Kr{\"a}mer, Stefan and Mottok, J{\"u}rgen and Meier, Hans}, title = {Multi-Core Scheduling in Embedded Systemen, Teil 2}, series = {Hanser Automotive}, journal = {Hanser Automotive}, number = {3-4}, pages = {23 -- 25}, language = {en} } @article{KraemerMottokMeier, author = {Kr{\"a}mer, Stefan and Mottok, J{\"u}rgen and Meier, Hans}, title = {Multi-Core Scheduling in Embedded Systemen, Teil 3}, series = {Hanser Automotive}, journal = {Hanser Automotive}, number = {5-6}, pages = {14 -- 16}, language = {en} } @inproceedings{RaabKraemerMottoketal., author = {Raab, Peter and Kr{\"a}mer, Stefan and Mottok, J{\"u}rgen and Meier, Hans and Racek, Stanislav}, title = {Safe software processing by concurrent execution in a real-time operating system}, series = {16th International Conference on Applied Electronics (AE 2011), 2011, Pilsen, Czech Republic}, booktitle = {16th International Conference on Applied Electronics (AE 2011), 2011, Pilsen, Czech Republic}, pages = {315 -- 319}, abstract = {The requirements for safety-related software systems increases rapidly. To detect arbitrary hardware faults, there are applicable coding mechanism, that add redundancy to the software. In this way it is possible to replace conventional multi-channel hardware and so reduce costs. Arithmetic codes are one possibility of coded processing and are used in this approach. A further approach to increase fault tolerance is the multiple execution of certain critical parts of software. This kind of time redundancy is easily realized by the parallel processing in an operating system. Faults in the program flow can be monitored. No special compilers, that insert additional generated code into the existing program, are required. The usage of multi-core processors would further increase the performance of such multi-channel software systems. In this paper we present the approach of program flow monitoring combined with coded processing, which is encapsulated in a library of coded data types. The program flow monitoring is indirectly realized by means of an operating system.}, language = {en} } @inproceedings{JupkeReindlMeieretal., author = {Jupke, Michael and Reindl, Andrea and Meier, Hans and Niemetz, Michael}, title = {Bidirectional DC-DC Converter with Digital Droop Parameterization}, series = {26th 2021 International Conference on Applied Electronics (AE): 7-8 Sept. 2021 Pilsen, Czech Republic}, booktitle = {26th 2021 International Conference on Applied Electronics (AE): 7-8 Sept. 2021 Pilsen, Czech Republic}, editor = {Pinker, Jiř{\´i}}, publisher = {Institute of Electrical and Electronics Engineers}, isbn = {978-80-261-0972-3}, doi = {10.23919/AE51540.2021.9542920}, pages = {1 -- 6}, abstract = {The key for decentralized battery systems is a robust and communication-less control strategy for autonomous power sharing of parallel-connected DC-DC converters. Battery systems improve the reliability and quality of power supply in renewable energy systems and enable power supply for off-grid, mobile applications, including islanded grids, home storage, and electric vehicles. In many cases, components with different electrical properties require different voltage levels. An adaptation is consequently essential and is normally implemented in DC grids for the batteries via bidirectional DC-DC converters. The power flow in both directions can thus be ensured. To achieve a power distribution in parallel connected DC-DC converters, a droop control in the form of a virtual internal resistor can be used. This paper presents a novel approach of a DC-DC converter with a digitally parameterizable droop resistor, whose voltage regulation is based on an analog operational amplifier circuit to ensure low delays and robustness. The droop resistor is adjusted with a microcontroller, which offers the possibility to apply a higher-level control for load sharing via an interface. Mathematical correlations are used to clearly define the parameters of the control. Furthermore, the circuit was completely simulated and tested in the hardware setup. The shown results verify the functionality and indicate only minor deviations. Therefore, this circuit is important for future use in distributed battery systems.}, language = {en} } @inproceedings{ReindlMeierNiemetz, author = {Reindl, Andrea and Meier, Hans and Niemetz, Michael}, title = {Scalable, Decentralized Battery Management System Based on Self-organizing Nodes}, series = {Architecture of computing systems - ARCS 2020: 33rd international conference, Aachen, Germany, May 25-28, 2020, proceedings}, volume = {12155}, booktitle = {Architecture of computing systems - ARCS 2020: 33rd international conference, Aachen, Germany, May 25-28, 2020, proceedings}, editor = {Brinkmann, Andr{\´e} and Karl, Wolfgang and Lankes, Stefan and Tomforde, Sven and Pionteck, Thilo and Trinitis, Carsten}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-030-52793-8}, doi = {10.1007/978-3-030-52794-5_13}, pages = {171 -- 184}, abstract = {Due to the transition to renewable energy sources and the increasing share of electric vehicles and smart grids, batteries are gaining in importance. Battery management systems (BMSs) are required for optimal, reliable operation. In this paper, existing BMS topologies are presented and evaluated in terms of reliability, scalability and flexibility. The decentralisation of BMSs and associated advantages are shown. A scalable, reconfigurable BMS based on a distributed architecture of self-organized, locally controlled nodes is proposed. For distributed system control, producers, batteries and consumers each are equipped with a local microcontroller based control unit, which monitors and controls the local parameters with its own computing and communication resources. Features, advantages and challenges to overcome of the proposed approach are described.}, language = {en} } @inproceedings{HerboldReindlMeieretal., author = {Herbold, Florian and Reindl, Andrea and Meier, Hans and Niemetz, Michael and Kr{\"a}mer, Stefan}, title = {Secure Software Updates: Challenges and Solutions for Embedded IoT Systems}, series = {Proceedings of the 9th Embedded Systems Workshop: July 1-3, 2021 Horomerice, Czech Republic}, booktitle = {Proceedings of the 9th Embedded Systems Workshop: July 1-3, 2021 Horomerice, Czech Republic}, editor = {Kub{\´a}tov{\´a}, Hana and Fišer, Petr and Boreck{\´y}, Jaroslav}, isbn = {978-80-01-06858-8}, pages = {5 -- 13}, abstract = {The invention of the internet made the development of intelligent networking of millions of embedded systems possible. This enabled smart buildings, power grids and cities as well as applications in the fields of health, agriculture and industry. These systems frequently perform safety-critical applications and operations. This makes it urgent to protect these sensible systems as effectively as possible. Especially firmware updates are often the weak point in the systems. If unauthorised persons gain access to the system during the update, malware can be injected or sensitive data can be read and stolen. This paper describes the challenges of secure firmware updates. To protect an embedded system from potential attackers, the concepts integrity, authenticity and confidentiality have to be adhered during the update process. Otherwise, there is an increased risk of modifying or reverse engineering the firmware image. Likewise, inadequately protected software can enable the installation of third-party firmware as well as the installation of firmware on a third-party system. Threat prevention is presented with solutions derived from functional safety and IT security. Aspects of protection against errors in the transmission of updates and against attacks aiming to compromise the system are explained. Finally, a possible sequence of a secure update process is examined in detail for a real embedded system implementation. For this purpose, the preparation, transmission and installation of a firmware update in the bootloader are discussed}, language = {en} }