2010

@inproceedings{Baier2010, author = {P. Baier and N. Petri and W. Voelker and K. Schilling}, title = {Simulation of Virtual Arteries based on Sweep Surfaces}, booktitle = {SESAM 2010 – Linking high tech to high touch}, address = {University Medical Center Groningen}, month = {June}, year = {2010}, page = {44} }

Interventional cardiology procedures involve a complex combination of visual and tactile feedback. In order to get good medical training in the simulation of catheter based coronary interventions, it is essential to have realistic arteries models. In this work we address the problem of building robust and realistic geometric model of arteries, taking into account the three layers of the artery tissue. We propose a method based on the Sweep surfaces which allow expanding the generated triangular tubular surface in three (or more) tetrahedral volumetric levels.

@INPROCEEDINGS{Drentschew2010a, author = {M. Drentschew and F. Zeiger and K. Schilling}, title = {Automated Environmental Monitoring with Remote Biological Sensors for Large Areas}, booktitle = {The Second IFAC Symposium on Telematics Applications (TA 2010)}, pages = {169-174}, year = {2010}, }

Currently, ecological monitoring is an important issue of discussions in science, industry, and politics. This work presents a distributed telematics infrastructure which allows for flexible ecological monitoring of large areas. By interconnecting beehives, a large network of distributed sensors is installed, which allows not only for a detailed long term and near real- time monitoring of the bee behavior in different environments. Also the information which can be deducted from the bees themselves (e.g. about pollution) can be collected this way, which enables monitoring of large areas surrounding the hives. In this work, a system is proposed which provides the telematics infrastructure to realize this method of ecological monitoring. It can also be extended by mobile robots with special sensor equipment to get more detailed and accurate measurements in zones of special interest. Details on requirements, system design, and the implementation are given.

@inproceedings{Eck2010a, author = {D. Eck and F. Leutert and K. Schilling}, title = {Entwicklung einer Kollisionsvermeidung für einen teil-autonomen Scooter zur Unterstützung der Mobilität leistungsgewandelter Personen}, booktitle = {Ambient Assisted Living 2010 - Tagungsbandbeiträge 3. Deutscher AAL-Kongress mit Ausstellung, Assistenzsysteme im Dienste des Menschen - zuhause und unterwegs}, year = {2010}, publisher = {Vde Verlag Gmbh, Berlin ; Offenbach}, pages = {19.5}, address = {Berlin, Germany}, isbn ={978-3-8007-3209-8} }

One goal of the Fit4Mobility project is the development of a semi-autonomous Scooter, to support the mobility of eld-erly people. The challenge of operating the Scooter will be decreased for elderly people with onboard drive assistance systems. One of these drive assistance systems is the collision avoidance system. For this purpose different sensors are mounted on the scooter to detect obstacles. The velocity of the Scooter will be decreased according to the distance and position of obstacles. This system will raise the operation safety on public roads and at the same time the mobility of elderly people will be preserved.

@INPROCEEDINGS{Eck2010b, author = {Daniel Eck and Matthias Baumann and Laszlo Lemmer and Klaus Schilling}, title = {UKF Sensor Data Fusion for Localisation of a Mobile Robot}, booktitle = {Proceedings of the 41st International Symposium on Robotics (ISR)}, pages ={362-369}, address = {Munich, Germany}, year = {2010} }

The localisation of outdoor mobile robots is one of the most important challenges for implementing applications such as search and rescue, reconnaissance, surveillance and monitoring. The Global Positioning System (GPS) is a common used sensor system for localisation but the drawbacks of its limited accuracy are well known. These effects can cause mission failure especially for small sized mobile robots. To compensate these drawbacks, a sensor data fusion is introduced based on an Unscented Kalman Filter (UKF) that fuses GPS, inertial and incremental sensor data in an adaptive way. In case of GPS outages the typical INS drift can be avoided by a new alternative position update, which is calculated based on the last pose and the kinematic model that uses incremental encoder and yaw rate sensor data. The whole system is implemented on a low power micro controller.

