A system-based design methodology and architecture for highly adaptive small satellites

Ekpo, Sunday; George, Danielle

doi:10.1109/systems.2010.5482323

Cited by 14 publications

(9 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Then, it completes its execution at t = 8. However, the second job J 1, 2 3 of the job J 1 3 begins its execution at t = 6 because all the three processors are occupied by higher priority jobs. Then, it misses its absolute deadline at t = 8 because it does not execute completely for C k = 4.…”

Section: Tl-nmr Frameworkmentioning

confidence: 99%

See 1 more Smart Citation

An N-Modular Redundancy Framework Incorporating Response-Time Analysis on Multiprocessor Platforms

Baek

Yoo

et al. 2019

Symmetry

View full text Add to dashboard Cite

A timing constraint and a high level of reliability are the fundamental requirements for designing hard real-time systems. To support both requirements, the N modular redundancy (NMR) technique as a fault-tolerant real-time scheduling has been proposed, which executes identical copies for each task simultaneously on multiprocessor platforms, and a single correct one is voted on, if any. However, this technique can compromise the schedulability of the target system during improving reliability because it produces N identical copies of each job that execute in parallel on multiprocessor platforms, and some tasks may miss their deadlines due to the enlarged computing power required for completing their executions. In this paper, we propose task-level N modular redundancy (TL-NMR), which improves the system reliability of the target system of which tasks are scheduled by any fixed-priority (FP) scheduling without schedulability loss. Based on experimental results, we demonstrate that TL-NMR maintains the schedulability, while significantly improving average system safety compared to the existing NMR.

show abstract

Section: Tl-nmr Frameworkmentioning

confidence: 99%

“…In addition to meeting the timing constraints of a hard real-time system, the systems functional accuracy should be guaranteed [2]. An output produced in a timely manner is not reliable when the system is out of the specified functional correctness.…”

Section: Introductionmentioning

confidence: 99%

An N-Modular Redundancy Framework Incorporating Response-Time Analysis on Multiprocessor Platforms

Baek

Yoo

et al. 2019

Symmetry

View full text Add to dashboard Cite

show abstract

“…Moreover, the integrated cost, size, weight, and power (C-SWaP) limitations of small satellites are not the core systemlevel design considerations [8] since commercial-off-the-shelf components are often favored for this type of mission. Ekpo and George [5] and Waseem and Sadiq [10] provide small satellite architecture technologies, and model-based systems engineering in conceptual design of small satellites that satisfy delineated "all-analog" and "all-digital" system designs only.…”

Section: Introductionmentioning

confidence: 99%

Parametric System Engineering Analysis of Capability-Based Small Satellite Missions

Ekpo

2019

IEEE Systems Journal

View full text Add to dashboard Cite

To achieve appropriate link budget and system engineering analyses of capability-based small satellites missions, an objective assessment and computation of the component-, subsystem-, and system-levels parameters requirements must be carried out. This paper presents the measurement-derived parametric models for the system engineering analysis of communication, meteorology, planetary, and other small satellite programs with recourse to the initial mission, conceptual design, and postmission objectives. Mass and power margins are the critical resources under investigation besides the link contingencies and operational times. The case study spacecraft systems engineering analyses indicate a transmit power for data transmission uplink and downlink of at least 33 dBm for the generic communication, meteorology, and planetary missions applications. The presented parametric models also reveal a signal-to-noise ratio of at least 16 dB per radio communication link for worst case noise floor and path loss. For a 30-W power utilization, a two-power communicationoverpower mode mission operates for an extra 8.3 min compared with a three-power payload-overpower mode mission. This holds a great promise for the development of adaptive subsystems for reconfigurable multiband, and multistandard transponders for multipurpose missions and postmission applications.

show abstract

“…Hard real-time systems have been employed in many fields such as the military, aeronautics, and astronautics in which systems are susceptible to faults that produce a functional error. For example, a satellite system is deployed in a harsh operational environment where the state of the software can be affected by cosmic radiation [2]. In addition, such systems tend to be situated in remote and inaccessible locations, which necessitates the use of fault-tolerant real-time scheduling.…”

Section: Introductionmentioning

confidence: 99%

Task-Level Re-Execution Framework for Improving Fault Tolerance on Symmetry Multiprocessors

Baek

Lee

2019

Symmetry

View full text Add to dashboard Cite

Hard real-time systems are employed in military, aeronautics, and astronautics fields where deployed systems are susceptible to software faults that can result in functional errors. Thus, there is a need to use fault-tolerant (FT) real-time scheduling. Among the various fault-tolerant real-time scheduling techniques, re-execution has been applied widely to existing real-time systems owing to its simplicity and applicability. However, re-execution requires multiple executions of every task, and some tasks miss their deadlines owing to the prolonged execution time; therefore, it has been found to be suitable for only soft real-time systems. In this paper, we propose an FT policy that can be incorporated into most (if not all) existing real-time scheduling algorithms on multiprocessor systems, which improves the reliability of the target system without a tradeoff against schedulability. As a case study, we apply the FT policy to existing fixed-priority scheduling and earliest deadline zero-laxity scheduling, and we demonstrate that it enhances reliability without schedulability loss.

show abstract

A system-based design methodology and architecture for highly adaptive small satellites

Cited by 14 publications

References 3 publications

An N-Modular Redundancy Framework Incorporating Response-Time Analysis on Multiprocessor Platforms

An N-Modular Redundancy Framework Incorporating Response-Time Analysis on Multiprocessor Platforms

Parametric System Engineering Analysis of Capability-Based Small Satellite Missions

Task-Level Re-Execution Framework for Improving Fault Tolerance on Symmetry Multiprocessors

Contact Info

Product

Resources

About