Johannes Tümler

Mobile Augmented Reality in industrial applications: Approaches for solution of user-related issues

Augmented Reality (AR) uses computer-generated virtual information to enhance the userpsilas information access. While numerous previous studies have demonstrated the large potential of AR to improve industrial processes by enhancing product quality and reducing production times it is still unclear if and how long term usage of such AR technology produces stress and strain. This paper presents an approach to use the analysis of Heart Rate Variability to objectively measure current user strain during different work tasks. Results of a user study comparing strain during an AR supported and a non-AR supported work task in a laboratory setting are presented and discussed.

Pick-by-Vision: A first stress test

In this paper we report on our ongoing studies around the application of Augmented Reality methods to support the order picking process of logistics applications. Order picking is the gathering of goods out of a prepared range of items following some customer orders. We named the visual support of this order picking process using Head-mounted Displays “Pick-by-Vision”. This work presents the case study of bringing our previously developed Pickby-Vision system from the lab to an experimental factory hall to evaluate it under more realistic conditions. This includes the execution of two user studies. In the first one we compared our Pickby-Vision system with and without tracking to picking using a paper list to check picking performance and quality in general. In a second test we had subjects using the Pick-by-Vision system continuously for two hours to gain in-depth insight into the longer use of our system, checking user strain besides the general performance. Furthermore, we report on the general obstacles of trying to use HMD-based AR in an industrial setup and discuss our observations of user behaviour.

Perceptual issues in optical-see-through displays

Optical see-through devices enable observers to see additional information embedded in real environments. There is already some evidence of increasing visual load in respective systems. We investigated visual performance when users performed visual search tasks or dual tasks only on the optical see-through device, only on a computer screen, or switching between both. In spite of having controlled for basic differences between both devices, switching between the presentation devices produced costs in visual performance. The assumption that these decreases in performance are partly due to differences localizing the presented objects was confirmed by convergence data.

Extended investigations of user-related issues in mobile industrial AR

The potential of Augmented Reality (AR) to support industrial processes has been demonstrated in several studies. While there have been first investigations on user related issues in the long-duration use of mobile AR systems, to date the impact of theses systems on physiological and psychological aspects is not explored extensively. We conducted an extended study in which 19 participants worked 4 hours continuously in an order picking process with and without AR support. Results of the study comparing strain and work efficiency are presented and open issues are discussed.

Distribution of visual attention in head-worn displays

With head-worn displays, information can be presented in addition to the real surround. But, the virtual information is self-illuminating, has an unclear depth, and, depending on the visual background, the signal-noise ratio and the brightness contrast varies. We examined performance in a visual search task in which a 0 had to be found under O. The head-worn display was placed in front of the monitor so that the stimuli covered the same parts of the visual field. Performance on the head-worn display was worse than on the monitor. Searching a mixed display (half of the stimuli occurred on the monitor, half on the head-worn display) took more time than expected by unitary performances. These costs must be attributed to switching between both media. The results suggest that the distribution of attention in depth is restricted.

Virtuelle Techniken und Semantic-Web

Virtuelle Techniken (VT) haben schon seit vielen Jahren in der Industrie in vielfaltiger Weise Eingang gefunden. Ebenso gibt es durchaus umfangreiche, interoperable Anwendungen in anderen Fachdomanen, die auf etablierten, standardisierten Web-Technologien beruhen. Daher liegt es nahe, die unbestreitbaren Vorteile von semantischen Web-Technologien fur den Aufbau interoperabler VT-Anwendungen zu nutzen. In diesem Kapitel werden daher grundlegende Elemente und der aktuelle Entwicklungsstand virtueller Techniken sowie auch die Grundkonzepte semantischer Web-Technologien beschrieben. Im Uberblick wird deutlich, dass zahlreiche Einzelkomponenten fur komplexere VT-Anwendungen zusammenarbeiten mussen und dass neben der Interoperabilitat die erreichte Gesamtperformanz einer Anwendung eine essentielle Anforderung fur die ARVIDA-Referenzarchitektur ist. Die gewunschte Kapselung der hier beschriebenen Einzelelemente in Web-Dienste ist bisher noch im Forschungsstadium. Eine detaillierte Beschreibung, wie semantische Web-Technologien aus dem ARVIDA-Projekt heraus fur VT-Anwendungen angewendet werden, ist in den Folgekapiteln zu finden.

Investigation of an Augmented Reality-Based Machine Operator Assistance-System

In this work we propose three applications towards an augmented reality-based machine operator assistance system. The application context is worker training in motor vehicle production. The assistance system visualizes information relevant to any particular procedure directly at the workplace. Mobile display devices in combination with augmented reality (AR) technologies present situational information. Head-mounted displays (HMD) can be used in industrial environments when workers need to have both hands free. Such systems augment the user’s field of view with visual information relevant to a particular job. The potentials of HMDs are well known and their capabilities have been demonstrated in different application scenarios. Nonetheless, many systems are not user-friendly and may lead to rejection or prejudice among users. The need for research on user-related aspects as well as methods of intuitive user interaction arose early but has not been met until now. Therefore, a robust prototypical system was developed, modified and validated. We present image-based methods for robust recognition of static and dynamic hand gestures in real time. These methods are used for intuitive interaction with the mobile assistance system. The selection of gestures (e.g., static vs. dynamic) and devices is based on psychological findings and ensured by experimental studies.