The paper deals with the scheduling of periodic information flow in a FieldBus environment. The scheduling problem is defined from an analytical point of view, giving a brief survey of the most well-known solutions. O...
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The paper deals with the scheduling of periodic information flow in a FieldBus environment. The scheduling problem is defined from an analytical point of view, giving a brief survey of the most well-known solutions. One of these is called multicycle polling scheduling, which is based on the hypothesis that all the production periods of the periodic processes to be scheduled are harmonic. Although in some process control or manufacturing scenarios, this hypothesis may be acceptable, there are many real industrial processes to which it cannot be applied. The aim of the paper is to make a contribution towards solving the scheduling problem. It essentially concerns extension of the theory on which multicycle polling scheduling is based to a much more realistic and general scenario, where the periods of all the processes to be scheduled have arbitrary values. The authors present a new formulation of multicycle polling scheduling, called extended multicycle polling scheduling, and demonstrate that it comprises the scenario currently considered in the literature. Two algorithmic solutions for extended multicycle polling scheduling are then proposed, giving a computational complexity analysis which will highlight the capability of the algorithmic scheduling solutions to be performed on-line. The paper concludes by comparing the multicycle polling scheduling approach known in literature and the one presented in the paper. Comparison is performed by evaluating the use of available bandwidth to serve both periodic and asynchronous traffic in the two approaches.
Time-critical requirements of real time systems are provided by software applications running on real time operating systems. These software tasks must be scheduled based on software and hardware events. There are som...
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ISBN:
(纸本)9781728175652
Time-critical requirements of real time systems are provided by software applications running on real time operating systems. These software tasks must be scheduled based on software and hardware events. There are some services (priority based preemption etc.) in real time operating systems to control software tasks. But in some situations there is a need for scheduling algorithms in real time systems. This need arises especially when time-critical software tasks need to run at different working periods and on a specific timeline. Different scheduling algorithms can be selected to meet the requirements of the system. The flight software that runs on the real-time operating system, especially on satellite platforms, is responsible for time-critical tasks. Main goals of this paper are providing analyze of scheduling algorithms using in real time operating systems, giving the method which is used to apply scheduling algorithms in a real time operating system and providing performance results of these scheduling algorithms obtained as a result of this application. In addition, it is mentioned that which of these algorithms are preferred in space domain.
This paper studies the almost sure exponential stability (ASES) with a random switching process of stochastic nonlinear semi-Markov jump T-S Fuzzy systems (SMJT-SFSs) based on an intermittent scheduling controller. Th...
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This paper studies the almost sure exponential stability (ASES) with a random switching process of stochastic nonlinear semi-Markov jump T-S Fuzzy systems (SMJT-SFSs) based on an intermittent scheduling controller. The intermittent scheduling controller is established by the earliestdeadlinefirst (EDF) algorithm, where the controller is enabled to take a rest interval. By building a mode-dependent Lyapunov function and employing the It & ocirc;formula, the sufficient stability conditions of the SMJT-SFSs with intermittent scheduling controller are obtained about solvable forms of linear matrix inequalities (LMIs). Furthermore, we explore two special cases involving linear systems and deterministic systems. In addition, an application example of the nonlinear robot arm model of single-link is provided to illustrate the results.
In data-intensive real-time applications, e.g., transportation management and location-based services, the amount of sensor data is exploding. In these applications, it is desirable to extract value-added information,...
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ISBN:
(纸本)9781479989386
In data-intensive real-time applications, e.g., transportation management and location-based services, the amount of sensor data is exploding. In these applications, it is desirable to extract value-added information, e.g., fast driving routes, from sensor data streams in real-time rather than overloading users with massive raw data. However, achieving the objective is challenging due to the data volume and complex data analysis tasks with stringent timing constraints. Most existing big data management systems, e.g., Hadoop, are not directly applicable to real-time sensor data analytics, since they are timing agnostic and focus on batch processing of previously stored data that are potentially outdated and subject to I/O overheads. To address the problem, we design a new real-time big data management framework, which supports a non-preemptive periodic task model for continuous in-memory sensor data analysis and a schedulability test based on the EDF (earliestdeadlinefirst) algorithm to derive information from current sensor data in real-time by extending the map-reduce model originated in functional programming. As a proof-of-concept case study, a prototype system is implemented. In the performance evaluation, it is empirically shown that all deadlines can be met for the tested sensor data analysis benchmarks.
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