Vibration measurement method based on single-frame coded illumination and compressive sensing

Abstract

A visual vibration measurement method based on single-frame coded illumination and compressive sensing is proposed. The projector projects concentric rectangles with different sizes at different time points in a single camera exposure. According to the size of the rectangles, the image collected by the camera is separated into different sub frames. The centroids of the concentric rectangles are considered as the virtual feature points to record the vibration information of the object. The projector operates according to the random unequal interval trigger signal, and the projection is used as the sampling signal to encode the measured object. Discrete cosine transform is used as sparse basis, and sparsity adaptive matching pursuit and spectral projected gradient for L1 minimization (SPGL1) are used for signal reconstruction. Simulation analysis shows that the proposed method is feasible, and SPGL1 algorithm is more suitable for our signal reconstruction. The experiments indicate that the maximum absolute error of the proposed method for frequency measurement is 0.2985 Hz, and the maximum relative error is 1.6587 × 10 − 3. It is also applicable to multi-frequency measurement.