scholarly journals A Methodology to Analyze the Fault Tolerance of Demosaicking Methods against Memory Single Event Functional Interrupts (SEFIs)

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1619
Author(s):  
Luis Alberto Aranda ◽  
Alfonso Sánchez-Macián ◽  
Juan Antonio Maestro
Keyword(s):  
Fault Tolerance ◽  
Fault Tolerant ◽  
Soft Errors ◽  
Normal Operation ◽  
Harsh Environments ◽  
Single Event ◽  
Electronic Circuits ◽  
Memory Chip ◽  
Interpolation Algorithms ◽  
Rgb Images

Electronic circuits in harsh environments, such as space, are affected by soft errors produced by radiation. A single event functional interrupt (SEFI) can affect the behavior of a memory chip, with one or more rows, columns or even the whole device producing a wrong value when reading a set of stored bits. This problem may affect raw Bayer images stored in satellites and other spacecraft. In this paper, we present a methodology to analyze how different interpolation algorithms behave when they try to reconstruct the affected Bayer images into standard red, green and blue (RGB) images. This methodology can be used to compare and develop new fault-tolerant algorithms. The proposed methodology has been illustrated by studying a subset of interpolation algorithms. The results obtained from this example show that the interpolation algorithms that traditionally offer better results in a normal operation (in the absence of errors) are not always the best when SEFI errors are present in the Bayer images.

Loss Analysis of Three-Level Active Neutral Point Clamped Converter under Fault Tolerance Operation

2012 ◽  
Vol 588-589 ◽  
pp. 847-850
Author(s):  
Wei Jing ◽  
Ran Ding
Keyword(s):  
Fault Tolerance ◽  
Fault Tolerant ◽  
Short Circuit ◽  
Phase Relationship ◽  
Open Circuit ◽  
Neutral Point ◽  
Normal Operation ◽  
Switching Frequency ◽  
Continuous Output ◽  
Control Schemes

Compared with traditional three-level neutral-point-clamped (NPC) converter, the recently proposed three-level active NPC (ANPC) converter has the ability to overcome the unbalanced loss distribution, and therefore result in increased output power or switching frequency. In industrial applications, fault tolerance ability of power converters is very important considering system availability, safety and reliability. This paper introduced the control schemes to get stable and continuous output under single device fault for both open-circuit and short-circuit fault cases. By analyzing the phase relationship of reference voltage and load current, the loss calculation method under fault tolerant operation was proposed. Calculation results show that the devices junction temperatures under fault tolerant operation are within the safe operation area (SOA) even they are a little bit higher compared to normal operation, which also confirm the effectiveness of the fault tolerant control schemes.

Fault tolerance criteria and walking capability analysis of a novel parallel-parallel hexapod break walking robot

Robotica ◽  
2014 ◽  
Vol 34 (3) ◽  
pp. 619-633 ◽  
Author(s):  
Yang Pan ◽  
Feng Gao ◽  
Hui Du
Keyword(s):  
Fault Tolerance ◽  
Parallel Mechanism ◽  
Fault Tolerant ◽  
Legged Robots ◽  
Harsh Environments ◽  
Walking Robot ◽  
Passive Joint ◽  
Actuation System ◽  
Capability Analysis ◽  
Simulation Results

SUMMARYFault tolerance is a very important issue for legged robots, especially in some harsh environments. One of the most fragile parts is the actuation system. There are two common faults of robot actuators: (1) the motor is locked and could not move anymore; (2) the motor is uncontrollable and can be treated as a passive joint. In this paper, we first discuss all fault combinations of a single leg of a hexapod walking robot with parallel-parallel mechanism topology. Then, the leg tolerable criterion is brought out, which defines whether a leg is fault tolerant. After that, the fault tolerance of the whole robot is researched, and we found that the robot can walk with one tolerable leg or two opposite tolerable legs. Finally, relative simulation results are given, which show the robot walk with one or two broken legs.

scholarly journals Open-Circuit Fault Tolerance Method for Three-Level Hybrid Active Neutral Point Clamped Converters

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1535 ◽  
Author(s):  
Laith M. Halabi ◽  
Ibrahim Mohd Alsofyani ◽  
Kyo-Beum Lee
Keyword(s):  
Fault Tolerance ◽  
Fault Tolerant ◽  
Harmonic Distortion ◽  
Industrial Applications ◽  
Open Circuit ◽  
Neutral Point ◽  
Normal Operation ◽  
Recent Developments ◽  
Additional Costs ◽  
Tolerance Method

Three-level converters are the most important technologies used in high power applications. Among these technologies, active neutral point clamped (ANPC) converters are mainly used for industrial applications. Meanwhile, recent developments have reduced losses and increased efficiency by using a hybrid combination of Si-IGBT and SiC-MOSFET switches to achieve hybrid ANPC (HANPC) converters. Open-circuit failure is regarded as a common and serious problem that affects the operational performance. In this paper, an effective fault-tolerant method is proposed for HANPC converters to safely re-utilize normal operation and increase the reliability of the system under fault conditions. Sequentially, regarding different topologies with reference to earlier fault tolerance methods which could not be applied to the HANPC, the proposed strategy enables continuous operation under faulty conditions effectively without using any additional devices by creating new voltage references, voltage offset, and switching sequences under the faulty conditions. Consequently, no additional costs or changes are associated with the inverter. A detailed analysis of the proposed strategy is presented highlighting the effects on the voltage, currents, and the corresponding total harmonic distortion (THD). The simulation and experimental results demonstrate the capability and effectiveness of the proposed method to maintain normal operation and eliminate the output distortion.

