scholarly journals Preliminary study towards the definition of a PHM framework for the hydraulic system of a fly-by-wire helicopter

2020 ◽  
Vol 12 (1) ◽  
pp. 13
Author(s):  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Massimo Sorli
Keyword(s):  
Flight Control ◽  
Hydraulic System ◽  
Preliminary Analysis ◽  
Failure Modes ◽  
Health Management ◽  
Management Approach ◽  
Critical System ◽  
Wide Range ◽  
The Subject ◽  
Definition Of

On-board hydraulic systems are tasked to provide a number of critical functions to ensure the in-flight operability of rotary-wings vehicles; the hydraulic plant is required to supply power to the flight control actuators and utilities, as well as condition the hydraulic fluid, under a wide range of possible in-service conditions. Being a flight-critical system, the definition of a Prognostics and Health Management framework would provide significant advantages to the users, such as better risk mitigation, improved availability and a reduction in the occurrences of unpredicted failures which still represent one of the more known downsides of helicopters. A preliminary analysis on the effects of the inception and progression of several degradation types is the first step towards assessing if such PHM system is feasible, and which failure modes are more likely to be observed. Moreover, since several key components are frequently provided by different suppliers to the airframer, this preliminary analysis would allow to better assess if an Integrated Vehicle Health Management approach, integrating signals coming from different components, could be beneficial. To pursue this study, a complete model of the hydraulic system for a fly-by-wire helicopter has been prepared. Then, an in-depth simulation campaign was pursued with the aim of studying the interactions between different failure modes, the effects that the propagating degradations have on the system performances and which signals can be used to define a robust set of features. The paper introduces the case-study under analysis, a general configuration for fly-by-wire helicopters, presenting the most prominent peculiarities of the system and the effect of such peculiarities on the definition of health monitoring schemes. The model is then used to describe the behavior of the system under nominal and degraded conditions is introduced. Between the possible failure modes, the interaction between wear in several mechanical components and the occlusion of the hydraulic lines filters was chosen as the subject of this study; motivations are provided and the degradation model described in detail. Hence, results of a wide-ranging simulation campaign are presented, where the time-domain response of the system is used to guide in the definition of a proper set of features able to characterize the selected fault cases. Selected features are presented, chosen according to significant metrics such as correlation with the simulated degradations, signal-to-noise ratio and accuracy. Two different approaches with a varying degree of integration between system signals are proposed and compared. Prognostics is then pursued through well-known particle filter algorithms. The analysis provides promising results on the capability of successfully detecting, isolating and identifying the selected fault mode; laying the foundations for further and more comprehensive studies on the subject.

Typologization of security regulation

2020 ◽  
pp. 20-27
Author(s):  
Denis Tikhomirov
Keyword(s):  
Social Relations ◽  
Scientific Literature ◽  
Legal Regulation ◽  
Procedural Understanding ◽  
Limited Ability ◽  
Methodological Basis ◽  
Wide Range ◽  
The Subject ◽  
Definition Of ◽  
Legal Understanding

The purpose of the article is to typologize terminological definitions of security, to find out the general, to identify the originality of their interpretations depending on the subject of legal regulation. The methodological basis of the study is the methods that made it possible to obtain valid conclusions, in particular, the method of comparison, through which it became possible to correlate different interpretations of the term "security"; method of hermeneutics, which allowed to elaborate texts of normative legal acts of Ukraine, method of typologization, which made it possible to create typologization groups of variants of understanding of the term "security". Scientific novelty. The article analyzes the understanding of the term "security" in various regulatory acts in force in Ukraine. Typological groups were understood to understand the term "security". Conclusions. The analysis of the legal material makes it possible to confirm that the issues of security are within the scope of both legislative regulation and various specialized by-laws. However, today there is no single conception on how to interpret security terminology. This is due both to the wide range of social relations that are the subject of legal regulation and to the relativity of the notion of security itself and the lack of coherence of views on its definition in legal acts and in the scientific literature. The multiplicity of definitions is explained by combinations of material and procedural understanding, static - dynamic, and conditioned by the peculiarities of a particular branch of legal regulation, limited ability to use methods of one or another branch, the inter-branch nature of some variations of security, etc. Separation, common and different in the definition of "security" can be used to further standardize, in fact, the regulatory legal understanding of security to more effectively implement the legal regulation of the security direction.

