1,334 research outputs found
An energy-aware architecture : a practical implementation for autonomous underwater vehicles
Energy awareness, fault tolerance and performance estimation are important aspects for
extending the autonomy levels of today’s autonomous vehicles. Those are related to the
concepts of survivability and reliability, two important factors that often limit the trust
of end users in conducting large-scale deployments of such vehicles. With the aim of
preparing the way for persistent autonomous operations this work focuses its efforts on
investigating those effects on underwater vehicles capable of long-term missions.
A novel energy-aware architecture for autonomous underwater vehicles (AUVs) is
presented. This, by monitoring at runtime the vehicle’s energy usage, is capable of
detecting and mitigating failures in the propulsion subsystem, one of the most common
sources of mission-time problems. Furthermore it estimates the vehicle’s performance
when operating in unknown environments and in the presence of external disturbances.
These capabilities are a great contribution for reducing the operational uncertainty that
most underwater platforms face during their deployment. Using knowledge collected while
conducting real missions the proposed architecture allows the optimisation of on-board
resource usage. This improves the vehicle’s effectiveness when operating in unknown
stochastic scenarios or when facing the problem of resource scarcity.
The architecture has been implemented on a real vehicle, Nessie AUV, used for real sea
experiments as part of multiple research projects. These gave the opportunity of evaluating
the improvements of the proposed system when considering more complex autonomous
tasks. Together with Nessie AUV, the commercial platform IVER3 AUV has been involved
in the evaluating the feasibility of this approach. Results and operational experience,
gathered both in real sea scenarios and in controlled environment experiments, are
discussed in detail showing the benefits and the operational constraints of the introduced
architecture, alongside suggestions for future research directions
Risk analysis and decision making for autonomous underwater vehicles
Risk analysis for autonomous underwater vehicles (AUVs) is essential to enable AUVs to
explore extreme and dynamic environments. This research aims to augment existing risk
analysis methods for AUVs, and it proposes a suite of methods to quantify mission risks and to
support the implementation of safety-based decision making strategies for AUVs in harsh
marine environments. This research firstly provides a systematic review of past progress of risk
analysis research for AUV operations. The review answers key questions including fundamental
concepts and evolving methods in the domain of risk analysis for AUVs, and it highlights future
research trends to bridge existing gaps. Based on the state-of-the-art research, a copula-based
approach is proposed for predicting the risk of AUV loss in underwater environments. The
developed copula Bayesian network (CBN) aims to handle non-linear dependencies among
environmental variables and inherent technical failures for AUVs, and therefore achieve
accurate risk estimation for vehicle loss given various environmental observations. Furthermore,
path planning for AUVs is an effective decision making strategy for mitigating risks and
ensuring safer routing. A further study presents an offboard risk-based path planning approach
for AUVs, considering a challenging environment with oil spill scenarios incorporated. The
proposed global Risk-A* planner combines a Bayesian-based risk model for probabilistic risk
reasoning and an A*-based algorithm for path searching. However, global path planning
designed for static environments cannot handle the unpredictable situations that may emerge,
and real-time replanned solutions are required to account for dynamic environmental
observations. Therefore, a hybrid risk-aware decision making strategy is investigated for AUVs
to combine static global planning with dynamic local re-planning. A dynamic risk analysis
model based on the system theoretic process analysis (STPA) and BN is applied for generating
a real-time risk map in target mission areas. The dynamic window algorithm (DWA) serves for
local path planning to avoid moving obstacles. The proposed hybrid risk-aware decisionmaking
architecture is essential for the real-life implementation of AUVs, leading eventually to
a real-time adaptive path planning process onboard the AUV
Proposal of a health care network based on big data analytics for PDs
