72,478 research outputs found

    Automatically synthesizing a planning and control subsystem for the DARPA urban challenge

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    To incorporate robots into society, they must be able to perform complex tasks while interacting with the world around them in a safe and dependable manner. The recent DARPA 2007 Urban Challenge made a step towards that goal by testing how well robotic vehicles can interact in an urban environment while dealing with static and dynamic obstacles and other cars. This paper uses the Urban challenge to demonstrates a general approach for automatically synthesizing correct hybrid controllers from high level descriptions. Here we create a planning and control subsystem for the vehicle that, if the information gathered by the sensor is correct, satisfies the requirements of the challenge for different dynamic environments. This approach automatically produces a system that is guaranteed to behave according to the traffic laws while interacting with other vehicles. Furthermore, it allows systems to be changed rapidly and easily thus reducing design time and eliminating human error

    Fully-deterministic execution of IEC-61499 models for Distributed Avionics Applications

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    © 2018 by the authors. The development of time-critical Distributed Avionics Applications (DAAs) pushes beyond the limit of existing modeling methodologies to design dependable systems. Aerospace and industrial automation entail high-integrity applications where execution time is essential for dependability. This tempts us to use modeling technologies from one domain in another. The challenge is to demonstrate that they can be effectively used across domains whilst assuring temporally dependable applications. This paper shows that an IEC61499-modeled DAA can satisfy temporal dependability requirements as to end-to-end flow latency when it is properly scheduled and realized in a fully deterministic avionics platform that entails Integrated Modular Avionics (IMA) computation along with Time-Triggered Protocol (TTP) communication. Outcomes from the execution design of an IEC61499-based DAA model for an IMA-TTP platform are used to check runtime correctness through DAA control stability. IEC 61499 is a modeling standard for industrial automation, and it is meant to facilitate distribution and reconfiguration of applications. The DAA case study is a Distributed Fluid Control System (DFCS) for the Airbus-A380 fuel system. Latency analysis results from timing metrics as well as closed-loop control simulation results are presented. Experimental outcomes suggest that an IEC61499-based DFCS model can achieve desired runtime latency for temporal dependability when executed in an IMA-TTP platform. Concluding remarks and future research direction are also discussed

    Initial trust establishment for personal space IoT systems

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    University of Technology Sydney. Faculty of Engineering and Information Technology.Internet of Things (IoT) is becoming a reality with innovative applications, and IoT platforms have been developed to transfer technologies from research to business solutions. With IoT applications, we have greater control over personal devices and achieve more insights into the resource consumption habits; business processes can be streamlined; people are also better connected to each other. Despite the benefits derived from the IoT systems, users are concerned about the trustworthiness of their collected data and offered services. Security controls can prevent user’s data from being compromised during transmission, storage or unauthorized access, but do not provide a guarantee against the misbehaved devices that report incorrect information and poor services or avoid conducting a common task. Establishing trust relationship among devices and continuously monitoring their trust is the key to guarantee a reliable IoT system and hence mitigate user’s concerns. In this dissertation, we propose and investigate a novel initial trust establishment architecture for personal space IoT systems. In the initial trust establishment architecture, we propose a trust evidence generation module based on a challenge-response mechanism to generate the trust evidence relying on the device’s responses to the challenges, a trust knowledge assessment module to obtain the knowledge about the device from the generated trust evidence, and a trust evaluation scheme to quantify the initial trust level of the devices. We design and investigate a challenge-response information design to determine feasible designs of the challenge-response mechanism that ensure meaningful and related trust knowledge about the device’s trustworthiness captured from the challenge-response operations. A new trust-aware communication protocol is designed and implemented by incorporating the proposed initial trust establishment architecture into existing Bluetooth Low Energy (BLE) protocol to demonstrate the feasibility and efficiency of the proposed initial trust establishment architecture in practice. In this work, we first study building blocks and possible architectures of the IoT and analyze key requirements of an IoT system. Based on the analysis, we identify the critical role of the initial trust establishment model and the challenges of establishing initial trust in IoT systems due to the lack of knowledge for the trust assessment to work. To address the challenges, we propose a novel initial trust establishment architecture that can generate trust evidence for assessing the initial trust level of new devices by conducting challenge-response operations within a limited time window before they are admitted to the system. We propose three new initial trust establishment models based on the proposed architecture. An implicit relationship between the responses and the challenges is assumed for the system to judge the initial trustworthiness of the devices. The first model assesses the initial trust value based on a probability associated with the device’s behavior captured from the challenge-response process. The second model investigates the initial trust value based on a binary outcome set, and the third model quantifies the initial trust level based on a multiple-component outcome set from the challenge-response process. Subsequently, we propose the challenge-response information design where the challenge-response process is investigated and designed to determine the information space of the challenger’s view on its environment so that the challenge can invite relevant responses from the target environment. Based on the design of the challenge-response mechanism, the system can capture meaningful trust knowledge about the devices from challenge-response operations at their admission phase. We finally design and implement the initial trust-aware BLE protocol which incorporates the proposed initial trust establishment architecture into the existing BLE protocol. The simulation results show the efficiency, feasibility, and dependability of using initial trust-aware BLE protocol for building a trustworthy personal space IoT systems. The novelty of this research lies in assessing the devices’ initial trust level within a limited time window, before their admission to the personal space IoT system, without requiring prior experience or recommendations. The major contribution of this thesis is that it helps the IoT business solution providers to build secure and trustworthy IoT systems by admitting dependable devices, monitoring the trust of admitted devices, detecting maligned devices, and building long-term trust among. As a result, it mitigates the user’s concerns about the trustworthiness of IoT systems and encourages broader adoption of IoT applications

