Real-time embedded system

Embedded systems can be divided in to real-time and non-real time embedded systems. Real-time embedded systems have various timing constraints on their behavior, they are required to react and respond to such constraints. Correctness of their behavior depends on the ability to perform it in the given time frame or before a certain deadline. Whereas, non-real time embedded systems do not have time obligations. 

Real-time embedded systems can further be categorized in hard and soft real-time embedded systems. Hard real-time systems have tight timing constrains with nearly zero-tolerance level. Failure to meet the deadlines causes the operations to stop and is considered an anomaly. Mission critical systems usually fall in hard real-time embedded systems category. Soft real-time constrains can be found in video streaming applications for... 

The magnitude of constraints on QAs defines the nature of a system as either a non-real time, soft or hard real-time embedded system. This magnitude must be explicitly defined and is based on the domain for which the system is developed. Furthermore, it serves as an important factor during QAs tradeoff. 

AADL Is used to model real time embedded systems particularly in the avionics domain. 

Modechart Is used to describe architecture for hard real-time embedded systems. 

We also discussed how the magnitude of constraints on requirements of embedded systems categorizes them in non-real time, hard and soft real-time embedded systems. 

Object Management Group A UML profile for Modeling and Analysis of Real Time Embedded Systems (MARTE) (November 2009), vl.O, formal/2009-11-02... 

Real-time embedded system should be designed in a way, that the real-time aspects are covered as precise as necessary, and performance and timely responses should be achieved as good as possible. 

The Object Management Group UML Profile for MARTE Modeling and Analysis of Real-time Embedded Systems (2011). http //www.01ng.0rg/spec/MARTE/l.l/ Wartel, F. et al. Measurement-based probabilistic timing analysis Lessons from an integrated-modular avionics case study. In Proc. of the 8th IEEE International Symposium on Industrial Embedded Systems (SIES), pp. 241-248 (2013)... 

AADL [3] is an industrial ADL for critical domains like avionics, aerospace and automotive. It is standardized by the SAE (Society of Automotive Engineers), the last version (version 2) was published in 2009. AADL is a rich language with a textual syntax and graphical representation. It allows the modeling of the structure, behaviour and configuration of distributed real-time embedded systems. Like... 

In the context of our partitioned platform, space and time partitioning are provided through XtratuM [3], an ARINC-653-like hypervisor especially designed for real-time embedded systems and developed at the Real-Time System Group of the Institute de Automatica e Informatica Industrial of the Universitat Politecnica de Valencia... 

Zhan, J., Stoimenov, N., Oyang, J., Thiele, L., Narayanan, V., Xie, Y. Designing eneigy-efficient NoC for real-time embedded systems through slack optimization. In 50th Annual Design Automation Conference (2013)... 

ECEN 5623/4623—Real-Time Embedded Systems, ESE Program, http //ecee.colorado.edu/ ecen4623/. Accessed July 2015... 

An attack on time management consists, for a malevolent partition, in being able to modify the execution duration of a critical partition. These execution durations are very important in such hard real-time embedded systems and any modification of these durations is, at least for safety, not acceptable. 

The HIL simulation technique is used to develop and tests real time embedded systems. 

In compliance to the definition of ADL, AADL provides a modeUtng formalism accompanied by a toolset to support modelling activities and analysis. OriginaUy developed for modelling and analysis of systems in the domain of avionics, it has been standardized by the Society of Automotive Engineers. Because of its rich modelling and analysis capabilities it is widely used for embedded systems in other domains as well, especially suitable for model-based analysis and specification of complex real-time embed systems (Feiler et al., 2006). In this section a brief introduction is given on the AADL architectural notations, its analysis and its tool sup>port. 

The landing gear software runs under a bespoke operating system. This embedded real-time operating system extends the ARINC 653 standard and has been qualified to DO- 178B Level A for this aircraft programme. 

Much of the thinking behind lEC 61508 and DEF STAN 00-55 seems to be targeted at real-time, embedded software. Modem safety-related software can be an application mnning on a standard desktop operating system, it can be previously developed software re-used in a new application, it can be part of a complex system-of-systems Demonstrating the safety of these types of system introduces new issues, which 61508 and 00-55 do not address. 

Bohlin, M., Lu, Y., Kraft, J., Kreuger, P. Nolte, T. (2009). Simulation-Based Timing Analysis of Complex Real-Time Systems, Proceedings of the 15th IEEE International Conference on Embedded and Real-Time Computing Systems and Applications (RTCSA 09), pp. 321-328. 

Lv, M., Guan, N., Zhang, Y., Deng, Q., Yu, G. Zhang, J. (2009). A survey of WCET analysis of real-time operating systems, 2009 IEEE International Conference on Embedded Software and Systems pp. 65-72. 

Bastide, R., Navarre, D., Palanque, P., Sch , A., Dragicevic, P. Model-Based Approach for Real-Time Embedded Multimodal Systems in Military Aircrafts. In Proc. ICMI 2004, pp. 243-250. ACM Press, New York (2004)... 

The UPMSat-2 satelhte project has proven to be a relevant demonstrator for many kind of experiments and technology. Several research groups and industry proposed a wide number of experiments in different fields. With regard to the Real-Time Systems Group, the project has given several scenarios in which to exercise our knowledge and tools in real-time embedded for a real project. 

CHESS project suggested that resorting to a reference software architecture in combination with a model-based component-oriented development process can be a very effective strategy for the industrial development of real-time embedded software [11]. A reference software architecture can be thought of as a template architectural blueprint defining the methodology and architectural practices that form a common baseline solution for software systems of a specific domain. A reference architecture exhibits at least the following traits, as defined in [10]. 

Panunzio, M., Vardanega, T. An architectural approach with separation of concerns to address extra-functional requirements in the development of embedded real-time software systems. Journal of Systems Architecture 60(9), 770-781 (2014) Panunzio, M., Vardanega, T. A component-based process with separation of concerns for the development of embedded real-time software systems. Journal of Systems and Software 96, 105-121 (2014)... 

Block, A., Leontyev, H., Brandenburg, B., Anderson, J. A flexible real-time locking protocol for multiprocessors. In 13th IEEE Embedded and Real-Time Computing Systems and Applications (RTCSA) (2007)... 

CPU. A standard Motorola CPU was selected, which works under a powerful real-time, multi-task operating system (VxWorks), and has embedded Ethernet interface. This CPU also features 4 IP slots to which can be plugged ... 

The main objective for an intelligent system in electrolyser operations is to gather and process valuable information for a greater control and efficiency. To achieve the aforementioned objective, two key functions have to be performed properly. Firstly, accurate and precise real-time data need to be obtained and secondly, the system should be able to process and interpret these data based on fundamental and acquired industrial electrochemical knowledge. In the case of R2 s EMOS , this second key element refers directly to its capability to use embedded human expertise to find optimal operating solutions and to detect and correctly identify equipment degradation or other anomalies. 

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