Rajkumar Roy

City, University of London · School of Mathematics Computer Science and Engineering

Augmented Reality (AR) has shown great potential for improving human performance in Maintenance, Repair, and Overhaul (MRO) operations. Whilst most studies are currently being carried out at an academic level, the research is still in its infancy due to limitations in three main aspects: limited hardware capabilities, the robustness of object recog...

Self-engineering (SE) systems have valuable abilities to register and respond to lost function and return it. A self-cleaning (SC) system was designed for effective automated cleaning of a heat exchanger (HX) fouled by brewing wort. The system uses temperature outputs in a Digital Twin (DT) simulation and a controller to identify when fouling occur...

Self-engineering (SE) systems aim to autonomously respond to a loss of function and take action to return functionality. Recently there have been a number of demonstrations of SE using multi-rotor drones to inspect and repair systems (such as repairing potholes), though many of these systems do not meet all the requirements of a SE system. This res...

Pulsed thermography has been used significantly over the years to detect near and sub-surface damage in both metals and composites. Where most of the research has been in either improving the detectability and/or its applicability to specific parts and scenarios, efforts to analyse and establish the level of uncertainty in the measurements have bee...

Failures in high value, safety-critical, inaccessible, and productivity-critical systems is an area of significant research interest. Despite advances in predictive and continuous maintenance services, there is still a need for a more ambitious approach to preserve a system’s functions despite degradation and damage. This paper presents the concept...

Engineering systems must function effectively whilst maintaining reliability in service. Predicting maintenance costs and asset availability raises varying degrees of uncertainty from multiple sources. Previous reviews in this domain have assessed cost uncertainty and estimation for the entire life cycle. This paper presents a systematic review to...

A self-engineering (SE) system is an ability designed and built into a system which allows it to respond to functionality lost automatically and restore it fully or partially to maintain its availability. Examples include self-healing, self-repair, self-reconfiguring, built-in redundancy and self-adapting systems. SE systems aim to increase product...

In this paper, a new recursive structure based on the convolution model of discrete cosine transform (DCT) for designing of a finite impulse response (FIR) digital filter is proposed. In our derivation, we start with the convolution model of DCT-II to use its Z-transform for the proposed filter structure perspective. Moreover, using the same algori...

Engineered products are becoming more complex and need longer lifetime availability; there is a need for new approaches in maintaining, repairing and overhaul (MRO). This paper presents the concept of self-engineering; the aim is to preserve the functions of a product or system and extend its lifetime and automate MRO processes. New developments in...

The combination of viable heuristic attributes with statistical measurements presents significant challenges in industrial maintenance for complex assets under through-life service contracts. Techniques to obtain and process heuristic attributes raise numerous uncertainties which often go undefined and unmitigated. A holistic view of these uncertai...

The changing nature of manufacturing, in recent years, is evident in industry’s willingness to adopt network-connected intelligent machines in their factory development plans. A number of joint corporate/government initiatives also describe and encourage the adoption of Artificial Intelligence (AI) in the operation and management of production line...

The Internet of Things (IoT) has significant potential in upgrading legacy production machinery with monitoring capabilities to unlock new capabilities and bring economic benefits. However, the introduction of IoT at the shop floor layer exposes it to additional security risks with potentially significant adverse operational impact. This article ad...

For complex manufacturing systems, the current hybrid Agent-Based Modelling and Discrete Event Simulation (ABM–DES) frameworks are limited to component and system levels of representation and present a degree of static complexity to study optimal resource planning. To address these limitations, a modular hybrid simulation framework for complex manu...

Non-destructive testing (NDT) techniques have become attractive trends of product manufacturing, installation and post-maintenance in the aerospace, automotive and manufacturing industry, because of its benefits such as cost saving, easy to use and high efficiency etc. With the industrial products becoming large-scale, high integration and complica...

