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Also, sensors or sensor module can be attached to other parts of human body.
Several studies have proposed the foot attached method. This is a straight forward
method since the step length can be calculated directly based on foot acceleration
information [20, 21, 22]. However, these methods suffered from large vibrations and
uncertainties brought by foot movement.
In order to overcome these shortcomings, researchers tend to attached as many
sensors as possible to human body [23, 24]. In these studies, sensors are attached to two
knees, two feet, waist, and head. Unfortunately, with so many sensors and wires attached
to human body, it is difficult to walk as a normal person.
Based on this thought, our method is different from above. In our study, sensors
are only attached to one knee and waist. The sensors on knee will measure the angular
rate of leg swing and the sensors on waist will also measure the angular rate of turning.
As a result, both distance and heading information can be obtained. Furthermore, since
acceleration is not a concern here, this method suffers little from the cumulative errors.
Several methods were compared in this thesis through a series of experiments.
Further discussions and experiments setup will be in the following chapter.
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