Spencer Onuh

Reverse engineering and rapid tooling as enablers of agile manufacturing

Rapid response manufacturing is a new manufacturing pattern that can be used to implement the concept of agile design and manufacturing, but there are some new problems associated with it. Rapid Prototyping (RP) is one of the enablers of Reverse Engineering (RE). Two separate studies have been carried out to verify the degree of the activities of RP as an enabler of RE. Results show that the product development cycle and cost have been reduced and that data can be accurately transferred between the different equipment without additional new software. Hence, RP is an enabler of agile manufacturing.

A robotic welding system using image processing techniques and a CAD model to provide information to a multi‐intelligent decision module

Purpose – The paper aims to propose a system that uses a combination of techniques to suggest weld requirements for ships parts. These suggestions are evaluated, decisions are made and then weld parameters are sent to a program generator.Design/methodology/approach – A pattern recognition system recognizes shipbuilding parts using shape contour information. Fourier‐descriptors provide information and neural networks make decisions about shapes.Findings – The system has distinguished between various parts and programs have been generated so that the methods have proved to be valid approaches.Practical implications – The new system used a rudimentary curvature metric that measured Euclidean distance between two points in a window but the improved accuracy and ease of implementation can benefit other applications concerning curve approximation, node tracing, and image processing, but especially in identifying images of manufactured parts with distinct corners.Originality/value – A new proposed system has bee...

Reverse engineering of pelvic bone for hip joint replacement

Research into fabrication of hip joint replacements combines knowledge from distinct domains, such as engineering, materials and medical fields. Recent computer assisted technologies have played an important role in the medical field. Unlike the modelling of most of the human bones, the creation of an accurate 3D model of a pelvic bone has been a challenging task. The main source of difficulties in this case has proven to be the complexity of the structure of the pelvis, having basically a free-form shape with a hole in the middle constituting some over-shadowed areas (undercuts), various cavities, areas with high form curvature, variable wall thickness with some very thin sections and inside layers with different mechanical properties. In this research work, a pelvic bone is generated using reverse engineering, rapid prototyping and rapid tooling techniques. The geometric data obtained from reverse engineering through laser scanning are used and manipulated to create accurate 3D CAD representations of these devices. These CAD models can be used for various virtual tests and simulations, as well as for reproduction through rapid manufacturing processes and then used as prototypes in tooling, physical tests and planning of surgical operations.

Lean “Leadership People Process Outcome” (LPPO) implementation model

Purpose – The purpose of this paper is to present the Lean “Leadership People Process Outcome” (LPPO) implementation model. Design/methodology/approach – The model is developed from existing models through literature review and its success from use in lean implementation is reported in case studies. Findings – The LPPO model is a Lean implementation model that is flexible and easily adaptable. It is system based, people driven, customer centred, with measurable outcome and a drive for continuous improvement. Research limitations/implications – This work is based on existing literature and case studies. Practical implications – The paper would be of interest to Lean practitioners as the model developed is system generic and easily adaptable. Originality/value – The LPPO model presented in this paper has been newly developed and the successful application is seen in the case studies.

Dimensional error analysis in point cloud-based inspection using a non-contact method for data acquisition

The digital reconstruction of a computer aided design model from a physical object in the case of non-existence of such models has been a great challenge to engineers. With the advent of coordinate measuring machines (CMM), topological information of the points on the objects surface can be extracted in the form of a point cloud. However, CMM has been a very slow process with relatively low resolution which becomes a hurdle for a rapid manufacturing process. As a result, a non-contact method has been developed to provide higher speed and high resolution scanning. Therefore, the source of uncertainties for a non-contact probe, especially the laser scanner, had been reviewed to identify the potential improvement areas. Although the uncertainties are related to data acquisition capability, the surface construction effectiveness from the point clouds has similar importance to obtain the most accurate contour with minimum deviation from the actual surface. This can be achieved by eliminating the noise and by fitting the best shape according to the feature, such as a plane, cylinder or sphere, to the point cloud. The main aim of this work is to analyse and improve the performance of the laser scanner in terms of dimensional accuracy. A DIGIBOT II™ 3D laser digitizer which uses a remote ranging method was examined in the present work. The triangulation scanning system of this digitizer uses a high energy light source projected on the objects surface and a detector to sense the reflection. It was found that the scanning errors consist of random errors and systematic errors. For this scanner, the scanning data are random and follow the Gaussian distribution after the outliers are eliminated from the point cloud. The random error follows a systematic pattern where it varies with the scan depth and it is at a minimum when the y-coordinate is 228 mm and where the value of the error would be −0.0642 mm. The first systematic error is caused by the difference in the efficiency of photodetectors and the second systematic error is caused by the reflected laser intensity decrement as the scan depth increases. The second systematic error changes linearly when the y-coordinate is positive. Other methods for improving the scanning accuracy of the scanner have been recommended.

