Fault Tolerance Measures Research Articles

Redundancy Control Strategy for a Dual-Redundancy Steer-by-Wire System

Currently, key factors hindering application of steer-by-wire systems are their inadequate safety and reliability, which are significant criteria for evaluating automotive active safety. Based on the steer-by-wire platform, a dual-redundant steering motor control system is proposed, featuring dual three-phase permanent magnet synchronous motors as execution motors, achieving redundancy from hardware. A torque vector-space-decoupling control method is introduced for these motors to ensure balanced and stable torque output. Upon a fault, fault-tolerant measures are taken by disconnecting power supply to the affected motor, which, despite reducing system functionality, allows for normal steering control. This research starts with modeling the dual three-phase motors to construct a simulation model. It then proceeds with hardware-in-the-loop testing integrated with the dual-redundancy steer-by-wire control system, conducting tests under dual-lane-change trajectory conditions. Finally, a steering system fault is simulated to assess fault handling and functional degradation. These experiments confirmed that the proposed method enabled balanced torque output from the dual three-phase motors in the redundant steering control and facilitated fault-tolerant processing post fault, ensuring the vehicle’s steering functions were maintained.

Real-time energy management simulation for enhanced integration of renewable energy resources in DC microgrids

The presented work addresses the growing need for efficient and reliable DC microgrids integrating renewable energy sources. However, for the sake of practicality, implementing complex control strategies can increase system complexity. Thus, efficient methodologies are required to provide efficient energy management of microgrids while increasing the integration of renewable energy sources. The primary contribution of this work is to investigate the issues related to operating a DC microgrid with conventional control designed to power DC motors using readily available, non-advanced control strategies with the objective of achieving stable and reliable grid performance without resorting to complex control schemes. The proposed microgrid integrates a combination of uncontrollable renewable distributed generators (DGs) alongside controllable DGs and energy storage systems, including batteries and supercapacitors, connected via DC links. The Incremental Conductance (InCond) algorithm is employed for maximum power point tracking to maximize power output from the PV system. The energy management strategy prioritizes the solar system as the primary source, with the battery and supercapacitor acting as backup power sources to ensure overall system reliability and sustainability. The effectiveness of the microgrid under various operating conditions is evaluated through extensive simulations conducted using MATLAB. These simulations explore different power generation scenarios, including normal operation with varying load levels and operation under Standard Test Conditions (STC). Moreover, fault analysis of the DC microgrid is performed to examine system reliability. The system performance is evaluated using real-time simulation software (OPAL-RT) to validate the effectiveness of the approach under real-time conditions. This comprehensive approach demonstrates the efficacy of operating a DC microgrid with conventional controllers, ensuring grid stability and reliability across various operating conditions and fault scenarios while prioritizing the use of renewable energy sources. The results illustrated that system efficiency increases with load, but fault tolerance measures, can introduce trade-offs between reliability and peak efficiency.

Fault-tolerant one-bit addition with the smallest interesting color code.

Fault-tolerant operations based on stabilizer codes are the state of the art in suppressing error rates in quantum computations. Most such codes do not permit a straightforward implementation of non-Clifford logical operations, which are necessary to define a universal gate set. As a result, implementations of these operations must use either error-correcting codes with more complicated error correction procedures or gate teleportation and magic states, which are prepared at the logical level, increasing overhead to a degree that precludes near-term implementation. Here, we implement a small quantum algorithm, one-qubit addition, fault-tolerantly on a trapped-ion quantum computer, using the [Formula: see text] color code. By removing unnecessary error correction circuits and using low-overhead techniques for fault-tolerant preparation and measurement, we reduce the number of error-prone two-qubit gates and measurements to 36. We observe arithmetic errors with a rate of ∼1.1 × 10-3 for the fault-tolerant circuit and ∼9.5 × 10-3 for the unencoded circuit.

Steel-ball-type six-dimensional dynamic force measurement platform with fault-tolerant performance

To satisfy the requirement of dynamic vibration testing of aerospace equipment on the ground prior to orbiting in space to guarantee the stable functioning of precision components, a steel-ball-type dynamic force measuring platform is suggested. First, based on two traditional platforms, a novel dynamic force measuring platform with fault-tolerant function, higher load capacity, and higher fundamental frequency is proposed, with its fault-tolerant measurement method theoretically deduced. Next, the study focuses on improving the measuring performance of redundant platforms by transforming conventional hard-connected branches into steel-ball branches. The structural parameters of these branches are examined theoretically, and simulations are used to confirm the theory's accuracy. Ultimately, the prototypes of the redundant steel-ball and hard-connected platforms are fabricated. Comparative experiments demonstrate that the steel-ball platform has superior performance, with static and dynamic measuring errors of 1.2% and 2.3%, respectively, and static and dynamic average coupling errors of 0.3% and 1.5%, respectively. The fault-tolerance function's validity is also confirmed.

