Ultrasonic Sensor

A device that measures distance to objects by emitting high-frequency sound waves and calculating the time it takes for the echo to return. In assistive technology, ultrasonic sensors are commonly used in electronic travel aids and wearable navigation devices for blind and visually impaired people, detecting obstacles that may not be reachable by a white cane, such as objects at head or chest height. They are valued for their low cost, reliability, and ability to work in varying light conditions.