@INPROCEEDINGS{Eck2010c, author = {Daniel Eck and Sebastian Biedermann and Klaus Schilling}, title = {Adjustment of the hand throttle of a mobility scooter for elderly people}, booktitle = {Proceeding of the 55th Internationales Wissenschaftliches Kolloquium}, pages = {364-369}, address = {Ilmenau, Germany}, year = {2010} }

In the last years assistive technologies to preserve elderly people a self determined and independent life receive growing attention. Mobility is one of the biggest issues for a self-determined life, in particular for elderly people. Social participation and daily activities like shopping, errands or doctor visits require mobility. Therefore mobility is a prerequisite to maintain autonomy and self-determination in old age. Mobility scooter are able to preserve the mobility of elderly people, but it is very challenging to control such a vehicle, especially for elderly people. Therefore this paper presents some drive assistance function to support the operator and increase the safety. Three different functions to improve the security and decrease the challenging control will be introduced: a hand throttle regulation, a drive off function and an emergency stop. Some of these functions were validated and tested by several elderly people to find the best configuration.

@article{Eck2010d, author = {D. Eck and K. Schilling}, title = {Robotic and Telematic Assistant Technologies to Support Aging People }, Journal = {Journal of eHealth Technology and Application (JETA)}, volume = {8(2)}, pages ={152-155}, year = {2010}, }

Assistive technologies to support a self-determined living of elderly people receive growing attention due to the aging populations. In this context robotic and sensoric approaches can balance handicaps to improve safe mobility approaches. By telematic methods health data can be transmitted to enable a continuous monitoring of endangered people in their home or while travelling. Thus assistant technologies will support an independent living of elderly people in their used environment without missing the quick support by medical services.

@inproceedings{Herrmann2010, author = {C. Herrmann and L. Ma and K. Schilling}, title = {Modeling a HexaPOD for Tumor Motion Compensation in Robot AssistedRadiotherapy}, booktitle = {Proceedings of the Joint Conference of 41st International Symposium on Robotics and 6th German Conference on Robotics (ISR 2010)}, year = {2010}, pages = {1019-1025}, address = {Munich, Germany}, month = {June} }

This paper addresses modeling a HexaPOD treatment couch used in robot assisted radiotherapy for motion compensation of lung tumors. The HexaPOD, on which the patient is lying, is supposed to move the patient to counteract the tumor motion. For the purpose of modeling the dynamic behavior of the HexaPOD, linear ARX models are used. It was found that these models work when no velocity saturation occurs. However, from real patient data acquired by our clinical system it is shown in this work that, during some phases, the HexaPOD needs to operate at its maximum velocity. This imposes nonlinearities on the ARX model which cause their performance to degrade. To overcome this drawback, the models are enhanced with a nonlinear extension which can be applied in a generic way to a wide variety of models. It is proved by experimental data that the extended model is capable of exhibiting linear behavior from the underlying ARX model where it is necessary while it can simultaneously deal with velocity saturation. Emphasis is laid on system identification as this is a crucial topic to achieve good model performance.

@inproceedings{Hess2010a, author = { R. Hess and M. Kraus and K. Schilling}, title = { GPS/Galileo Testbed using a high precision optical positioning system}, booktitle = {The Second International Conference on Simulation, and Programming for Autnonous Robots (SIMPAR)}, year = {2010}, month = {November} }

This paper presents a new approach for verifying and testing devices and algorithms that use position information determined by the Global Position System (GPS), a GPS testbed. A high precision tracking system is used measuring the position of an object and error terms and an oset are added in order to simulate its GPS position. The distribution of the position error of a common GPS receiver is analyzed in this paper and applied to a random number generator used for simulating the errors. Finally experiments with a real mobile robot are made to verify the presented system.

@inproceedings{Lemmer2010a, author = {L. Lemmer and R. Hess and M. Kraus and K. Schilling}, title = {Calibration of a Car-Like Mobile Robot with a High-Precision Positioning System}, booktitle = {The Second IFAC Symposium on Telematics Applications (TA 2010)}, year = {2010}, pages = {37-42}, month = {October} }

This paper presents the calibration procedure of a car-like mobile robot with a high-precision positioning system. The mobile robot, which was calibrated, is a small outdoor vehicle designed for teleoperated missions. The aim of the calibration is the achievement of an accurate locomotion, therefore the incremental propulsion sensor, the gyroscope, the propulsion actuator and the steering actuator were analyzed with the help active optical high-precision positioning system.