A New Measure of Fault-Tolerance for Network Reliability: Double-Structure Connectivity

A New Measure of Fault-Tolerance for Network Reliability: Double-Structure Connectivity

Real-time current sensor fault detection and localization in DFIG wind turbine systems

<span lang="EN-US">The degree of reliability is one of the main issues in having the uninterrupted operation of fault-tolerant measurement and control systems. This paper presents a technique for detecting and localizing current sensor fault in doubly fed induction generator wind turbine systems (DFIG-WT). For this purpose, a methodology divided into three steps has been carried out and is presented as follows: the first step is the application of the zero-sequence component as an indicator of the presence of the sensor fault. The second step is based on the application of Concordia transformation on the current signals to generate different criteria for localizing the faulty sensor. Finally, an artificial neural network model is developed to analyze the localization criteria and identify the faulty sensor. All simulations are carried out in MATLAB/Simulink environment. Results show that the proposed technique is effective and can be used in real-time fault detection and localization in the DFIG-WT.</span>

Improved Cauchy Reed-Solomon Codes for Cloud Data Retrieval and Secured Data Storage using Role-Based Cryptographic Access and forensic investigation

Doling out client consent strategies to PC frameworks presents a huge test in guaranteeing legitimate approval, especially with the development of open frameworks and scattered stages like the cloud. RBAC has turned into a broadly involved strategy in cloud server applications because of its versatility. Granting access to cloud-stored data for investigating potential wrongdoings is crucial in computer forensic investigations. In cases where the cloud service provider's reliability is questionable, maintaining data confidentiality and establishing an efficient procedure for revoking access upon credential expiration is essential. As storage systems expand across vast networks, frequent component failures require stronger fault tolerance measures. Our work secure data-sharing system combines role (Authorized) based access control and AES encryption technology to provide safe key distribution and data sharing for dynamic groups. Data recovery entails protecting data dispersed over distributed systems by storing duplicate data and applying the erasure code technique. Erasure coding strategies, like Reed-Solomon codes, guarantee disc failure robustness while cutting down on data storage expenses dramatically. They do, however, also result in longer access times and more expensive repairs. Consequently, there has been a great deal of interest in academic and business circles for the investigation of novel coding strategies for cloud storage systems. The objective of this study is to present a novel coding method that utilizes the intricate Cauchy matrix in order to improve Reed-Solomon coding efficiency and strengthen fault tolerance.

Hyper [formula omitted] and sub-[formula omitted] fault tolerance of star graphs

Given a connected subgraph H of an interconnection network G, the H-structure connectivity κ(G;H) and the H-substructure connectivity κs(G;H) of G are two important measurements for fault tolerance of G. The n-dimensional star graph Sn is an attractive interconnection network candidate for multiprocessor systems, and it is (n−1)-regular. Let n≥4 and 0≤r≤n−1. In this paper, we prove that (i)κ(Sn;K1,r)=κs(Sn;K1,r)=n−1, and (ii) the removal of any minimum K1,r-cut (or, minimum sub-K1,r-cut) will split Sn into exactly two components, one of which is a singleton, where K1,r is a tree on 1+r vertices, r of which are leaves. The main results generalize some known ones.

Demonstrating multi-round subsystem quantum error correction using matching and maximum likelihood decoders

Quantum error correction offers a promising path for performing high fidelity quantum computations. Although fully fault-tolerant executions of algorithms remain unrealized, recent improvements in control electronics and quantum hardware enable increasingly advanced demonstrations of the necessary operations for error correction. Here, we perform quantum error correction on superconducting qubits connected in a heavy-hexagon lattice. We encode a logical qubit with distance three and perform several rounds of fault-tolerant syndrome measurements that allow for the correction of any single fault in the circuitry. Using real-time feedback, we reset syndrome and flag qubits conditionally after each syndrome extraction cycle. We report decoder dependent logical error, with average logical error per syndrome measurement in Z(X)-basis of ~0.040 (~0.088) and ~0.037 (~0.087) for matching and maximum likelihood decoders, respectively, on leakage post-selected data.

The generalized measure of edge fault tolerance in exchanged 3-ary n-cube

The exchanged 3-ary n-cube , proposed by Lv et al. in 2021, is obtained by removing edges from a 3-ary n-cube , where r + s + t + 1 = n. The topological interconnection network of a multiprocessor system can be modeled as a connected graph. Analyzing the fault tolerance of its topological structure is critical in the course of design and maintenance of it. Given a connected graph G, let F be an edge subset of G. F is called an h-edge-cut of G, if G−F is disconnected and each remaining component has the minimum degree of at least h. The h-edge-connectivity is the minimum cardinality of all h-edge-cuts of G. For and , in this paper, we determine the -edge-connectivity of exchanged 3-ary n-cubes, , and prove the exact values .

