Wilhelm Frederik van der Vegte

INCLUDING HUMAN BEHAVIOR IN PRODUCT SIMULATIONS FOR THE INVESTIGATION OF USE PROCESSES IN CONCEPTUAL DESIGN: A SURVEY

In this paper, approaches for behavioral simulation of humans and human-artifact systems are reviewed The objective was to explore available knowledge for the development of a new method and system for the simulation of use processes of consumer durables in conceptual design. A key issue is to resolve the trade-off between minimizing the modeling and computing effort on the one hand, and maximizing the amount of valuable information obtained from simulations to facilitate improving the product. After drawing up review criteria, we reviewed existing simulation approaches, which we characterized based on the simulation models. We found that the surveyed approaches can only address limited, largely unconnected subsets of the various behaviors that can be simulated. For the most advanced approaches, the subsets can be clustered into three main groups: (i) kinematics and rigid-body kinetics simulated with non-discretized object models, (ii) mechanical-deformation behavior and non-mechanical physical behavior simulated with discretized object models and (iii) interpreted physical behavior (information processing) simulated with finite-state machines. No clear-cut solutions for integrated behavioral simulation of use processes have been found, however, we could identify opportunities to bridge the gaps between the three groups of behavior, which can help us to resolve the aforementioned trade-off. In the first place, it seems that the possibilities for using discretized models in kinematics simulation (especially with consideration of the large deformations that are common in biomechanics) have not been fully explored. Alternatively, a completely new uniform modeling paradigm, possibly based on particles, might also help to resolve the gap between the two distinct groups of physical behaviors. Finally, hybrid simulation techniques can bridge the gap between the observed physical behaviors and interpreted physical behaviors. Here, the combination with the object models commonly used for simulations in group (i) and (ii) seems to be largely unexplored. Our findings offered valuable insights as a starting point for developing an integrated method and system for modeling and simulating use processes. We expect that other researchers dealing with similar issues in combining seemingly disconnected simulation approaches could benefit as well.

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 computer-supported inclusion and integration of life cycle processes in product conceptualization based on the process tree

Abstract Development of computer support in design is showing several shifts in focus over the latest decades. This paper relates to the shifts from detail design to conceptualization, from artifact geometry definition only to the inclusion of process knowledge, and from isolated aspects to integrated aspects. It discusses a possible solution for simultaneous consideration of life cycle process aspects during conceptual design using the process tree representation. Integrating process aspects can be considered a preparation for an integrated representation of artifact and process aspects to be used in a front–end environment for conventional CAD detailing systems

Achieving closed-loop control simulation of human-artefact interaction: a comparative review

To include user interactions in simulations of product use, the most common approach is to couple human subjects to simulation models, using hardware interfaces to close the simulation-control loop. Testing with virtual human models could offer a low-cost addition to evaluation with human subjects. This paper explores the possibilities for coupling human and artefact models to achieve fully software-based interaction simulations. We have critically reviewed existing partial solutions to simulate or execute control (both human control and product-embedded control) and compared solutions from literature with a proof-of-concept we have recently developed. Our concept closes all loops, but it does not rely on validated algorithms to predict human decision making and low-level human motor control. For low-level control, validated solutions are available from other approaches. For human decision making, however, validated algorithms exist only to predict the timing but not the reasoning behind it. To identify decision-making schemes beyond what designers can conjecture, testing with human subjects remains indispensable.

Theoretical underpinning and prototype implementation of scenario bundle-based logical control for simulation of human-artifact interaction

This article presents a new methodology that enables designers to include in simulations not only the physics aspects of artifact behavior, but also human actions. The motivation for this research came from the fact that none of the conventional approaches to engineering simulations includes manipulative control of products by users as foreseen by designers. By implementing control over physics simulations, changes in parameters can be introduced that alter the course of the simulated process. As a means to do this, we propose to use scenario bundles, with which designers can operationalize their conjectures of how human users interact with products as a series of interconnected simulations. For the imaginary use process described in a scenario bundle, the designer can specify various product designs, user characteristics, and environments, which may in each case lead to different concatenations of simulation actions. The proposal facilitates the exploration of possible mismatches and anomalies in use processes. In this article, we describe the theoretical fundamentals and the overall concept of the proposed methodology, as well as its realization as a proof-of-concept implementation. This implementation can be used as a tool to specify scenario bundles and to perform controlled simulations of human-product interaction. The use of the tool is demonstrated through a practical example. Although the implementation has proven to be successful in terms of executing scenario bundles, two bottlenecks need further attention: (i) devising stable algorithms for large deformations in physical interaction simulation and (ii) incorporation of already existing algorithms for simulation of low-level human motion control.

Towards Improved User-Product Testing With Cognitively Enhanced Scenarios

With the increasing information-intensiveness of products, users are challenged with expanding options and possible ways to interact. Rapidly escalating numbers of possible useroperation sequences hinder designers in anticipating all possible (unacceptable) outcomes. Interactively simulating product models with human subjects to explore all options is not practicable. Virtual simulation with computer models of users can open the way towards faster-than-real-time performance and investigation of massive numbers of interaction sequences. This paper reports on opportunities to improve realism of virtual-use simulations by incorporating knowledge about the workings of the human brain We elaborate how, in particular, cognitive-architecture simulations developed by cognitive scientists and error phenotypes identified in human reliability analysis (HRA) can extend a virtual-use simulation approach that we have proposed in foregoing work, by offering the prospective of generating interaction sequences with erroneous user actions unforeseen by the designer. We outline how such an integrated system can be implemented and also discuss validation issues.