@inproceedings{Leutert2010a, author = {F. Leutert and D. Eck and K. Schilling}, title = {Einsatz von Industrierobotern zur Entlastung von leistungsgewandelten Arbeitern}, booktitle = {Ambient Assisted Living 2010 - Tagungsbandbeiträge 3. Deutscher AAL-Kongress mit Ausstellung, Assistenzsysteme im Dienste des Menschen - zuhause und unterwegs}, year = {2010}, publisher = {Vde Verlag Gmbh, Berlin ; Offenbach}, pages = {P4.2}, address = {Berlin, Germany}, isbn = {978-3-8007-3209-8} }

One goal of the Fit4Work project is to develop a system incorporating a manipulator robot that supports and relieves especially older workers in their physical labour in industrial assembly lines. The assemblyman works directly besides the robot, which holds the work piece in gravitational balance and can be guided using a moment-of-force sensor. Thus, only small forces are required to push it to the assembling position. This system combines the superior strength and accuracy of an industrial robot with the higher human apprehension. However, as the user is standing directly besides the robot and possibly does not have experience with manipulators, special safety and assistance functions are required to deploy the system safely and efficiently.

@inproceedings{Ma2010, author = {L. Ma and C. Herrmann and K. Schilling}, title = {On Challenges of Robot Assisted Radiotherapy for Lung Tumors}, booktitle = {Proceedings of the IEEE International Conference on Robotics and Biomimetics (ROBIO 2010)}, year = {2010}, pages = {773-778}, address = {Tianjin, China}, month = {December 10-14} }

This paper is concerned with recent development in robot assisted radiotherapy for lung tumors. The paper first analyzes technical challenges regarding tumor position determination and prediction, by invasive and non-invasive methods, correlation models of the tumor motion and the respiratory signals, as well as modeling and control of the robot manipulator. Several currently available solutions and concepts are then briefly introduced. Emphasis is placed on the ATTS (adaptive tumor tracking system) system developed at the University of Würzburg. Within the ATTS, information of the tumor motion is used to control a robotic treatment couch HexaPOD, which moves in six degrees of freedom and maintains the tumor in a certain fixed spatial position. With this new technology it is possible to avoid gating during the radiotherapy as well as active breathing control, such that duration and cost of the therapy as well as trauma of the patient can be reduced. The tumor position is obtained by data fusion from two sensing system. Correlation methods for data fusion were extensively investigated and a prediction model for tumor motion is found that can forecast the tumor position for up to one respiratory period. Modeling of the HexaPOD treatment couch is addressed. The most suitable model is found to be a low-order linear dynamic equation together with a saturation component. Three different control methods and comparative test results are then presented to show feasibility of the proposed model and control schemes.

@inproceedings{Sauer2010a, author = {M.Sauer and F. Leutert and K. Schilling}, title = {An Augmented Reality Supported Control System for Remote Operation and Monitoring of an Industrial Work Cell}, booktitle = {Proceedings 2nd IFAC Symposium on Telematics Applications}, pages = {63-68}, year = {2010} }

Telematic control systems have a lot of potential applications in teleservicing of remote sites: they range from surveillance of regular operations over optimization of existing processes to remote error resolving. In this paper, we describe the general architecture of a telematic control system employed to survey an industrial work cell, and show how Augmented Reality (AR) can support an operator in grasping events and conditions at the remote site more clearly, thus getting a better situational awareness. After describing several specific examples from the AR tool-range, potential uses of the system are presented.

