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Efficient schedulability analysis for mixed-criticality systems under deadline-based scheduling

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Chinese Journal of Aeronautics 2014年第4期27卷 856-866页

作者： Chen Yao Li Qiao Li Zheng Xiong Huagang School of Electronic and Information Engineering Beihang University

Safety-critical avionics systems which become more complex and tend to integrate multiple functionalities with different levels of criticality for better cost and power efficiency are subject to certifications at various levels of rigorousness. In order to simultaneously guarantee temporal constraints at all different levels of assurance mandated by different criticalities, novel scheduling techniques are in need. In this paper, a mixed-criticality sporadic task model with multiple virtual deadlines is built and a certification-cognizant dynamic scheduling approach referred as earliest virtual-deadline first with mixed-criticality（EVDF-MC） is considered, which exploits different relative deadlines of tasks in different criticality modes. As for the corresponding schedulability analysis problem, a sufficient and efficient schedulability test is proposed on the basis of demand-bound functions derived in the mixed-criticality scenario. In addition, a modified simulated annealing（MSA）-based heuristic approach is established for virtual deadlines assignment. Experiments performing simulations with randomly generated tasks indicate that the proposed approach is computationally efficient and competes well against the existing approaches.

关键词： Avionics systems Mixed-criticality Real-time scheduling schedulability analysis Simulated annealing

schedulability analysis Method of Timing Constraint Petri Nets

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Tsinghua Science and Technology 2002年第6期7卷 596-601页

作者：李慧芳范玉顺 Department of Automation Tsinghua University Beijing 100084 China

Timing constraint Petri nets (TCPNs) can be used to model a real-time system specification and to verify the timing behavior of the system. This paper describes the limitations of the reachability analysis method in analyzing complex systems for existing TCPNs. Based on further research on the schedulability analysis method with various topology structures, a more general state reachability analysis method is proposed. To meet various requirements of timely response for actual systems, this paper puts forward a heuristic method for selecting decision-spans of transitions and develops a heuristic algorithm for schedulability analysis of TCPNs. Examples are given showing the practicality of the method in the schedulability analysis for real-time systems with various structures.

关键词： timing constraint Petri nets schedulability analysis decision-span

Research on Scheduling of Cluster Tools with Residency Time

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Research on Scheduling of Cluster Tools with Residency Time

Design of Energy-efficient Hierarchical Scheduling for Integrated Modular Avionics Systems

第26届中国控制与决策会议

作者： Lu Rui Liaoning Police College Academy

ISBN: (纸本)9781479937066

Because of residency time constraits for cluster tools, it is very difficult to schedule them. This paper addresses their scheduling issues and conducts their schedulability and scheduling analysis. A linear programming model with temporal constraints of dual-blade robot and processing modules is developed. With the model, the cycle process of the dual-blade robot and processing module is analyzed. Based on the model and the analysis, necessary and sufficient conditions under which the system is schedulable are presented. At the same time, the control strategy to make the non-schedulability scheme into schedulable scheme is discussed by means of decreasing the processing mudule number and choosing the appropriate processing time. The simulation results show that the mentioned model and control strategy is helpful to decrease the number of the test wafers and to increase the wafer productivity.

关键词： Semiconductor Manufactory Cluster Tools schedulability analysis Residency Time

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Chinese Journal of Aeronautics 2012年第1期25卷 109-114页

作者： ZHOU Tianran XIONG Huagang School of Electronics and Information Engineering Beihang UniversityBeijing 100191China

Recently the integrated modular avionics （IMA） architecture which introduces the concept of resource partitions becomes popular as an alternative to the traditional federated architecture. This study investigates the problem of designing hierarchical scheduling for IMA systems. The proposed scheduler model enables strong temporal partitioning, so that multiple hard real-time applications can be easily integrated into an uniprocessor platform. This paper derives the mathematic relationships among parti- tion cycle, partition capacity and schedulability under the real-time condition, and then proposes an algorithm for optimizing partition parameters. Real-time tasks with arbitrary deadlines are considered for generality. To further improve the basic algo- rithm and reduce the energy consumption for embedded systems in aircraft, a power optimization approach is also proposed by exploiting the slack time. Experimental results show that the designed system can guarantee the hard real-time requirement and reduce the power consumption by at least 14%.

关键词： system integration IMA real-time systems hierarchical scheduling power optimization schedulability analysis