中文摘要：

基于振动信号的故障诊断方法在某些场合下存在着局限性。机械噪声蕴含着丰富的设备状态信息，而且具有非接触式测量的优点，可以部分地替代振动信号，用于故障诊断。传统的噪声诊断方法主要基于频谱分析，无法反映声源位置和强度的变化信息，只能进行初步的故障诊断。基于此，提出一种基于声全息的故障诊断方法。该方法采用由少量传声器组成的阵列测量声压，应用波叠加法重构物体的外部声场，可以方便快速地进行声场可视化。一旦准确地重建出物体的外部声场，就可以利用这些全息场的信息进行故障诊断。通过建立基于全息图的正常状态与故障状态的模板，将机器的运行信息与这些模板对比，就可以判定机器的运行状态，从而进行故障诊断。采用由多个脉动球组成的声源模型进行了数值仿真，并在消声室内对两只音箱噪声源进行了试验研究，都准确地识别出辐射体声场状态变化，找出了故障。从而验证了该方法的正确性和实用性，为其在现场应用打下基础。

英文摘要：

Fault diagnosis method based on vibration signals has limits in certain situations. However, machine noise contains abundant condition information about machines. It possesses the advantage of non-contacting test. It can be used for fault diagnosis as a substitution of vibration signals. Traditional fault diagnosis methods based on noise signals are mainly on the basis of spectrum analysis. They cannot provide the location and the strength of sound sources. So they can only be used in some simple conditions. A fault diagnosis method based on acoustic holography is presented. A microphone array composed of a few microphones is used to acquire sound field. And the wave superposition method is adopted for sound field reconstruction. The sound field around a machine can be easily visualized by using such a method. Once the exterior sound field around the machine is reconstructed, the information extracted from the holography can be used for fault diagnosis. A number of templates of normal condition and fault condition can be made from the holography. A certain condition of the machine can be confirmed by comparison of it with these templates. Then the faults of the machine can be found. Numerical simulations are performed on the basis of a multiple pulse-ball sound source model, and experiments are also done with two sound boxes in an anechoic chamber. Both the simulations and the experiments have accurately identified the changes of the sound field radiated from the radiator, and have found out the faults. It shows that the method is validated and feasible, which lays a foundation for its on-site applications.