Obstacle detection & location using acoustic technology in time domain

The development and application of Ultrasonic Phased array, as a stand-alone technology, reached a mature status at the beginning of the twenty-first century. New advances in Piezocomposite technology, micro-machining, microelectronics, and computing power (including simulation packages for probe design and beam components interaction), all contributed to the revolutionary development of phased array technology by the end of 1990. Phased array principles have not been extensively applied for acoustic imaging in air. Electronic Travel aids, which transform visual environment cues in to another sensory modality, have been proven to help visually impaired people to travel with a great degree of psychological comfort and independence. Designing an obstacle detector for visually impaired, which is a part of digital navigation system, is a challenging problem, which current science and technology have not yet solved. Although a number of designed devices have helped visually impaired people, there are only few systems which give the exact position of the obstacle.