@inproceedings{Sauer2010, author = {M.Sauer and F. Leutert and K. Schilling}, title = {Occlusion Handling in Augmented Reality User Interfaces for Robotic Systems}, booktitle = {Proceedings of the 41st International Symposium on Robotics (ISR 2010) and 6th German Conference on Robotics (Robotik 2010)}, pages = {177-183}, year = {2010}, }

When working with Augmented Reality (AR) interfaces, achieving realistic occlusion between real and virtual objects can be critical for certain applications: it is one of the most decisive elements in depth perception of humans. Several techniques for achieving accurate and stable occlusion with moderate computational effort are presented in this paper: first, a model-based approach is shown, that is extended to include the measurements of a spatial sensor for also determining dynamic occlusions with objects that are not in the existing 3D-model. Finally, a technique that does not require any predefined 3D-models at all is introduced using distance information from a 3D time-of-flight camera. This approach also allows leaving the egocentric view of the camera that is providing the pictures for the AR-application to an arbitrary exocentric view, and can be directly employed on a stereo display without actually deploying a real stereo camera.

@inproceedings{Sauer2010b, author = {M.Sauer and F. Zeiger and K. Schilling}, title = {Mixed Reality User Interface for Mobile Robot Teleoperation in Ad-Hoc Networks}, booktitle = {Proceedings 2nd IFAC Symposium on Telematics Applications}, pages = {130-135}, year = {2010}, }

Conventional approaches for the implementation of modern user interfaces for teleoperation of mobile robots in ad-hoc networks target to optimize only the communication link. Thus, remaining effects from network behavior in the user interface are still visible to the human operator. Here an approach is presented which aims to minimize also the perception by the human of these effects. This work shows and compares the behavior of three different user interface implementations which are capable for mobile robot teleoperation via ad-hoc networks. As starting point, a user interface is used which is not reacting on the situations of the communication link. Here, all changes in the network topology and network configuration, as well as the effects of the network load are directly visible for the user. The traditional approach uses an intelligent traffic shaping between the mobile robot and the user interface. Thus, short disruptions of the communication link or small delays are avoided. Nevertheless, a longer communication break down is still influencing the teleoperation capabilities of the user. The ”predictive interface” which is is presented within the frame of this work also allows for teleoperation of the mobile robot while compensating longer communication losses. Finally, this work discusses constraints and requirements for a successful realization of predictive interfaces for mobile robot teleoperation via ad-hoc networks.

@inproceedings{Schilling2010a, title = {Telematik-Methoden zur Fernbetreuung von Risiko-Patienten im häuslichen Umfeld}, author = {Klaus Schilling and Berthold Jany}, booktitle= {Tagungsband 11. Würzburger Medizintechnik Kongress}, year = {2010}, pages = {191-195} }

Coming Soon...

@inproceedings{Schmidt2010, author = {M. Schmidt and K. Schilling}, title = {Ground Station Majority Voting for Communication Improvement in Ground Station Networks}, booktitle = {SpaceOps 2010 conference}, year = {2010}, }

In the last years many small satellite mission have been initiated for space research at academic institutions. As a result many ground stations were built up for satellite operations at the corresponding institutes, several projects are currently working on network establishment of these ground stations. By combination of ground station ressources in a cooperating network, the efficiency of the network can be improved in different aspects. This work deals with data recovery capabilities in ground station networks, using redundant information in the received data signals. This is realized through the inherent redundancy in the network and the communication links. A performance increase, measured as a decrease of the packet error rate, can be achieved with the proposed algorithm.

@inproceedings{Schmidt2010a, author = {Schmidt, M. and Bolvansky, J. and Schilling, K.}, title = {Satellite Operation Improvement through Efficient Data Combination in Ground Station Networks}, booktitle = {IFAC Symposium on Automatic Control in Aerospace}, year = {2010} }

Due to the recent advances in miniaturization of small satellites, a huge amount of pico and nano satellite missions have been launched in the last years. In this scope also several projects related to networking of ground stations have been established, to increase access to the satellites and to improve operations performance. An important aspect for efficient usage of ground station resources is the application of modern data management methods. This work describes a new approach to efficiently combine data streams in academic ground station networks.

