TY - CHAP A1 - Krückel, Kai A1 - Nolden, Florian A1 - Ferrein, Alexander A1 - Scholl, Ingrid T1 - Intuitive visual teleoperation for UGVs using free-look augmented reality displays T2 - 2015 IEEE International Conference on Robotics and Automation (ICRA), Seattle, WA Y1 - 2015 U6 - https://doi.org/10.1109/ICRA.2015.7139809 SP - 4412 EP - 4417 ER - TY - CHAP A1 - Priede, Gareth A1 - Ferrein, Alexander T1 - Towards passive walking for the fully-actuated biped robot Nao T2 - Emerging trends in computing, informatics, systems sciences, and engineering. (Lecture notes in electrical engineering : vol. 151) N2 - Many biped robots deploy a form of gait that follows the zero moment point (ZMP) approach, that is, the robot is in a stable position at any point in time. This requires the robot to be fully actuated. While very stable, the draw-backs of this approach are a fairly slow gait and high energy consumption. An alternative approach is the so-called passive-dynamic walking, where the gait makes use of the inertia and dynamic stability of the robot. In this paper we describe our ongoing work of combining the principles of passive-dynamic walking on the fully-actuated biped robot Nao, which is also deployed for robotic soccer applications. We present a simple controller that allows the robot to stably rock sidewards, showing a closed limit-cycle. We discuss first results of superimposing a forward motion on the sidewards motion. Based on this we expect to endow the Nao with a fast, robust, and stable passive-dynamic walk on the fully-actuated Nao in the future. Y1 - 2013 SN - 978-1-4614-3557-0 ; 978-1-4614-3558-7 U6 - https://doi.org/10.1007/978-1-4614-3558-7_18 SP - 225 EP - 236 PB - Springer CY - New York, NY ER - TY - JOUR A1 - Ferrein, Alexander A1 - Schiffer, Stefan A1 - Lakemeyer, Gerhard T1 - Embedding fuzzy controllers in golog / Ferrein, Alexander ; Schiffer, Stefan ; Lakemeyer, Gerhard JF - IEEE International Conference on Fuzzy Systems, 2009. FUZZ-IEEE 2009 Y1 - 2009 SN - 978-1-4244-3596-8 SP - 894 EP - 899 PB - IEEE CY - New York ER - TY - CHAP A1 - Neumann, Tobias A1 - Dülberg, Enno A1 - Schiffer, Stefan A1 - Ferrein, Alexander T1 - A rotating platform for swift acquisition of dense 3D point clouds T2 - Intelligent Robotics and Applications: 9th International Conference, ICIRA 2016, Tokyo, Japan, August 22-24, 2016, Proceedings, Part I Y1 - 2016 SN - 978-3-319-43505-3 (Print) SN - 978-3-319-43506-0 (Online) U6 - https://doi.org/10.1007/978-3-319-43506-0_22 N1 - Series: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) VL - 9834 SP - 257 EP - 268 PB - Springer ER - TY - JOUR A1 - Ferrein, Alexander A1 - Fritz, Christian A1 - Lakemeyer, Gerhard T1 - On-Line Decision-Theoretic Golog for Unpredictable Domains / Ferrein, Alexander ; Fritz, Christian ; Lakemeyer, Gerhard JF - KI 2004: Advances in Artificial Intelligence : 27th Annual German Conference on AI, KI 2004, Ulm, Germany, September 20-24, 2004. Proceedings Y1 - 2004 N1 - Lecture Notes in Computer Science ; 3238 SP - 322 EP - 336 PB - Springer CY - Berlin ER - TY - CHAP A1 - Alhwarin, Faraj A1 - Ferrein, Alexander A1 - Scholl, Ingrid T1 - IR stereo kinect: improving depth images by combining structured light with IR stereo T2 - PRICAI 2014: Trends in artificial intelligence : 13th Pacific Rim International Conference on Artificial Intelligence : Gold Coast, QLD, Australia, December 1-5, 2014 : proceedings. (Lecture notes in computer science ; vol. 8862) N2 - RGB-D sensors such as the Microsoft Kinect or the Asus Xtion are inexpensive 3D sensors. A depth image is computed by calculating the distortion of a known infrared light (IR) pattern which is projected into the scene. While these sensors are great devices they have some limitations. The distance they can measure is limited and they suffer from reflection problems on transparent, shiny, or very matte and absorbing objects. If more than one RGB-D camera is used the IR patterns interfere with each other. This results in a massive loss of depth information. In this paper, we present a simple and powerful method to overcome these problems. We propose a stereo RGB-D camera system which uses the pros of RGB-D cameras and combine them with the pros of stereo camera systems. The idea is to utilize the IR images of each two sensors as a stereo pair to generate a depth map. The IR patterns emitted by IR projectors are exploited here to enhance the dense stereo matching even if the observed objects or surfaces are texture-less or transparent. The resulting disparity map is then fused with the depth map offered by the RGB-D sensor to fill the regions and the holes that appear because of interference, or due to transparent or reflective objects. Our results show that the density of depth information is increased especially for transparent, shiny or matte objects. Y1 - 2014 SN - 978-3-319-13559-5 (Print) ; 978-3-319-13560-1 (E-Book) U6 - https://doi.org/10.1007/978-3-319-13560-1_33 SP - 409 EP - 421 PB - Springer CY - München ER - TY - JOUR A1 - Ferrein, Alexander A1 - Jacobs, Stefan A1 - Lakemeyer, Gerhard T1 - Unreal Golog Bots / Jacobs, Stefan ; Ferrein, Alexander ; Lakemeyer, Gerhard JF - IJCAI-05 Workshop on Reasoning, Representation, and Learning in Computer Games Y1 - 2005 SP - 31 EP - 36 ER - TY - JOUR A1 - Ferrein, Alexander A1 - Böhnstedt, Lutz A1 - Lakemeyer, Gerhard T1 - Options in readylog reloaded -- generating decision-theoretic plan libraries in golog / Böhnstedt, Lutz ; Ferrein, Alexander ; Lakemeyer, Gerhard JF - KI 2007: advances in artificial intelligence : 30th Annual German Conference on AI, KI 2007, Osnabrück, Germany, September 10 - 13, 2007 ; proceedings Y1 - 2007 SN - 978-3-540-74564-8 N1 - Lecture Notes in Computer Science ; 4667 SP - 352 EP - 366 PB - Springer CY - Berlin ER - TY - CHAP A1 - Neumann, Tobias A1 - Ferrein, Alexander A1 - Kallweit, Stephan A1 - Scholl, Ingrid T1 - Towards a mobile mapping robot for underground mines T2 - 7th Conference of Robotics and Mechatronics : RobMech 2014 : 27th and 28th Nov. 2014, Cape Town Y1 - 2014 SP - 1 EP - 6 ER - TY - JOUR A1 - Ferrein, Alexander A1 - Meyer, Thomas T1 - A Brief Overview of Artificial Intelligence in South Africa JF - AI Magazine N2 - South Africa in recent years is the establishment of a number of research hubs involved in AI activities ranging from mobile robotics and computational intelligence, to knowledge representation and reasoning, and human language technologies. In this survey we take the reader through a quick tour of the research being conducted at these hubs, and touch on an initiative to maintain and extend the current level of interest in AI research in the country. Y1 - 2012 U6 - https://doi.org/10.1609/aimag.v33i1.2357 SN - 0738-4602 VL - 33 IS - 1 SP - 99 EP - 101 PB - AAAI CY - Menlo Park ER -