Jennifer Bützler

Anthropomorphic design of robotic arm trajectories in assembly cells

BACKGROUND: Anthropomorphism is attribution of human form or behavior to non-human agents. Its application in a robot increases occupational safety and user acceptance and reduces the mental effort needed to anticipate robot behavior. OBJECTIVE: The research question focuses on how the anthropomorphic trajectory and velocity profile of a virtual gantry robot affects the predictability of its behavior in a placement task. METHODS: To investigate the research question, we developed a virtual environment consisting of a robotized assembly cell. The robot was given human movements, acquired through the use of an infrared based motion capture system. The experiment compared anthropomorphic and constant velocity profiles. The trajectories were based on human movements of the hand-arm system. The task of the participants was to predict the target position of the placing movement as accurately and quickly as possible. RESULTS: Results show that the anthropomorphic velocity profile leads to a significantly shorter prediction time (α = 0.05). Moreover, the error rate and the mental effort were significantly less for the anthropomorphic velocity profile. Based on these findings, a speed-accuracy trade-off can be excluded. CONCLUSIONS: Participants were able to estimate and predict the target position of the presented movement significantly faster and more accurately when the robot was controlled by the human-like velocity profile.

A Symbolic Approach to Self-optimisation in Production System Analysis and Control

With steadily increasing customer requirements on quality of both products and processes, companies are faced with increasing organisational and technical challenges. The market is characterised by individualised customer wishes which result in individual adaptations of the products. In order to manage this rapidly growing variety of products, the production system has to become much more flexible with respect to the product structure to be manufactured and the corresponding production and assembly processes. Especially in the field of assembly systems the increasing variety of products adds new complexities to the planning process and increases the costs, because (re-)planning efforts tend to grow exponentially to the number of variants.

Development of Interaction Concepts for Touchless Human-Computer Interaction with Geographic Information Systems

Interaction concepts in 3D GIS are yet limited to 2D input methods like mouse and keyboard. This work describes elaboration of a concept of touchless interaction for a prototype that aims to be used in maritime GIS applications. Experts from the maritime field have been interviewed to construct a rigorous scenario settled in the maritime field. Besides the planning and conversion of a stereoscopic GIS prototype a touchless interaction concept for stereoscopic environments under consideration of three different hand models is developed and presented. Implementation of these different hand models is planned for future evaluation.

Icon Design for Older Users of Project Management Software

Working in projects is an important part of many jobs in service industry. Due to their knowledge and experience project planning is often accomplished by older employees. Therefore, and with regard to the demographic change an integration of the needs of older employees into the work environment is required. Common to most IT-based systems, including project management software, is the use of icons. To investigate different icon sets in project management software, regarding age related differences, two studies were conducted. The first study aimed at investigating two different icon sets regarding execution times and eye movements in an applied setting. The second study consisted of a questionnaire where subjects had to map different icons to their corresponding functions and had to compare these icons regarding their intuitiveness. Results revealed that older users profit from an icon design which is low in complexity but no impact by different icon designs was found for younger users.

Ergonomic Design of Human–Computer Interfaces for Aging Users

The demographic changes taking place in many industrialized countries and the increased use of information technology in the workplace are creating an urgent need to carefully consider how older users work with computing systems. The changes in perceptual, cognitive and motor skills that often accompany the aging process can have important implications for the design of the human–computer interface. We investigated human–computer interaction exemplarily on the basis of self-developed project management application software for two reasons. First, computer aided project management (CAPM) is important in many manufacturing and service industries; and second, older workers are often responsible for the coordination and controlling of complex projects due to their extensive experience and excellent communication skills.

Development of Usability-Criteria for the Selection Process of Document Management Systems

As the overload of digital information in the SMEs requires an adequate management, document management systems (DMS) increasingly gain significance since they enhance the automation of processes within documents’ registration, classification, processing, archiving and forwarding. However, in current selection processes of DMS the usability aspect seems to be unconsidered. For this purpose criteria are developed that measure the usability of existing DMS and allow the selection of a DMS according to usability aspects.

Age differentiated usability evaluation of project management software

Computer aided project management is a useful tool in project planning especially when dealing with large and complex project plans. Project planning is often accomplished by older employees due to their knowledge and experience. This paper describes a usability study in which three off-the-shelf software tools were investigated regarding execution times, fixation durations and user acceptance for two different age groups. As a result deficits in the de-facto standard are detected and implications for further research are derived.

Development and Evaluation of an Input Method Using Virtual Hand Models for Pointing to Spatial Objects in a Stereoscopic Desktop Environment with a Fitts’ Pointing Task

Virtual Reality for desktop or table mounted display environments can be a strong tool in supporting users in sighting spatial information and give a better understanding in their spatial relationships. Visualization of spatial data incorporates spatial interaction and manipulation with six degrees of freedom for data processing which is part of current research objectives. Modern tracking devices for desktop applications allow capturing a model of the human hand with three translational and three rotatory degrees of freedom which can be used as an input system allowing the control over a virtual hand model in a stereoscopic desktop system. Interaction with complex data in rich environments using virtual hand models, such as three-dimensional geographic information systems with integrated spatial data, requires visualization with a low degree of occluding virtual entities in the virtual scene but a high degree of recognition. An experimental task using a Fitts’ pointing task is conducted to investigate different minimalistic modeling approaches of virtual hand models using the Leap Motion Controller in a stereoscopic desktop environment. Movement times are analyzed for pointing movements in three different depth layers. Results indicate that a kinematic visualization of a virtual hand model produces significantly better movement times in pointing over a minimalistic point cloud model.

Postural load balancing in daily personnel planning in an assembly line for trailer production by working posture analysis

In this industrial engineering study working postures of 57 workers in an assembly of a trailer manufacturer were analyzed according to the OWAS method and its extension to head postures. For eight especially stressful work tasks 19714 body postures were analyzed. Overall the working posture analysis identified a largely acceptable postural load. A significant influence of the work task on relative frequencies of posture categories and work posture combinations assigned to the same action category was found. Differences in working postures within the same work task could be identified. Finally it is shown that the conducted work posture analysis can help to improve the stress situation of workers through postural load balancing.