@article{StrohmeierWalterRotheetal.2018,
  author    = {Strohmeier, Michael and Walter, Thomas and Rothe, Julian and Montenegro, Sergio},
  title     = {Ultra-wideband based pose estimation for small unmanned aerial vehicles},
  series = {IEEE Access},
  volume    = {6},
  journal   = {IEEE Access},
  doi       = {10.1109/ACCESS.2018.2873571},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177503},
  pages     = {57526-57535},
  year      = {2018},
  abstract  = {This paper proposes a 3-D local pose estimation system for a small Unmanned Aerial Vehicle (UAV) with a weight limit of 200 g and a very small footprint of 10 cm×10cm. The system is realized by fusing 3-D position estimations from an Ultra-Wide Band (UWB) transceiver network with Inertial Measurement Unit (IMU) sensor data and data from a barometric pressure sensor. The 3-D position from the UWB network is estimated using Multi-Dimensional Scaling (MDS) and range measurements between the transceivers. The range measurements are obtained using Double-Sided Two-Way Ranging (DS-TWR), thus eliminating the need for an additional clock synchronization mechanism. The sensor fusion is accomplished using a loosely coupled Extended Kalman Filter (EKF) architecture. Extensive evaluation of the proposed system shows that a position accuracy with a Root-Mean-Square Error (RMSE) of 0.20cm can be obtained. The orientation angle can be estimated with an RMSE of 1.93°.},
  language  = {en}
}
@article{KaiserLeschRotheetal.2020,
  author    = {Kaiser, Dennis and Lesch, Veronika and Rothe, Julian and Strohmeier, Michael and Spieß, Florian and Krupitzer, Christian and Montenegro, Sergio and Kounev, Samuel},
  title     = {Towards Self-Aware Multirotor Formations},
  series = {Computers},
  volume    = {9},
  journal   = {Computers},
  number    = {1},
  issn      = {2073-431X},
  doi       = {10.3390/computers9010007},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200572},
  pages     = {7},
  year      = {2020},
  abstract  = {In the present day, unmanned aerial vehicles become seemingly more popular every year, but, without regulation of the increasing number of these vehicles, the air space could become chaotic and uncontrollable. In this work, a framework is proposed to combine self-aware computing with multirotor formations to address this problem. The self-awareness is envisioned to improve the dynamic behavior of multirotors. The formation scheme that is implemented is called platooning, which arranges vehicles in a string behind the lead vehicle and is proposed to bring order into chaotic air space. Since multirotors define a general category of unmanned aerial vehicles, the focus of this thesis are quadcopters, platforms with four rotors. A modification for the LRA-M self-awareness loop is proposed and named Platooning Awareness. The implemented framework is able to offer two flight modes that enable waypoint following and the self-awareness module to find a path through scenarios, where obstacles are present on the way, onto a goal position. The evaluation of this work shows that the proposed framework is able to use self-awareness to learn about its environment, avoid obstacles, and can successfully move a platoon of drones through multiple scenarios.},
  language  = {en}
}
@article{WernerStrohmeierRotheetal.2022,
  author    = {Werner, Lennart and Strohmeier, Michael and Rothe, Julian and Montenegro, Sergio},
  title     = {Thrust vector observation for force feedback-controlled UAVs},
  series = {Drones},
  volume    = {6},
  journal   = {Drones},
  number    = {2},
  issn      = {2504-446X},
  doi       = {10.3390/drones6020049},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-262153},
  year      = {2022},
  abstract  = {This paper presents a novel approach to Thrust Vector Control (TVC) for small Unmanned Aerial Vehicles (UAVs). The difficulties associated with conventional feed-forward TVC are outlined, and a practical solution to conquer these challenges is derived. The solution relies on observing boom deformations that are created by different thrust vector directions and high-velocity air inflow. The paper describes the required measurement electronics as well as the implementation of a dedicated testbed that allows the evaluation of mid-flight force measurements. Wind-tunnel tests show that the presented method for active thrust vector determination is able to quantify the disturbances due to the incoming air flow.},
  language  = {en}
}