University of Twente Student Theses
A New Angle on Turn Detection : A Method for Turn Detection for Varied Angles and Walking Speeds Using IMU's
Sinnema, Noah (2024) A New Angle on Turn Detection : A Method for Turn Detection for Varied Angles and Walking Speeds Using IMU's.
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| Abstract: | In this study, a method was developed for turn detection and turn estimation. This is to distinguish straight from non-straight walking. These turn parameters could provide insight into turn capacity and turn performance to adjust rehabilitation tactics for patients such as the elderly or those suffering from neurological or musculoskeletal diseases such as Parkinson's disease, Alzheimer's disease, multiple sclerosis and osteoarthritis. A turn experiment was done by taking measurements of four healthy individuals with three inertial measurement units (IMU) at slow, preferred and fast walking speeds. The IMUs were placed on the left foot (LF), the right foot (RF) and the sacrum (SA). For filtering a low-pass cutoff frequency of f_(c,low) = 0.5Hz was used. Half of the data was the method developed while the other half was used for validation. The mean absolute error (MAE) and the mean relative error (MRE) were used to evaluate the results. The sensor on the SA yielded the best results when estimating turns compared to the LF and the RF. The sensitivity of the turn detection of the combined signal was 100% but with some false positive turns detected. The method is, as a consequence of its design, not able to distinguish turns less than 2s apart from each other. The MAE is the smallest for the SA. Mean values of the MAE for the SA sensor were found to be 3.62degree, 3.42degree and 3.76degree for slow, preferred and fast walking speeds respectively. There was a positive relation between the walking speed and the MAE for the LF and the RF. The lowest and highest MRE values between all Participants, for all angles and the sensor on the SA, were found to be between 1.71% and 8.56%. The MRE is the largest for smaller turn angles. It is recommended to use a 0.5Hz low-pass cutoff frequency when turns are not expected more than once every 2s. Otherwise, a higher low-pass cutoff frequency should be used of up to 1.5Hz. For future research characterising this relation between turn frequency and cutoff frequencies should be examined. Validation with video is yet to be used to find the accuracy of turn duration. |
| Item Type: | Essay (Bachelor) |
| Clients: | Unknown organization, Netherlands |
| Faculty: | TNW: Science and Technology |
| Subject: | 33 physics, 42 biology, 50 technical science in general, 80 pedagogy |
| Programme: | Biomedical Technology BSc (56226) |
| Link to this item: | https://purl.utwente.nl/essays/103597 |
| Export this item as: | BibTeX EndNote HTML Citation Reference Manager |
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