Integrated System Health Management

Perspectives on Systems Engineering Techniques

Jiuping Xu, Lei Xu

• Publisher: Academic Press
• Year: 2017
• Print ISBN:
  9780128122075
• eBook ISBN:
  9780128132685
• Topic: Technology & Engineering
• Subtopic: Industrial Engineering
• Index: Technology & Engineering

ISHM is an innovative combination of technologies and methods that offers solutions to the reliability problems caused by increased complexities in design, manufacture, use conditions, and maintenance. Its key strength is in the successful integration of reliability (quantitative estimation of successful operation or failure), "diagnosibility" (ability to determine the fault source), and maintainability (how to maintain the performance of a system in operation). It draws on engineering issues such as advanced sensor monitoring, redundancy management, probabilistic reliability theory, artificial intelligence for diagnostics and prognostics, and formal validation methods, but also "quasi-technical" techniques and disciplines such as quality assurance, systems architecture and engineering, knowledge capture, information fusion, testability and maintainability, and human factors. This groundbreaking book defines and explains this new discipline, providing frameworks and methodologies for implementation and further research. Each chapter includes experiments, numerical examples, simulations and case studies. It is the ideal guide to this crucial topic for professionals or researchers in aerospace systems, systems engineering, production engineering, and reliability engineering. - Solves prognostic information selection and decision-level information fusion issues - Presents integrated evaluation methodologies for complex aerospace system health conditions and software system reliability assessment - Proposes a framework to perform fault diagnostics with a distributed intelligent agent system and a data mining approach for multistate systems - Explains prognostic methods that combine both the qualitative system running state prognostics and the quantitative remaining useful life prediction

Chapter One

ISHM for Complex Systems

Abstract

Complex systems, such as aerospace vehicles, are precise physical practical engineering systems consisting of many interrelated subsystems. As the main problem with complex systems is ensuring that the system continues to run safely, there has been significant research devoted to the maintenance of complex systems to extend the life of normal operations. Although maintenance has generally been carried out under fault conditions for complex spacecraft systems, this does not prevent huge losses or catastrophic accidents. Complex systems such as spacecraft have large number of fuzzy and uncertain factors with the nonlinearity degree increasing with technological development; in other words, integrated system health management (ISHM) has become an increasingly important application complex problem and has received a great deal of attention by governments and researchers. This chapter will take an overview of the overall ISHM for complex systems, identify its key issues emerged from its development course, and discuss the related systems engineering application features.

Keywords

Integrated health management; systematic review; capability development; key issues

1.1 Overall Integrated System Health Management

Integrated system health management (ISHM), which is an integrated artificial intelligence and information test application, has evolved to include a management ability that can autonomously reconfigure and assign resources to ensure mission safety and efficiency. This section will take an overview of the development of ISHM system, analyze the characteristics of ISHM for complex system from perspectives on systems engineering techniques, as well as its advancements combined with typical architectures, technical promoters, implementations, and challenges.

1.1.1 ISHM advancements

1.1.1.1 The ISHM foundation

As space contains infinite resources, the knowledge and development of advanced space high-tech cutting-edge technologies are becoming important when measuring a country’s comprehensive national strength. In the 19th and 20th centuries, it was said that whoever controlled the ocean, controlled the continent; however, as resources have depleted on earth, it is now said that whoever controls space, controls the entire planet. With rapid industrial and technological development in aerospace engineering, space exploration has developed from near-Earth observations to deep-space exploration. ISHM systems have evolved to include a management ability that can autonomously reconfigure and assign resources to ensure mission safety and efficiency. However, for deep-space exploration missions, communication delays and outages mandate that most ISHM functions now performed by ground controllers need to be performed onboard the spacecraft using a combination of human and autonomous control. In 2011, NASA retired the 30-year-old space shuttle program and announced plans to design a new manned spacecraft to replace the space shuttle for deep-space exploration missions [1]. Commercial space companies such as SpaceX have achieved significant breakthroughs in rocket launch recycling and have even begun to plan a Mars exploration and settlement expedition [2]. The United States and Russia have discussed cooperation for the construction of nuclear powered spacecraft, and China’s first official space station is scheduled to launch and be able to dock with the Shenzhou series spacecraft by 2020. At the same time, the European Space Agency and Japan have accelerated the implementation of manned space flight and deep-space exploration. In this process, as space vehicles, including manned spacecraft, are going to become indispensable for future space exploration, space complex systems are going to be primary to the peaceful development, exploration and utilization of space and its resources [3]. With the increased focus on deep-space exploration, there is a higher demand for spacecraft autonomy and the development of reliable, secure efficient complex systems. Fig. 1.1 illustrates the growth in demand for autonomous spacecraft demand released by NASA.

Figure 1.1 Autonomous spacecraft demand growth.

