Fast beacon recognition for accurate ultrasonic indoor positioning

A proof-of-principle demonstrator based on ultra-sonic technology capable of identifying the beacon node within 450 μs is discussed. Time difference of arrival is measured by means of a microcontroller-based board Nucleo STM32 L152RE combined with a custom receiving circuit. The position is computed using a personal computer after the demonstrator acquisition. The demonstrator is validated by static 2D position measurements using two synchronized emitting beacon nodes in a 1.8 m × 2.0 m area with an accuracy of 5.59 cm.