3-D Microwave Displacement Sensor: 3-D Displacement Measurement Using a Single Microwave Transceiver

Accurate spatial 3-D vibration and deformation displacement measurement is essential in various fields, including structural health monitoring and smart manufacturing. However, traditional techniques such as laser and visual-based approaches suffer from limitations in performance, system complexity, and adaptability to harsh environments. In this article, we develop a novel spatial displacement measurement approach with a single microwave transceiver, creating the first unique 3-D microwave displacement sensor (3D-MDS), which can get rid of the fundamental issue of the 1-D displacement measurement along the line-of-sight in microwave sensing. In 3D-MDS, we utilize three noncollinear reference targets to establish the measurement coordinate system and further extract the desired 3-D displacement. To this end, a rigorous 3-D displacement reconstruction method is established leveraging on the multivariate function for spatial position and displacement with Taylor expansion. Moreover, the overall implementation procedures and primary considerations are described. Finally, the performance of the proposed method is validated through simulation and experiment with various scenarios, offering an appealing approach for accurate 3-D displacement measurement with microwave sensing.