Accuracy improvement of positional measurement system using ultrasonic waves for indoor flying robot

Abstract

It is important that an autonomous flying robot measures its self-position accurately in order to fly indoors. However, a GPS cannot be used because of the indoor accuracy problem. Therefore, we have proposed a positional measurement system that uses ultrasonic waves for indoor use. This paper proposes two techniques to improve the accuracy for the positional measurement system using ultrasonic waves. One uses the second harmonic wave generated by the nonlinear propagation of ultrasonic waves in order to double the resolution. The other applies a threshold detector on both sides of the wave in the ultrasonic receiver in order to double the resolution. By using the proposed methods, the resolution increases to four times. From a developed prototype system and several experimental results, this paper shows the availability of the proposed methods for an improved positional measurement system using ultrasonic waves for a flying robot.