Adrie Kooijman

An Information Technological Specification of Abstract Prototyping for Artifact and Service Combinations

Various early prototyping techniques have been proposed for specific purposes and products, for instance for user-centered design of software tools, or interface design of consumer durables. Our research focuses on the development of a comprehensive approach, called abstract prototyping, to support a rich and complete prototyping of artifact-service combinations (ASCs). In this paper we present the concept and implementation of abstract prototypes (APs) from an information system point of view, and discuss both the general information structure and the specific information constructs used in our approach. First, the main constituents of APs are identified. Then, formal definitions of the involved information constructs are introduced. Afterwards, the practical implementation of the information constructs is discussed. As an information processing activity, abstract prototyping decomposes to four stages: (i) aggregation of information about the innovated ASCs, (ii) compilation and testing of the technical contents for abstract prototype(s), (iii) demonstration of the abstract prototype(s) to stakeholders, and (iv) refinement of the contents towards a final abstract prototype. It is assumed that ideation and elaboration of the concepts of the new artifact-service combinations precedes and produces input for abstract prototyping. It is proposed that APs should demonstrate real life manifestation of all characteristic operation and interaction/use processes, including the operation of the conceptualized artifact-service combination, the actions of the human actors, and the happenings in the surrounding environment. This can be achieved through the inclusion and proper instantiation of the necessary information constructs in the APs. The real life processes established by the existence and operations of ASCs is modeled and represented by scenarios. The contents of the abstract prototype are designed and demonstrated taking the interests and needs of the stakeholders into consideration. Eventually, an abstract prototype consists of two main constituents, namely narration and enactment, which enable the presentation of the technical contents. The former conveys a story about the manifestation of the ASCs and highlights the accompanying processes, and the latter visualizes the components, actors, arrangements, procedures, and happenings involved in them. The presented approach of information content development has been tested in master graduation projects, certain cycles of PhD research, and a company orientated process innovation project. The follow up research focuses on the development of a dedicated tool for abstract prototyping, and on the validation of proposed development and application methodology in complex industrial cases.Copyright

Towards Ubiquitous Design Support

Efficient computer support of product innovation processes has become an important issue of industrial competitiveness in the last forty years. As a consequence, there has been a growing demand for new computer-based tools and system. Various hardware, software and knowledge technologies have been used over the years as the basis of design support systems. With the appearance of network technologies, the conventional standalone workstation paradigm has been replaced by the paradigm of web-interconnected collaborative environments. Currently, the emerging and rapidly proliferating mobile and ubiquitous computing technologies create a technological push again. These technologies force us to reconsider not only the digital information processing devices and their interconnection, but also the way of obtaining, processing and communicating product design information. Many researches and laboratories are engaged with the development of novel concepts, architectures, tools and methods for next-generation design support environments. They will integrate many resources of the current collaborative design environments with pervasive computing functionality and large-scale mobility in a volatile manner. Part of the design support tools will have fixed location, but will be remotely accessible through wireless networks. Other part of the tools will be moving with the designers as portable, embedded, wearable and transferable devices, and will feature ad hoc connectivity. These not only offer new ways for aggregation, processing and presentation of design information, but also enable alternative ways of completing design activities. Our current research concentrates on three interrelated main issues: (i) studying workflow scenarios for future design support environment, (ii) investigation and integration of multiple technologies into an ad hoc interconnected heterogeneous infrastructure, and (iii) exploring efficient methods for utilizing new affordances in supporting product innovation. In this paper we report on the results of our recent technology study that analyzed the current results and trends of ubiquitous technology development, and tried to form a vision about the possible manifestation of future ubiquitous design support environments. Essentially, they have been conceptualized as ad hoc and volatile networks of fixed and mobile information collection, processing and communication units. This network functions as a complex service provider system, with special attention to the on-demand information management in the fuzzy front end of design projects.Copyright

Implementation and Validation of Engagement Monitoring in an Engagement Enhancing Rehabilitation System

