Planar ground float glass surfaces and the surfaces within holes are polished using fluid jet polishing (FJP) in order to improve their visual appearance or material strength. The large flexibility of FJP makes it suitable for polishing holes and other complex geometries. The influence of polishing speed, incident angle, distance, pressure, abrasive concentration, and nozzle diameter are investigated. Al2O3 is the abrasive used. The surface quality is evaluated visually and also measured with an optical profiler. The mechanical strength of the polished holes are evaluated with an MTS testing machine. Planar surfaces, and the surfaces of drilled and water cut holes are greatly improved by polishing. For a planar surface the lowest root mean square surface slope, Sdq, value achieved is 0·5 deg using 50% abrasive and 1000 mesh grains. The failure load of the glass with drilled holes increased 20% with FJP

Virtual machine concepts supporting optimisation of machine tools have been developed in earlier work. The virtual machine concept is a tool that can describe the behaviour of a machine tool while considering the interaction between mechanics of the machines and the control system. Considerable amount of work has been done proving the concept and showing the potential of such a design tool in different contexts. Several studies have shown the potential of using the virtual machine concept, although, no work has been found that is exploring the potential of a full optimisation study. The aim of this work is to show the potential of the virtual machine concept in an optimisation study of the complete machine tool, including the mechanical system, parameters in the control system, the NC-code as well as choice of servo and drive systems. An efficient optimisation strategy is presented, making it possible to solve the complex optimisation problem within a reasonable amount of time. A combination of optimisation algorithms is used to achieve a fast and accurate way of solving the complex task to optimise the complete machine tool. Genetic algorithms, gradient based algorithms and more traditional hands on engineering are used for solving the optimisation problem. Post processing and data mining is suggested as a way of extracting as much information as possible from optimisation results with the aim to increase the knowledge about the studied system. An important conclusion is that the virtual machine should support the decision making in product development, not replace the product developers as regards decision making.

When designing CNC machine tools it is important to consider the dynamics of the control, the electrical components and the mechanical structure of the machine simultaneously. This paper describes the structure and implementation of a concept for real-time simulation of such machine tools using a water jet cutting machine as an application. The concept includes a real control system, simulation models of the dynamics of the machine and a virtual reality model for visualisation. The real-time capability of the concept, including the simulation of electrical and rather detailed mechanical component models is proofed. The validation process indicates good agreement between simulation and measurement, but suggests further studies on servo motor, connection and flexibility modelling. However, already from the initial simulation results presented in this paper it can be concluded that the influence of structural flexibility on manufacturing accuracy is of importance at desired feeding rates and accelerations. The fully automated implementation developed in this work is a promising base for dealing with this trade-off between productivity and accuracy of the manufacturing process through multidisciplinary optimisation.

A spring and damper contact force element is often used for modelling impact in multi-body dynamics. The related condition for transition between contact and non-contact is, however, inconsistently implemented in the literature and commercial software. This comparative study aims to clarify the implications of four commonly used transition conditions. Principal differences are discussed and, by simulation of a typical system, it is shown that there are significant differences in the dynamics of the system depending on the different conditions. Two of them give unrealistic contact forces and should imply incorrect prediction of system dynamics in most applications. This suggests that it is important to review results obtained from using these conditions and to eliminate them from commercial software. A discussion of the two other conditions culminates in a recommendation.

Major drivers behind increased efforts in product development are the increased competition due to globalisation and the urgent transformation of society towards sustainability. Furthermore, the average product lifetime has been compressed significantly over the last decade. Due to these trends, there is increasing demand for an efficient product development process. Cutting time-to-market, reducing costs and increasing quality are widely accepted as key factors to successful product development. Consideration of sustainability aspects in product development is also becoming increasingly important. Methods and tools that are useful also for small and medium sized enterprises are of particular importance for the Swedish industry. This thesis suggests a definition of lean prototyping and points to its potential for supporting efficient product development. This is done through two case studies: a soil compactor machine treated as a multi-body system and a water jet cutting machine treated as a mechatronic system. Lean prototyping is defined as a coordinated approach to experimentation with the purpose of achieving cost-efficient and accurate enough prediction of product characteristics to support optimisation and well-informed design decisions during product development, especially in the early stages. This often involves an iterative search for and use of a suitable combination of virtual and limited physical prototypes as well as the reuse of knowledge from previous projects. The case studies are performed in cooperation with one small and one medium sized company, indicating the usefulness of the approach for different product types as well as for different company sizes. More specifically, the validated multi-body model of the soil compactor machine describes the dynamics of the machine satisfactorily and the optimisation study shows a significant potential for improved compaction capacity. This potential would not likely been found through traditional physical prototyping. The related comparative study of contact transition conditions is a contribution to consistent impact modelling in multi-body dynamics in general. The real-time virtual machine concept for simulation of the water jet cutting machine, including detailed mechanical component models, is unique. The fully automated concept implementation makes it a promising base for multidisciplinary design optimisation of the water jet cutting machine, and probably of mechatronic products in general.

Traditionally, the development of mechatronic systems starts with the mechanical design. Later electronic components and program logic for the product are added. This work proposes an improved interdisciplinary concurrent product development process with an enhanced function structure for the conceptual design phase. The new methodology is based on the German guideline VDI 2221 [1]. Transition conditions, time aspects and logic flow are added to the normal function structure. An example shows how to use the improved function structure. The enhanced function structure is used to derive the initial logic for the development of the PLC program controlling the machine later on. Since the extended function structure also covers the traditional information, it can still be used when building the assembly tree. By adding more information in the neutral function structure, the same information can be used for the mechanical design as well as for the electronic and logical design. The interdisciplinary communication and documentation among the engineers will be improved and errors in the concept will be detected earlier.

