scholarly journals Analysis of the Critical Bits of a RISC-V Processor Implemented in an SRAM-Based FPGA for Space Applications

Electronics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 175 ◽  
Author(s):  
Luis Alberto Aranda ◽  
Nils-Johan Wessman ◽  
Lucana Santos ◽  
Alfonso Sánchez-Macián ◽  
Jan Andersson ◽  
...  
Keyword(s):  
Ad Hoc ◽  
Fault Tolerant ◽  
Fault Injection ◽  
Electronic Components ◽  
Fpga Design ◽  
Specific Nature ◽  
Space Applications ◽  
Onboard Computer ◽  
Target Architecture ◽  
Definition Of

One of the traditional issues in space missions is the reliability of the electronic components on board spacecraft. There are numerous techniques to deal with this, from shielding and rad-hard fabrication to ad-hoc fault-tolerant designs. Although many of these solutions have been extensively studied, the recent utilization of FPGAs as the target architecture for many electronic components has opened new possibilities, partly due to the distinct nature of these devices. In this study, we performed fault injection experiments to determine if a RISC-V soft processor implemented in an FPGA could be used as an onboard computer for space applications, and how the specific nature of FPGAs needs to be tackled differently from how ASICs have been traditionally handled. In particular, in this paper, the classic definition of the cross-section is revisited, putting into perspective the importance of the so-called “critical bits” in an FPGA design.

scholarly journals Robust Output Synchronization of Arrays of Chaotic Sprott Circuits

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Ernesto V. Gonzalez Solis ◽  
David I. Rosas Almeida
Keyword(s):  
Parametric Uncertainties ◽  
Electronic Components ◽  
Closed Loop System ◽  
Pass Filter ◽  
Low Pass Filter ◽  
State Variable ◽  
Output Synchronization ◽  
Low Pass ◽  
Definition Of ◽  
Real Time Simulations

This article presents a technique for synchronizing arrays of a class of chaotic systems known as Sprott circuits. This technique can be applied to different topologies and is robust to parametric uncertainties caused by tolerances in the electronic components. The design of coupling signals is based on the definition of a set of functionals which depend on the errors between the outputs of the nodes and the errors between the output of a reference system and the outputs of the nodes. When there are no parametric uncertainties, we establish a criterion to design the coupling signals using only one state variable of each system. When the parametric uncertainties are present, we add a robust observer and a low pass filter to estimate the perturbation terms, which are subsequently compensated through the coupling signals, resulting in a robust closed loop system. The performance of the synchronization technique is illustrated by real-time simulations.

Research on robust adaptive sliding film fault-tolerant control under nonlinear distortion of signal transmission in amorphous flat air-to-ground wireless ad-hoc network system

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zhifang Wang ◽  
Jianguo Yu ◽  
Shangjing Lin
Keyword(s):  
Nonlinear Distortion ◽  
Ad Hoc ◽  
Fault Tolerant ◽  
Signal Transmission ◽  
Network System ◽  
Long Distance ◽  
Content Type ◽  
Wireless Signal ◽  
Robust Adaptive ◽  
Self Organizing

Purpose To solve the above problems and ensure the stability of the ad hoc network node topology in the process of wireless signal transmission, this paper aims to design a robust adaptive sliding film fault-tolerant controller under the nonlinear distortion of signal transmission in an amorphous flat air-to-ground wireless ad hoc network system. Design/methodology/approach This paper designs a robust adaptive sliding film fault-tolerant controller under the nonlinear distortion of signal transmission in an amorphous flat air-to-ground wireless ad hoc network system. Findings The simulation results show that the amorphous flat wireless self-organizing network system has good nonlinear distortion fault-tolerant correction ability under the feedback control of the designed controller, and the system has the asymptotically stable convergence ability; the test results show: the node topology of the self-organizing network structural stability is significantly improved, which provides a foundation for the subsequent realization of long-distance transmission of ad hoc network nodes. Research limitations/implications Because of the chosen research approach, the research results may lack generalizability. Therefore, researchers are encouraged to test the proposed propositions further. Originality/value The controller can extract the fault information caused by nonlinear distortion in the wireless signal transmission process, and at the same time, its feedback matrix K can gradually converge the generated wireless signal error to zero, to realize the stable transmission of the wireless signal.