Health care networks for Parkinson's disease (PD) already exist and have been already proposed in the literature, but most of them are not able to analyse the vast volume of data generated from medical examinations and collected and organised in a pre-defined manner. In this work, the authors propose a novel health care network based on big data analytics for PD. The main goal of the proposed architecture is to support clinicians in the objective assessment of the typical PD motor issues and alterations. The proposed health care network has the ability to retrieve a vast volume of acquired heterogeneous data from a Data warehouse and train an ensemble SVM to classify and rate the motor severity of a PD patient. Once the network is trained, it will be able to analyse the data collected during motor examinations of a PD patient and generate a diagnostic report on the basis of the previously acquired knowledge. Such a diagnostic report represents a tool both to monitor the follow up of the disease for each patient and give robust advice about the severity of the disease to clinicians
A patient agent controlled customized blockchain based framework for internet of things
Although Blockchain implementations have emerged as revolutionary technologies for various industrial applications including cryptocurrencies, they have not been widely deployed to store data streaming from sensors to remote servers in architectures known as Internet of Things. New Blockchain for the Internet of Things models promise secure solutions for eHealth, smart cities, and other applications. These models pave the way for continuous monitoring of patient’s physiological signs with wearable sensors to augment traditional medical practice without recourse to storing data with a trusted authority. However, existing Blockchain algorithms cannot accommodate the huge volumes, security, and privacy requirements of health data. In this thesis, our first contribution is an End-to-End secure eHealth architecture that introduces an intelligent Patient Centric Agent. The Patient Centric Agent executing on dedicated hardware manages the storage and access of streams of sensors generated health data, into a customized Blockchain and other less secure repositories. As IoT devices cannot host Blockchain technology due to their limited memory, power, and computational resources, the Patient Centric Agent coordinates and communicates with a private customized Blockchain on behalf of the wearable devices. While the adoption of a Patient Centric Agent offers solutions for addressing continuous monitoring of patients’ health, dealing with storage, data privacy and network security issues, the architecture is vulnerable to Denial of Services(DoS) and single point of failure attacks. To address this issue, we advance a second contribution; a decentralised eHealth system in which the Patient Centric Agent is replicated at three levels: Sensing Layer, NEAR Processing Layer and FAR Processing Layer. The functionalities of the Patient Centric Agent are customized to manage the tasks of the three levels. Simulations confirm protection of the architecture against DoS attacks. Few patients require all their health data to be stored in Blockchain repositories but instead need to select an appropriate storage medium for each chunk of data by matching their personal needs and preferences with features of candidate storage mediums. Motivated by this context, we advance third contribution; a recommendation model for health data storage that can accommodate patient preferences and make storage decisions rapidly, in real-time, even with streamed data. The mapping between health data features and characteristics of each repository is learned using machine learning. The Blockchain’s capacity to make transactions and store records without central oversight enables its application for IoT networks outside health such as underwater IoT networks where the unattended nature of the nodes threatens their security and privacy. However, underwater IoT differs from ground IoT as acoustics signals are the communication media leading to high propagation delays, high error rates exacerbated by turbulent water currents. Our fourth contribution is a customized Blockchain leveraged framework with the model of Patient-Centric Agent renamed as Smart Agent for securely monitoring underwater IoT. Finally, the smart Agent has been investigated in developing an IoT smart home or cities monitoring framework. The key algorithms underpinning to each contribution have been implemented and analysed using simulators.Doctor of Philosoph
Oceanids C2: An Integrated Command, Control, and Data Infrastructure for the Over-the-Horizon Operation of Marine Autonomous Systems