En ny metodik för utveckling av mekatroniska produkter har föreslagits. Den nya metodiken inkluderar en förbättrad funktionsbeskrivning som stimulerar det interdisciplinära utvecklingsarbetet.

This paper presents an overview of the historical background of the virtual machine, containing a real control, a machine simulation and a 3D machine visualisation. This setup enables realistic system simulations, since the simulation input comes from a real control. The first known implementation of the virtual machine using xPC Target is described with an existing water jet cutting machine as an example. MathWorks products offer all necessary software for the presented setup, except the interface for the actual speed value from the simulated incremental encoder to the control. The unique xPC driver implementation, as a noninlined C-MEX S-Function, is presented at the end of this paper. The successful implementation of the virtual machine demonstrates the feasibility of the presented approach.

Koncepetet för den virtuella maskinen beskrivs och implementeras med hjälp av xPC Target. En vattenskärningsmaskin används som exempel för implementeringen.

Modern manufacturing machines are highly multidisciplinary, and with demands on short time-to-market, product development based on traditional prototype testing has become impractical. By using virtual models, it is possible to test large numbers of variants and optimise the product with the aid of a minimum of physical prototypes. Due to the immense development of software and hardware for simulation and visualisation it should today be possible also for small and medium sized enterprises to use methods that just few years ago were too expensive and complicated. There is however still a great need for building knowledge and compe-tence. This work is an early step in a project aiming at a virtual water jet cutting machine to be used by the industrial partner for optimisation during the development process. The possibility of performing real-time simulations of this machine in a virtual environment, using a normal PC and commercial software, will be in-vestigated. Initially strongly simplified models of the system components are used and the focus is on the overall system model and the interaction between the operator and the virtual machine. It is shown that real-time interaction is possible with this system and with the obtained flexibility of the overall virtual model it should be easy to include more realistic component models for improved accuracy in future work. Preliminary results indicate however that to include, for example, flexibility within the mechanic structure, component modelling will be delicate. These models must describe relevant characteristics accurately enough while still being computationally effective enough for real-time interaction and systems optimisation to be possible. This will probably be a challenge in the continuation of the project, even with an expected continued strong devel-opment of computer capacity.

Ett koncept för multidisciplinära realtidssimuleringar kopplade till en virtuell miljö har utvecklats. Koncpetet visar på stora möjligheter till användning vid produktutveckling av nya tillverkningsmaskiner, t.ex. vattenskärningsmaskiner.

Rein mechanische Lösungen werden zunehmend von mechatronischen Systemen abgelöst. Der X-by-wire Ansatz zeigt auch, dass der Anteil an mechanischen Teillösungen eines mechatronischen Systems immer weiter zurückgeht. Der vorliegende Beitrag skizziert einen Entwicklungsprozess für SPS-gesteuerte mechatronische Systeme, der dem immer wichtiger werdenden Steuerungsanteil Rechnung trägt. Dabei steht das parallele Arbeiten der Steuerungstechnik und der Konstruktion im Vordergrund, um die Entwicklungszeiten zu verkürzen und Fehler früher zu erkennen. Realisiert wird dies durch eine fachspezifische Modularisierung, deren erste Modulhierarchie als Ausgangslage der jeweiligen Disziplinen fungiert und somit einen parallelen Start ermöglicht. In dieser Arbeit werden Regeln vorgestellt, um die fachspezifischen Module von einer Funktionsstruktur abzuleiten. Abschliessend wird das Vorgehen anhand eines Industriebeispieles erläutert.

Regler för att gå från funktionsstruktur till produktmoduler har tagits fram och implementationen av dessa visas i ett exempel.

Rammer compactor machines perform impact soil compaction, which is very efficient compared to static compaction. They are often used in places where a high degree of compaction is needed and the space for operation is limited. The complexity of this machine type makes design optimisation through traditional prototype testing impractical. This has pointed to the need for a theoretical model and simulation procedure for prediction of the dynamic behaviour of the machine. To be useful for optimisation as design parameters are changed during product development the theoretical model and simulation procedure must be verified. By concurrently working with theoretical modelling, simulations, experimental verifications, and optimisation an efficient analysis support for product development is achieved. This co-ordination works both ways in an iterative manner. Experimental investigations are used to verify theoretical models and simulations. Theoretical models and simulations are used to design good experiments. This Complete Approach concept makes better decisions possible earlier in the development process, resulting in decreased time to market and improved quality. In this paper the Complete Approach concept is described. It is applied on a rammer soil compactor machine. An introductory iteration, with emphasis on the experimental part, is described. In the experimental set-up the rammer foot is attached to a linear spring foundation. This eliminates uncertainties related to soil modelling and makes a check of the model of the machine itself possible. The good agreement between theoretical and experimental results indicates that the theoretical model and simulation procedure should be useful for introductory optimisation studies. Reasons for the discrepancy are discussed and suggestions for improvements of both the theoretical model and the experimental set-up in coming iterations are given.

En experimentell undersökning av det dynamiska beteendet hos en jordkompakteringsmaskin har gjorts. Resultaten visar att tidigare simuleringsmodeller saknar ett hastighetsberoende som kan påvisas vid analys av mätresultaten