Ultrasonic speakers let people who are blind read Braille in mid-air
Ultrasonic speakers let people who are blind read Braille in mid-air. Technology 27 May 2020 By Donna Lu An ultrasonic device could help people with visual impairments access private data in publicHaptic device being used at an ATMPeople who are blind can read Braille in mid-air using their hands thanks to a grid of speakers that emit ultrasound waves. The device create points in the air that are similar to the dots that form Braille character. On the skin this feels like a gentle breeze of air, says Viktorija Paneva at the University of Bayreuth in Germany. The mid-air dots are perceptible on a persons palm when they hold their hand up.
The assistance system for visually impaired people has been implemented by using ultrasonic principle to provide navigation. The presented system functions in 2 modes of operation that are obstacle recognition mode and fixed path mode. Obstacle detection mode uses grouping of ultrasonic transceivers for solid obstacle detection and water sensor to identify liquid obstacles by employing a microcontroller.
A high frequency sound signal would be sent by an ultrasonic sensor which is used in the system for obstacle detection, then the signal would be reflected back to the sensor, detect the liquid obstacle. When there is a liquid obstacle and the sensor comes into the vicinity of water, then the wires associated with the sensor (two wires) get short circuited. After this an alert would be generated and sent to the respective blind person through a voice message. The sequence generates an analog output and provides the moisture content information. A microcontroller present in the system would receive all this information and then further process it. After this the information would proceed to Bluetooth.