High precision ultrasonic positioning using a robust optimization approach

Typically, indoor positioning systems require higher precision than outdoor positioning systems. Outdoor positioning technologies such as GPS provide poor accuracy in indoor environments due to signal attenuation by the building fabric. In indoor environments, commercial motion-capture systems are proficient at measuring the 3D position of an object precisely. The main disadvantages of this method include its cost and complexity. In this paper, we present a precise 3D ultrasonic positioning system for medical applications, using a robust steepest descent optimization algorithm, to estimate the 3D position of an ultrasonic transmitter. Our experimental results show that the proposed system has the precision required for medical applications and has lower cost and complexity when compared with the alternative traditional optical systems.