Design of a Multi-Functional Module for Visually Impaired Persons

Measuring a distance through an ultrasonic sensor and creating haptic alert information by a vibrotactile actuator are two major functions in an electronic aid for a visually impaired person. It is quite challenging to combine and to efficiently execute these two functions with a single module. Thus, this study presents a new structure that measures the distance and generates haptic information with only one module. The design focus of the proposed module is to maximize its vibrotactile amplitude and to minimize its measured distance error. In order to evaluate the performance of the proposed module, a test setup was constructed. Using the setup, the vibrotactile strength of the proposed module was investigated according to the input frequency, and then the distance between the proposed module and a target object was measured. The results show that the proposed module effectively produces haptic information while measuring the distance well between the module and a target object.