Showing papers in "International Journal of Design Engineering in 2010"
TL;DR: A new evolutionary design tool is presented, which uses shape grammars and a grammar-based form of evolutionary computation, grammatical evolution (GE), which allows forms to be iteratively selected.
Abstract: A new evolutionary design tool is presented, which uses shape grammars and a grammar-based form of evolutionary computa- tion, grammatical evolution (GE). Shape grammars allow the user to specify possible forms, and GE allows forms to be iteratively selected,
53 citations
TL;DR: In this article, a variable lift cam follower system is proposed, where follower lift varies according to the input or camshaft speed, and the height of the cam varies along the axis of the shaft and it slides in the axial direction.
Abstract: This work proposes a novel variable lift cam follower system. Here follower lift varies according to input or camshaft speed. The system comprises a trapezoidal shape cam with ping finite spline curve as displacement profile. The height of the cam varies along the axis of the shaft and it slides in the axial direction so that the lift of the cam varies. Sliding motion of cam was executed by actuating mechanism and it works on principle of centrifugal actuation. When input speed varies, due to centrifugal force, actuator initiates linear axial movement of bush and cam on the shaft. This axial movement of cam varies the follower lift with respect to speed. Various components of proposed mechanism are designed and fabricated by proper processes and assembled together with suitable provisions. The system is tested experimentally and follower lift was measured using the computerised measuring system. Results show that the mechanism works properly and is useful to get variable lift. The proposed mechanism can be used in automotive engines as a valve train for variable valve actuation with necessary modifications.
23 citations
TL;DR: In this article, a review of the field of design and optimisation of microelectromechanical systems (MEMS) is presented, with a general interest in the automated DO techniques, particularly, the evolutionary methods.
Abstract: This article provides an inclusive review on the field of design and optimisation (DO) of microelectromechanical systems (MEMS) since its emergence, about two decades ago. Fundamentals and applications of MEMS are presented herein, followed by a comprehensive review on the conventional tools and practices developed for MEMS DO throughout. The limitations of these techniques are identified, and the necessity for automated DO methods for MEMS technology is therefore justified and evaluated. A recent trend in DO of microsystems is inspired by the natural evolution and the survival of the fittest hypothesises. Motivated by its achievements in other engineering DO problems, evolutionary computation has also been adopted for the DO of MEMS, at different levels. A thorough review of this infant area of research is also presented in this article and highlights of the main challenges facing this field are discussed. Prior to a major research in the area, this article provides an update of the state-of-the-art on MEMS technology with a general interest in the automated DO techniques, particularly, the evolutionary methods.
19 citations
TL;DR: In this article, a tool adaptation and implementation process is introduced to improve the adoption of eco-innovation tools in industry, and results from the industrial application of this process within one of six case-study companies from the electrical and electronic equipment industry are presented.
Abstract: Despite the proliferation of eco-design and eco-innovation tools emerging from academia in the last 20 years, the uptake of such tools remains poor with usage limited to a few specific niche areas. In this paper, how eco-innovation tools could gain 'mainstream' popularity is considered, and it is proposed that adapting eco-innovation tools to the specific requirements of companies and their designers is the key to improve their adoption by industry. A tool adaptation and implementation process is introduced. Results from the industrial application of this process within one of six case-study companies from the electrical and electronic equipment industry are presented. The results reveal that design teams are willing and able to engage in the process of adapting eco-innovation tools to better suit their needs; that the co-development of tool evaluation metrics is a useful part of this process; and that the current understanding of designers requirements for eco-design tools may not be directly applicable in the case of eco-innovation tools.
16 citations
TL;DR: This study first attempts to demonstrate the usefulness of both the qualitative and quantitative approaches to deal with uncertainty, and proposes joint implementation of both of these approaches to estimate uncertainties when performing LCA of complex systems.