Non-destructive-testing (NDT), including active thermography, has become an inevitable part of composite process and product verification, post-manufacturing. However, there is no reliable NDT technique available to ensure the interlaminar bond integrity during composite laminates integration, bonding or repair where the presence of thin airgaps in...

Augmented Reality (AR) has experienced an increasing trend in applied research in the last few years. This emerging trend is focused in content-related challenges: mainly creation (Authoring), adaptation (Context-Awareness) and improvement (Interaction-Analysis) of augmented content. Research in these techniques has enabled Academia to recognise Au...

The changing nature of manufacturing, in recent years, is evident in industries willingness to adopt network connected intelligent machines in their factory development plans. While advances in sensors and sensor fusion techniques have been significant in recent years, the possibilities brought by Internet of Things create new challenges in the sca...

Carbon fibre reinforced polymer (CFRP) composites are now a common occurrence in the aerospace sector especially with their introduction into the aero-engine. With their ever-increasing use in harsh and extreme environments, it is important to understand their behaviour and performance when exposed to such working conditions. This paper presents a...

Industrial Product-Service Systems (IPS²) can provide insights to enhance the environmental sustainability and lower environmental impact. However, its successful realisation for preventing the production of waste, while increasing efficiencies in the uses of energy and human capital remains a highly convoluted problem. This research article aims t...

Complex engineering systems present a wealth of uncertainties concerning aspects ranging from performance measurements to maintainability and through-life characteristics. A quantifiable understanding of these uncertainties is vital to system optimisation and plays a key role in decision-making processes for manufacturing organisations worldwide; i...

This paper presents an experimental investigation on the influences of laser trepanning drilling process parameters on the recast layer thickness and surface crack formation in CMSX-4 nickel-based superalloy angled holes. The effects of peak power, pulse frequency and the trepanning speed as input parameters were investigated in details by varying...

From product maintenance and service point of view, high-value sophisticated computer numerical control (CNC) machine tools in modern manufacturing factories play important roles: they are manufacturing equipment, and on the other hand, they are also products supplied by equipment manufacturers. There is a trend that manufacturers are extending the...

Industry 4.0 has encouraged manufacturing organisations to update their systems and processes by implementing Internet of Things (IoT) technology in legacy systems to provide new services such as autonomous condition monitoring and remote maintenance. However, there is still no literature that guides in realizing the advantages and disadvantages of...

Inclusive Manufacturing is a new paradigm concept, where all parts of the lifecycle of a manufactured product is made accessible to people from all strata of the society, so as to accelerate sustainable development and dignified well-being for all. Inclusive Manufacturing aims at empowering people, especially those who are spatially, temporally, ph...

This paper introduces a novel approach to fatigue life prediction modelling considering the laser drilling effect on film cooling holes of turbine vanes. The methodology proposed is based on a stress-life model such as the Basquin law and the introduction of manufacturing damage effect. The proposed empirical model gives a unique versatility compar...

Information asymmetry (IA) in terms of contextual variety and importance is one of the most challenging aspects of through-life costing in product-service systems (PSS). IA is an imbalance in the information, data and knowledge shared among the parties involved in a contractual agreement. In manufacturing systems under PSS, interaction and effectiv...

The trend of Industry 4.0 encourages the next generation of manufacturing to be flexible, intelligent, and interoperable. The implementations of the Artificial Intelligence (AI) technology could potentially enhance maintenance in efficiency, and accuracy. However, it will not be a substitution to the human operator’s flexibility, decision-making an...

The brake disc is considered a safety critical components in vehicles, hence the growing concern on its service life performance. Brake disc performance is measured by several criteria of which prominent amongst these criteria is fatigue life and disc thermal deflection. This study considers the influence of geometric design features of a vented br...

Through the Internet of Things (IoT) interaction between objects becomes possible in a way we have never seen before. With the advent of IoT and its introduction into almost all aspects of life, safety and security of IoT devices has to be considered for their whole life cycle. This concerns not only the large amounts of data that needs to be excha...