Spacecraft complexity means that the many subcomponents need to work together to ensure reliability and safety. In these complex modular systems, errors can occur in individual modules, severely affecting the interaction between modules, and possibly causing further errors which could evolve into faults or critical failures. One of the biggest security challenges for today’s complex systems is finding or preventing system faults and failures before they cause system failure. Therefore, based on the complexity and high-risk nature of space missions, many specialists are needed to perform operational and maintenance tasks. However, complex systems such as the software and hardware in spacecraft modules are often difficult to detect and diagnose under existing technical conditions. Further, as these systems tend to slow down or behave differently during spaceflight, catastrophic accidents can occur if a problem appears [4]. From 1959 to the end of 1995, the United States and Russia (as the Soviet Union) carried out 249 manned space missions, in which a total of 166 faults occurred, and four of which resulted in serious manned space accidents causing all astronauts to die: Apollo 4A in January 1967, Union 1 in April 1967, Union 11 in June 1971, and Challenger in January 1986. In addition, in a short period of 1 month from April to May 1999, the launch of the Hercules 4B, Athena 2, and Delta 2 launch vehicles from the United States all failed, resulting in billions of dollars in losses. In February 1996, China’s Long March III B launch vehicle failed on its first mission after a ground explosion killed eight people and injured dozens, in July and October 1999, a Russian proton rocket twice failed to launch satellites, in November 1999 the Japanese H2 launch vehicle failed to launch, in February 2003, the United States Columbia space shuttle explosion occurred, resulting in seven astronaut deaths and direct economic losses of $1.2 billion, and in June 2015 and September 2016, SpaceX’s rocket Falcon 9 exploded on launch. These serious spacecraft accidents not only resulted in a significant increase in systematic diagnostics research, but also highlighted the necessity for the comprehensive monitoring and accurate assessment of spacecraft system health conditions, fault diagnostics, failure prognostics, and the provision of system health management (SHM) architecture that could guarantee astronaut safety and mission success [5].

Space flight plans are under increasing pressure to improve operational and maintenance efficiencies while reducing the risk of spacecraft flight and achieving safe and reliable mission completion. For deep-space spacecraft, the harsh operating environment, the inability to repair or replace malfunctioning equipment, and the increasing task cycles and complexities increase the risk of mission failure and remain as major challenges [6]. As traditional complex space system design has focused on minimizing security risks, and protecting astronauts, workers, people, and expensive equipment assets, aerospace complex systems have focused on the development of highly reliable components and maintenance techniques to maximize security requirements and avoid mission failures. Therefore, ISHM was introduced to provide quasi-real-time evaluations of the system condition, safety margins, and maintenance to address spacecraft system safety and maintenance requirements. NASA defines ISHM as the process, approaches, and techniques to prevent or minimize the effects of faults in the system’s design, analysis, manufacture, validation, and operation [7]; therefore, ISHM covers design and manufacturing as well as management and operations. As ISHM development is focused on security, it has evolved from a traditional time-based maintenance [8] system to a preventive maintenance and condition-based maintenance (CBM) [9] system, in which the preventive maintenance arranges the maintenance plan based on the complex system fault characteristics to ensure trouble-free operations and training or mission completion, and the CBM allows the system to evaluate its own health condition, apply prognostics, and manage the faults. ISHM optimizes the use of sensor-collected system data based on information fusion techniques, utilizes appropriate analytical algorithms to evaluate the system health condition, monitors the fault symptoms in advance, applies failure prognostics before the fault occurs [10], and combines corresponding health management decision-making to apply appropriate support measures to achieve system CBM [11]. ISHM protects system functional integrity and space mission security and is the basis of the autonomous spacecraft.

1.1.1.2 The ISHM concept

Health management evolved from health monitoring theory and failure prognostics on the basis of condition assessment and fault diagnostics [11]. NASA, Boeing, and others have proposed concepts such as airplane health management (AHM) [12], the health and usage monitoring system (HUMS) [13], integrated vehicle health management (IVHM) [14], prognostics and health management (PHM) [15], ISHM [16]. The European Union has also launched Technologies and Techniques for New Maintenance Concepts and vigorously conducted health management methods research enhancing on-line, real-time, integrated monitoring, and strengthening remaining useful life (RUL) forecasting and maintenance decision support based on health condition and reliability. In November 2005, NASA held the first International Forum on Integrated System Health Engineering and Management (ISHEM) [17] in Napa, California, USA, which made the key decision to clearly identify ISHEM as a discipline with ISHM being the development and integration of the various approaches and techniques. In the following, a brief review is given of the evolution of health management-related discip...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Acknowledgments
• Chapter One. ISHM for Complex Systems
• Chapter Two. Sensor System and Health Monitoring
• Chapter Three. Information Fusion
• Chapter Four. Performance Evaluation
• Chapter Five. System Assessment
• Chapter Six. Fault Diagnostics
• Chapter Seven. Failure Prognostics
• Chapter Eight. Maintenance Decision Support
• Chapter Nine. Affordability and Life-Cycle Costs Analysis
• Index