Architecting Integrated System Health Management for Airworthiness

Integrated System Health Management (ISHM) for Unmanned Aerial Systems (UAS) has been a new area of research - seeking to provide situational awareness to mission and maintenance operations, and for improved decision-making with increased self-autonomy. This research effort developed an analytic architecture and an associated discrete-event simulation using Arena to investigate the potential benefits of ISHM implementation onboard an UAS. The objective of this research is two-fold: firstly, to achieve continued airworthiness by investigating the potential extension of UAS expected lifetime through ISHM implementation, and secondly, to reduce life cycle costs by implementing a Condition-Based Maintenance (CBM) policy with better failure predictions made possible with ISHM. Through a series of design experiments, it was shown that ISHM presented the most cost-effective improvement over baseline systems in situations where the reliability of the UAS is poor (relative to manned systems) and the baseline sensor exhibited poor qualities in terms of missed detection and false alarm rates. From the simulation results of the test scenarios, it was observed that failure occurrence rates, sensor quality characteristics and ISHM performance specifications were significant factors in determining the output responses of the model. The desired outcome of this research seeks to provide potential designers with top-level performance specifications of an ISHM system based on specified airworthiness and maintenance requirements for the envisaged ISHM-enabled UAS

Beyond financial metrics, the place and role of technical and other additional due diligence in the process of Mergers & Acquisitions transactions. Case study in the Engineering Services Industry.

This paper aims at complementing the literature on Mergers & Acquisitions (M&A) with a case study to provide the lecturer with a full insight on the diversity of the challenges inherent to M&A transactions. Especially, a strong emphasis will be made on extra-financial analysis of the target. Indeed, a M&A process always includes a very formal and standardized financial analysis of the target, called the Financial Due Diligences, very often including also a similar Tax & Legal Due Diligences process. However, the collection and analysis of other information relative to the business and its specificities are much less standardized. As regards to the technical capabilities of the target or economic and operational considerations, the level of information available to the purchaser might be significantly variable from an acquisition to another, depending on the availability of the info first, but also on the quality of the analysis of them. This case study will provide concrete examples of what additional analysis to the financial ones can be performed on the target and its environment. It will be then discussed how crucial they might be in the decision-making process of pursuing with the acquisition or not. The discussion will be extended to the place that take each of those analysis (financial and extra-financial ones) in the valuation of the target and the consistency of current valuation methods as regard to the importance of each element

Probabilistic Regime Recognition and Damage Estimation for Rotary and Fixed Wing Aircraft

Regime recognition is a critical tool used for condition-based maintenance, fatigue life prediction, and creation of usage spectra for military and commercial rotorcraft. Regime recognition is the process by which aircraft state data is analyzed and vehicle maneuvers are identified with respect to time. While a variety of regime recognition algorithms are currently in use, many current algorithms suffer from an over-reliance on training data or poor classification performance. This work seeks two main goals, the first is to introduce a new type of regime recognition algorithm based on a multiple model adaptive estimation scheme, known as an interacting multiple model (IMM) estimator. IMM estimators use a bank of dynamic models to evaluate the likelihood of the system existing in one of various possible dynamic modes. In the regime recognition context, each mode represents the system operating in a given maneuver regime. Compared with other approaches, IMM estimators offer the benefits of probabilistic regime classification and the incorporation of knowledge of the aircraft flight dynamics, which reduces reliance on training data. This dissertation presents a novel formulation of an IMM estimator for regime recognition wherein mode probabilities from a bank of IMM filters are combined in Bayesian framework to yield maneuver regime probabilities. Second, this work introduces a novel approach to condition based maintenance (CBM) that is designed to be used in conjunction with a probabilistic regime recognition scheme. The proposed methodology results in a probability distribution of incurred damage for specified life-limited components on an individual aircraft basis, with applications to fleet-wide probabilistic damage spectrum. The primary advantage of the proposed methodology is the rigorous treatment of regime uncertainty that is quantified in probabilistic regime recognition. A Gaussian probability density approximation is used to improve computational efficiency of the damage estimation method, and effects of the flight condition on the uncertainty in the damage estimation are investigated. Following a detailed explanation of the proposed methodologies, results are provided by applying the algorithms to both simulated and real helicopter data, and compared against “standard” rule-based approaches. Lastly, some of the methodologies presented in this dissertation are appropriately modified and applied to fixed wing aircraft and results are shown using simulated data for the F-16.Ph.D