Interaction, engagement, and perceived interactivity in single-handed interaction

2016 ◽  
Vol 26 (5) ◽  
pp. 1134-1157 ◽  
Author(s):  
Donghee Shin ◽  
Myunggoon Choi ◽  
Jang Hyun Kim ◽  
Jae-gil Lee
Keyword(s):  
Behavioral Intention ◽  
Interaction Techniques ◽  
Content Type ◽  
Thumb Movement ◽  
Wide Range ◽  
Mobile Industry ◽  
Perceived Interactivity ◽  
The Subject ◽  
Definition Of ◽  
Practical Implications

Purpose The purpose of this paper is to examine the effects of interaction techniques (e.g. swiping and tapping) and the range of thumb movement on interactivity, engagement, attitude, and behavioral intention in single-handed interaction with smartphones. Design/methodology/approach A 2×2 between-participant experiment (technological features: swiping and tapping×range of thumb movement: wide and narrow) was conducted to study the effects of interaction techniques and thumb movement ranges. Findings The results showed that the range of thumb movement had significant effects on perceived interactivity, engagement, attitude, and behavioral intention, whereas no effects were observed for interaction techniques. A narrow range of thumb movement had more influence on the interactivity outcomes in comparison to a wide range of thumb movement. Practical implications While the subject of actual and perceived interactivity has been discussed, the issue has not been applied to smartphone. Based on the research results, the mobile industry may come up with a design strategy that balances feature- and perception-based interactivity. Originality/value This study adopted the perspective of the hybrid definition of interactivity, which includes both actual and perceived interactivity. Interactivity effect outcomes mediated by perceived interactivity.

scholarly journals A Case Study on the Detection and Prognosis of Internal Leakages in Electro-Hydraulic Flight Control Actuators

Actuators ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 215
Author(s):  
Antonio Carlo Bertolino ◽  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Massimo Sorli
Keyword(s):  
Flight Control ◽  
Particle Filtering ◽  
Health Management ◽  
State Of The Art ◽  
Commercial Aircraft ◽  
Flight Data ◽  
Prognostic System ◽  
Hydraulic Servo ◽  
Definition Of

Electro-hydraulic servo-actuators (EHSAs) are currently considered the state-of-the art solution for the control of the primary flight control systems of civil and military aircraft. Combining the expected service life of a commercial aircraft with the fact that electro-hydraulic technology is employed in the vast majority of currently in-service aircraft and is planned to be used on future platforms as well, the development of an effective Prognostic and Health Management (PHM) system could provide significant advantages to fleet operators and aircraft maintenance, such as the reduction of unplanned flight disruptions and increased availability of the aircraft. The occurrence of excessive internal leakage within the EHSAs is one of the most common causes of return from the field of flight control actuators, making this failure mode a priority in the definition of any dedicated PHM routine. This paper presents a case study on the design of a prognostic system for this degradation mode, in the context of a wider effort toward the definition of a prognostic framework suitable to work on in-flight data. The study is performed by means of a high-fidelity simulation model supported by experimental activities. Results of both the simulation and the experimental work are used to select a suitable feature, then implemented within the prognostic framework based on particle filtering. The algorithm is at first theoretically discussed, and then tested against several degradation patterns. Performances are evaluated through state-of-the-art metrics, showing promising results and providing the basis towards future applications on real in-flight data.

A Simulation Survey on the Effects of Progressing Faults Within the SCAS of a Flight Control Actuator for Helicopters

2021 ◽  
Author(s):  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Massimo Sorli ◽  
Giuseppe Vitrani
Keyword(s):  
Flight Control ◽  
Health Management ◽  
Risk Mitigation ◽  
Selection Process ◽  
Stability Control ◽  
Features Selection ◽  
Vertical Walls ◽  
Low Altitude ◽  
Definition Of ◽  
Rotary Wing

