Robert M. Parkin

A survey of virtual prototyping techniques for mechanical product development

Abstract Repeated, efficient, and extensive use of prototypes is a vital activity that can make the difference between successful and unsuccessful entry of new products into the competitive world market. In this respect, physical prototyping can prove to be very lengthy and expensive, especially if modifications resulting from design reviews involve tool redesign. The availability and affordability of advanced computer technology has paved the way for increasing utilization of prototypes that are digital and created in computer-based environments, i.e. they are virtual as opposed to being physical. The technology for using virtual prototypes was pioneered and adopted initially by large automotive and aerospace industries. Small-to-medium enterprises (SMEs) in the manufacturing industry also need to take virtual prototyping (VP) technology more seriously in order to exploit the benefits. VP is becoming very advanced and may eventually dominate the product development process. However, physical prototypes will still be required for the near future, albeit less frequently. This paper presents a general survey of the available VP techniques and highlights some of the most important developments and research issues while providing sources for further reference. The purpose of the paper is to provide potential SME users with a broad picture of the field of VP and to identify issues and information relevant to the deployment and implementation of VP technology.

Global optimization of a feature-based process sequence using GA and ANN techniques

Operation sequencing has been a key area of research and development for computer-aided process planning (CAPP). An optimal process sequence could largely increase the efficiency and decrease the cost of production. Genetic algorithms (GAs) are a technique for seeking to ‘breed’ good solutions to complex problems by survival of the fittest. Some attempts using GAs have been made on operation sequencing optimization, but few systems have intended to provide a globally optimized fitness function definition. In addition, most of the systems have a lack of adaptability or have an inability to learn. This paper presents an optimization strategy for process sequencing based on multi-objective fitness: minimum manufacturing cost, shortest manufacturing time and best satisfaction of manufacturing sequence rules. A hybrid approach is proposed to incorporate a genetic algorithm, neural network and analytical hierarchical process (AHP) for process sequencing. After a brief study of the current research, relevant issues of process planning are described. A globally optimized fitness function is then defined including the evaluation of manufacturing rules using AHP, calculation of cost and time and determination of relative weights using neural network techniques. The proposed GA-based process sequencing, the implementation and test results are discussed. Finally, conclusions and future work are summarized.

Engineering education for mechatronics

This paper defines mechatronics, explains mechatronics philosophy, and describes characteristics of mechatronics products and systems. It reviews aspects of education and training for mechatronics and compares the two different approaches to engineering education: generalist engineering versus specialist engineering. It also examines the Japanese approach to product development strategies and mechatronics education and training. It also gives an overview of mechatronics education in higher education institutions across the world with a specific reference to a typical mechatronics engineering degree program. Finally it concludes that there will be an increasing need in the future for discipline-based mechatronics engineers.

Vibration characteristics of MR cantilever sandwich beams: experimental study

The concept of vibration controllability with smart fluids within flexible structures has been of significant interest in the past two decades. Although much research has been done on structures with embedded electrorheological (ER) fluids, there has been little investigation of magnetorheological (MR) fluid adaptive structures. In particular, a body of research on the experimental work of cantilever MR beams is still lacking. This experimental study investigates the controllability of vibration characteristics of magnetorheological cantilever sandwich beams. These adaptive structures are produced by embedding an MR fluid core between two elastic layers. The structural behaviour of the MR beams can be varied by applying an external magnetic field to activate the MR fluid. The stiffness and damping structural characteristics are controlled, demonstrating vibration suppression capabilities of MR fluids as structural elements. MR beams were fabricated with two different materials for comparison purposes. Diverse excitation methods were considered as well as a range of magnetic field intensities and configurations. Moreover, the cantilever MR beams were tested in horizontal and vertical configurations. The effects of partial and full activation of the MR beams were outlined based on the results obtained. The controllability of the beams vibration response was observed in the form of variations in vibration amplitudes and shifts in magnitudes of the resonant natural frequency.