@inproceedings{Schmidt2010b, author = {Schmidt, M. and Schilling, K.}, title = {Formation Flying Techniques for Pico-Satellites}, booktitle = {6th International Workshop on Satellite Constellation and Formation Flying}, year = {2010} }

Realization of satellite formations within the limited resources of a pico‐satelllite at a total mass of about 1 kg raises challenges in implementation, but offers interesting application perspectives. The University of Wuerzburg defined a roadmap for technology development to prepare, implement and test crucial related technologies in orbit. So far two pico-satellite technology demonstration missions have already been launched: - UWE‐1: the first German pico‐satellite mission was launched in 2005 and tested successfully parameter adaptations of Internet Protocols in space environment. This provides the basis for future inter‐satellite links in a distributed multi‐satellite system with dynamically changing link topologies, as typical for satellites in low Earth orbits. - UWE‐2: since 2009 in orbit, hosted a GPS to derive the position and combined several miniature sensors for attitude determination purposes. These position and attitude data provide an appropriate basis to initiate as next step related control actions to be demonstrated by UWE‐3, being currently in the implementation phase. This contribution will review obtained achievements and will point out further technology developments in order to finally realize formation flying with very small satellites. The integration of these technologies for future multi‐satellite formations balances the low performance of each small satellite by fusion of data from several satellites. This concept offers innovative distributed space systems approaches for Earth observation and for low‐bandwidth telecommunication systems at competitive costs.

@inproceedings{Schmidt2010c, author = {Schmidt, M. and Schilling, K.}, title = {Ground Station Network for Efficient Small Satellite Operations}, booktitle = {1st International SPACE World Conference}, year = {2010} }

The success of small satellite development led to the launch of a huge number of pico, nano and microsatellites in the last years. An innovative approach is the realization of new applications with distributed satellite systems in combination with ground station networks. In this work approaches to improve the data return for small satellite projects using academic ground station networks will be described. Key aspects of the presented work are proper scheduling and data management, which is necessary when parallel satellite tracking is desired, e.g. for redundancy purposes. Due to the similar architecture of academic ground stations, the interoperability is already given by the utilized hardware (mainly using VHF/UHF frequency bands). An interesting capability of such a system is, that even with a small number of ground stations combined in a network the communication performance can be increased significantly.

@inproceedings{Schmidt2010d, author = {Schmidt, M. and Schilling, K.}, title = {Data combination mechanism in highly distributed ground station networks}, booktitle = {International Astronautical Congress}, year = {2010} }

In last years a large amount of small satellites have been brought into orbit. In this scope also several projects related to networking of ground stations have been established. An important aspect for ecient usage of ground station resources is the application of modern data management methods to increase access to the satellite resources and to improve operations performance. This work describes a new approach to automatically synchronize and combine data streams in academic ground station networks. The algorithms have been varified with hardware in the loop experiments, the results illustrate the great potential of the introduced approach.

@INBOOK{leutert2010, chapter = {Mensch-Roboter-Kooperation zur Erhöhung der Mitarbeitereinsetzbarkeit}, pages = {79-111}, title = {Alternsgerechte Arbeitsplatzgestaltung in Produktion und Logistik - Studie aus dem Bayerischen Forschungsverbund FitForAge}, publisher = {Lehrstuhl für Fördertechnik Materialfluß Logistik (fml) TU München}, year = {2010}, editor = {Gerhäuser, H; Günther, W.A.; Lang, F.R.; Reinhart, G.; Schilling, K.(Hrsg.)}, author = {Spillner, R.; Leutert, F.; Schilp, J.; Schilling, K.}, isbn = {ISBN 978-3-941702-16-5} }

