Robust Design of a Test Bench for PHM Study of Ball Screw Drives

2019 ◽  
Author(s):  
A. C. Bertolino ◽  
A. De Martin ◽  
G. Jacazio ◽  
S. Mauro ◽  
M. Sorli
Keyword(s):  
Flight Control ◽  
Test Bench ◽  
Test Procedure ◽  
Ball Screw ◽  
Process Noise ◽  
Safety Issues ◽  
Research Themes ◽  
Definition Of ◽  
Ball Screw Drives ◽  
Fidelity Model

Abstract Over the last two decades, one of the most prominent research themes in the aerospace community involved the definition of “more electric aircrafts”. For flight control systems the trend is to replace the traditional electro-hydraulic solution with electro-mechanical actuators. However, safety issues severely hinder the diffusion of this technology. A possible breakthrough in this field can be the development of robust PHM techniques to anticipate the occurrence of failures. Ball screws feature one of the highest failure rate within EMAs’ mechanical components. Since their accurate modeling is fairly complex, experimental results are needed to support simulation outcomes to help in the definition of reliable health monitoring schemes. This paper presents the model-based design of a novel test bench intended for PHM analyses of ball screw drives. At first the test bench layout is introduced and compared to the state of the art. A high-fidelity model of the test bench is presented and exploited to perform a Monte Carlo simulation campaign with the goal to characterize its behavior versus measure and process noise in presence of varying size backlash. Finally, a test procedure for backlash identification is defined.

High Fidelity Model of a Ball Screw Drive for a Flight Control Servoactuator

2017 ◽  
Author(s):  
Antonio C. Bertolino ◽  
Giovanni Jacazio ◽  
Stefano Mauro ◽  
Massimo Sorli
Keyword(s):  
Sensitivity Analysis ◽  
Flight Control ◽  
Contact Stiffness ◽  
Rolling Friction ◽  
Operating Conditions ◽  
Ball Screw ◽  
High Fidelity ◽  
Health State ◽  
Electric Equipment ◽  
Fidelity Model

Over the past years, a trend toward “more electric” equipment has arisen including flight control systems, leading to a tendency to replace the electro-hydraulic actuators (EHSAs) with electro-mechanical actuators (EMAs), which have however a too high jamming probability for a primary flight control system. An innovative jam tolerant approach is to make the EMA “jam-predictive” by monitoring its health state using effective prognostic algorithms. The need for a high-fidelity model is then paramount. In this study, basing on a typical architecture of an EMA, a detailed analysis of the developed dynamic non-linear ball screw model is presented. The backlash, friction parameters, a model of the rolling/sliding behaviour of a ball with rolling friction are taken into account, contact stiffness and preload are introduced. A discussion is presented on the results of a sensitivity analysis on the efficiency of the mechanism with respect to the above mentioned characteristic parameters under different operating conditions. The model and the results of the sensitivity analysis can be used to better understand the physics within the actuator and the ensuing fault-to-failure mechanisms which are needed for developing more efficient prognostic algorithms.

High-Fidelity Model of Electro-Hydraulic Actuators for Primary Flight Control Systems

2018 ◽  
Author(s):  
Andrea De Martin ◽  
Andrea Dellacasa ◽  
Giovanni Jacazio ◽  
Massimo Sorli
Keyword(s):  
Control System ◽  
Control Systems ◽  
Flight Control ◽  
Weather Condition ◽  
High Fidelity ◽  
Flight Control System ◽  
Hydraulic Actuators ◽  
Wide Range ◽  
Definition Of ◽  
Fidelity Model

Hydraulic actuators are the de facto standard for primary flight control systems, since they provide low jamming probability and intrinsic damping capabilities. Electro-Hydraulic Actuators theoretically provide a number of advantages over the traditional hydraulic systems, such as the decrease in the overall power consumption, easier installation and reduced weight of the flight control system, but are so far mostly used as back-up solutions in civil applications. Flight control actuators can face an extremely wide range of operational scenarios depending on the aircraft route, weather condition, pilot behavior and components health. The use of high-fidelity models is instrumental in the design of both actuators and control laws and can enhance the definition of a Prognostics and Health Monitoring system, given its capability to simulate a huge number of possible in-flight situations. In this paper, we provide the mathematical definition of a novel high-fidelity model for primary flight control system, discuss its implementation and results in nominal and off-nominal conditions.

scholarly journals Research on Organizational Communication

2007 ◽  
Vol 28 (1) ◽  
pp. 93-110 ◽  
Author(s):  
Catrin Johansson
Keyword(s):  
Organizational Communication ◽  
Case Study Research ◽  
Public Information ◽  
International Perspective ◽  
Internal Communication ◽  
Information Campaigns ◽  
Research Themes ◽  
Wide Definition ◽  
Definition Of

Abstract Swedish research on organizational communication is characterized by empirical, qualitative research. The tradition of holistic and profound case studies is strong. In this article, a wide definition of organizational communication is employed, including research focusing on both internal and external communication. Research themes and methods are reviewed and discussed. The majority of the studies concern public information, including health communication and crisis communication. Particularly, scholars have studied planning and evaluation of information campaigns concerning health, traffic and environment; and more recently, authority communication during major crises in society. Research focusing on organizations’ internal communication includes topics such as superior-subordinate communication, organizational learning, sensemaking, communication strategies and communication efficiency. Strengths and weaknesses following from this empirical case study research tradition are highlighted. Finally, the contribution of Swedish research in an international perspective is discussed.

