Research on an Electromagnetic Induction-Based Deep Displacement Sensor

A novel deep displacement sensor based on the electromagnetic induction theory is investigated and designed, which can directly convert the varied sliding displacement and tilt angle at any depth within the landslide mass to the variation of mutual inductance, so it has advantages, such as simple sensor structure, high sensitivity, accurate positioning of sliding surface and position, a remote, as well as real-time and automatic monitoring toward the underground landslide mass over the conventional deep displacement monitoring methods. The structure design, sensing principle, and theory modeling for the proposed sensor are presented. In order to improve the sensor´s performance, the complicated relationship between the landslide mass´s sliding magnitude and direction, the sensor´s geometric parameters, and its corresponding mutual inductance were derived by theoretical modeling. Furthermore, a series of ground-based testing experiments and theoretical modeling simulation are conducted and compared in detail, which not only initially shows the design feasibility and modeling effectiveness for the proposed sensor, but is also useful to give an in-depth understanding of the sensor property and optimize the sensor design.