Fault Injection Campaign for a Fault Tolerant Duplex Framework

2007 ◽  
Author(s):  
Gian Franco Sacco ◽  
Robert D. Ferraro ◽  
Paul von Allmen ◽  
Dave A. Rennels
Keyword(s):  
Fault Tolerant ◽  
Fault Injection

scholarly journals Establishing an ad hoc COVID-19 mortality surveillance during the first epidemic wave in Belgium, 1 March to 21 June 2020

2021 ◽  
Vol 26 (48) ◽  
Author(s):  
Françoise Renard ◽  
Aline Scohy ◽  
Johan Van der Heyden ◽  
Ilse Peeters ◽  
Sara Dequeker ◽  
...  
Keyword(s):  
Ad Hoc ◽  
Participation Rate ◽  
Term Care ◽  
Data Flows ◽  
Care Facilities ◽  
Definition Of ◽  
High Level ◽  
Mortality Surveillance ◽  
Related Mortality

Background COVID-19-related mortality in Belgium has drawn attention for two reasons: its high level, and a good completeness in reporting of deaths. An ad hoc surveillance was established to register COVID-19 death numbers in hospitals, long-term care facilities (LTCF) and the community. Belgium adopted broad inclusion criteria for the COVID-19 death notifications, also including possible cases, resulting in a robust correlation between COVID-19 and all-cause mortality. Aim To document and assess the COVID-19 mortality surveillance in Belgium. Methods We described the content and data flows of the registration and we assessed the situation as of 21 June 2020, 103 days after the first death attributable to COVID-19 in Belgium. We calculated the participation rate, the notification delay, the percentage of error detected, and the results of additional investigations. Results The participation rate was 100% for hospitals and 83% for nursing homes. Of all deaths, 85% were recorded within 2 calendar days: 11% within the same day, 41% after 1 day and 33% after 2 days, with a quicker notification in hospitals than in LTCF. Corrections of detected errors reduced the death toll by 5%. Conclusion Belgium implemented a rather complete surveillance of COVID-19 mortality, on account of a rapid investment of the hospitals and LTCF. LTCF could build on past experience of previous surveys and surveillance activities. The adoption of an extended definition of ‘COVID-19-related deaths’ in a context of limited testing capacity has provided timely information about the severity of the epidemic.

scholarly journals Ad Hoc or Institutional Arbitration - A Clear-Cut Distinction? A Closer Look at Borderline Cases

2017 ◽  
Author(s):  
Ulrich G. Schroeter
Keyword(s):  
Ad Hoc ◽  
Theory And Practice ◽  
Present Contribution ◽  
Borderline Cases ◽  
Institutional Rules ◽  
Clear Cut ◽  
Definition Of ◽  
Core Characteristics ◽  
Insight Into ◽  
Mix And Match

It is generally accepted in both theory and practice of arbitration that there are two basic forms of arbitration, ad hoc and institutional. This long established dichotomy has rarely been questioned, and it has mostly worked well in international arbitration practice.The present contribution investigates the traditional distinction between ad hoc and institutional arbitration in more detail by looking at "borderline cases", i.e. constellations that cannot easily be allocated to one of these two categories. Four groups of borderline cases are discussed: (1) UNCITRAL arbitrations, in particular those administered by arbitral institutions; (2) cases in which the parties have chosen institutional rules, but not the issuing institution (and vice versa), (3) the modification of institutional rules by the parties and the identification of a possible "mandatory" core of institutional rules, and (4) "mix and match" (or "hybrid") arbitrations combining one arbitral institution's rules with the case's administration by a different arbitral institution. By identifying the factors that were decisive for these borderline cases being regarded as institutional or ad hoc, the article is trying to gain insight into the core characteristics underlying each arbitration category. Drawing on these insights, it develops and explains a novel definition of "institutional arbitration".

scholarly journals CREATION OF SPECIAL BATCHES OF DEVICES TO IMPROVE RELIABILITY OF ELECTRONIC COMPONENTS FOR SPACE APPLICATIONS