scholarly journals VLSI based Error Correction Code Using Fault-tolerant Parallel FFTs

2019 ◽  
Vol 8 (6) ◽  
pp. 2361-2364
Keyword(s):  
Fault Tolerance ◽  
Low Power ◽  
Error Correction ◽  
Fault Tolerant ◽  
Soft Errors ◽  
Building Blocks ◽  
Digital Circuit ◽  
Protection Scheme ◽  
On Demand ◽  
Digital World

systems increasing year by year. This results in the on demand for scaling and integration with the help of advanced CMOS technologies. Soft errors are reliability thread on modern digital world which explains the need of protection against errors in digital circuit applications. In some applications, techniques like Algorithm based fault tolerance (ABFT) are used to detect and correct error with the help of algorithm properties. As the filters are the basic building blocks in most of systems, FFTs are used with the protection scheme using parseval checks which detects and corrects errors. The proposed technique consume low power. A technique is proposed using parseval checks to protect the circuits from single bit errors and is further improved for multi bit errors detection and correction and are evaluated in area and delay parameters

Fault Tolerant Guidance of Under-Actuated Satellite Formation Flying Using Inter-Vehicle Coulomb Force

2019 ◽  
Vol 2 (1) ◽  
pp. 43-52
Author(s):  
Alireza Alikhani ◽  
Safa Dehghan M ◽  
Iman Shafieenejad
Keyword(s):  
Fault Tolerance ◽  
Formation Flying ◽  
Fault Tolerant ◽  
Coulomb Force ◽  
Control Law ◽  
Triangular Form ◽  
Satellite Formation Flying ◽  
Satellite Formation ◽  
Guidance Law ◽  
Tolerance Approach

In this study, satellite formation flying guidance in the presence of under actuation using inter-vehicle Coulomb force is investigated. The Coulomb forces are used to stabilize the formation flying mission. For this purpose, the charge of satellites is determined to create appropriate attraction and repulsion and also, to maintain the distance between satellites. Static Coulomb formation of satellites equations including three satellites in triangular form was developed. Furthermore, the charge value of the Coulomb propulsion system required for such formation was obtained. Considering Under actuation of one of the formation satellites, the fault-tolerance approach is proposed for achieving mission goals. Following this approach, in the first step fault-tolerant guidance law is designed. Accordingly, the obtained results show stationary formation. In the next step, tomaintain the formation shape and dimension, a fault-tolerant control law is designed.

Fault Tolerant Reliable Protocol (FTRP) Performance Evaluation in Wireless Sensor Networks: An Extensitive Study

2019 ◽  
pp. 1-36
Keyword(s):  
Wireless Sensor Networks ◽  
Fault Tolerance ◽  
Sensor Networks ◽  
Fault Tolerant ◽  
Cluster Head ◽  
Biological Data ◽  
Wireless Sensor ◽  
Delivery Ratio ◽  
Good Performer ◽  
Wide Range

Fault Tolerant Reliable Protocol (FTRP) is proposed as a novel routing protocol designed for Wireless Sensor Networks (WSNs). FTRP offers fault tolerance reliability for packet exchange and support for dynamic network changes. The key concept used is the use of node logical clustering. The protocol delegates the routing ownership to the cluster heads where fault tolerance functionality is implemented. FTRP utilizes cluster head nodes along with cluster head groups to store packets in transient. In addition, FTRP utilizes broadcast, which reduces the message overhead as compared to classical flooding mechanisms. FTRP manipulates Time to Live values for the various routing messages to control message broadcast. FTRP utilizes jitter in messages transmission to reduce the effect of synchronized node states, which in turn reduces collisions. FTRP performance has been extensively through simulations against Ad-hoc On-demand Distance Vector (AODV) and Optimized Link State (OLSR) routing protocols. Packet Delivery Ratio (PDR), Aggregate Throughput and End-to-End delay (E-2-E) had been used as performance metrics. In terms of PDR and aggregate throughput, it is found that FTRP is an excellent performer in all mobility scenarios whether the network is sparse or dense. In stationary scenarios, FTRP performed well in sparse network; however, in dense network FTRP’s performance had degraded yet in an acceptable range. This degradation is attributed to synchronized nodes states. Reliably delivering a message comes to a cost, as in terms of E-2-E. results show that FTRP is considered a good performer in all mobility scenarios where the network is sparse. In sparse stationary scenario, FTRP is considered good performer, however in dense stationary scenarios FTRP’s E-2-E is not acceptable. There are times when receiving a network message is more important than other costs such as energy or delay. That makes FTRP suitable for wide range of WSNs applications, such as military applications by monitoring soldiers’ biological data and supplies while in battlefield and battle damage assessment. FTRP can also be used in health applications in addition to wide range of geo-fencing, environmental monitoring, resource monitoring, production lines monitoring, agriculture and animals tracking. FTRP should be avoided in dense stationary deployments such as, but not limited to, scenarios where high application response is critical and life endangering such as biohazards detection or within intensive care units.

