| 摘要 |
PURPOSE:To improve the precision of angle measurement with simple constitution by converting a received acoustic wave into an electric signal and detecting its arrival azimuth from the frequency of a delay time control signal. CONSTITUTION:Receivers 1 and 2 convert received acoustic waves into electric signals respectively; and a delay circuit 33 delays the output of the receiver 1 by a time corresponding to the frequency of the delay time control signal, and a delay circuit 33 delays the output of the receiver 2 as specified. Further, a circuit 35 detects the phase difference between the outputs of the circuits 33 and 34, a circuit 36 integrates sampled values of the circuit 35 at each interval of time, and a circuit 37 generates the delay time control signal of frequency corresponding to the output of the circuit 36. Then, the arrival azimuth of the received acoustic waves are detected from the frequency of the delay time control signal, so the angle measurement precision is improved with the simple constitution. |
