Use of ultrasonic sensors in the development of an Electronic Travel Aid

Ultrasonic sensors present one of the most cost-effective digital distance measurement systems available for mobile applications. Their effectiveness is limited, however, in applications involving complex environments and when information on sensor position is unavailable. This paper focuses on the implementation and limitations of ultrasonic sensors and system design considerations during development of an Electronic Travel Aid [ETA] for the visually impaired utilizing ultrasonic sensors and vibrotactile feedback. Our work with sensors included signal filtering and triangulation to improve performance characteristics of ultrasonic-based measurements. Additionally, we describe the use of computer modeling to aid in the design of ultrasonic sensor systems.