scholarly journals Fault Analysis and Non-Redundant Fault Tolerance in 3-Level Double Conversion UPS Systems Using Finite-Control-Set Model Predictive Control

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2210
Author(s):  
Luís Caseiro ◽  
André Mendes
Keyword(s):  
Fault Tolerance ◽  
Model Predictive Control ◽  
Predictive Control ◽  
Fault Tolerant ◽  
Finite Control ◽  
Control Set ◽  
Corrective Actions ◽  
Uninterruptible Power ◽  
Hardware Reconfiguration ◽  
Redundant Fault

Fault-tolerance is critical in power electronics, especially in Uninterruptible Power Supplies, given their role in protecting critical loads. Hence, it is crucial to develop fault-tolerant techniques to improve the resilience of these systems. This paper proposes a non-redundant fault-tolerant double conversion uninterruptible power supply based on 3-level converters. The proposed solution can correct open-circuit faults in all semiconductors (IGBTs and diodes) of all converters of the system (including the DC-DC converter), ensuring full-rated post-fault operation. This technique leverages the versatility of Finite-Control-Set Model Predictive Control to implement highly specific fault correction. This type of control enables a conditional exclusion of the switching states affected by each fault, allowing the converter to avoid these states when the fault compromises their output but still use them in all other conditions. Three main types of corrective actions are used: predictive controller adaptations, hardware reconfiguration, and DC bus voltage adjustment. However, highly differentiated corrective actions are taken depending on the fault type and location, maximizing post-fault performance in each case. Faults can be corrected simultaneously in all converters, as well as some combinations of multiple faults in the same converter. Experimental results are presented demonstrating the performance of the proposed solution.

scholarly journals An FTC Design via Multiple SOGIs with Suppression of Harmonic Disturbances for Five-Phase PMSG-Based Tidal Current Applications

2021 ◽  
Vol 9 (6) ◽  
pp. 574
Author(s):  
Zhuo Liu ◽  
Tianhao Tang ◽  
Azeddine Houari ◽  
Mohamed Machmoum ◽  
Mohamed Fouad Benkhoris
Keyword(s):  
Fault Tolerance ◽  
Energy Conversion ◽  
Tidal Current ◽  
Fault Tolerant ◽  
Tidal Current Energy ◽  
Electromagnetic Forces ◽  
Model Free ◽  
Energy Conversion Systems ◽  
Power Scale ◽  
Current Energy

This paper firstly adopts a fault accommodation structure, a five-phase permanent magnet synchronous generator (PMSG) with trapezoidal back-electromagnetic forces, in order to enhance the fault tolerance of tidal current energy conversion systems. Meanwhile, a fault-tolerant control (FTC) method is proposed using multiple second-order generalized integrators (multiple SOGIs) to further improve the systematic fault tolerance. Then, additional harmonic disturbances from phase current or back-electromagnetic forces in original and Park’s frames are characterized under a single-phase open condition. Relying on a classical field-oriented vector control scheme, fault-tolerant composite controllers are then reconfigured using multiple SOGIs by compensating q-axis control commands. Finally, a real power-scale simulation setup with a gearless back-to-back tidal current energy conversion chain and a small power-scale laboratory prototype in machine side are established to comprehensively validate feasibility and fault tolerance of the proposed method. Simulation results show that the proposed method is able to suppress the main harmonic disturbances and maintain a satisfactory fault tolerance when third harmonic flux varies. Experimental results reveal that the proposed model-free fault-tolerant design is simple to implement, which contributes to better fault-tolerant behaviors, higher power quality and lower copper losses. The main advantage of the multiple SOGIs lies in convenient online implementation and efficient multi-harmonic extractions, without considering system’s model parameters. The proposed FTC design provides a model-free fault-tolerant solution to the energy harvested process of actual tidal current energy conversion systems under different working conditions.

A Design for Fault-Tolerant Communication Middleware Based on Time-Triggered

2014 ◽  
Vol 548-549 ◽  
pp. 1326-1329
Author(s):  
Juan Jin ◽  
Qing Fan Gu
Keyword(s):  
Fault Tolerance ◽  
Real Time ◽  
Fault Location ◽  
Fault Tolerant ◽  
Application Software ◽  
Tolerance Mechanisms ◽  
The Real ◽  
Communication Middleware ◽  
Fault Mechanism ◽  
Health Diagnosis

Against to the unsustainable problems of health diagnosis, fault location and fault tolerance mechanisms that existing in the current avionics applications, we proposed a fault-tolerant communication middleware which is based on time-triggered in this paper. This middleware is designed to provide a support platform for applications of the real-time based on communication middleware. From the communication middleware level and also combined with time-triggered mechanism and fault-tolerant strategy, it diagnoses the general faults first, and then routes them to the appropriate fault mechanism to process it. So the middleware completely separates fault-tolerant process from the application software functions.

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