Conceptualisation and formalisation of technical functions

In the engineering design research community, function-based descriptions have become a popular means to describe products and systems using abstract building blocks. A claimed advantage is that they allow designers to synthesise and describe their designs early in the design process without having to consider physical principles, material selection, and geometric shapes and features. In addition, they can be used for critical investigation of both unfinished designs and existing products, in which case functions are supposed to facilitate decoupling of perceived needs of end users from concrete solution elements. This solution independence has been said to encourage out-of-the-box thinking and thus increase creativity and innovation, both in novel designs and in redesign. In order to facilitate a comprehensive investigation of the functional capabilities of products, the technical functions are often taken into consideration together with the utility functions. In the case of the development of new products or components, technical functions are the building blocks or elements of a solution independent functional synthesis, which is typically followed by the investigation of possible realisations of functions and converting the functional schemes into feasible component structures and numerically testable virtual and physical prototypes. Since the mid-twentieth century a large number of publications have appeared on technical functions. Figure 1 illustrates that the number of scientific articles referring to technical functions has dramatically increased since the early 1990s. Academic debate on functions in design and engineering has also been the topic for several special issues of various journals. These have been edited by Sticklen and Bond (1991), Kumar (1994), Chakrabarti and Blessing (1996), Chittaro and Kumar (1998), Stone and Chakrabarti (2005) and Kroes and Meijers (2006). Despite the growing attention that technical functions receive in academia, they are not widely used by designers and have hardly been incorporated in computer tools developed for industrial users. As Birkhofer (2011) stated, ‘there is an urgent need to close the gap between conceptual approaches in design methodology and the involvement in embodiment and detailed design in design practice’. In a recent survey of design synthesis systems by Chakrabarti et al. (2011), the state-of-the-art computer tools for function-based synthesis were reviewed and it was concluded that, among other things, (i) the systems need to be scaled-up to support problem solving at the levels of complexity expected in practice and (ii) a better understanding is needed on how the systems can be integrated into current design processes in practice. In addition, it was found that rigorous means for evaluating the systems are missing, and that still no commonly accepted terminology is available to foster exchange of research models, methods and results. The extensive criticism that the whole concept of ‘technical function’ has been receiving in recent years underpins and explains the critique and reservations towards computer-based functional design systems. Horváth (2000) identified 12 areas where scientific understanding is

Taking Advantage of Data Generated by Products: Trends, Opportunities and Challenges

Now that all kinds of products are increasingly getting connected to the Internet, it is expected that it will become easier to collect data on how they are actually used during the middle-of-life stage of their product lifecycles. At the same time, a growing number of data analytics technologies offers opportunities to transform this data into actionable knowledge. Over the years, such knowledge extracted from usage data has already become a reliable input for managing maintenance and related services, but other uses such as feedback to design – where product data management systems have started to offer support for data collection practices – and providing advice to end users are now also being considered. Most data from sensors and other product-embedded information devices are collected in batches and analyzed retrospectively. In order for companies to further benefit from data collection in terms of efficacy and acceptance in society, two key challenges are (i) finding ways to effectively use data analytics techniques – which currently do not seem to be used to their full potential, and (ii) finding a good trade-off between respecting privacy and yet producing useful knowledge.

Hybrid Simulation of Use Processes With Scenario Structures and Resource-Integrated Models

The approach described in this paper aims to offer designers a new way to investigate use processes of a product, by integrating scenarios of expected user behavior with simulations of artifact behavior. We introduce a method and system framework to model and simulate virtual human-artifact systems, aiming to resolve two knowledge-related issues in use-process simulation: (i) the integration of distinct modeling and simulation approaches (ii) extending the deployability of simulations towards conceptual design. This paper elaborates on achievements in the first area. Currently, performing complete-picture simulations in which the product and the human user react on each other’s behaviors is not practicable. To make this possible, a hybrid approach is proposed. Behavior that is commonly modeled based on the laws of physics is simulated as continuous behavior, while information-processing behavior is simulated as discrete behavior. Discrete behavior is represented by finite state machines, which are behavioral models encompassing human decision-making and information-processing by artifacts. They enable the designer to perform what-if studies involving different ‘scenario structures’ of human decisions during simulated use, and thus to address an important factor contributing to the diversity of use processes. For continuous (physical) behavior multibody dynamics simulation and simulation with discretized 3D object models can be considered. A pilot study of a basic use process showed that our concept of hybrid simulation successfully enables investigation of multiple courses of use processes. However, the applicability of multibody simulation turned out to be limited, because of the crucial role of large deformations in human-artifact interaction. To overcome these limitations, discretized models are proposed for the next steps towards building a full-fledged system.Copyright

Studying a New Embarking and Disembarking Process for Future Hyperloop Passengers

This paper presents an embarking and disembarking process for the hyperloop, a future high-speed transportation of passengers and goods in tubes. A concept of the (dis)embarking process has been designed and tested with two experiments. The first experiment was performed to compare the new concept to one that is more similar to the current embarking setup of trains on the aspects of efficiency and experience. Participants were asked to (dis)embark in the test settings that simulate the new concept and the conventional situation with luggage. As a result, new passenger flow saves 40% of the time for vehicles to stay on the platform. Follow-up questionnaires and interviews with the participants show that the proposed passenger flow gives a better experience in terms of efficiency, seamlessness and friendliness. The new solution increases the number of doors, which increases the manufacturing complexity and the chance of failure. Narrowing the door size minimizes this effect. Subsequently, a second experiment has been carried out to study the influence of door width on (dis)embarking efficiency and passenger experience following a similar method. It turns out that narrowing the door width does not noticeably influence the embarking time, but the disembarking time does increase. Interviews show that half of the participants sense a negative experience with narrower doors, while the other half do not notice a difference.