    Software Diversity: Challenges to handle the imposed, Opportunities to harness the chosen

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    National audienceDiversity emerges as a critical concern that spans all activities in software engineering (from design to verification, from deployment to runtime resilience) and appears in all sorts of domains, which rely on software intensive systems, from systems of systems to pervasive combinations of Internet of Things and Internet of Services. If these domains are apparently radically different, we envision a strong convergence of the scientific principles underpinning their construction and validation towards flexible and open yet dependable systems. In this paper, we discuss the software engineering challenges raised by these requirements for flexibility and openness, focusing on four dimensions of diversity: the diversity of functionalities required by the different customers; the diversity of languages used by the stakeholders involved in the construction of these systems; the diversity of runtime environments in which software has to run and adapt; the diversity of failures against which the system must be able to react. In particular, we want to emphasize the challenges for handling imposed diversity, as well as the opportunities to leverage chosen diversity. The main challenge is that software diversity imposes to integrate the fact that software must adapt to changes in the requirements and environment -- in all development phases and in unpredictable ways. Yet, exploiting and increasing software diversity is a great opportunity to allow the spontaneous exploration of alternative software solutions and proactively prepare for unforeseen changes. Concretely, we want to provide software engineers with the ability: to characterize an 'envelope' of possible variations; to compose 'envelopes' (to discover new macro envelopes in an opportunistic manner); to dynamically synthesize software inside a given envelop

    A novel distributed architecture for IoT image processing using low-cost devices and open internet standards

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    Industry 4.0 can be defined as the integration of computers and automation to current industrial processes, with addition of smart and autonomous systems leveraged by machine learning techniques. In this scenario, a compact, dependable and fast controller is desired, featuring low energy consumption, easily programming and maintenance, with no mobile parts. Nowadays, computing power in single board computers, e.g. the Raspberry Pi among others, has been increased at a very important rate. In just three generations, Pi computers offer almost a two-fold speed gain, when compared to first models. Its design, an underlying video driver with general capabilities of regular OSes, makes them quite suitable to build image processing systems at very low cost, with no mobile parts and low energy consumption. However, designing such a system for industrial image processing is a tough challenge, since it implies to integrate cameras, image processing libraries, database servers and application software with graphical user interface, in an already resource constrained device. This work presents a new architecture for this kind of systems, by means of open internet standards, using a self-contained, high performance web server to publish a RESTful API and a set of web pages that use latest HTML5 capabilities to manage USB webcams and system data. This proposal also integrates OpenCV as a compiled script on client-side using the new WASM paradigm, with an optimized storage for images using -industry-standard RDBMS and a modular design that can target Windows and Linux as well.Sociedad Argentina de Informática e Investigación Operativ

    A synthesis of logic and biology in the design of dependable systems

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    The technologies of model-based design and dependability analysis in the design of dependable systems, including software intensive systems, have advanced in recent years. Much of this development can be attributed to the application of advances in formal logic and its application to fault forecasting and verification of systems. In parallel, work on bio-inspired technologies has shown potential for the evolutionary design of engineering systems via automated exploration of potentially large design spaces. We have not yet seen the emergence of a design paradigm that combines effectively and throughout the design lifecycle these two techniques which are schematically founded on the two pillars of formal logic and biology. Such a design paradigm would apply these techniques synergistically and systematically from the early stages of design to enable optimal refinement of new designs which can be driven effectively by dependability requirements. The paper sketches such a model-centric paradigm for the design of dependable systems that brings these technologies together to realise their combined potential benefits

    On cost-effective reuse of components in the design of complex reconfigurable systems

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    Design strategies that benefit from the reuse of system components can reduce costs while maintaining or increasing dependability—we use the term dependability to tie together reliability and availability. D3H2 (aDaptive Dependable Design for systems with Homogeneous and Heterogeneous redundancies) is a methodology that supports the design of complex systems with a focus on reconfiguration and component reuse. D3H2 systematizes the identification of heterogeneous redundancies and optimizes the design of fault detection and reconfiguration mechanisms, by enabling the analysis of design alternatives with respect to dependability and cost. In this paper, we extend D3H2 for application to repairable systems. The method is extended with analysis capabilities allowing dependability assessment of complex reconfigurable systems. Analysed scenarios include time-dependencies between failure events and the corresponding reconfiguration actions. We demonstrate how D3H2 can support decisions about fault detection and reconfiguration that seek to improve dependability while reducing costs via application to a realistic railway case study
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