Electronic Travel Aid for the Blind

This paper presents a simple concept and design for a travel aid for the visually impaired. The proposed device uses ultrasonic signal in sensing and detecting an object (obstacles). The aid can inform the user about the distance of the detected obstacles by means of tactile vibrations. A prototype device called the intelligent walking stick (INSTICK) was developed under this concept. The INSTICK involves four main portions, ultrasonic transmitters, ultrasonic receiver, control unit and the output portions that consists of a vibrator motor and a speech synthesizer unit. Concept of radio detection is being employed here to receive the returned echo of ultrasonic signals reflected by the obstacles. The echo travel time is used to determine the distance from the user to the obstacle. A PIC microcontroller is used to control the transceiver and process the received signal to an audible format through speech synthesizer. A few tests and survey were carried out involving visually impaired and despite some limitations satisfactory results were observed.