三维时域散斑动态干涉测量系统的集成化设计

Integrated design of three-dimensional continuous displacement measurement with temporal speckle interferometry

三维电子散斑干涉技术(3D ESPI)具有非接触、高精度、高灵敏度和全场测量等优点,被广泛应用于许多领域。为了实现非接触动态全场三维测量,设计并建立了一个紧凑、完备的三维测量系统。用一个多波长光纤耦合激光器代替3个独立光源,产生的离面、面内散斑干涉图仅用一台彩色CCD相机就能捕捉和处理;整个测量系统采用笼式结构,具有高度的灵活性和稳定性;对基于小波变换的相位展开算法进行了编程,实现了被测物体三维位移信息的完整提取。实验证明该测量系统可以实时获取被测物体的三维位移,在测量实验中,获得的三维位移值17.68μm、36.23μm、13.85μm,相比于实际位移值18.1μm、36.4μm、14.0μm它们的绝对误差分别为0.42μm、0.17μm、0.15μm,相对误差分别为2.3%、0.5%、1.1%。

The three-dimensional electronic speckle pattern interferometry(3D ESPI)is widely used in many fields due to its ascendancy of non-contact,high precision,high sensitivity and full-field measurement.In order to realize the non-contact dynamic full-field 3 D measurement,a compact and complete 3D measurement system was designed and set up.Three independent lasers were replaced by a single multi-wavelength fibre coupling laser to produce the speckle pattern interferograms of out-of-plane and in-plane,which could be captured and processed by only one charge coupled device(CCD)camera.The entire measurement system adopted cage construction with high flexibility and stability.The phase unwrapping algorithm based on the wavelet transform was programmed to realize the complete extraction of 3D displacement information on the measured object.The experimental results show that this measurement system can obtain the 3D displacement of the measured object.The 3D displacement values in the experiments are 17.68μm,36.23μm and 13.85μm,compared with the actual displacement values of 18.1μm,36.4μm and 14.0μm,the absolute errors are 0.42μm,0.17μm and 0.15μm,respectively,and the relative errors are 2.3%,0.5%and 1.1%.