printlogo
http://www.ethz.ch/index_EN
Welcome
 
print
  

Automatic parameter extraction methods for athlete swimming

Media

 Electronics Lab 

Info_Media

More »»

Job Links

 Open Position »»

Latest News

May 9, 2012
Franz Gravenhorst in 20 minutes ‘Uni-Sport erleichtert die Integration’ read more
May 1, 2012
Daniel Waltisberg joins the Wearable Computing Group.
February 1, 2012
Luisa Petti joins the Wearable Computing Group.

Type: Semester thesis
Students: Dominik Breu, Jürg Germann
Advisor: Marc Bächlin, Kilian Förster

The purpose of this thesis is the investigation of automatic methods based on peak detection and template matching that extract significant parameters of the swimmers wrist acceleration.

The SwimRecorder, a waterproof standalone 3D-acceleration recording device for the wrist has been developed. Figure 1 shows the developed SwimRecorder mounted on the wrist with the axes drawn in. Its usability has been proved in several experiments. Overall more than 1300min of swim data has been recorded with 16 persons.

Two adequate swim experiments, the 7 x50m Stroke Efficiency Test and the 4 x200m Individual Medley Experiment have been selected and accomplished to evaluate the algorithms. The two experiments enable an evaluation of the automatic detected swim parameters like the stroke type and the stroke event.

 
Figure 1:SwimRecorder
Figure 1:SwimRecorder

Two automatic parameter extraction methods, the Peak detection and the Template matching, have been developed. Both methods recognized the different stroke events and types with a high success rate of over 90%. The Peak detection method performes better in the exact determination of turns. On the other hand the Template matching based algorithm copes better with fast changes of the swim stroke type.
A complete automatic method based on the Peak detection algorithm for the 7x50m Stroke Efficiency Test has been developed and compared with a manual measurement. The automatic method showed a comparable accuracy to the manual measurement. Figure 2 shows a processed 4x200m Individual Medley dataset with all detected stroke events and stroke types. Since both the Peak detection algorithm and the Template Matching algorithm do not require complex computations it is possible to implement them as onlinealgorithms on the SwimRecorder device itself. This would be a further step towards an improved and user friendly direct feedback system.

Figure 2: 3D-Swim-Accelerometer signal with detected stroke events and types
Figure 2: 3D-Swim-Accelerometer signal with detected stroke events and types
 

Wichtiger Hinweis:
Diese Website wird in älteren Versionen von Netscape ohne graphische Elemente dargestellt. Die Funktionalität der Website ist aber trotzdem gewährleistet. Wenn Sie diese Website regelmässig benutzen, empfehlen wir Ihnen, auf Ihrem Computer einen aktuellen Browser zu installieren. Weitere Informationen finden Sie auf
folgender Seite.

Important Note:
The content in this site is accessible to any browser or Internet device, however, some graphics will display correctly only in the newer versions of Netscape. To get the most out of our site we suggest you upgrade to a newer browser.
More information

© 2012 ETH Zurich | Imprint | 19 March 2009
top