Two-Dimensional Airborne Position and Velocity Measurements Using a Pair of Linear-Period-Modulated Ultrasonic Waves

This paper proposes an idea for position and velocity measurements for a moving object with the echolocation technique under the ultrasonic system. The moving-object location is based on the time-of-flight (TOF). Cross correlation, low-calculation-cost Doppler-shift compensation, plays an important role in the TOF determination. The over-sampling cross-correlation function is obtained from single-bit signal processing. The velocity of the moving object is determined from the peak interval and peak form in the cross-correlation function. Linearperiod-modulated (LPM) ultrasonic waves are employed to support the influence of the Doppler effect. In this paper, the ultrasonic two-dimensional position and velocity vector measurement exploits two microphones. The validity of this paper is experimentally evaluated.