Enhancing engagement of patients during stroke rehabilitation exercises are in the focus of current research. Various methods and computer supported tools have been developed for this purpose, which try to avoid mundane exercising that is prone to become a routine or even boring for the patients and leads to ineffective training. This paper introduces an engagement enhancing cyber-physical stroke rehabilitation system (CP-SRS) aiming at enhancing the patient’s engagement during rehabilitation training exercises. This paper focuses on introducing the implementation and validation of the engagement monitoring subsystem (EMS) in the CP-SRS. The EMS is expected to evaluate the patient’s actual engagement levels in motor, perceptive, cognitive and emotional aspects. Experiments in these four aspects were conducted separately, in order to characterize the range and accuracy of the engagement indicators by influencing the subjects into different engaged states. During the experiments, different setups were created to mimic the situations in which the subject was engaged or not engaged. The subjects involved in the experiments were healthy subjects. Results showed that the measurement in motor, perceptive, cognitive, and emotional aspects can represent the corresponding engagement level. More experiments will be conducted in the future to validate the efficiency of the CP-SRS in enhancing the engagement with stroke patients.

GPU Implementation of the LFT Shape Matching Algorithm

Registration of partial scan data sets is still a challenge for todays CAD systems and CAD system users. Many of the known methods rely on user interaction or feature recognition. For non-regular users this is too time consuming and error prone. The paper describes a method to register partial scan data by fitting a large fat tetrahedron (LFT) in the target point cloud. The method is computational intensive and in its CPU implementation not fit for interactive use. The independency of the points in the data-sets makes massive parallel computing applicable. The paper describes the implementation of the method on a GTX260 GPU using the CUDA programming environment. A performance gain of 10 times compared to a conventional CPU implementation was achieved, which can be further improved by implementing a pre selection method of the result, bringing interactive use in range after further optimization.

From Virtual Reality to Tangible Virtuality: An Inventory of the Technological Challenges

The paradigm of tangible virtuality (TV) has grown out from the paradigm of virtual reality (VR), leaving some key concepts of projective and immersive VR behind, but introducing many new ones. The ultimate objective of TV is to intuitively generate air-borne synthetic objects (SOs), share them between remote work environments in real time, simulate their physical behavior, and enable a physics-obeying interaction of humans with SOs. The major challenges for the implementation of TV originate in the need for multi-sensory integral rendering of SOs and un-instrumented generation of high fidelity sensations. These scientific and technological challenges have a strong influence on the current advancement of TV. Actually, implementation of fully featured TV environments is still in its infancy. The goal of this paper is to analyze the main implementation concepts and to make an inventory of the technological challenges and opportunities. Six major issues have been identified: (i) use of natural interaction modalities to express SOs, (ii) multi-aspect (e.g., tactile, haptic and auditory) volumetric rendering and sensation of air-borne SOs, (iii) simulation of physical behavior of interacting SOs, and (iv) manipulative human interaction with SOs. The paper investigates the opportunities of a short-term implementation based on the current technologies and of a near-future implementation based on emerging and anticipated technologies. The conclusion is that current technologies allow only a limited implementation of SOs and a low fidelity multi-sensorial experience. For a full scale implementation, radically new technologies and implementation concepts are needed, but it also requires a goal-driven extension of the existing scientific knowledge.Copyright

Virtual Prototyping by Using Holographic Displays: But What About Large Data Problems?

The work reported in this paper is part of the research that explores the viability of using holographic displays as part of virtual prototyping package of supporting tools. The focus is principally on handling of large data problems, which are among the common problems of most volumetric displays. The paper first reviews related works. After describing the large data related problems that designers might face in using holographic displays and identifying the conceptual design tasks that could be supported by using these displays, a concept for handling the large data problems through elimination of irrelevant image details is introduced. An application example showing how some elements of the proposed concept function in the real world is also presented. The main contributions of this work can be summarized as follows: (i) we have demonstrated that through simplifications, visual abstractions, data clustering or other generalization methods, less complicated holographic images that require less computing resources but yet suitable 3D for some conceptual design tasks or virtual prototyping can be created; and (ii) we have defined the steps of a scalable high-level algorithm, that can be expanded or tuned to suit visualization demands in various conceptual design tasks. In the ongoing work, we aim to develop built in procedures within the proposed algorithm that would reduce the amount of image details without significantly affecting the appropriateness of the overall virtual model. And because of the reduced image details, it would be possible to display less complicated 3D virtual objects and in this way computing resources could be saved.Copyright

Toward Enhancement of the Airborne 3D Visualization Capabilities of the Holovizio System