In the context of non-destructive testing, quantification of uncertainty caused by various factors such as inspection technique, testing environment and the operator is important and challenge. This paper introduces a concept of contour-based confidence map and an application framework for pulsed thermography that offers enhanced flexibility and re...

The digitization of manufacturing through the introduction of Industrie 4.0 technologies creates additional business opportunities and technical challenges. The integration of such technologies on legacy production machinery can upgrade them to become part of the digital and smart manufacturing environment. A typical example is that of industrial m...

This paper introduces a new method to improve the reliability and confidence level of defect depth measurement based on pulsed thermographic inspection by addressing the over-fitting problem. Different with existing methods using a fixed model structure for all pixels, the proposed method adaptively detects the optimal model structure for each pixe...

This paper presents an assessment of ageing for thin Thermal Barrier Coatings (TBC) using active thermography. As TBCs undergo ageing during their service life, sintering changes the porosity, elements migrate from the substrate, and micro-cracks build up in the structure of the material, exhibiting a change in thermal conductivity and diffusion pr...

Abstract The effect of laser trepanning speed and, as a result, recast layer thickness on the high temperature corrosion fatigue behaviour of CMSX-4 superalloy acute angled holes was investigated. The experimental test results show that an increasing laser drilling speed caused a reduction in corrosion fatigue life by 30-50% at 850°C, under low cyc...

“Defence Support Services” (DS2) for the Royal Navy are a particular form of “Product-Service Systems” (PSS). PSS deliver on a turn-key basis equipment/system with related spare parts, training and upgrades to the Royal Navy. In order to stimulate and reward the DS2 provider to improve its services and performance, the Royal Navy wants to shift its...

The globally growing market for polymer composites and their increasing use within aircraft structures has necessitated reliable bonding of composite laminates to prevent structural failure. However, knowledge behind the interaction between curing process parameters and the failure of polymer composite bonded joints is not keeping pace with the mar...

The Internet of Things (IoT) is continuously growing and is now reaching into the industrial environment through new services such as remote maintenance for machine tools. Industrial applications of IoT require an increased awareness of security at all times. It is not only necessary that the data is exchanged securely; also the design of the hardw...

Through the Internet of Things (IoT) interaction between objects becomes possible in a way we have never seen before. With the advent of IoT and its introduction into almost all aspects of life, safety and security of IoT devices has to be considered for their whole life cycle. This concerns not only the large amounts of data that needs to be excha...

This edited book offers further advances, new perspectives, and developments from world leaders in the field of through-life engineering services (TES). It builds up on the earlier book by the same authors entitled: “Through-life Engineering Services: Motivation, Theory and Practice.” This compendium introduces and discusses further, the developmen...

Predictive maintenance needs to forecast the numbers of rejections at any overhaul point before any failure occurs in order to accurately and proactively take adequate maintenance action. In healthcare, prediction has been applied to foretell when and how to administer medication to improve the health condition of the patient. The same is true for...

This article introduces maintenance informatics dashboard design approach for visualising maintenance, repair and overhaul events on a timeline. This paper presents a proposed methodology for aggregate visualisation techniques and a 2D graphical plot method as well as a summary of events on a timeline. In this paper, these events are occurrences wh...

The civil aviation industry has captured the world’s share both in terms of operations and markets. The International Civil Aviation Organisation (ICAO) reported an increase of 6.3 percent in passenger traffic to 3.7billion in 2016 based on recorded departures globally. This paper is an effort to understand the driving force for the civil aviation...

The advent of advanced, innovative and complex engineered systems has established new technologies that are far more superior and perform well even in harsh environments. It is well established that such next generation systems need to be maintained regularly to prevent any catastrophic failure as a result of regular wear and tear. Non-destructive...

