Abstract: This groundbreaking paper presents the development and validation of a new type of displacement-based miniatured laser vibrometer. The device is crucial for applications such as experimental modal analysis, model validation, and structural health monitoring in the engineering field. Compared with traditional contact-type vibration measurement equipment, this miniaturized laser vibrometer features a compact size and lightweight design, enabling flexible installation on various mobile platforms (e.g., unmanned aerial vehicles and robotic arms) to achieve agile vibration measurement capabilities.
The paper first introduces the fundamental principles and significance of laser Doppler vibrometers (LDV).
It then elaborates on the motivations and technical challenges in developing the new miniaturized laser vibrometer, including the application of integrated optics in such devices and the advantages it brings.
A chip-based high-precision laser vibrometer is proposed, which enhances accuracy by integrating two or more orthogonal demodulation networks into its design.
Through a series of vibration measurement experiments across a frequency range from 0.1 Hz to 1 MHz, the proposed laser vibrometer demonstrates repeatability, accuracy, and robustness against test surface conditions.
The paper also includes a detailed description of the working principle of the proposed laser vibrometer and how digital demodulation methods are employed to improve performance and compensate for environmental influences.
Conclusion: This study successfully developed a new type of miniaturized laser vibrometer that directly measures structural vibration displacement through phase demodulation, offering high precision and wide-frequency-range measurement capabilities. Experimental validation shows that the device exhibits excellent repeatability and accuracy under various test conditions and has good robustness against test surface conditions.