Der demographische Wandel in Deutschland macht Änderungen in allen Aspekten des Lebens notwendig, im privaten Bereich ebenso wie am Arbeitsplatz. Körperlich fordernde Tätigkeiten sind dabei vom Leistungswandel im Alter stärker betroffen als bspw. ein Bildschirmarbeitsplatz. Fokus des Fit4Work-Teilprojektes III-3 ist die Industriemontage. Ältere und körperlich eingeschränkte Mitarbeiter sollen hier bei ihrer physisch anspruchsvollen Arbeit durch ein roboterbasiertes System unterstützt und entlastet werden. Dazu kann der Roboter beispielsweise als Manipulator eingesetzt werden, um schwere Werkstücke kollaborierend mit dem Menschen handzuhaben. Ein derartiges System kombiniert Kraft, Ausdauer und Präzision eines Industrieroboters mit der Auffassungsgabe und kognitiven Leistung des Menschen. Bestimmte Teile des Montageprozesses können dabei autonom vom Roboter erledigt werden, so dass bisher serielle Prozesse parallel und damit schneller ausgeführt werden. Andere Montage- oder Nebenprozesse, die etwa ein hohes Verständnis von der aktuellen Situation erfordern oder sehr komplex zu automatisieren wären, werden vom Menschen überwacht und gesteuert. Dadurch erhält man ein anpassungs- und leistungsfähiges Montagesystem, welches von der besonders altersveränderlichen physischen Leistungsfähigkeit der Mitarbeiter deutlich weniger abhängt. Um Montagearbeitern eine sichere und gleichzeitig effiziente Arbeit neben und mit den Roboterassistenten zu ermöglichen, ohne dass Expertenwissen vorausgesetzt werden muss, sind spezielle Sicherheits- und Assistenzfunktionen notwendig. Auch die Akzeptanz, d. h. die Frage ob das System im Einsatz tatsächlich genutzt wird, ist über gestalterische Maßnahmen zu fördern. Die grundlegenden Faktoren und Anforderungen werden im Folgenden erläutert und an einem Einsatzbeispiel konkret dargestellt und besprochen.

@ARTICLE{Wil10, author = {J. Wilbert and K. Baier and A. Richter and C. Herrmann and L. Ma and M. Flentje and M. Guckenberger}, title = {Influence of Continuous Table Motion on Patient Breathing Patterns}, journal = {International Journal of Radiation Oncology Biology Physics}, year = {2010}, volume = {77}, pages = {622--629}, number = {2}, month = {June}, doi = {10.1016/j.ijrobp.2009.08.033}, issn = {0360-3016} }

Purpose: To investigate the influence of continuous table motion on patient breathing patterns for compensation of moving targets by a robotic treatment couch.
Methods and Materials: Fifteen volunteers were placed on a robotic treatment couch, and the couch was moved on different breathing-correlated and - uncorrelated trajectories. External abdominal breathing motion of the patients was measured using an infrared camera system. The influence of table motion on breathing range and pattern was analyzed.
Results: Continuous table motion was tolerated well by all test persons. Volunteers reacted differently to table motion. Four test persons showed no change of breathing range and pattern. Increased irregular breathing was observed in 4 patients; however, irregularity was not correlated with table motion. Only 4 test persons showed an increase in mean breathing amplitude of more than 2mm during motion of the couch. The mean cycle period decreased by more than 1 s for 2 test persons only. No abrupt changes in amplitude or cycle period could be observed.
Conclusions: The observed small changes in breathing patterns support the application of motion compensation by a robotic treatment couch.

@INPROCEEDINGS{Zeiger2010a, author = {F. Zeiger and F. Kempf and K. Schilling}, title = {UMTS One Way Delay Characterization for Mobile Robot Teleoperation}, booktitle = {Proceedings of the 41st International Symposium on Robotics (ISR) and 6th German Conference on Robotics (ROBOTIK)}, pages ={827-834}, year = {2010} }

In the meantime, the UniversalMobile Telecommunications System (UMTS) has reached an expansion stage which allows for using this communication technology in the area of networked robotics and for the teleoperation of mobile robots. The support of mobility, the availability of wireless communication, and the provided bandwidth are typical major criterion for the evaluation of a communication technology in robotics scenarios. Nevertheless, mobile robot teleoperation has different requirements on the communication channel based on the setup of the scenario and the task definition. Many applications also require additional knowledge of the one way delay of the communication channel in order to allow for a seamless integration of the telerobotic system. With respect to availability, mobility, and the supported bandwidth UMTS is already analyzed and telecommunication providers give detailed information. By contrast, information on the expected one way delays in such systems are given only rarely and not as comprehensive as required for real implementations of telerobotic systems. This work gives a detailed analysis of the one way delay characteristics of the communication channel for different application scenarios of mobile robot teleoperation via UMTS. The distribution of one way delays are evaluated for different setups and for different data stream characteristics which are typical in the area of networked robotics. Also the measurement setup is described in detail and an approach for measuring one way delays is presented which allows for measurements of the required resolution by using standard equipment.