Abstract: Since the emergence of life cycle assessment (LCA), many studies have focused on the integration of uncertainties. Nevertheless, data quality assessment and statistical approaches are not yet widely used to quantify uncertainty, and when used, methodologies are neither uniform nor rigorous. Moreover, the data required to propagate and estimate the overall uncertainty are often lacking. Finally, the quantification of uncertainty could introduce more confusion in decision-making. In this context, we propose joint implementation of both the qualitative and quantitative approaches to estimate uncertainties when performing LCA of complex systems. Using an existing LCA on grocery bags, this study first attempts to demonstrate the usefulness of both the qualitative and quantitative approaches to deal with uncertainty. Secondly, given that data collection is very time-consuming, the usefulness of both the qualitative and quantitative approaches will be discussed.
11 citations
TL;DR: The surface constructor tool as discussed by the authors is a tool for the meshing of gears, which has been used for a variety of applications, such as special grinding wheel generation, double modified worm gearing, generating gear pairs by an intermediary generating surface like hypoid bevel gear pair and a novel worm gearing type characterised by continuous meshing in a point.
Abstract: The paper introduces the latest results achieved using the surface constructor computer programme, which is intended for accomplishing gear investigations, development and innovation. The first part introduces the reaching model conjugate surface generating theory as the core of the kinematical modelling and simulation software application. Then a short description summarises the structure and the capabilities of the tool. Finally, concrete examples demonstrate the versatility of the application in modelling the meshing of gears. The introduced cases are special grinding wheel generation, double modified worm gearing, generating gear pairs by an intermediary generating surface like hypoid bevel gear pair and a novel worm gearing type characterised by continuous meshing in a point.
9 citations
TL;DR: A new design of Arabic keyboard layout for convenient typing and effective use of keyboard is proposed that shows better ergonomic performance than the present keyboard being used in Arabic world with a 36.3% improvement.
Abstract: A new design of Arabic keyboard layout for convenient typing and effective use of keyboard is proposed. The design methodology is based on ergonomic criteria that evaluate and compares different keyboard layouts for optimal characters distribution. The proposed design criteria are simulated by a mathematical model that uses: 1) best distribution of the typing effort among the ten fingers of the typist; 2) accessibility of commonly used characters; 3) various other factors as constraint equations to reach an optimal keyboard layout that is ergonomically improved. This task is carried out using a genetic algorithm based optimisation framework. The new keyboard layout shows better ergonomic performance than the present keyboard being used in Arabic world with a 36.3% improvement.
6 citations
TL;DR: In this article, a method to rapid prototype the robots in virtual environments to conduct controller tests is presented. The procedure is implemented in a gimbal-based joystick production process and verified controllers are then employed in actual robot prototype.
Abstract: Production of a new mechanism involves design, manufacturing and testing phases. In order to achieve shorter turn-around times, researchers have studied methods of shortening these phases. Today, structural tests and simulations conducted in virtual environments prior to manufacturing are a part of most of the standard production processes. However, in robot production not only the structural aspect of the mechanism but also its controller is required to be tested. This paper summarises a versatile method to rapid prototype the robots in virtual environments to conduct controller tests. The verified controllers are then employed in actual robot prototype. The procedure is implemented in a gimbal-based joystick production process.
5 citations
TL;DR: In this article, a two-degree-of-freedom (dof) spherical linkage driven by two fixed motors is proposed for the stabilised platform of a flying base to track fixed and flying objects.
Abstract: A target seeker is an important portion of the guidance system for the flying vehicles to track fixed/flying objects. In the target seeker, the stabilised platform is fundamental as it provides pointing capability to maintain the apparatus mounted on it a desired time-invariant or time-variant pose. In this paper, a new design of the stabilised platform is investigated using a two-degree-of-freedom (dof) spherical linkage driven by two fixed motors. The configuration, forward and inverse kinematics, singularity as well as linearity are discussed. Then, the driving torques are modelled and investigated that leads to balance design. Furthermore, the balance design is detailed considering the motion of the flying base. Simulations illustrate the new design and a prototype is developed in the laboratory.
