A Model-Driven Co-Design Framework for Fusing Control and Scheduling Viewpoints

Model-Driven Engineering (MDE) is widely applied in the industry to develop new software functions and integrate them into the existing run-time environment of a Cyber-Physical System (CPS). The design of a software component involves designers from various viewpoints such as control theory, software engineering, safety, etc. In practice, while a designer from one discipline focuses on the core aspects of his field (for instance, a control engineer concentrates on designing a stable controller), he neglects or considers less importantly the other engineering aspects (for instance, real-time software engineering or energy efficiency). This may cause some of the functional and non-functional requirements not to be met satisfactorily. In this work, we present a co-design framework based on timing tolerance contract to address such design gaps between control and real-time software engineering. The framework consists of three steps: controller design, verified by jitter margin analysis along with co-simulation, software design verified by a novel schedulability analysis, and the run-time verification by monitoring the execution of the models on target. This framework builds on CPAL (Cyber-Physical Action Language), an MDE design environment based on model-interpretation, which enforces a timing-realistic behavior in simulation through timing and scheduling annotations. The application of our framework is exemplified in the design of an automotive cruise control system

Contracts for Systems Design: Methodology and Application cases

Recently, contract based design has been proposed as an ”orthogonal” approach that can beapplied to all methodologies proposed so far to cope with the complexity of system design. Contract baseddesign provides a rigorous scaffolding for verification, analysis and abstraction/refinement. Companionreport RR-8759 proposes a unified treatment of the topic that can help in putting contract-based design in perspective.This paper complements RR-8759 by further discussing methodological aspects of system design withcontracts in perspective and presenting two application cases.The first application case illustrates the use of contracts in requirement engineering, an area of system designwhere formal methods were scarcely considered, yet are stringently needed. We focus in particular to thecritical design step by which sub-contracts are generated for suppliers from a set of different viewpoints(specified as contracts) on the global system. We also discuss important issues regarding certification inrequirement engineering, such as consistency, compatibility, and completeness of requirements.The second example is developed in the context of the Autosar methodology now widely advocated inthe automotive sector. We propose a contract framework to support schedulability analysis, a key step inAutosar methodology. Our aim differs from the many proposals for compositional schedulability analysisin that we aim at defining sub-contracts for suppliers, not just performing the analysis by parts—we knowfrom companion paper RR-8759 that sub-contracting to suppliers differs from a compositional analysis entirelyperformed by the OEM. We observe that the methodology advocated by Autosar is in contradiction withcontract based design in that some recommended design steps cannot be refinements. We show how tocircumvent this difficulty by precisely bounding the risk at system integration phase. Another feature ofthis application case is the combination of manual reasoning for local properties and use of the formalcontract algebra to lift a collection of local checks to a system wide analysis

Fusion of Model-free Reinforcement Learning with Microgrid Control: Review and Vision

Challenges and opportunities coexist in microgrids as a result of emerging large-scale distributed energy resources (DERs) and advanced control techniques. In this paper, a comprehensive review of microgrid control is presented with its fusion of model-free reinforcement learning (MFRL). A high-level research map of microgrid control is developed from six distinct perspectives, followed by bottom-level modularized control blocks illustrating the configurations of grid-following (GFL) and grid-forming (GFM) inverters. Then, mainstream MFRL algorithms are introduced with an explanation of how MFRL can be integrated into the existing control framework. Next, the application guideline of MFRL is summarized with a discussion of three fusing approaches, i.e., model identification and parameter tuning, supplementary signal generation, and controller substitution, with the existing control framework. Finally, the fundamental challenges associated with adopting MFRL in microgrid control and corresponding insights for addressing these concerns are fully discussed.Comment: 14 pages, 4 figures, published on IEEE Transaction on Smart Grid 2022 Nov 15. See: https://ieeexplore-ieee-org.utk.idm.oclc.org/stamp/stamp.jsp?arnumber=995140

Contracts for Systems Design: Theory

Aircrafts, trains, cars, plants, distributed telecommunication military or health care systems,and more, involve systems design as a critical step. Complexity has caused system design times and coststo go severely over budget so as to threaten the health of entire industrial sectors. Heuristic methods andstandard practices do not seem to scale with complexity so that novel design methods and tools based on astrong theoretical foundation are sorely needed. Model-based design as well as other methodologies suchas layered and compositional design have been used recently but a unified intellectual framework with acomplete design flow supported by formal tools is still lacking.Recently an “orthogonal” approach has been proposed that can be applied to all methodologies introducedthus far to provide a rigorous scaffolding for verification, analysis and abstraction/refinement: contractbaseddesign. Several results have been obtained in this domain but a unified treatment of the topic that canhelp in putting contract-based design in perspective is missing. This paper intends to provide such treatmentwhere contracts are precisely defined and characterized so that they can be used in design methodologiessuch as the ones mentioned above with no ambiguity. In addition, the paper provides an important linkbetween interface and contract theories to show similarities and correspondences.This paper is complemented by a companion paper where contract based design is illustrated throughuse cases

A conceptual framework for linking worker and organizational needs to data and information requirements

Data and information intensiveness is increasing at the shop floor in the manufacturing industry, which leads to the fragmentation of tasks as the needed information is often scattered in different places. The challenge is to provide correct and right amount of information both to increase job satisfaction of workers and to increase productivity. The objective of this study is to identify what kind of manufacturing data, information and intelligent knowledge is needed by workers at the shop floor, and to identify the requirements when opening the knowledge flows between the shop floor and management processes. As a results of the study, a conceptual framework is created to link workers’ and organizational needs to data and information requirements. The framework identifies information and knowledge flows from and to required human-machine interfaces. This study also highlights the link between work processes at the shop floor to the innovation and organizational learning processes of manufacturing companies

