The multi-rotor type unmanned aerial vehicle (UAV) controls the movement through the rotational speed of each rotor. Since the phase of each rotor is different and minute variations of the rotational speed are always accompanied during flight, frequency modulation of the drone noise occurs. In this study, a new approach, called the rotation per minute (RPM) fluctuation correction method, was developed to consider the frequency modulation effects through correcting the signals predicted by the classical rotorcraft noise prediction methods. For verification of the suggested method, two experiments were performed for a single isolated rotor and a full vehicle. The measured spectra of the isolated rotor were used for verifying the spectrum before the correction. Also, the spectra corrected by the RPM fluctuation correction method were compared and verified with the noise of the full vehicle, which has frequency modulation effects.

多旋翼型无人机（UAV）通过每个旋翼的转速控制运动。由于每个转子的相位不同，并且在飞行过程中总是伴随着转速的微小变化，因此会发生无人机噪音的频率调制。在这项研究中，开发了一种新方法，称为每分钟转速（RPM）波动校正方法，该方法通过校正经典旋翼飞机噪声预测方法预测的信号来考虑频率调制效果。为了验证建议的方法，对单个隔离的转子和整车进行了两个实验。在校正之前，将隔离转子的测量光谱用于验证光谱。也，