4 citations
TL;DR: The creative design approach was adopted in this work and showed that the proposed approach could create a near optimal solution for the minimum spanning tree (MST) problem at reasonable and reliable computation time.
Abstract: Finding the optimal broadcasting tree is a challenging problem in networks like mobile add-hoc network (MANET). Finding the optimal tree faces engineering problems such as the broadcasting storm problem and the complexity of computations. Therefore, several heuristic approaches have been introduced in order to find a sub-optimal solution. In this work, the creative design approach was adopted in order to provide means to tackle this problem by searching for a structure of a suitable spanning tree. This structure can then be optimised in order to meet the performance indexes related to the broadcasting problem. The proposed model was compared with three main algorithms: simple flooding (SF), counter base scheme (CBS) and minimum spanning tree (MST). The results showed that the proposed approach could create a near optimal solution for the minimum spanning tree (MST) problem at reasonable and reliable computation time. Additionally, it has lower redundancy and the broadcasting overhead than the simple flooding and the counter base scheme.
4 citations
TL;DR: In this article, a neural network model was developed to determine the failure load and drift of infilled frames under lateral loading, where the backpropagation neural network was used to evaluate the failure criteria on the infilled frame using the analytically generated data.
Abstract: A neural network model to determine the failure load and drift of infilled frames under lateral loading is developed in the present paper. The backpropagation neural network is used to evaluate the failure criteria on the infilled frames using the analytically generated data. Training of the network is done by considering the aspect ratio, number of bays, area of column, area of beam, grade of concrete, grade of steel used for the construction and a non-dimensional parameter λh as the input parameters. To validate the efficacy of the model, an experimental investigation was carried out and the results are compared with that obtained using the ANN model. The experimentation is carried out under the same conditions used for the generation of the analytical data. The agreement was found to be good.
TL;DR: In this article, the authors investigate new concepts, methods and an integrated system for designing sustainable electrical/electronic consumer products from a holistic point of view taking into consideration a set of interrelated aspects such as design for environment, design process optimisation, materials used, production, energy saving techniques and end-life analysis.
Abstract: The aims of this research are to investigate new concepts, methods and an integrated system for designing sustainable electrical/electronic consumer product from a holistic point of view. Taking into consideration a set of interrelated aspects such as design for environment, design process optimisation, materials used, production, energy saving techniques and end of life analysis. A new integrated system called 'SustainDesign' that provides designers with the relevant background knowledge for designing sustainable products and guides users step by step through the design process from the conceptual phase to the detailed realisation phase has been developed. The system integrates a set of user friendly tools and techniques for evaluating the environmental impacts of the product during the design and development processes. It also highlights the areas that may require further refinement within the product and then provides users with material declaration and life cycle assessment analysis reports.
TL;DR: Functional analysis is used in the paper as a tool for investigating the miniaturisation issues and for highlighting the critical parts or features that mainly are affected by downscaling.
Abstract: Functional analysis is a powerful tool to describe and represent both macro and micro devices Functional analysis is used in the paper as a tool for investigating the miniaturisation issues and for highlighting the critical parts or features that mainly are affected by downscaling A systematic method, based mainly on functional analysis, and a series of additional tools are illustrated by analysing the design of a new micro fluidic system starting from the corresponding macro product The functional analysis seems to be a good tool as well for novice designers as for expert designers facing up with design issues at different scales The micro world introduces micro-specificities that have to be considered as additional constraints to design
TL;DR: In this paper, the authors presented a systematic approach for manoeuvre load alleviation with multi-objective formulation and optimisation methods, which is a subset of active control technology and deals with optimal rotation of control surfaces to redistribute the forces on airframe.