This paper introduces a coefficient clustering analysis method to detect and quantitatively measure damage occurring in composite materials using pulsed thermographic inspection. This method is based on fitting a low order polynomial model for temperature decay curves, which a) provides an enhanced visual confirmation and size measurement of the da...

High value and long life products require continuous maintenance throughout their life cycle to achieve required performance with optimum through-life cost. This paper presents foundations and technologies required to offer the maintenance service. Component and system level degradation science, assessment and modelling along with life cycle ‘big d...

The speed of manufacturing processes today depends on a trade-off between the physical processes of production, the wider system that allows these processes to operate and the co-ordination of a supply chain in the pursuit of meeting customer needs. Could the speed of this activity be doubled? This paper explores this hypothetical question, startin...

A major challenge for Augmented Reality (AR) in real life maintenance is varying lighting conditions. This research developed a novel registration technique to use AR effectively in real life lighting conditions, where registration is the accurate alignment of real and virtual images. The study has demonstrated that the registration technique can r...

Organisations need to develop attitudes and practices to manage risks, which surround any project. Project failure comes from inadequate implementation of risk management. Thus, risk management processes must be accurate, feasible and explain what should be included and not, clarify tasks and responsibilities and the way it should be accomplished....

Software plays an important role in Defence industry. Almost every project in defence manufacturing sectors has got software with various degrees of complexity and dependencies. Whilst various research and studies has been conducted on system obsolescence, and tools developed to cost systems and components obsolescence, no major research has been u...

In today's competitive market, servitisation as a relatively new term in academia and industry is finding its place to offer services within selling products, as after sale products and sometimes offering services instead of products. Different types of servitisation have been introduced during the last two decades, where each implementation has it...

In the modern competitive environments companies must have rapid production systems that are able to deliver parts that satisfy highest quality standards. Companies have also an increased need for advanced machines equipped with the latest technologies in maintenance to avoid any reduction or interruption of production. Eminent therefore is the nee...

Thermographic inspection is a relatively new technique for Non-Destructive Testing (NDT) which has been gathering increasing interest due to its relatively low cost hardware and extremely fast data acquisition properties. This technique is especially promising in the area of rapid automated damage detection and quantification. In collaboration with...

This chapter presents the challenges and opportunities which were identified from a review of the literature and during several key events which brought academics, researchers and industrialists together to discuss the way forward. It presents opinions and insights taken from comments made by stakeholders and from event transcripts and of discussio...

The article investigates a generic framework to estimate maintenance costs attributed to the No Fault Found (NFF) phenomenon. Such overhead costs are particularly difficult to quantify due to potentially serviceable equipment being returned for repair. Other factors, such as a reduction in the availability of the system, compromising reliability of...

This study mainly deals with the evaluation of various degradation mechanisms that heat exchangers are susceptible to with an aim of evaluating future design requirements. A heat exchanger is a heat management system that uses fluids to transfer heat from one medium to the other; the most common types of fluids being air, water, oil or specialised...

The speed of manufacturing processes today depends on a trade-off between the physical processes of production, the wider system that allows these processes to operate and the co-ordination of a supply chain in the pursuit of meeting customer needs. Could the speed of this activity be doubled? This paper explores this hypothetical question, startin...

Conventionally there is a strong relation between manufacturing and services in complex engineering industries. For companies which aim to last in the competitive manufacturing market choosing appropriate decision making methods to improve their maintenance delivery has a vital role. The aim of this paper is to review Multi Criteria Decision Making...

Current aircraft design cost models explicitly represent components, attributes of components and relationships between components. These designerfocused cost models do not represent conceptual definitions of components that are important for understanding and sharing task knowledge that are important for calculating component costs, such as pseudo...

Demonstrating the latest research and analysis in the area of through-life engineering services (TES), this book utilizes case studies and expert analysis from an international array of practitioners and researchers – who together represent multiple manufacturing sectors: aerospace, railway and automotive – to maximize reader insights into the fiel...