Implementation of tangible virtuality means providing means for creating airborne visual images, rendering them with physical properties and making them sensible for the human senses. Airborne creation and direct manipulation requires separating the virtual objects from the image generating (physical rendering) device. One step in this direction is using electroholographic, or pseudo-electroholographic, devices which are able to create virtual objects in mid-air by various light interference techniques. A virtual object is a computer model, visualized by the projection system to appear as a real, tangible object. Te enable the required direct interaction with the virtual objects these have to be perceptually separated from the projected device, they have to be perceived as floating in the air. In our research we use the Holovizio Hv128WD system, a mono-parallax, high resolution holographic imaging device supporting 3D image visualization rather than physical rendering of virtual objects. The device generates 62 views of virtual objects where each view is visible from a specific viewing direction. The user of the system perceives this as a stereo view to the object. We have been collecting application experiences related to this device for more than one year, and we have found some restrictions and limitations in the image creating capabilities which we are trying to eliminate in our current research. This paper reports on the first phase of research which focuses on some major image generation problems and exploration of possible hardware, software or data management causes. The goal of this first phase is to develop and validate the proper measurement methods. A pilot experiment is performed to verify the applicability of the method. The results show that the proposed measurement methods are feasible and helpful in analyzing the observed problems. Some problems appear to have a more fundamental cause and may only be worked around.Copyright

Improving minimum strain energy curve calculations for flexible blade cutting

A flexible blade cutting technique is applied for large physical prototypes. The flexible blade is heated and can shape thick layers of polystyrene foam. For tool path generation a numerical calculation model is available. In practice, the shape calculation time for the hot blade used in the flexible blade cutting process increases with approximately the 3rd power of the number of segments used in the blade model. For better accuracy of the blade shape representation a higher number of segments is required and this results in unacceptable calculation times. A changed procedure of blade shapes calculating has been implemented and tested. The method starts with a small number of segments and after shaping according to the minimum strain energy principle, all segments are subdivided in equal segments of half the length of the previous segments. The resulting blade shaping model is then the starting configuration for the next shaping calculation. This is done until the required number of segments or the requested representation accuracy is reached. A second improvement of the shape representation of the basic calculation method is also implemented, namely the angle setting segments (originally the first and last segments) are extended with two extra segments that fix the setting angles at the blade clamping location. This enables the blade to bend from the first up to the last segment. This provides a higher representation quality and enables more shape freedom resulting in a broader parameter space that can be used. Both enhancements of the blade shaping model provide are demonstrated with a few typical examples

Speed Control for Flexible Blade Cutting of Thick Foam Layers

The FF-TLOM (Free Form Thick Layered Object Manufacturing) process is based on heated flexible blade cutting of thick foam layers in a free form manner. Both blade ends are supported in a U-shaped tool frame. During cutting the blade is shaped in a minimal strain energy curve. Positioning the tool in an optimal orientation is provided by pitch, roll, yaw and positioning of the tool frame. A restriction of the FF-TLOM cutting is the cutting speed. The cutting speed depends on melting of the foam at the blade location and does not allow outside forces on the blade. Nevertheless the manufacturing time must be as rapid as possible. In this paper an estimation method is proposed for the overall speed setting along a tool path. Hereto the blade is subdivided in blade segments and each segment is analyzed for the encountered speed and in the same time to prevent that the maximum allowable cutting speed is exceeded.Copyright

Matching Minimum Strain Energy Curves to B-Spline Curves for Thick Layer Manufacturing

One of the key issues of thick layer manufacturing is matching the shape of the flexible cutting blade to the local surface curvature of the model to be created. In this paper we explore a method to find the best matching minimum strain energy (MSE) curve for a given B-spline curve. For this purpose we developed software to a) generate a dataset containing MSE curves for a range of settings of the cutting tool and b) find the best matching curve from this MSE dataset to the given target curve. Both the MSE and the target curves are represented as point sets, the target curves having a considerable higher point density than the curves in the MSE dataset. The best matching MSE curve is defined as the curve with the minimum directed Hausdorff distance to the target curve. It is found that despite the relative low density of the dataset, for several practical domains of target curve shape, a satisfying match can be found. Numerical results concerning the matching accuracy are presented.Copyright