Abstract: The focus of the paper is to present the systematic approach for manoeuvre load alleviation (MLA) problem with multi-objective formulation and optimisation methods. MLA is a subset of active control technology (ACT) and deals with optimal rotation of control surfaces to effectively redistribute the forces on airframe. The mathematical model consists of flight control parameters as design variables, bending and twisting moment at the wing root as multiple independent conflicting fitness functions along with aircraft stability equations as equality constraints. By and large this MLA problem is addressed as single objective optimisation. The present work emphasises multi-objective problem formulation and presents the population based NSGA-II of multi-objective evolutionary algorithm (MOEA) as solution method. Symmetric manoeuvres with vertical acceleration load cases are optimised. The approach presented provides significant reduction of wing root bending and twisting moment through optimal ELEVator and aileron (ELEVON) rotations.
TL;DR: In this paper, the authors present an approach for precision prediction of parallel kinematics machine tools by virtual prototyping using advanced software tools, such as MSC/ADAMS, for the proposed parallel drilling module mounted on a serial milling machine base.
Abstract: We present a new approach for precision prediction of parallel kinematics machine tools by virtual prototyping (VP) using advanced software tools. VP modelling and kinematics simulation using MSC/ADAMS was carried out for the proposed parallel drilling module mounted on a serial milling machine base, to perform a 3-PRS-PP hybrid-mechanism-based machine tool. The related kinematic analysis, such as the displacement and velocity analysis of the drilling tool end, the rotation angle analysis of the ball joints, the linear movements of the prismatic joints, is obtained. Kinematics analyses and simulations were carried out with and without manufacturing and assembly deviations. The effects of deviations on machine performances were analysed using two-dimensional probability distribution analysis. We present the application of a virtual prototype simulation approach in the parametric design process, structural design and error budget determination for new types of machine tools.
TL;DR: In this paper, a haptic-based cutting force model and a virtual cutting operation application are developed in which the user is provided to feel the deformable object by probing and then to physically deform it.
Abstract: In this study, a haptic-based cutting force model and a virtual cutting operation application are developed in which the user is provided to feel the deformable object by probing and then to physically deform it. A cutting force model that depends on the spring-damper method is proposed for interacting with volumetric data for both cutting force and torque calculations in real-time with the flexibility of different cutting tool head shapes, sizes and rotation speeds. The realism of the force-rendering is enhanced in medical and CAD/CAM fields. To compare the realism of the model, however, tooth data is implemented in the application. A novel 6DOF multi-contact method is introduced for reducing the computational load of voxel-based collision checks. For deformation of an object, 'L' shaped tool handles and different tool heads (spherical, conical and flat) with different cutting speeds and sizes are used. Conical and flat tool heads are physically modelled and applied.
TL;DR: In this article, a general numerical model for five-axis machining is proposed covering all possible tool geometries, and the proposed process model predicts total cutting forces acting on the tool given the cutter profile geometry, process conditions and material specifications without preliminary cutting operations.
Abstract: In this study, a general numerical model for five-axis machining is proposed covering all possible tool geometries. The proposed process model predicts total cutting forces acting on the tool given the cutter profile geometry, process conditions and material specifications without preliminary cutting operations. Tool envelope is extracted from CAD data, and helical flutes points are represented in cylindrical coordinates. Equal parallel slicing method is utilised to find cutter engagement boundaries (CEB) determining cutting region of the tool surface for each axial level in the tool axis direction. For each level uncut chip thickness value is found and total forces are calculated by summing force values for each point along the cutting flutes. For arbitrary cases forces are simulated and obtained results are experimentally verified.
TL;DR: The design methodology presented in this study involves a critical examination of material testing procedures, material model selection, and coefficient identification and the identified coefficients are verified through finite element analysis and actual test results.
Abstract: The basic problem in the finite element analysis of parts made of hyperelastic materials is the identification of mathematical material model coefficients. Furthermore, selection of a suitable mathematical hyperelastic material model may not be straightforward. In this study, a design methodology is presented for hyperelastic suspension jounce bumpers. The commonly used traditional trial-and-error method for jounce bumper design results in high mould costs for prototype production and prolongs the time required. The design methodology presented in this study involves a critical examination of material testing procedures, material model selection, and coefficient identification. The identified coefficients are verified through finite element analysis and actual test results.