Abstract Stability Control Augmentation Systems (SCAS) are widely adopted to enhance the flight stability of rotary-wing aircraft operating in difficult aerodynamic conditions, such as low altitude missions, stationary flight nearby vertical walls or in presence of heavy gusts. Such systems are based upon small electro-hydraulic servosystems controlled in position through a dedicated servovalve. The SCAS operates with limited authority over the main control linkage translating the pilot input in the movement of the main flight control actuator. Being critical for the operability of the helicopter, the definition of a Prognostics and Health Management (PHM) framework for the SCAS systems would provide significant advantages, such as better risk mitigation, improved availability, and a reduction in the occurrences of unpredicted failures which still represent one of the most known downsides of helicopters. This paper provides the results of a preliminary analysis on the effects of the inception and progression of several degradation types within a simulated SCAS system. Signals usually available within such devices are hence combined with measurements provided by additional sensors to check the feasibility of a PHM system with and without dedicated sensors. The resulting features selection process shows that although the dedicated measurements are required to design a complete PHM system, it appears nonetheless possible to obtain valuable information on the health status of the SCAS system without resorting to additional sensors.

scholarly journals R2U2: Tool Overview

10.29007/5pch ◽  
2018 ◽  
Author(s):  
Kristin Yvonne Rozier ◽  
Johann Schumann
Keyword(s):  
Health Management ◽  
Autonomous Systems ◽  
Building Blocks ◽  
Unmanned Aerial Systems ◽  
Critical System ◽  
Safety Critical System ◽  
Target Architecture ◽  
Wide Range ◽  
Aerial Systems ◽  
Temporal Formula

R2U2 (Realizable, Responsive, Unobtrusive Unit) is an extensible framework for runtime System Health Management (SHM) of cyber-physical systems. R2U2 can be run in hardware (e.g., FPGAs), or software; can monitor hardware, software, or a combination of the two; and can analyze a range of different types of system requirements during runtime. An R2U2 requirement is specified utilizing a hierarchical combination of building blocks: temporal formula runtime observers (in LTL or MTL), Bayesian networks, sensor filters, and Boolean testers. Importantly, the framework is extensible; it is designed to enable definitions of new building blocks in combination with the core structure. Originally deployed on Unmanned Aerial Systems (UAS), R2U2 is designed to run on a wide range of embedded platforms, from autonomous systems like rovers, satellites, and robots, to human-assistive ground systems and cockpits.R2U2 is named after the requirements it satisfies; while the exact requirements vary by platform and mission, the ability to formally reason about Realizability, Responsiveness, and Unobtrusiveness is necessary for flight certifiability, safety-critical system assurance, and achievement of technology readiness levels for target systems. Realizability ensures that R2U2 is sufficiently expressive to encapsulate meaningful runtime requirements while maintaining adaptability to run on different platforms, transition be- tween different mission stages, and update quickly between missions. Responsiveness entails continuously monitoring the system under test, real-time reasoning, reporting intermediate status, and as-early-as-possible requirements evaluations. Unobtrusiveness ensures compliance with the crucial properties of the target architecture: functionality, certifiability, timing, tolerances, cost, or other constraints.

scholarly journals “Alle Hilfsmittel an der Hand”: note sulle prime fotografie collezionate da Aby Warburg

2020 ◽  
Vol 5 (10) ◽  
pp. 122-139
Author(s):  
Katia Mazzucco
Keyword(s):  
20Th Century ◽  
Art History ◽  
Research Tool ◽  
Theoretical Position ◽  
Wide Range ◽  
The Subject ◽  
Methodological Approaches ◽  
Definition Of ◽  
Aby Warburg ◽  
Made In

There is no evidence of a consistent theoretical position of Aby Warburg regarding photography, but his scattered notes on the subject allow for a deductive evaluation. The considerable use of photographs that he made in his work suggests a wide range of methodological approaches, with significant implications for the disciplinary and methodological definition of art history and the development of photographic documentation at the turn of the 20th century. This essay provides examples of Warburg’s early attention to photography, both as a research tool and a required piece of equipment for any research institute.

Mutt Methods, Minimalism, and Guiding Heuristics for UX Project Management

2015 ◽  
Vol 7 (3) ◽  
pp. 38-48 ◽  
Author(s):  
Andrew Mara ◽  
Jessica Jorgenson
Keyword(s):  
Project Management ◽  
Evaluation Criteria ◽  
Management Approach ◽  
Work Style ◽  
Wide Range ◽  
Narrow Definition ◽  
Management Approaches ◽  
Definition Of

UX has coalesced from a multiplicity of perspectives and approaches, and is held together by a focus on the user. In order to create the flexibility necessary to accommodate the wide range of projects and perspectives, it is necessary to narrow down the UX team concerns and goals before the project management approach is selected. Rather than depending upon a narrow definition of project management that grows out of an overall work style—whether, Agile, lean, or waterfall—the UX project can usefully benefit from a tailored project management approach that matches the project demands. To narrow down the team focus, the authors propose four heuristics to locate: 1. project scope, 2. project agents, 3. evaluation timing, and 4. evaluation criteria. Once those four questions are answered, the UX team can then better locate what kind of project management approaches and genres will best accomplish the team goals.