Health and Usage Monitoring: Autonomous Vehicles

This thesis presents a work in progress related to the use of Health and Usage Monitoring Systems (HUMS) data to actuate an adaptive control system on an autonomous vehicle operating in an Intelligent Transportation Systems (ITS). The autonomous passenger vehicle has rapidly matured from a speculative concept to a reality that is quickly appearing within our sightlines. Autonomous (also called self-driving, driverless, or robotic) vehicles have long been predicted in science fiction and discussed in popular science media. Recently, major corporations have announced plans to begin selling such vehicles in the near future, and some jurisdictions have passed legislation to allow such vehicles to operate legally on public roads. Autonomous vehicles will be performing intelligent functions (navigation, maneuver, behavior, or task) by perceiving the environment and implementing a responsive action based on HUMS input. Once these vehicles begin to operate on public roads as a norm, safety and reliability becomes a major factor. The implementation or expanded use of HUMS can perceivably render these systems reliable and safe to operate in any environment or mode. This thesis also depicts a notational framework for HUMS in autonomous vehicles operating on ITS networks and future research needed to make this a reality. Keywords: Health and Usage Monitoring System (HUMS), Reliability, Adaptive Systems, Prognostics, Autonomous Vehicle, Intelligent Transportation SystemM.S., Mechanical Engineering and Mechanics -- Drexel University, 201

Simulation of aircraft maintenance improvement using RFID systems

International audienceThe paper describes the maintenance process applied to an aircraft part along periodic maintenance operations and/or failure repairs. This paper deals with the assessment of RFID (Radio Frequency IDentification) technology contribution to the follow-up of aircraft parts. The construction of a simulation model and validation of the study are based on both experts' knowledge and data on flight and maintenance operations. Each stage of the maintenance process is modelled in terms of time (average times and boundaries) and the transition probability between stages. The impact of RFID technologies in the overall maintenance process is assessed. The main use of the analysis is the evaluation of different maintenance strategies and a first quantification of the impacts related to introducing RFID in maintenance processes. It should be helpful to support the decisions on RFID integration. The model could be used to design a decision support tool for maintenance designers and managers

Fatigue in Offshore Helicopter Pilots

Na indústria de petróleo e gás, os trabalhadores são transportados principalmente por helicóptero de terra para/de alto mar. O trabalho varia de 45 a 90 minutos de tempo de voo para cada segmento de perna. Com uma atividade de rotina onde o período de carga de trabalho das tripulações de voo muitas vezes varia, até 12 horas de período de serviço e um máximo de 8 horas de voo. Durante os voos, os pilotos são expostos a diversas condições de trabalho que causam fadiga física e psicológica. Este estudo de pesquisa tem como objetivo avaliar a exposição de pilotos de helicóptero à vibração de corpo inteiro (VCI) e ao ruído sonoro como principal causa de fadiga e a idade como factor secundário. No sentido de cumprir com o objetivo do estudo de investigação, foi seleccionada, oportunisticamente, uma amostra dimensional de 50 pilotos, de uma população situada no país de Angola, sendo uma do sexo feminino e 49 do sexo masculino. É uma amostra não probabilística de conveniência composta por uma única empresa. A metodologia empregue foi uma questionario voluntário online. Realizado por meio de um estudo correlacional com delineamento transversal realizado online e foi compilado a partir de diversas questões relacionadas aos factores humanos. Em termos de resultados, o autor gostaria de enfatizar a exposição de outros efeitos externos que também teriam contribuído para o cansaço dos pilotos. No entanto, para este estudo, eles foram negligenciados. Os dados recolhidos foram utilizados para desenvolver a análise do melhor esquema de escala de serviço nos operadores aéreos de helicopteros de suporte à industria petroliferica de óleo e gas. Participantes forma pilotos de helicoperos, 97% eram do sexo masculino, 63% com idade inferior a 40 anos, 71% copilotos, 63% tinham licença de piloto comercial e 58% com menos de dez anos de experiência. Escala de rotação de serviço, quando combinados quase 75% consideraram o melhor esquema de rotação entre 21 a 28 dias de serviço (ON) / folga (off). Fadiga afetada o desempenho e alerta degradada relatado por mais de 56%. Acenando ocasionalmente durante o voo a cabeça em 34,8%, mas apenas 21,7% recusaram um voo devido à fadiga.In the oil and gas industry, workers are mainly transported by helicopter from Onshore to/from Offshore. The travel varies between 45 to 90 minutes of flight time for each leg segment. Under a routine activity, the flight crews workload period often varies up to 12 hours of duty period and a maximum of 8 hours flying. During flight missions, pilots are exposed to several work-related conditions that cause physical and psychological fatigue. Accordingly, this research study aims to evaluate the exposure of helicopter pilots towards whole-body vibration (WBV) and noise as the leading cause of fatigue and age as the secondary factor. In the direction of fulfilling the research study goal, a sample size of 50 pilots were opportunistically selected, from a population working in Luanda, Angola; being one Female and 49 Males. The study is non-probabilistic with a convenience sampling composed of a single company. The methodology employed was a voluntary online survey, accomplished by a correlational study with a cross-sectional design conducted online and was compiled of several questions related to human factors. In terms of results, the author would like to emphasize the exposure of other external effects impacting the pilot's fatigue; however, for this study, these contributing factors were neglected. The data collected were utilized to develop the analysis of the most effective roster scheme in the helicopter offshore service provider. Looking at the pilot demographics, 97% were male, 63% with age below 40 years, 71% copilots, 63% have a commercial pilot license, and 58% with less than ten years of experience. Schedule Schemes and Rostering, when combined almost 75% considered best rostering scheme between 21 to 28 days on/off. The study highlights the fact that fatigue affects and degrades performance and alertness as reported by more than 56 %. Occasionally nodding during flight by 34.8%; however, only 21.7% turned down a flight due to fatigue

