TY  - CHAP
A1  - Altay, Okyay
A1  - Taddei, Francesca
A1  - Butenweg, Christoph
A1  - Klinkel, Sven
T1  - Vibration mitigation of wind turbine towers with tuned mass dampers
T2  - Wind turbine control and monitoring. (Advances in industrial control)
N2  - Because of its minor environmental impact, electricity generation using wind power is getting remarkable. The further growth of the wind industry depends on technological solutions to the challenges in production and construction of the turbines. Wind turbine tower vibrations, which limit power generation efficiency and cause fatigue problems with high maintenance costs, count as one of the main structural difficulties in the wind energy sector. To mitigate tower vibrations auxiliary measures are necessary. The effectiveness of tuned mass damper is verified by means of a numeric study on a 5 MW onshore reference wind turbine. Hereby, also seismic-induced vibrations and soil–structure interaction are considered. Acquired results show that tuned mass damper can effectively reduce resonant tower vibrations and improve the fatigue life of wind turbines. This chapter is also concerned with tuned liquid column damper and a semiactive application of it. Due to its geometric versatility and low prime costs, tuned liquid column dampers are a good alternative to other damping measures, in particular for slender structures like wind turbines.
Y1  - 2014
SN  - 978-3-319-08412-1 (Print) ; 978-3-319-08413-8 (E-Book)
U6  - https://doi.org/10.1007/978-3-319-08413-8_12
SP  - 337
EP  - 373
PB  - Springer
CY  - Cham ; Heidelberg ; New York ; Dordrecht ; London
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  -