Rapid prototyping: practical approach to enabling reverse engineering

It has been reported that Rapid Prototyping (RP) is one of the enablers of Reverse Engineering (RE). Two separate studies have been carried out to verify the degree of the activities of RP as an enabler of RE. These studies which, are both experimental and theoretical in nature, considered two different components that were reversed engineered using CMM, 3D-laser Scanner and ProEngineer CAD package for final model in Stereolithography system. This involves the redesigning of parts using the original component as a template to retrieve the dimensional information required to rebuild the component on a Computer Aided Design (CAD) based program before the alterations can be made to improve it. The main area of studies is concerned with the interlinking of the two processes stated above. More accurately the computer data transfer of the dimensions of the component straight from the CMM or laser scanning machine on to the CAD based program considered, ProEngineer was used for this application. This would produce the model directly from the data transfer without any necessary physical drawing onto ProEngineer. The model production is generated at a considerable speed at minimal cost to ensure the components suitability for its specific use, giving the designer a physical model of the part. The purpose of doing this is to find a way of transferring data from the CMM or Laser Scanner to the RP system without the use of any other software and to cut down on the time and cost of Product development cycle. In this study these have been achieved.

Trends in agility for rapid product development and manufacturing – a review

With the rapid changes taking place in the global market, it has become clear that enterprises working on rapid manufacturing need to integrate Agile Manufacturing (AM) concept with their systems. Rapid Prototyping (RP), tooling and manufacture have come to stay as enablers of agility. Another emerging manufacturing philosophy is Mass Customisation, which is expected to become a market leader in manufacturing in the 21st century. To design efficient production systems and factories operating in these manufacturing paradigms, new design approaches need to be developed. This paper reviews some of the important research work done on RP, Rapid Manufacturing (RM) and AM, to show how RP/RM has been used successfully for implementing agility in a number of research fields.

Lean Six Sigma deployments in agile industrial environment: the key factors

Successful deployment of Lean Six Sigma entails making a committed and coordinated effort to achieve better, easier, quicker and safer output for customers and all other stakeholders at a competitive lower cost. Thus enabling the organisation to strategically simplify its processes, optimise its resources, and improve its quality thereby creating real value for its customers and stakeholders. This paper introduces the Lean leadership, people, process and outcome (LPPO) model for Lean Six Sigma deployment and carries out a comparative study of the deployment of Lean Six Sigma in two companies using the soft systems methodology. The findings underscores, the importance of visible leadership commitment, right people, right organisational structure, right project and the right supporting structures in the successful deployment of Lean Six Sigma.

Lean: a continuous improvement philosophy in agile systems based on quality management principles

The lean philosophy is based on optimisation through continuous improvement and absolute waste minimisation by factual analysis, just-in-time (JIT) in material sourcing, production and delivery to customer, total preventive maintenance (TPM), total quality management (TQM) and strategic competitive human resource management (HRM). These are lean practices which have spanned decades and centuries in one form or another, under countless innovative concepts aimed at attaining superior performance and quality at a lower cost that guarantees strategic competitive advantage. This paper takes a comparative look at the lean philosophy and the quality management principles from the leadership, people, process and outcome perspective.

Sustaining the Human Resource ‘the real quality’ in Lean Production system

Lean Production is a time tested and trusted world class production system which does more and achieve more with less resources by eliminating waste and ensuring continuous improvement within its value stream. Understandably, it has today become the cynosure of all eyes and center of most scholarly discuss from all fields of human endeavor due to its acclaimed success. But its continuous mill of success seems to be slowing down and dwindling by the day due to the relegation almost to extinction of the intellectually unique Human Resource which is at the heart of the Lean philosophy. It is therefore expedient that the foundation principles and pillars of all lean practicing system especially its Human Resource foundation be fortified. This paper takes an in-depth look into the Human aspects in todays Lean practice.