The impact of TQM in UK SMEs

Notes that while implementation of total quality management (TQM) in large organizations has been widely documented, it has received far less attention in relation to small and medium‐sized enterprises (SMEs), in which most of the UK labour force is employed. Reports the results of an investigation into SME management attitudes towards TQM in the East Midlands region of the UK. Compares them with UK‐based Japanese‐owned companies and discovers that the UK‐owned SMEs are better at implementing TQM. Concludes that there is room for improvement in all companies in the translation of management philosophy into employee action.

Laser welding of thin polymer films to container substrates for aseptic packaging

Keyhole laser welding of polymers is a subject well covered and researched, but relatively little information exists regarding the welding of thin polymer films, particularly to a heavier substrate. This paper presents the design of a suitable test apparatus for laser welding thin film to a heavier substrate, and shows the results of an investigation into the feasibility of laser welding multi-layer polymer film lids to tubs for the manufacture of aseptic food containers. A consistent weld, free from defects, is the key to process success. Typical welding defects have been synthesised in order to investigate, and consequently remove, their cause. The result is a reliable welding method based on even film clamping. With careful attention to machine design, a seal of high mechanical strength and chemical integrity is possible.

Waves on wood

Abstract The rotary machining process as applied to timber is introduced and compared with the milling and grinding of metals. The emphasis of this work is on the waviness surface quality of the machined timber and initially focuses on a review of the techniques applied to improve surface quality at higher workpiece feed velocities—typically 120 m/min. The main work concentrates on mathematical and computer-based modelling of surface waviness defects generated by two classical woodworking machine engineering science phenomena, caused primarily by forced structural vibration. Surface assessment of machined timber is discussed, with results from contact and non-contact methods highlighted. The causes of surface waviness defects are presented and possible solutions are outlined.

The Use of Aerial Images and GPS for Mobile Robot Waypoint Navigation

The application of aerial and satellite imagery for mobile robot path planning and navigation has shown potential in recent years. Their uses vary from identifying terrain properties for creating traversability maps to extracting landmarks for autonomous navigation. With the freely available differential positioning system, Wide Area Augmentation System (WAAS)/European Geostationary Navigation Overlay Service (EGNOS), the use of the GPS with aerial images providing valuable contextual data demonstrates potential in waypoint-based navigation of mobile robots. However, important issues relating to the spatial accuracies of image, waypoint, and GPS-derived data, vital for obtaining accurate navigation results, are often overseen. This paper defines the causes of spatial inaccuracies in order to develop optimal waypoint navigation parameters and provides researchers with sufficient knowledge to reproduce similar results. An improvement of up to 48% in the number of waypoints reached, depending on the radius, was determined for the positional correction of the GPS. The results are shown with a simulated synchronous drive robot in Matlabs Simulink environment. The reader is presented with a method for easily creating waypoints from aerial images, yielding results to a similar level of accuracy to conventional and often tedious manual methods.

Piezomechanics as a subsystem of mechatronics: present state of the art, problems, future developments

The concept of piezomechanics (piezoelectricity+mechanics+a control system) describing a complex interaction of dynamic effects and precision engineered devices is discussed. Piezomechanics is considered as part of the more broad philosophy of mechatronic devices. The object and structure of piezomechanics are presented as well as the primary linear and nonlinear effects, on which energy, motion and signal transformation processes are based. Novel applications are proposed to illustrate the potential benefits, including adaptive mechanical systems in addition to multifunctional and intelligent devices.

A novel approach for quality control system using sensor fusion of infrared and visual image processing for laser sealing of food containers.

This paper presents a new mechatronic approach of using infrared thermography combined with image processing for the quality control of a laser sealing process for food containers. The suggested approach uses an online infrared system to assess the heat distribution within the container seal in order to guarantee the integrity of the process. Visual image processing is then used for quality assurance to guarantee optimum sealing. The results described in this paper show examples of the capability of the condition monitoring system to detect faults in the sealing process. The results found indicate that the suggested approach could form an effective quality control and assurance system.