A Review on Immune-Inspired Node Fault Detection in Wireless Sensor Networks with a Focus on the Danger Theory.

The use of fault detection and tolerance measures in wireless sensor networks is inevitable to ensure the reliability of the data sources. In this context, immune-inspired concepts offer suitable characteristics for developing lightweight fault detection systems, and previous works have shown promising results. In this article, we provide a literature review of immune-inspired fault detection approaches in sensor networks proposed in the last two decades. We discuss the unique properties of the human immune system and how the found approaches exploit them. With the information from the literature review extended with the findings of our previous works, we discuss the limitations of current approaches and consequent future research directions. We have found that immune-inspired techniques are well suited for lightweight fault detection, but there are still open questions concerning the effective and efficient use of those in sensor networks.

Technical Committee on Fault Tolerant Measurement Systems

The goal of Technical Committee on Fault Tolerant Measurement Systems (TC-32) is to promote the research, training and outreach activities that cover all aspects of theory and practices of ensuring trustworthy measurement results under every operating condition. This is especially important in critical infrastructures where the cost of failure is very high. In recent years, TC-32 promotes and supports technical activities in reliable computation, propagation of uncertainty in signal processing systems and architectures/infrastructures/workflows to ensure fault tolerant instrumentation and measurements.

A Comprehensive Survey on Fault Tolerance in Multiphase AC Drives, Part 2: Phase and Switch Open-Circuit Faults

Multiphase machines are very convenient for applications that require high reliability. In this two-part survey, the state of the art about fault tolerance in multiphase drives is reviewed. In Part 1, an overview including numerous fault types was presented, along with fundamental notions about multiphase drives. Here, in Part 2, the focus is placed on phase/switch open-circuit (OC) faults in particular, which have received the most attention in the literature. Phase OC failures involve OCs in stator phases or in converter-machine connections, and switch/diode OCs are frequently dealt with similarly or identically. Thanks to the phase redundancy of multiphase drives, their operation can be satisfactorily continued under a certain number of OCs. Nonetheless, the procedure to follow for this purpose is far from unique. For given OC fault conditions, numerous fault-tolerant possibilities can be found in the literature, each of them with different advantages and disadvantages. Moreover, a great variety of methods have also been devised to detect and diagnose phase/switch OC failures so that, as soon as possible, the most appropriate fault-tolerance measures are applied. Thus, given the broad literature about tolerance to phase/switch OC faults in multiphase drives, the survey presented here is expected to be of great interest for the research community and industry.

Fault-Tolerant Parity Readout on a Shuttling-Based Trapped-Ion Quantum Computer

Quantum error correction requires the detection of errors by reliable measurements of suitable multi-qubit correlation operators. Here, we experimentally demonstrate a fault-tolerant weight-4 parity check measurement scheme. An additional 'flag' qubit serves to detect errors occurring throughout the parity measurement, which would otherwise proliferate into uncorrectable weight-2 errors on the qubit register. We achieve a flag-conditioned parity measurement single-shot fidelity of 93.2(2)\%. Deliberately injecting bit and phase-flip errors, we show that the fault-tolerant protocol is capable of reliably intercepting such faults. For holistic benchmarking of the parity measurement scheme, we use entanglement witnessing to show that the implemented circuit generates genuine six-qubit multi-partite entanglement. The fault-tolerant parity measurement scheme is an essential building block in a broad class of stabilizer quantum error correction protocols, including topological color codes. Our hardware platform is based on atomic ions stored in a segmented microchip ion trap. The qubit register is dynamically reconfigured via shuttling operations, enabling effective full connectivity without operational cross-talk, which provides key capabilities for scalable fault-tolerant quantum computing.

Emergency Operation in the Power Supply Domain According to ISO 26262

The automotive industry is currently driven by the megatrends electrification, automated driving, and connectivity. To cope with these trends, new functionalities and electric and/or electronic systems must be developed, which require a safe power supply by the power supply system. This leads to increased functional safety requirements for the power supply system, particularly regarding availability. Fault tolerance measures can be implemented to address a safety goal specifying a safety-related availability requirement. In this case, emergency operation (EO) may be necessary to reach a defined safe state. The definitions and examples provided in ISO 26262 focus on cold redundancy, whereby the backup system is not engaged during nominal operation. The objective of this paper is to evaluate EO in the context of ISO 26262 in detail and map the results to an exemplary power supply system architecture implementing cold redundancy. In general, the EO is considered to be free from unreasonable risk even though the actual automotive safety integrity level (ASIL) capability of the item is lower than the initially specified ASIL rating for the hazard due to its timing restrictions. To determine the maximum permissible duration of EO, not just random hardware faults shall be considered; additionally, systematic effects shall be considered. Furthermore, an EO may be entered due to transient faults potentially causing temporary EOs – introducing the necessity of an EO recording, e.g. by accumulating the time of all temporary EOs.

