基于结构光投影的薄膜振动模式分析

Analysis of membrane vibration modes based on structured light projection

为了验证薄膜振动模式的有效性,采用正弦条纹投影和傅里叶条纹分析的方法进行薄膜振动模式分析和振幅重建,并进行了理论分析和实验研究。在基于结构光的主动3维传感技术中,傅里叶变换轮廓术具有单帧获取、高分辨率、全场可实时测量等优势,成为可测量动态3维面形的一种实用方法。正弦光栅条纹被投影到振动中的薄膜表面,采用低帧频的CCD相机采集由薄膜振动导致条纹局部模糊的一系列变形条纹图。通过傅里叶变换轮廓术方法进行处理,最终得到不同频率下实际测量的薄膜振动模式结果。给出了理论计算结果与实测结果的验证比较。结果表明,该方法测量的振动模式结果准确反映了薄膜振动情况。3维面形测量结果和实验验证了该方法的可行性。

In order to verify membrane vibration modes,sinusoidal fringe projecting and Fourier fringe analysis were used in membrane vibration mode analysis and amplitude reconstruction. After theoretical analysis and experimental verification,among 3-D automatic sensor technologies based on structured light,Fourier transform profilometry（ FTP） with the advantages of single-frame capture,high resolution and real-time measurement became the practical method in dynamic three-dimensional shape measurement. A sequence of the deformed and partly blurred sinusoidal fringe images on the surface of a vibrating membrane was grabbed by a low sampling rate CCD camera. By FTP,the actual experimental results of membrane vibration modes at different frequencies were obtained. The theoretical vibration results and the vibration measurement results were compared. The results show that the vibration modes reflect the vibrating membrane accurately.The results of 3-D surface shape measurement and actual experiments give the verification of its validity.