Ludger Schmidt

Augmented Reality (AR) for Assembly Processes Design and Experimental Evaluation

Augmented reality (AR) for assembly processes is a new kind of computer support for a traditional industrial domain. This new application of AR technology is called ARsembly. The intention of this article is to describe a typical scenario for assembly and service personnel and how they might be supported by AR. For this purpose, tasks with different degrees of difficulty were selected from an authentic assembly process. In addition, 2 other kinds of assembly support media (a paper manual and a tutorial by an expert) were examined in order to compare them with ARsembly. The results showed that the assembly times varied according to the different support conditions. AR support proved to be more suitable for difficult tasks than the paper manual, whereas for easier tasks the use of a paper manual did not differ significantly from AR support. Tasks done under the guidance of an expert were completed most rapidly. Some of the information obtained in this investigation also indicated important considerations for improving future ARsembly applications.

The user in the loop: Enabling user participation for self-adaptive applications

Future computing systems must adjust to the users situations, habits, and intentions. Self-adaptive applications autonomously adapt to changing contexts without asking the user. However, the self-adaptive behaviour lacks of success if it does not correspond to the users personal interaction habits and intentions, particularly for complex scenarios with a high degree of user interaction. Concerning the interaction design, such adaptations can be irritating and distracting for the user if they do not match the current situation. In this article we provide a solution how to integrate the user in the self-adaptation feedback loop. The user will be able to influence the adaptation behaviour at run-time and in the long term by setting individual preferences. Consequently, we achieve a harmonisation between full application autonomy and user control. We implemented our generic concepts by extending an existing self-adaptation middleware with capabilities to respect the users application focus and interaction behaviour. A notification-based solution for user participation has been evaluated in a substantial user study with 62 participants. Although participants perceived much better control with our solution, the study made clear that notification design is specific for each adaptation type.

Designing socio-technical applications for ubiquitous computing: results from a multidisciplinary case study

A major challenge for ubiquitous system design is creating applications that are legal-compatible and accepted by their intended users. Todays European data protection principles contradict the ideas of ubiquitous computing. Additionally, users have to deal with unconventional interaction concepts leading to a low amount of trust and acceptance in such systems. Current development approaches do not sufficiently cover these concerns, as they do not systematically incorporate expertise from the relevant disciplines. We present a novel development approach for ubiquitous systems that explicitly addresses these concerns. Our primary task was to manage the increased number of stakeholders and dependencies, respectively conflicts between requirements of the particular disciplines. The approach incorporates predefined artifacts and a defined workflow with responsibilities, as well as suggesting how to develop mutual understanding. We apply this multidisciplinary approach to develop the ubiquitous application Meet-U.

Achieving user participation for adaptive applications

Adaptive applications establish the basis for many ubiquitous computing scenarios as they can dynamically adapt to changing contexts. But adaptive applications lack of success when the adaptive behaviour does not correspond to the users interaction habits. A user study revealed that such applications are not satisfying for complex scenarios with a high degree of user interaction. We claim that there must be a trade-off between automation and user participation. By extending an existing adaptation middleware with capabilities to respect user preference and interaction behaviour we demonstrate how to integrate the user in the self-adaptation loop. Interdisciplinary results from the fields of usability engineering and interaction design include the need for an adaptation notification concept to avoid mismatching adaptation behaviour.

Ergonomie und Mensch-Maschine-Systeme

Festschrift der Abteilung Ergonomie und Fhrungssysteme des Forschungsinstituts fr Kommunikation, Informationsverarbeitung und Ergonomie anlsslich 40 Jahre Ergonomie in der Forschungsgesellschaft fr Angewandte Naturwissenschaften.1967 wurde die Forschungsgruppe Anthropotechnik und Flugmesstechnik, die zuvor an der TU Berlin ttig war, in die Gesellschaft zur Frderung der astrophysikalischen Forschung e. V. eingegliedert. Zwei Jahre spter erfolgte mit einer Erweiterung des Aufgabenspektrums die Grndung des Forschungsinstituts fr Anthropotechnik (FAT). Aus dem FAT und zwei weiteren Instituten ging schlielich 1999 das FGAN Forschungsinstitut fr Kommunikation, Informationsverarbeitung und Ergonomie (FKIE) hervor, in dem das Arbeitsspektrum des bisherigen FAT nun von der Abteilung Ergonomie und Fhrungssysteme abgedeckt wurde. Heute arbeiten in der Abteilung ber 60 Mitarbeiter/-innen aus verschiedenen Ingenieurwissenschaften, der Informatik, Psychologie, Biologie, Mathematik, Physik u. a. interdisziplinr zusamme n. In der Abteilung Ergonomie und Fhrungssysteme werden Konzepte, Methoden und Werkzeuge zur benutzerzentrierten Gestaltung von Fhrungs- und Fhrungsinformationssysteme erforscht, entwickelt und angewandt. Aufbauend auf ergonomischen Anforderungsanalysen werden innovative Mensch-Maschine-Schnittstellen konzipiert, in Form von Prototypen realisiert und hinsichtlich ihrer nutzergerechten Gestaltung in Feld- und Laborstudien evaluiert.Grobgliederung anhand der Schwerpunkte von Forschung und Entwicklung:- Gestaltung und Bewertung von Mensch-Maschine-Systemen- 3D-Visualisierung und Interaktion- Fhrung unbemannter Robotersysteme- Methoden zur ergonomischen BewertungIn ca. 25 wissenschaftlichen Beitrgen wird in diesem Herausgeberwerk das Spektrum der Arbeiten im Bereich Ergonomie und Mensch-Maschine-Systeme dargestellt. Autoren sind aktive und ehemalige wissenschaftliche Mitarbeiter und Professoren des Institutes

