Corrections to and Discussion of "Implementation and Evaluation of Mixed-criticality Scheduling Approaches for Sporadic Tasks"

The AMC-IA mixed-criticality scheduling analysis was proposed as an improvement to the AMC-MAX adaptive mixed-criticality scheduling analysis. However, we have identified several necessary corrections to the AMC-IA analysis. In this letter we motivate and describe those corrections, and discuss and illustrate why the corrected AMC-IA analysis cannot be shown to outperform AMC-MAX

Modular and Reconfigurable Platform as New Philosophy for the Development of Updatable Vehicular Electronics

[EN] A new conception in the development of Electronic Control Units (ECUs), which are also called On-Board Units (OBUs), is discussed in this paper from an ontological vision oriented to the compatibility of vehicles with future technologies in the automotive field. This work also provides a new methodology in the design of On-Board vehicle units. The proposed technique is based on the concept of modular electronic units that can change their functionality depending on the modules they are consisted of. The study was initially designed at the theoretical level, analysing the problems in the sector in the face of the coexistence between vehicles today and those that are bound to appear in the near future, and that will incorporate capabilities making them connected and even autonomous. Additionally, a fully operational prototype has been developed so as to ascertain the possibilities of the proposed solution.[ES] Se presenta una nueva concepción en el desarrollo de Unidades Electrónicas de Control (ECU), también denominadas Unidades de a Bordo (OBU), desde una visión ontológica orientada en la compatibilización de los vehículos con las futuras tecnologías emergentes en el campo de la automoción. Se comienza por un estudio teórico que analiza la problemática en el sector del transporte que va a presentar la convivencia entre los vehículos actuales y los que van a ir apareciendo en el futuro; y que vendrán influenciados por conceptos tales como los vehículos conectados o los vehículos autónomos. Este artículo también aporta una nueva metodología en el diseño de unidades vehiculares de a bordo, basada en el concepto de unidades electrónicas modulares que definen su funcionalidad en base a los módulos que le sean acoplados. Adicionalmente se ha desarrollado un prototipo completo y totalmente funcional con el fin de analizar las posibilidades de la solución propuesta.Este trabajo ha sido realizado parcialmente gracias al apoyo recibido mediante la resolución del 31/07/2014, publicada por la Universidad de Castilla-La Mancha, que establece las bases reguladoras de la convocatoria para contratos predoctorales con objeto de preparar nuevos investigadores bajo el Plan Propio de I+D+i. [2014/10340]Cañas, V.; García, A.; De Las Morenas, J.; Blanco, J. (2019). Plataforma Modular Reconfigurable como Nueva Filosofía para el Desarrollo de Electrónica Vehicular Actualizable. Revista Iberoamericana de Automática e Informática. 16(2):200-211. https://doi.org/10.4995/riai.2018.9863SWORD20021116

Real-Time Reliable Middleware for Industrial Internet-of-Things

This dissertation contributes to the area of adaptive real-time and fault-tolerant systems research, applied to Industrial Internet-of-Things (IIoT) systems. Heterogeneous timing and reliability requirements arising from IIoT applications have posed challenges for IIoT services to efficiently differentiate and meet such requirements. Specifically, IIoT services must both differentiate processing according to applications\u27 timing requirements (including latency, event freshness, and relative consistency of each other) and enforce the needed levels of assurance for data delivery (even as far as ensuring zero data loss). It is nontrivial for an IIoT service to efficiently differentiate such heterogeneous IIoT timing/reliability requirements to fit each application, especially when facing increasingly large data traffic and when common fault-tolerant mechanisms tend to introduce latency and latency jitters. This dissertation presents a new adaptive real-time fault-tolerant framework for IIoT systems, along with efficient and adaptive strategies to meet each IIoT application\u27s timing/reliability requirements. The contributions of the framework are demonstrated by three new IIoT middleware services: (1) Cyber-Physical Event Processing (CPEP), which both differentiates application-specific latency requirements and enforces cyber-physical timing constraints, by prioritizing, sharing, and shedding event processing. (2) Fault-Tolerant Real-Time Messaging (FRAME), which integrates real-time capabilities with a primary-backup replication system, to fit each application\u27s unique timing and loss-tolerance requirements. (3) Adaptive Real-Time Reliable Edge Computing (ARREC), which leverages heterogeneous loss-tolerance requirements and their different temporal laxities, to perform selective and lazy (yet timely) data replication, thus allowing the system to meet needed levels of loss-tolerance while reducing both the latency and bandwidth penalties that are typical of fault-tolerant sub-systems

High Performance Real-Time Scheduling Framework for Multiprocessor Systems

Embedded systems, performing specific functions in modern devices, have become pervasive in today's technology landscape. As many of these systems are real-time systems, they necessitate operations with stringent time constraints. This is especially evident in sectors like automotive and aerospace. This thesis introduces a High Performance Real-time Scheduling (HPRTS) framework, which is designed to navigate the multifaceted challenges faced by multiprocessor real-time systems. To begin with, the research attempts to bridge the gap between system reliability and resource sharing in Mixed-Criticality Systems (MCS). In addressing this, a novel fault-tolerance solution is presented. Its main goal is to enhance fault management and reduce blocking time during fault tolerance. Following this, the thesis delves into task allocation in systems with shared resources. In this context, we introduce a distinct Resource Contention Model (RCM). Using this model as a foundation, our allocation strategy is formulated with the aim to reduce resource contention. Moreover, in light of the escalating system complexity where tasks are represented using Directed Acyclic Graph (DAG) models, the research unveils a new Response Time Analysis (RTA) for multi-DAG systems. This particular analysis has been tailored to provide a safe and more refined bound. Reflecting on the contributions made, the achievements of the thesis highlight the potency of the HPRTS framework in steering real-time embedded systems toward high performance

Allocation and Optimisation of Mixed Criticality Cyclic Executives

Incorporating applications of differing levels of criticality onto the same platform in an efficient manner is a challenging problem. Highly critical applications require stringent verification and certification while lower criticality work may seek to make greater use of modern processing power with little to no requirement for verification. Much study into mixed criticality systems has considered this issue by taking scheduling paradigms designed to provide good platform utilisation at the expense of predictability and attempting to provide mechanisms that will allow for the verification of higher criticality work. In this thesis we take the alternative approach, we utilise a cyclic executive scheduler. Such schedulers are used extensively in industrial practice and provide very high levels of determinism making them a strong choice for applications with strict certification requirements. This work provides a platform which supports the highly critical work, alongside work of lower criticalities in a cyclic executive context. The aim being to provide a near-future platform which is able to support existing legacy highly critical software alongside newer less critical software which seeks to utilise multi-core architectures. One of the fundamental challenges of designing a system for a static scheduler is the allocation of applications/tasks to the cores and, in the case of cyclic executives, minor cycles of the system. Throughout this work we explore task allocation, we make extensive use of Linear Programming to model and allocate work. We suggest a limited task splitting technique to aid in system design and allocation. Finally, we propose two ways in which an allocation of work might be optimised to meet some design goal. This thesis proposes a scheduling policy for mixed criticality multi-core systems using a cyclic executive scheduler and explores the design, allocation and optimisation of such a system