Safety-Related Availability in the Power Supply Domain

The automotive industry is currently driven by the megatrends electrification, automated driving and connectivity. To cope with these trends, new functionalities and electrical and/or electronic (E/E) systems need to be developed and deployed. Independent of the implementation of E/E systems, their power input shall be ensured by the power supply system as a shared resource – leading to increased functional safety requirements for power supply systems. If the loss of an item’s functionality can lead to a hazardous event, a safety goal (SG) specifying a safety-related availability (SaRA) requirement is derived. Thereby, switching to passive mode typically cannot be considered a safe state. To address an SG specifying a SaRA requirement, fault avoidance, fault forecasting and/or fault tolerance measures can be applied. In the case of fault tolerance measures implemented by redundancy, which leads to fail-active behavior, the performance of the backup system during nominal operation and after the first fault can be further refined. In this study, SaRA in the context of ISO 26262 is evaluated in detail and mapped to an example of the power supply domain.

Electric power steering systems: Electronic control strategies for enhanced performance and efficiency

This research paper explores advancements in electric power steering (EPS) systems, focusing on electronic control strategies that enhance vehicle performance and energy efficiency. EPS has become a crucial technology in modern vehicles, offering significant benefits over traditional hydraulic systems, including reduced energy consumption and greater integration potential with advanced driver assistance systems (ADAS). This study examines the evolution of steering systems, highlighting the transition from manual to hydraulic and eventually to EPS, as well as the key components and architecture of modern EPS systems.The paper further delves into innovative control algorithms, such as model-based, adaptive, and robust control strategies, which contribute to precise steering control and improved driving experience. In addition, it discusses performance enhancement techniques, including variable steering ratio and disturbance rejection, alongside energy-efficient motor control techniques and power-on-demand strategies that optimize system efficiency.Finally, this paper addresses the integration of EPS with ADAS and autonomous driving technologies, reliability and fault-tolerance measures, and the challenges and future trends shaping the next generation of steering systems. Through an analysis of current research and industry developments, this study provides a comprehensive overview of EPS technology and its future prospects.

Degenerate Quantum LDPC Codes With Good Finite Length Performance

We study the performance of medium-length quantum LDPC (QLDPC) codes in the depolarizing channel. Only degenerate codes with the maximal stabilizer weight much smaller than their minimum distance are considered. It is shown that with the help of OSD-like post-processing the performance of the standard belief propagation (BP) decoder on many QLDPC codes can be improved by several orders of magnitude. Using this new BP-OSD decoder we study the performance of several known classes of degenerate QLDPC codes including hypergraph product codes, hyperbicycle codes, homological product codes, and Haah's cubic codes. We also construct several interesting examples of short generalized bicycle codes. Some of them have an additional property that their syndromes are protected by small BCH codes, which may be useful for the fault-tolerant syndrome measurement. We also propose a new large family of QLDPC codes that contains the class of hypergraph product codes, where one of the used parity-check matrices is square. It is shown that in some cases such codes have better performance than hypergraph product codes. Finally, we demonstrate that the performance of the proposed BP-OSD decoder for some of the constructed codes is better than for a relatively large surface code decoded by a near-optimal decoder.

The [formula omitted]-restricted connectivity of balanced hypercubes

Restricted connectivity is a measure of fault-tolerance in multiprocessing systems. The h-restricted connectivity of a graph G, denoted by κh(G), is the minimum cardinality of vertex set F such that G−F is disconnected and the degree of each component is at least h. In this paper, we study the h-restricted connectivity of n-dimensional balanced hypercube BHn and prove that κ2h(BHn)=κ2h−1(BHn)=4h(n−h), where 1≤h≤⌊n2⌋ and n≥2.

The generalized measure of edge fault tolerance in exchanged crossed cube

This work considers the h-edge connectivity to measure the fault tolerance of exchanged crossed cube ECQ(s,t), an attractive variant network of hypercube. We get that the h-edge connectivity of ECQ(s,t) is 2h(s−h+1) if 0≤h≤s−1. It implies that at least 2h(s−h+1) edges have to be removed from ECQ(s,t) to get a disconnected graph that contains no vertices with degree less than h.