2020 ◽  
Vol 258 (3) ◽  
pp. 65-71
Author(s):  
V.I. Kuklin ◽  
V.I. Orlov ◽  
V.V. Fedosov
Keyword(s):  
Historical Background ◽  
Quality Level ◽  
Electronic Components ◽  
Joint Work ◽  
Space Applications ◽  
Manufacturing Plants ◽  
Term Operation ◽  
Optimal Approach ◽  
Improve Reliability

In this paper we give a brief historical background of the stages of work carried out by “ITC – NPO PM” JSC aimed at ensuring the long-term operation of electronic components for space applications. It is shown that the creation of specialized testing facilities is the optimal approach to make batches of electronic components of the Space quality level. We propose a further scenario to improve reliability of electronic components for space applications, involving the joint work of specialized testing facilities and manufacturing plants to make special batches of devices.

scholarly journals Planning Fail-Safe Trajectories for Space Robotic Arms

2021 ◽  
Vol 8 ◽  
Author(s):  
Oliver Porges ◽  
Daniel Leidner ◽  
Máximo A. Roa
Keyword(s):  
Degrees Of Freedom ◽  
Fault Tolerant ◽  
Robotic Manipulators ◽  
Task Completion ◽  
Joint Failure ◽  
Space Applications ◽  
Robotic Arms ◽  
Hazardous Environments ◽  
Potential Risks ◽  
Fail Safe

A frequent concern for robot manipulators deployed in dangerous and hazardous environments for humans is the reliability of task executions in the event of a joint failure. A redundant robotic manipulator can be used to mitigate the risk and guarantee a post-failure task completion, which is critical for instance for space applications. This paper describes methods to analyze potential risks due to a joint failure, and introduces tools for fault-tolerant task design and path planning for robotic manipulators. The presented methods are based on off-line precomputed workspace models. The methods are general enough to cope with robots with any type of joint (revolute or prismatic) and any number of degrees of freedom, and might include arbitrarily shaped obstacles in the process, without resorting to simplified models. Application examples illustrate the potential of the approach.

Distributed robust H∞ adaptive fault-tolerant control of amorphous and flat air-to-ground wireless self-organizing network system

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zhifang Wang ◽  
Jianguo Yu ◽  
Shangjing Lin ◽  
Junguo Dong ◽  
Zheng Yu
Keyword(s):  
Flight Control ◽  
Control Algorithm ◽  
Ad Hoc ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Integrated System ◽  
External Disturbances ◽  
Content Type ◽  
Actuator Failures ◽  
Wireless Signal

Purpose The paper takes the air-ground integrated wireless ad hoc network-integrated system as the research object, this paper aims to propose a distributed robust H∞ adaptive fault-tolerant control algorithm suitable for the system to distribute to solve the problem of control and communication failure at the same time. Design/methodology/approach In the paper, the authors propose a distributed robust H∞ adaptive fault-tolerant control algorithm suitable for the air-ground integrated wireless ad hoc network-integrated system. Findings The results show that the integrated system has good robustness and fault tolerance performance indicators for flight control and wireless signal transmission when confronted with external disturbances, internal actuator failures and wireless network associated failures and the flight control curve of the quadrotor unmanned aerial vehicle (UAV) is generally smooth and stable, even if it encounters external disturbances and actuator failures, its fault tolerance performance is very good. Then in the range of 400–800 m wireless communication distance, the success rate of wireless signal loop transmission is stable at 80%–100% and the performance is at least relatively improved by 158.823%. Originality/value This paper takes the air-ground integrated wireless ad hoc network-integrated system as the research object, based on the robust fault-tolerant control algorithm, the authors propose a distributed robust H∞ adaptive fault-tolerant control algorithm suitable for the system and through the Riccati equation and linear matrix inequation method, the designed distributed robust H∞ adaptive fault-tolerant controller further optimizes the fault suppression factor γ, so as to break through the limitation of only one Lyapunov matrix for different fault modes to distribute to solve the problem of control and communication failure at the same time.

Sign in / Sign up

Export Citation Format

Share Document