State-of-the-art in integrated vehicle health management

Integrated vehicle health management (IVHM) is a collection of data relevant to the present and future performance of a vehicle system and its transformation into information can be used to support operational decisions. This design and operation concept embraces an integration of sensors, communication technologies, and artificial intelligence to provide vehicle-wide abilities to diagnose problems and recommend solutions. This article aims to report the state-of-the-art of IVHM research by presenting a systematic review of the literature. The literature from different sources is collated and analysed, and the major emerging themes are presented. On this basis, the article describes the IVHM concept and its evolution, discusses configurations and existing applications along with main drivers, potential benefits and barriers to adoption, summarizes design guidelines and available methods, and identifies future research challenges

Programas de Manutenção de Aeronaves com Base em Monitorização/Controlo de Condição

No contexto da aviação militar onde a operação segura de aeronaves com o mínimo de custos é, cada vez mais, a única forma viável de garantir o cumprimento da missão, a manutenção condicionada, realizada quando há evidências de anomalias em detrimento de um calendário pré-definido, assume uma posição destacada, por permitir a deteção atempada de falhas, bem como a maximização do tempo de operação. Sustentada no controlo de condição, a deteção das anomalias de um equipamento/órgão realiza-se através da monitorização de parâmetros (vibrações, análises de óleo, temperatura, etc) associáveis a sintomas, permitindo, deste modo, aferir o respetivo estado de “saúde”. Partindo dessa realidade, este trabalho de investigação pretende analisar os fatores determinantes para o controlo de condição em órgãos mecânicos de aeronaves na Força Aérea Portuguesa (FAP). Essa análise realiza-se em várias vertentes, nomeadamente ao nível da gestão da manutenção, respetiva organização, documentação, recursos humanos e sistemas de informação. Outra vertente correspondeu aos objetivos a alcançar com os sistemas de monitorização, e aspetos relacionados com a sua implementação e exploração. É analisado o panorama internacional em termos de transportadoras aéreas comerciais, onde o controlo de condição é prática corrente, e na aviação militar, onde se verifica um grande investimento em controlo de condição, especialmente em helicópteros pela sua criticidade e devido, em grande parte, ao desenvolvimento tecnológico. Decorrente da investigação fica reforçada a ideia da centralização da análise da informação monitorizada como garantia de maior eficácia. Verifica-se que os fatores organizacionais e de fiabilidade dos sistemas de monitorização são tão ou mais importantes para o sucesso da manutenção condicionada do que a configuração dos mesmos. Também se comprova que os objetivos a atingir com o controlo de condição enquadram-se em qualquer modalidade de gestão, incluindo na gestão de contratos de manutenção. Constatase que a implementação de novos programas se aplica, essencialmente, a órgãos mecânicos críticos, tendo como garantida a sua viabilidade técnica e financeira. Para sustentar esta fundamentação, foram encontradas potenciais dificuldades. A par destas constatações, são identificadas vulnerabilidades que, embora passíveis de resolução, dificultam um controlo de condição efetivo. O controlo de condição é apontado como uma atividade que encerra um potencial evolutivo, desde que enquadrada numa estratégia global de gestão da manutenção.Abstract: In a context where the military aviation safe operation of aircraft with minimal costs is, increasingly, the only way to guarantee the accomplishment of the mission, condition based maintenance held when there is evidence of deficiencies at the expense of a pre-set timetable, takes a prominent position by enabling the timely detection of faults, as well as maximizing the time of operation. Backed in the condition monitoring, the detection of faults is held by monitoring parameters (vibration, oil analysis, temperature, etc.) related to symptoms, thus allowing the assessment of the state of "health". Starting from this reality, this piece of research seeks to analyze the determinants for the condition monitoring of mechanical components of aircraft in the Portuguese Air Force (PRTAF). This analysis was carried out through the definition of statements, related with the maintenance management, organization, documentation, human resources and information applications. On the other hand, the objectives to reach with condition monitoring systems, and aspects related with its implementation and exploration where analyzed. The international scenario was also analyzed in terms of civil and military aviation, verifying the tendency of investment in condition monitoring especially in helicopters given its criticality and, to a large extent, of technological development. As a result of the research it was stated that for the analysis of the monitoring information, centralization of this activity is more effective. It was verified that the organizational and reliability factors of the monitoring systems are as important, if not more, for the success of the condition based maintenance as its configuration. It is also proved that the objectives to reach with the condition monitoring are fit in any type of management, including the maintenance contract management. Finally, the implementation viability of new monitoring systems applies essentially to critical mechanical components, supported by a study to analyze whether it is technically viable and economically justifiable. In this context some difficulties were found to support that study. There are also some organizational difficulties identified to perform an effective condition monitoring, but with a resolution perspective. The condition monitoring is pointed out as an activity that contains potential evolution, as long as it is part of a global strategy of maintenance management