Staff Profile Pages

Linear acceleration measurement utilizing inter-instrument synchronization: A comparison between accelerometers and motion-based tracking approaches

Authors: Callaway, A.J. and Cobb, J.E.

Journal: Measurement in Physical Education and Exercise Science

Volume: 16

Issue: 2

Pages: 151-163

eISSN: 1532-7841

ISSN: 1091-367X

DOI: 10.1080/1091367X.2012.669336

Abstract:

Where as video cameras are a reliable and established technology for the measurement of kinematic parameters, accelerometers are increasingly being employed for this type of measurement due to their ease of use, performance, and comparatively low cost. However, the majority of accelerometer-based studies involve a single channel due to the difficulty associated with synchronizing multiple accelerometer channels. The authors of this article outline a method to synchronize multiple accelerometers using a maxima detection method. Results are presented that demonstrate the effectiveness of the new synchronization method with 52 of 54 recorded data sets showing no time lag error and two tests showing an error of.04 sec. Inter-instrument and instrument-video correlations are all greater than r =.94 (p <.01), with inter-instrument precision (Root Mean Square Error; RMSE) ≈ .1ms 2, demonstrating the efficacy of the technique. In conclusion, the new technique offers a robust solution, giving further support to the movement toward wider adoption of accelerometer-based performance measurement systems in sports science. © 2012 Copyright Taylor and Francis Group, LLC.

Source: Scopus

Linear acceleration measurement utilising inter-instrument synchronisation: A comparison between accelerometers and motion based tracking approaches.

Authors: Callaway, A. and Cobb, J.E.

Journal: Measurement in Physical Education and Exercise Science

ISSN: 1091-367X

Abstract:

Whilst video cameras are a reliable and established technology for the measurement of kinematic parameters accelerometers are increasingly being deployed for this type of measurement due to their ease of use, performance and comparatively low cost. Presently however, the majority of accelerometer based data loggers are single channel only. A key reason for this limitation is the difficulty associated with synchronising multiple accelerometer channels. This paper outlines a method to synchronise multiple accelerometers using a maxima detection method. Validity of this method is shown through correlation of the accelerometer data to kinematic data derived from video analysis. This gives further support to the movement towards wider adoption of accelerometer based performance measurement systems in sports science.

Results are presented that demonstrate the effectiveness of the new synchronisation method with 52 out of a total of 54 recorded data sets showing no time lag error with two tests showing an error of 0.04s. Inter-instrument and instrument-video correlations were all over 0.94 (r=0.01) demonstrating the efficacy of the multiple channel accelerometer based technique as a replacement for the traditional video based approaches. The measured error within these correlations, calculated with RMSE, showed inter-instrument RMSE were around 0.1ms-2 and instruments-video to be around 0.2ms-2, for all three axes tested. These results are relatively small in terms of kinematic data and in conclusion the new technique offers a robust solution for multiple channel accelerometer based performance monitoring in sports science

Source: Manual

Preferred by: Jon Cobb and Andrew Callaway