Design and laboratory testing of a MEMS accelerometer array for subsidence monitoring

Abstract

The monitoring of displacement variation is important for studying the seabed subsidence mechanism. To meet the multi-point measurement requirements for vertical displacement in subsidence monitoring of the seabed surface, a Micro-Electro-Mechanical Systems accelerometer array was designed. By sensing the tilt angles, displacements on the array can be calculated. The subsidence is calculated as the difference in the displacements from the initial values. To improve the accuracy of the displacement calculation, a calibration model of the tilt angle was presented. The model parameters are computed through a least squares estimation method, which is solved by the Levenberg-Marquardt algorithm. Experimental results show that the calibration model performs excellently with the maximum error of tilt angle being less than 1° in the measurement range (-90°, 90°). The displacement measurement accuracy of the array (2.1 m long) is almost less than 1 cm. Thus, the results show a strong agreement between the detected data and actual deformation in the test.

Theoretical Formulation/Development of Signal Sampling with an Equal Arc Length Using the Frame Theorem

“…is a mathematical expression of a detected object (such as a ribbon of terrain) which is a band limited function. The terrain is detected by a MEMS nine-axis sensor array [1][2][3]. In other words, () fx is sampled with the condition of equal arc length.…”

“…Sampling plays a critical role in signal analysis and contact sensor shape detection. However, samples cannot be collected uniformly in various applications, such as underwater terrain subsidence monitoring based on a Micro-Electro-Mechanical System (MEMS) 9-axis sensor array [1][2][3], shape monitoring based on the Fiber Bragg Grating (FBG) sensor array [4][5][6][7][8][9][10], and data gloves or motion capture devices based on fiber curvature sensor arrays [11,12]. The sensor array has an implicit characteristic-the arc length interval between the sensors is equal and constant when the sensor array moves with the detected object.…”

The Research on a Driving Device for Natural Gas Hydrate Pressure Core

“…In order to test the radial deformation of the lead screw with or without the support slider, a Micro-Electro-Mechanical Systems (MEMS) accelerometer array was used. The MEMS accelerometer array consists of several gravity-acceleration sensing units that are protected and positioned by the flexible circuit board and elastic steel tape, and all the units are connected to an IIC-communication bus [18]. By sensing the three-axis tilt angles, the direction and magnitude of the displacement for a measurement unit can be calculated, then the overall displacement of the array is calculated as the difference in the displacements from the initial values.…”

Experimental Research on Data Synchronous Acquisition Method of Subsidence Monitoring in Submarine Gas Hydrate Mining Area

“…These acoustic devices need to be mounted on a measuring platform, such as a surveying ship, a remotely controlled vehicle (ROV) or an autonomous underwater vehicle (AUV). These monitoring methods cannot achieve in-situ, long-term monitoring due to high costs [9,10,11,12].…”

“…Besides, there are many researches on data acquisition in multi-node and distributed systems, as well as time synchronization. Most of these systems are in the form of a single bus, and few articles use the combination of inter-integrated circuit (IIC) bus (short distance, high speed) and controller area network (CAN) bus (long distance, multi-node) to achieve high-speed and long-distance data transmission [11,16,17]. Meanwhile, underwater sensor networks have attracted more and more attention, and are widely used in marine environmental monitoring, resource exploration, target detection, tracking, and positioning [18,19].…”