for visually impaired people
The belt is designed to help visually impaired people navigate in their everyday life without having to rely on other people or long training. It guides the user with four vibration motors.
Project Partner Felix Waigner
My role User-testing, Prototyping
The core of the belt is an Arduino Nano. Four vibration motors are connected to the Arduino, which in the prototype can be controlled with a Bluetooth receiver.
The motors can be arranged freely on a Velcro fastening rail, so that the users waist measurement has no influence on the use. That is why we also relied on Velcro for the fastening. This allows the belt to be ideally adjusted to the user.
In the beginning, we analyzed already existing solutions, solutions under development and the underlying problems. For example, there are already models that communicate with the user via Wi-Fi. Surrounding buildings send signals which are then transmitted to the user through a headset. The problem: These devices rely on an area-wide network of buildings and other infrastructures which is not available in rural areas in particular.
We noticed that visually impaired people are generally very dependent on their hearing for spatial orientation in everyday life. However, many things like traffic and people are already placing demands on their hearing. We soon realized that our system had to work independently from the sense of hearing in order to avoid additional confunding input.
The navigation system should be adaptable to the current user.
The user should receive as little external audio input as possible to avoid interference with other external signals.
Its use should depend on as few external conditions as possible.
Initially, six motors were to be installed in order to allow precise diagonal guidance. However, it turned out that the angular motors could not be distinguished from the lateral ones while leading the user.
We decided to use only four motors. It should be noted that these should now primarily give directional instructions. The visually impaired person should still have a stick with him/her, with which obstacles in the way can be recognized. In addition, the stick also provides a recognition feature for passers-by.
Now we had to find out how we could most clearly communicate changes in direction. To do this, we carried out various tests, which allowed us to test the reaction of people who were not familiar with the system. We found that a permanent vibration was rather unpleasant and changes here could not be perceived well.
We tried to divide the vibration into four different lengths depending on how much distance was covered. This should make it possible to count the number of signals, and to know that after the fourth time a new direction is given. However, the differentiation of the different lengths and the counting of the vibrations proved to be problematic.
The final sequence was relatively simple but precise and proved to be reliable in our tests: A singular vibrationsignals the user in which direction he schould turn. A single vibration to the front then indicates when the correct direction has been reached. There are no more signals until another change in direction is required, which should prevent irritations. In case the user turns in a wrong direction the same principle is used for correction.
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