scholarly journals Judicial construction and technical expertise as a means of protecting the interests of participants of building process

2018 ◽  
Vol 170 ◽  
pp. 01009
Author(s):  
Andrey Butyrin ◽  
Ekaterina Stativa
Keyword(s):  
Public Relations ◽  
Legal Regulation ◽  
Technical Condition ◽  
Causal Connection ◽  
Technical Expertise ◽  
Building Process ◽  
Wide Range ◽  
The Subject ◽  
Definition Of ◽  
Judicial Expertise

The paper defines the significance of judicial construction and technical expertise as a means of protecting the rights and interests of participants of building process when considering and resolving economic and industrial disputes, significant number of which is based on the imperfect legal regulation of public relations of this activity. Noting the insufficient knowledge of the judicial community about the informational potential of this kind of judicial expertise, the authors presented a wide range of types of studies conducted by the building expert in practice. The presented list includes the following types of studies of the object of judicial construction and technical expertise: establishment of its existence; location; technical condition; its properties; qualitative and quantitative characteristics; cost; an object's belonging to a particular class, sort, kind, type, group; establishment of the conformity of its characteristics to a certain standard, rule or regulation. Consideration is also made of studies that have been conducted in judicial and investigation expert practice aimed at establishing the presence and types of causal connection between events that have been the subject of criminal investigation and (or) judicial proceeding, as well as establishing the object’s existence by its representation, belonging of a part of the object to the whole, definition of a unified source of origin (manufacturer) of several objects of judicial construction and technical expertise.

scholarly journals Design of a PHM system for electro-mechanical flight controls: a roadmap from preliminary analyses to iron-bird validation

2019 ◽  
Vol 304 ◽  
pp. 04018 ◽  
Author(s):  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Massimo Sorli
Keyword(s):  
Fault Diagnosis ◽  
Control Systems ◽  
Flight Control ◽  
Management System ◽  
Health Management ◽  
Prognostics And Health Management ◽  
Case Scenario ◽  
Flight Controls ◽  
Definition Of ◽  
New Algorithms

Literature on PHM is focused on research dedicated to the definition of new algorithms to achieve better failures prognosis or earlier and more accurate fault diagnosis, but lacks of examples on the design of novel PHM frameworks and the practical issues related with their implementation. This paper describes a roadmap for the design of a novel Prognostics and Health Management system while making reference to a real-case scenario applied to electro-mechanical actuators for flight control systems.

scholarly journals Comprehensive Safety Evaluation of Highly Automated Vehicles at the Roundabout Scenario

2021 ◽  
Author(s):  
Xinpeng Wang ◽  
Songan Zhang ◽  
Huei Peng
Keyword(s):  
Adaptive Sampling ◽  
Failure Modes ◽  
Initial Conditions ◽  
Safety Evaluation ◽  
Evaluation Framework ◽  
Test Case Generation ◽  
Test Case ◽  
Critical System ◽  
Wide Range ◽  
Game Theoretic

A highly automated vehicle (HAV) is a safety-critical system. Therefore, a verification and validation (V&V) process that rigorously evaluates the safety of HAVs is necessary before their release to the market. In this paper, we propose an interaction-aware safety evaluation framework for the HAV and apply it to the roundabout entering, a highly interactive driving scenario with various traffic situations. Instead of assuming that the primary other vehicles (POVs) take predetermined maneuvers, we model the POVs as game-theoretic agents. To capture a wide variety of interactions between the POVs and the vehicle under test (VUT), we use level-k game theory and social value orientation to characterize the interactive behaviors and train a diverse library of POVs using reinforcement learning. The game-theoretic library, together with initial conditions, form a rich testing space for the two-POV roundabout scenario. On the other hand, we propose an adaptive test case generation scheme based on adaptive sampling and stochastic optimization to efficiently generate customized challenging cases for the VUT from the testing space. In simulations, the proposed testing space design captured a wide range of interactive situations at the roundabout scenario. The proposed test case generation scheme was found to cover the failure modes of the VUT more effectively compared to other test case generation approaches.

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