A Vibrotactile Navigation Aid for the Visually Impaired

Posted by René on August 21, 2015

I supervised this Bachelor’s thesis by David Antón Sánchez.



OpenVNAVI is a vest equipped with a depth sensor and array of vibration motor units that allow people with visual impairment to avoid obstacles in the environment.

The ASUS Xtion PRO LIVE depth sensor, positioned onto the user’s chest scans the environment as the user moves. From the video feed of the depth sensor a frame is captured and then processed by the Raspberry Pi 2. Each frame is downsampled from 640x480 to 16x8 and each pixel is then mapped to a vibration motor unit forming an array positioned onto the user’s belly.

The grayscale value of each pixel on the lower resolution frame is assigned to a PWM voltage value generated by the Raspberry Pi 2 via PWM drivers that will drive each vibration motor obtaining a vibration amplitude value as a function of the proximity of an object.

With this method the vibration motor unit array is able to represent a vibratory image onto the user’s belly to help create a mental representation of the obstacles in the scene.

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