Sensing Property Modeling for the Novel Horizontal-vertical Composite Underground Displacement Sensor

1 Nanying Shentu, 2 Guohua Qiu, 1 Xiong Li, 1 Renyuan Tong, 1, * Qing Li

1 College of Mechatronics Engineering, China Jiliang University, Hangzhou, 310018, P. R. China

2 College of Information Engineering, China Jiliang University, Hangzhou, 310018, P. R. China

Abstract: Due to invisibility and complexity of the underground displacement monitoring, there exit few practical monitoring sensors capable of monitoring the underground horizontal and vertical displacements simultaneously. A novel electromagnetic underground displacement sensor able to monitor both the horizontal and the vertical displacements was proposed in our previous studies and abbreviated as the H-V type sensor. Through comprehensive application of Hall sensing mechanism analysis, 3D magnetic field distribution solution to the permanent magnet, and multidimensional numerical integration method, a model called the Equivalent Magnetic Charge-Numerical Integration Model (EMC-NI) is presented in this paper and serves as the H-V type sensor’s Hall voltage measurement model. This model can quantitatively evaluate the complicated relationship among the sensor’s Hall voltage output, its measuring parameters (underground horizontal displacement, vertical displacement and tilt angle at different depth within the monitored soil rock mass) and morphological parameters (geometry, shape and property parameters for the sensor units). Comprehensive studies and comparisons have conducted between the experimentally measured and EMC-NI modeled Hall voltage under counterpart conditions, through which not only the model’s modeling effectiveness and calculation accuracy are objectively evaluated, but also some valuable theoretical support is provided for the sensor’ sensing properties evaluation, design optimization, and subsequent study of displacement parameter inversion approach.

Keywords: Computational modeling, Hall effect, Horizontal displacement, Permanent magnet, Underground displacement sensor, Vertical displacement.