Latest Posts

Robots that sync and swarm: A proof of concept in ROS 2

By Agata Gniewek, Michał Barciś, and Christian Bettstetter

A unified mathematical model for synchronisation and swarming has been proposed recently. Each system entity, called “swarmalator”, coordinates its internal phase and location with the other entities in a way that these two attributes are mutually coupled. This paper realises and studies, for the first time, the concept of swarmalators in technical systems. We adapt and extend the original model for its use on mobile robots and implement it in the Robot Operating System 2 (ROS 2). Simulations and experiments with small robots demonstrate the feasibility of the model and show its potential to be applied in real-world systems. All types of space-time patterns achieved in theory can be reproduced in practice. Applications can be found in monitoring, exploration, entertainment and art, among other domains. Read More

Guarded access balances out waiting times in transport systems

A transport system with passengers traveling between stations in periodically arriving cabins is considered. We propose and evaluate an access control algorithm that dynamically limits the number of passengers who are allowed to board the current cabin. Simulation of a ski lift using empirical passenger data suggests that such access control can balance out the average waiting times at different stations. The algorithm works well with estimated values of the arrival and de-boarding rates.

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UWB connectivity in industrial environments

The introduction of wireless connectivity in industrial environments promises a rapid and cost-effective reconfiguration of machines and sensors. A key question in this context is: Which wireless technology is best suited for industrial settings? Many of the prevalent technologies, like WiFi and ZigBee, do not meet the requirements of certain industrial applications in terms of data rate, power consumption, and robustness. The lack of alternatives capable of achieving a good balance between these conflicting goals impedes progress.

This is why researchers from the University of Klagenfurt, Airbus, and Lakeside Labs investigate the use of ultra-wideband (UWB) communications for wireless connectivity in industrial environments. Interestingly, UWB is commonly used for localization but is not yet an option for communications. Experiments with IEEE 802.15.4-2011 UWB devices were conducted in two industrial scenarios, namely a large-size aircraft assembly hangar and a medium-size production hall. These measurements are the first ones reported for off-the-shelf UWB devices in such setting and shed light on the potential of UWB to support emerging industrial applications.

Jorge F. Schmidt, a senior researcher in this project, explains: “By comparing the packet loss rate of UWB to well-established ZigBee devices at different transmitter-receiver distances, we show that UWB can largely reduce the need for relay nodes thus contributing to a lower end-to-end latency.”

These results—together with inherent features, like robustness against narrowband interference and localization capabilities of state-of-the-art transceivers—position UWB as a promising radio interface to support emerging industrial applications. The discoveries of the research team will be presented and published at the European Wireless conference in Catania (Sicily, Italy) in early May. The work has been funded in part by the Kärntner Wirtschaftsförderungs Fonds (KWF).

Utilizing UWB for industrial applications like condition monitoring will be investigated in more detail in a recently commenced project that includes various industrial and research partners and is funded by the Austrian Research Promotion Agency (FFG).

Publication

J. F. Schmidt, D. Neuhold, J. Klaue, D. Schupke, C. Bettstetter.
Experimental Study of UWB Connectivity in Industrial Environments.
In Proc. European Wireless, Catania, Italy, May 2018. Download preprint.

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This post is based on the abstract and introduction of the mentioned publication written by all authors. Photo made by Daniel Neuhold at ZAL Zentrum für Angewandte Luftfahrtforschung with kind permission.

Packages delivered by air: Drones as delivery service

What has travelled by road to reach us until now could be delivered by drones in the future. This has many advantages: Poor rural transport infrastructure or persistent congestion in large cities can be bypassed. In 2013, Amazon was among the first to announce the intention to deliver goods using small autonomous drones. But when might this technology truly become part of our daily lives? Drone researcher Pasquale Grippa provides some answers. Read More

Intelligent boarding to ski lifts

A novel boarding solution for cabin-based transport systems — e.g., ski lifts, cable cars, subways — is being discussed in industry and has already been implemented in the Austrian skiing resort Bad Gastein: In order to avoid long queues at succeeding boarding stations, a display in the boarding area tells the guests how many of them are allowed to enter the next cabin. This form of access control guarantees spare seats for passengers waiting at the middle station to go to the top station. The overall objective is to install fair access conditions at all stations which would automatically improve waiting time and comfort of passengers. We expect some system intelligence to compute the number of passengers to enter at each station and adapt this number in real time according to the varying passenger load. Compared to extensions or modifications of tracks, cabins, or cabin vehicles, access control would be an inexpensive solution to optimize systems.

Researchers at the University of Klagenfurt and Lakeside Labs are currently assessing as to whether such access control can actually improve the service. Doctoral candidate Pasquale Grippa explains: “We derived expressions characterizing the stochastic properties of passenger queue length, waiting time, and cabin capacity using queuing theory. This was so far done for a transport line with deterministic arrivals of cabins and Poisson arrivals of passengers.” The key insight is interesting: A significant reduction of the waiting time at a given station is only possible at the cost of worsening the stability of one of the preceding stations. “Our industrial partner SKIDATA will now implement our algorithm and carry out experimental studies with real passengers,” Grippa’s advisor, professor Christian Bettstetter, adds.

The project is an interdisciplinary collaboration of Lakeside Labs GmbH, Bettstetter’s mobile systems group, and the production and logistics group led by professor Gerald Reiner, together with SKIDATA AG. It is partly funded by the regional funding agency KWF.

Publications

P. Grippa, U. Schilcher, C. Bettstetter.
On Access Control in Cabin-Based Transport Systems.
IEEE Transactions on Intelligent Transportation Systems.

P. Grippa, E. Yanmaz, P. Ladinig, C. Bettstetter.
Guarded by Gamora: How Access Control Balances Out Waiting Times in Transport Systems. In Proc. IEEE Intern. Conf. on Intelligent Transportation Systems (ITSC), Maui, Hawaii, USA, Nov 2018. ​Download arXiv preprint.

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This post is based on the abstract and introduction of the mentioned publication written by all three authors. The photo has been provided with kind permission by Jorge Clemente (SKIDATA).