Assistive technology design and development for acceptable robotics companions for ageing years

© 2013 Farshid Amirabdollahian et al., licensee Versita Sp. z o. o. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs license, which means that the text may be used for non-commercial purposes, provided credit is given to the author.A new stream of research and development responds to changes in life expectancy across the world. It includes technologies which enhance well-being of individuals, specifically for older people. The ACCOMPANY project focuses on home companion technologies and issues surrounding technology development for assistive purposes. The project responds to some overlooked aspects of technology design, divided into multiple areas such as empathic and social human-robot interaction, robot learning and memory visualisation, and monitoring persons’ activities at home. To bring these aspects together, a dedicated task is identified to ensure technological integration of these multiple approaches on an existing robotic platform, Care-O-Bot®3 in the context of a smart-home environment utilising a multitude of sensor arrays. Formative and summative evaluation cycles are then used to assess the emerging prototype towards identifying acceptable behaviours and roles for the robot, for example role as a butler or a trainer, while also comparing user requirements to achieved progress. In a novel approach, the project considers ethical concerns and by highlighting principles such as autonomy, independence, enablement, safety and privacy, it embarks on providing a discussion medium where user views on these principles and the existing tension between some of these principles, for example tension between privacy and autonomy over safety, can be captured and considered in design cycles and throughout project developmentsPeer reviewe

Automated Fault Tolerance Augmentation in Model-Driven Engineering for CPS

Cyber-Physical Systems are usually subject to dependability requirements such as safety and reliability constraints. Over the last 50 years, a body of efficient fault-tolerance mechanisms has been devised to handle faults occurring at run-time. However, properly implementing those mechanisms is a time-consuming task that requires a great deal of know-how. In this paper, we propose a general framework which allows system designers to decouple functional and non-functional concerns, and express non- functional properties at design time using domain-specific languages. In the spirit of generative programming, functional models are then automatically “augmented” with dependability mechanisms. Importantly, the real-time behavior of the initial models in terms of sampling times and meeting deadlines is preserved. The practicality of the approach is demonstrated with the automated implementation of one prominent software fault-tolerance pattern, namely N-Version Programming, in the CPAL model-driven engineering workflow

Contracts for System Design

Systems design has become a key challenge and differentiating factor over the last decades for system companies. Aircrafts, trains, cars, plants, distributed telecommunication military or health care systems, and more, involve systems design as a critical step. Complexity has caused system design times and costs to go severely over budget so as to threaten the health of entire industrial sectors. Heuristic methods and standard practices do not seem to scale with complexity so that novel design methods and tools based on a strong theoretical foundation are sorely needed. Model-based design as well as other methodologies such as layered and compositional design have been used recently but a unified intellectual framework with a complete design flow supported by formal tools is still lacking albeit some attempts at this framework such as Platform-based Design have been successfully deployed. Recently an "orthogonal" approach has been proposed that can be applied to all methodologies proposed thus far to provide a rigorous scaffolding for verification, analysis and abstraction/refinement: contractbased design. Several results have been obtained in this domain but a unified treatment of the topic that can help in putting contract-based design in perspective is still missing. This paper intends to provide such treatment where contracts are precisely defined and characterized so that they can be used in design methodologies such as the ones mentioned above with no ambiguity. In addition, the paper provides an important link between interfaces and contracts to show similarities and correspondences. Examples of the use of contracts in design are provided as well as in depth analysis of existing literature.Cet article fait le point sur le concept de contrat pour la conception de systèmes. Les contrats que nous proposons portent, non seulement sur des propriétés de typage de leurs interfaces, mais incluent une description abstraite de comportements. Nous proposons une méta-théorie, ou, si l'on veut, une théorie générique des contrats, qui permet le développement séparé de sous-systèmes. Nous montrons que cette méta-théorie se spécialise en l'une ou l'autre des théories connues

An annotated bibligraphy of multisensor integration

technical reportIn this paper we give an annotated bibliography of the multisensor integration literature

Self-adapting security monitoring in Eucalyptus cloud environment

This paper discusses the importance of virtual machine (VM) scheduling strategies in cloud computing environments for handling the increasing number of tasks due to virtualization and cloud computing technology adoption. The paper evaluates legacy methods and specific VM scheduling algorithms for the Eucalyptus cloud environment and compare existing algorithms using QoS. The paper also presents a self-adapting security monitoring system for cloud infrastructure that takes into account the specific monitoring requirements of each tenant. The system uses Master Adaptation Drivers to convert tenant requirements into configuration settings and the Adaptation Manager to coordinate the adaptation process. The framework ensures security, cost efficiency, and responsiveness to dynamic events in the cloud environment. The paper also presents the need for improvement in the current security monitoring platform to support more types of monitoring devices and cover the consequences of multi-tenant setups. Future work includes incorporating log collectors and aggregators and addressing the needs of a super-tenant in the security monitoring architecture. The equitable sharing of monitoring resources between tenants and the provider should be established with an adjustable threshold mentioned in the SLA. The results of experiments show that Enhanced Round-Robin uses less energy compared to other methods, and the Fusion Method outperforms other techniques by reducing the number of Physical Machines turned on and increasing power efficienc