Genetic manipulation on human beings

2010 ◽  
pp. 52-72
Author(s):  
Serena Zacchigna ◽  
Mauro Giacca
Keyword(s):  
Gene Therapy ◽  
Genetic Manipulation ◽  
Human Beings ◽  
Ethical Challenges ◽  
Genetic Characteristics ◽  
Safety Issues ◽  
The Public ◽  
Aesthetic Appearance ◽  
The Aesthetic ◽  
Definition Of

Since the early days of gene therapy, both the scientific community and the public have perceived the ethical challenges intrinsic to this discipline. First, the technology exploited by gene therapy is still experimental and burdened by important safety issues. Second, in several instances gene therapy aims at stably modifying the genetic characteristics of individuals. Third, the same modifications could in principle be applied also to embryos, foetuses or germ cells. Finally, while gene therapy applications are generally accepted for therapeutic purposes, the same gene transfer technologies could also be exploited to improve the aesthetic appearance, or the physical and intellectual performance of people. The definition of suitable guidelines for a controlled, ethically accepted translation of gene therapy to the clinics remains a major challenge for the near future.

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.

scholarly journals A Formalised Approach to the Management of Risk

2011 ◽  
Vol 2 (3) ◽  
pp. 63-80
Author(s):  
Mike Brownsword ◽  
Rossi Setchi
Keyword(s):  
Risk Management ◽  
Best Practice ◽  
Health And Safety ◽  
Active Management ◽  
Safety Issues ◽  
Economic Climate ◽  
Risk Management Process ◽  
Definition Of ◽  
Current Engineering

Observations made while working with industry and government organisations have shown a number of issues with the implementation of current risk management best practice. A major issue in many cases is the lack of pragmatism associated with the risk management process and the need for a more formalised approach to risk management. In this paper, the authors propose and validate a multi-view approach to defining the processes required to carry out risk management. The formalised approach proposed includes a definition of risk, an ontology, a set of processes, and a pragmatic methodology, which shows an application of these processes enabling pro-active management of change. The ability of the processes to be applied to different types of risk has been demonstrated through a case study highlighting health and safety issues. Within the current engineering and economic climate this logical approach provides a visualisation which is consistent, repeatable, view based, and pragmatic.

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.

ANALYSIS OF SPACECRAFT TELEMETRY INFORMATION USING THE KNOWLEDGE BASE, REPLENISHED DURING THEIR OPERATION

2021 ◽  
pp. 12-17
Author(s):  
S. V. Soloviev
Keyword(s):  
Time Series ◽  
Flight Control ◽  
Control Process ◽  
State Control ◽  
Mathematical Apparatus ◽  
Analysis Algorithm ◽  
Intelligent Analysis ◽  
Flight Controls ◽  
Basic Concepts ◽  
Definition Of

The method for intellectualizing the analysis of telemetric information from spacecraft arriving at ground-based flight controls is discusses. The features of state control during the spacecraft operation are formulated. The basic concepts, terms and basic properties of time series are presented, the definition of the physical meaning of the characteristic quantities for the spacecraft flight control process is given. The use of the mathematical apparatus for the analysis of time radars is substantiated in solving problems of telemetry support in the process of controlling the flight of spacecraft. A mathematical apparatus for analyzing time series is proposed to identify the actual trend. An approach to solving the problem of predicting the state of a spacecraft based on a comparative version is presented. Requirements for the intelligent analysis algorithm are presented and an integrated algorithm is proposed, a method based on time series.

Social Computing

2018 ◽  
pp. 7796-7804
Author(s):  
Nolan Hemmatazad
Keyword(s):  
Large Scale ◽  
Social Computing ◽  
Social Needs ◽  
Content Creation ◽  
Broad Definition ◽  
Practical Applications ◽  
Research Themes ◽  
The Social ◽  
Definition Of ◽  
Near Future

Broadly speaking, social computing encapsulates the idea of making technologies more aware of, and more in alignment with, the social needs of their users. This allows for the introduction of new modes of communication and collaboration among users, the ability to establish and grow communities of various constitutions, as well as for more dynamic and large scale content creation, dissemination, and evaluation. This chapter serves the ternary purpose of establishing a broad definition of social computing as it stands today and as it is expected to evolve in the near future, providing an overview of the practical applications of social computing, and examining the present and historic research themes that have made an impression on social computing as an area of academic intrigue. The chapter is intended to be accessible to casual readers, practitioners, and academicians alike, with little technical depth and broad focus throughout, for the purpose of establishing an initial acquaintance with the field.

Social Computing

2019 ◽  
pp. 1200-1210
Author(s):  
Nolan Hemmatazad
Keyword(s):  
Large Scale ◽  
Social Computing ◽  
Social Needs ◽  
Content Creation ◽  
Broad Definition ◽  
Practical Applications ◽  
Research Themes ◽  
The Social ◽  
Definition Of ◽  
Near Future

Broadly speaking, social computing encapsulates the idea of making technologies more aware of, and more in alignment with, the social needs of their users. This allows for the introduction of new modes of communication and collaboration among users, the ability to establish and grow communities of various constitutions, as well as for more dynamic and large-scale content creation, dissemination, and evaluation. This chapter serves the ternary purpose of establishing a broad definition of social computing as it stands today and as it is expected to evolve in the near future, providing an overview of the practical applications of social computing, and examining the present and historic research themes that have made an impression on social computing as an area of academic intrigue. The chapter is intended to be accessible to casual readers, practitioners, and academicians alike, with little technical depth and broad focus throughout, for the purpose of establishing an initial acquaintance with the field.

Sign in / Sign up

Export Citation Format

Share Document