Bernd Werther

Fiber-Optic Extrinsic Fabry-Perot Interferometer Strain Sensor with <50 pm displacement resolution using three-wavelength digital phase demodulation

A fiber-optic extrinsic Fabry-Perot interferometer strain sensor (EFPI-S) of ls = 2.5 cm sensor length using three-wavelength digital phase demodulation is demonstrated to exhibit <50 pm displacement resolution (<2nm/m strain resolution) when measuring the cross expansion of a PZT-ceramic plate. The sensing (single-mode downlead-) and reflecting fibers are fused into a 150/360 microm capillary fiber where the fusion points define the sensor length. Readout is performed using an improved version of the previously described three-wavelength digital phase demodulation method employing an arctan-phase stepping algorithm. In the resent experiments the strain sensitivity was varied via the mapping of the arctan - lookup table to the 16-Bit DA-converter range from 188.25 k /V (6 Volt range 1130 k ) to 11.7 k /Volt (range 70 k ).

Development of an augmented vision video panorama human-machine interface for remote airport tower operation

In this paper the development of a 180° high resolution video panorama system and results of initial field test at Braunschweig research airport are described. The system serves as main HMI for remote surface movement management of small airports or of movement areas not directly visible for the controller. It provides the framework for video-see-through augmented vision by integration of traffic and weather data and it allows for panorama replay. Preliminary evaluation of initial field tests quantify the visual resolution as compared to the real far view.

Colored Petri Net Based Modeling of Airport Control Processes

The paper shows a formal approach for the description and modeling of work processes based on a cognitive work analysis. It is shown how the results of a cognitive work analysis on a medium size airport are transferred into a formal executable human machine model for simulating the controllers work processes to control the airport processes. The formal model serves for an evaluation of different variants of work organization, a design of a new working position and monitoring of psychological parameters. Critical system states and inconsistencies in the human machine system are identified through comparison of the knowledge state of the controllers with process states of the airport system. The first steps of model verification and validation are introduced in this paper.

Colored Petri Net based formal airport control model for simulation and analysis of airport control processes

The development of the experimental Remote Tower Operation Human Machine Interface and the new Remote-Controller work position is supported by a cognitive work and task analysis (CWA) of the presently existing work environment and decision processes at airport Leipzig. This paper presents a formal approach for the description of the whole Human Machine System. It is shown how the results of a cognitive work analysis on a medium size airport are transferred into a formal executable human machine model for simulating the controllers work processes in relation to the airport processes. The model is implemented with Colored Petri Nets. The mathematical basis of Petri Nets allows a formal analysis of whole systems. Critical system states and inconsistencies in the human machine system are identified through comparison of knowledge states of the controllers with process states of the airport system by using State Space analysis. The represented formal work process model provides a valuable support for the communication between domain experts and system developers.

Formal Cognitive Resource Model: Modeling of human behavior in complex work environments

This paper presents a formal cognitive resource (FCR) model for the description of human behavior in complex work environments. As most important feature this model considers the motivated character of human work as related to the limitations of cognitive resources. The model is implemented with colored Petri nets. The formal description of colored Petri nets supports the simulation of the human-machine system in a completely consistent model structure. The mathematical basis of Petri nets allows a formal analysis of common systems. In a validation example the reasons for a specific behavior of human operators in a working environment are being identified depending on cognitive parameters of the FCR-model. It is shown how these parameters correspond to psychological performance properties