Long-range Marine Autonomous Systems (MAS), operating beyond the visual line-of-sight of a human pilot or research ship, are creating unprecedented opportunities for oceanographic data collection. Able to operate for up to months at a time, periodically communicating with a remote pilot via satellite, long-range MAS vehicles significantly reduce the need for an expensive research ship presence within the operating area. Heterogeneous fleets of MAS vehicles, operating simultaneously in an area for an extended period of time, are becoming increasingly popular due to their ability to provide an improved composite picture of the marine environment. However, at present, the expansion of the size and complexity of these multi-vehicle operations is limited by a number of factors: (1) custom control-interfaces require pilots to be trained in the use of each individual vehicle, with limited cross-platform standardization; (2) the data produced by each vehicle are typically in a custom vehicle-specific format, making the automated ingestion of observational data for near-real-time analysis and assimilation into operational ocean models very difficult; (3) the majority of MAS vehicles do not provide machine-to-machine interfaces, limiting the development and usage of common piloting tools, multi-vehicle operating strategies, autonomous control algorithms and automated data delivery. In this paper, we describe a novel piloting and data management system (C2) which provides a unified web-based infrastructure for the operation of long-range MAS vehicles within the UK's National Marine Equipment Pool. The system automates the archiving, standardization and delivery of near-real-time science data and associated metadata from the vehicles to end-users and Global Data Assembly Centers mid-mission. Through the use and promotion of standard data formats and machine interfaces throughout the C2 system, we seek to enable future opportunities to collaborate with both the marine science and robotics communities to maximize the delivery of high-quality oceanographic data for world-leading science
Environment-Centric Safety Requirements forAutonomous Unmanned Systems
Autonomous unmanned systems (AUS) emerge to take place of human operators in harsh or dangerous environments. However, such environments are typically dynamic and uncertain, causing unanticipated accidents when autonomous behaviours are no longer safe. Even though safe autonomy has been considered in the literature, little has been done to address the environmental safety requirements of AUS systematically. In this work, we propose a taxonomy of environment-centric safety requirements for AUS, and analyse the neglected issues to suggest several new research directions towards the vision of environment-centric safe autonomy
Mission Assurance for Autonomous Underwater Vehicles
The ubiquity of autonomous vehicles (AVs) is all but inevitable, and AVs have made fantastic leaps in their capabilities, partly thanks to advances in artificial intelligence and machine learning (AI/ML). With these great capabilities should come great assurance that AVs will behave safely and achieve their operational goals, or mission, despite foreseen and unforeseen circumstances. AV software is highly complex, increasing the likelihood of faults. AI/ML decision making is poorly understood. And, all computer-based systems are vulnerable to malicious software and other cybersecurity threats. Eliminating or mitigating any one of these is an open research problem. AVs must handle all three, without the benefit of a human operator. This dissertation investigates several aspects of AV mission assurance, and offers solutions for test and evaluation starting early in the development cycle, a use case with which to experiment, and a methodology for iteratively improving assurance as more is learned about a mission and its specific risks.
This dissertation focuses on autonomous underwater vehicles (AUVs). Each chapter explores particular aspects of AUV mission assurance and presents approaches to address them. We discuss the risks specific to AUV safety and mission assurance. We introduce the Digital Environment for Simulated Cyber Resilience Engineering, Test and Experimentation (DESCRETE) testbed that enables cost-effective AUV simulation, particularly with respect to system-level faults and attacks. We present the mission-assured AUV (MAAUV) use case, which we used to gather data on DESCRETE to improve the testbed and better understand mission assurance. We propose an iterative mission-assurance refinement analysis (IMARA) methodology for understanding system-failure impacts to mission. Applying IMARA to the MAAUV, we provide a guide for AUV and mission designers to best use limited assurance improvement and mitigation resources. Combining all these provides a comprehensive set of tools to improve AUV assurance
Electrical and Computer Engineering Annual Report 2015
Faculty Directory Faculty Awards Google ATAP—Michigan Tech MURA The Sound Beneath the Surface Advancing Microgrid Deployment Clearing the Air Power in Their Hands Faculty Publications Graduate Student Highlights Staff Profile—Chito Kendrick New ECE Concentrations SLAM Systems Senior Design and Enterprise External Advisory Committee Contracts and Grants Departmental Statistics Lind Memorial Endowed Fellowshiphttps://digitalcommons.mtu.edu/ece-annualreports/1003/thumbnail.jp
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