Development of error-compensating UI for autonomous production cells

This contribution deals with the impact of human error on the overall system reliability in flexible manufacturing systems (FMS). Autonomous production cells are used to illustrate an error-compensating system design on the basis of Sheridans (1997) paradigm of supervisory control. In order to specify human errors and their effects in terms of system disturbances, a taxonomy of system disturbances is recommended. This taxonomic approach was derived by a value benefit analysis and is based on HEDOMS (Human Error and Disturbance Occurrence in Manufacturing Systems) with slight modifications and Reasons GEMS (Generic Error Modelling System). The taxonomy is used for data acquisition. Next, a risk priority equivalent to FMEA (Failure Mode and Effect Analysis) is introduced to structure the data according to their relevance. Then, Vicentes and Rasmussens guidelines (1987) for an ecological interface design are related to the paradigm of supervisory control. On the basis of these guidelines four case studies are presented to show their successful applicability for interface design in FMS.

A human task-oriented simulation study in autonomous production cells

Simulation on human tasks has become increasingly important in manufacturing systems’ design, assessment and improvement. In order to evaluate working processes and human factors in autonomous production cells (APCs), a collective analyzis of human-centred simulation approaches in advanced manufacturing systems is carried out, and a human task-oriented simulation methodology is proposed in this paper. Based on the methodology, a comparative simulation study is carried out in a 3D laser welding production cell from the aspects of human task spectrum, human error and occupational requirements. Human task network models of both conventional working process and APC working process are constructed using timed coloured Petri Nets. The evaluation criteria architecture for the simulation is formulated and the respective algorithms and parameters for the criteria are discussed in detail. A simulation program using C++ is developed based on Poses++ Petri Net simulator. The simulation results show some important transitions of system performance and human factors from the conventional production cell to the APC, which can support the decision-making when redesigning the conventional production cells to fit the requirements of APCs.

Comparison Between the Strain Indicator HRV of a Head-Based Virtual Retinal Display and LC-Head Mounted Displays for Augmented Reality

Augmented Reality uses Head Mounted Displays (HMD) to overlay the real word with additional virtual information. Virtual Retinal Displays (VRD), a new display technology, no longer requires Liquid Crystal Displays (LCD). VRD technology addresses the retina directly with a single laser stream of pixels. There are no studies on the user’s informational strain in this new VRD technology. Various papers have shown that Heart Rate Variability (HRV) is a valid indicator for the user’s informational strain. An empirical test revealed no difference in the user’s HRV between VRD technology and LCD technology. Consequently, there seems to be a comparable user informational strain regarding the display types.

On Socio-technical Enablers for Ubiquitous Computing Applications

The focus of this paper is on context-aware, self-adaptive ubiquitous computing applications that involve mobile users. The development of such applications is inherently complex for two main reasons: From a technical perspective, context management and adaptation management add complexity to the application design and implementation. From a socio-technical perspective, concerns and requirements related to the social embedding and user acceptance must be addressed in the application design and lead to additional complexity, particularly because sensitive personal data is collected, processed, stored and communicated by such applications. In this position paper we present an analysis of the problem space and a solution approach. We have developed an interdisciplinary methodology that systematically addresses technical as well as non-technical concerns. Our conclusion is that solving the socio-technical challenges will be a key enabler for ubiquitous computing.

Person-centred simulation of product development processes

In enterprises with multiple projects, product developers often fail to act according to project plans, even though the plans have been developed very thoroughly. The proposed person-centred simulation model can simulate more realistic courses of development projects. A major difference to existing models is the bounded rational decision making of the simulated product developers. The model was formally described by Timed Stochastic Coloured Petri Nets and was systematically verified using an analysis of variance. The results of a case study in a medium-sized enterprise show that the simulated project durations do not significantly differ from the historical data.