CN-121994194-A - Foundation pit inclinometer depth positioning method based on magnetic field feature matching

CN121994194ACN 121994194 ACN121994194 ACN 121994194ACN-121994194-A

Abstract

The invention provides a depth positioning method of a foundation pit inclinometer based on magnetic field feature matching, and relates to the technical field of foundation pit horizontal displacement monitoring; the method comprises the steps of obtaining motion state estimation sequence of an inclinometer by integrating IMU data and odometer data through a filtering algorithm, carrying out space resampling on triaxial magnetic field data based on the odometer data, converting the triaxial magnetic field data into magnetic field characteristic sequences distributed along the mileage direction, matching the magnetic field characteristic sequences with a background magnetic field characteristic database constructed in advance to obtain matched mileage values, associating the motion state estimation sequence of the inclinometer with the matched mileage values, and recalibrating accurate depth coordinates of each deformation point of the inclinometer by taking the matched mileage values as uniform depth references, and calculating deformation amounts of the same depth position in different periods.

Inventors

YANG YUAN
XING JIANMING
TAN LI
CAO YUNFEI
ZHANG ZHIYONG
SHI KAIQI

Assignees

湖北能源集团溇水水电有限公司

Dates

Publication Date: 20260508
Application Date: 20251208

Claims (10)

1. The depth positioning method of the foundation pit inclinometer based on magnetic field feature matching is characterized by comprising the following steps: controlling an inclinometer carrying an Inertial Measurement Unit (IMU), an odometer and a magnetometer to move in an inclinometer pipe, and synchronously acquiring IMU data, triaxial magnetic field data and odometer data marked in a unified time; The IMU data and the odometer data are fused by adopting a filtering algorithm to restrain drift errors calculated by the IMU, so that a motion state estimation sequence of the inclinometer is obtained; Performing space resampling on the triaxial magnetic field data based on the odometer data, converting the triaxial magnetic field data into magnetic field feature sequences distributed along the mileage direction, and matching the magnetic field feature sequences with a pre-constructed background magnetic field feature database to obtain a matched mileage value, wherein the background magnetic field feature database comprises magnetic field feature data of an inclinometer in a reference state, and is constructed by taking depth coordinates as indexes; And correlating the motion state estimation sequence of the inclinometer with the matched mileage value, and recalibrating the accurate depth coordinates of each deformation point of the inclinometer by taking the matched mileage value as a uniform depth reference, and calculating deformation amounts of the same depth position in different periods.
2. The method for positioning the depth of the foundation pit inclinometer based on magnetic field feature matching as set forth in claim 1, wherein the constructing step of the background magnetic field feature database specifically includes: Controlling an inclinometer carrying an IMU, an odometer and a magnetometer to reciprocate in a standard state in an inclinometer pipe at a constant speed according to a preset speed, and synchronously acquiring IMU data, triaxial magnetic field data and odometer data marked with uniform time; calculating the IMU data, calculating the attitude, speed and position information of an inclinometer through inertial navigation mechanics arrangement, fusing the calculated result of inertial navigation with the odometer data by adopting a Kalman filtering algorithm, compensating the error of IMU data calculation, and generating a high-precision depth coordinate sequence by adopting a reverse smoothing algorithm; and extracting the magnetic field characteristics of the triaxial magnetic field data corresponding to each depth coordinate by taking the depth coordinate sequence as an index to form a structured background magnetic field characteristic database which is arranged in a depth increasing mode.
3. The foundation pit inclinometer depth positioning method based on magnetic field feature matching of claim 2, wherein the reference state comprises a data acquisition state which is performed under the working condition that the inclinometer is not deformed after the installation of the inclinometer pipe is completed and no magnetic interference equipment is operated; the magnetic field characteristics include a triaxial magnetic field strength, a total magnetic field strength, and a triaxial magnetic field gradient.
4. The method for positioning the depth of the foundation pit inclinometer based on the matching of magnetic field characteristics according to claim 1, wherein the magnetometer is fixedly installed on the inclinometer body, the installation distance of the magnetometer relative to the measurement front end of the inclinometer is measured, and when the accurate depth coordinates of each deformation point of the inclinometer pipe are recalibrated, the installation distance is compensated as deviation so as to ensure that the spatial references of the IMU, the odometer and the magnetometer are consistent.
5. The method for positioning the depth of the foundation pit inclinometer based on the magnetic field feature matching according to claim 1, wherein when the resolving result of inertial navigation is fused with the odometer data, whether the inclinometer is in a static state in an inclinometer pipe is judged, if so, a difference value between a theoretical zero speed and an actual resolving speed is taken as a strong observation information updating filter, and an error of IMU data resolving is corrected.
6. The method for locating the depth of the foundation pit inclinometer based on magnetic field feature matching according to claim 5, wherein after correcting the error of the IMU data calculation, the motion state estimation sequence is optimized again from back to front by using the observation data in all measurement periods so as to fuse the observation information at the future time and output a global smooth track and a state sequence.
7. The method for positioning the depth of the foundation pit inclinometer based on magnetic field feature matching according to claim 1, wherein the step of matching the magnetic field feature sequence with a pre-constructed background magnetic field feature database specifically comprises: and matching the actually measured magnetic field characteristics with the background magnetic field characteristics by elastically aligning the nonlinear expansion and contraction of the magnetic field characteristic sequence and the background magnetic field characteristic database on a time axis by adopting a dynamic time warping algorithm or a sliding window cross-correlation analysis method.
8. Foundation ditch inclinometer degree of depth positioning system based on magnetic field characteristic matches, its characterized in that includes: The acquisition module is used for controlling the inclinometer carrying the inertial measurement unit IMU, the odometer and the magnetometer to move in the inclinometer pipe and synchronously acquiring IMU data, triaxial magnetic field data and odometer data marked by unified time; The motion estimation module is used for fusing the IMU data and the odometer data by adopting a filtering algorithm so as to inhibit a drift error calculated by the IMU and obtain a motion state estimation sequence of the inclinometer; The magnetic field matching module is used for carrying out space resampling on the triaxial magnetic field data based on the odometer data, converting the triaxial magnetic field data into magnetic field feature sequences distributed along the mileage direction, and matching the magnetic field feature sequences with a pre-constructed background magnetic field feature database to obtain a matched mileage value, wherein the background magnetic field feature database comprises magnetic field feature data of an inclinometer in a reference state, and is constructed by taking depth coordinates as indexes; and the deformation detection module is used for correlating the motion state estimation sequence of the inclinometer with the matching mileage value, recalibrating the accurate depth coordinates of each deformation point of the inclinometer by taking the matching mileage value as a uniform depth reference, and calculating deformation amounts of the same depth position in different periods.
9. An electronic device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor, when executing the computer program, implements the steps of the method for depth positioning of a foundation pit inclinometer based on magnetic field feature matching as set forth in any one of claims 1 to 7.
10. A non-transitory computer readable storage medium having stored thereon a computer program, wherein the computer program when executed by a processor implements the steps of the method for depth positioning of a foundation pit inclinometer based on magnetic field signature matching of any one of claims 1 to 7.

Description

Foundation pit inclinometer depth positioning method based on magnetic field feature matching Technical Field The invention relates to the technical field of foundation pit horizontal displacement monitoring, in particular to a depth positioning method of a foundation pit inclinometer based on magnetic field feature matching. Background In recent years, with the continuous expansion of construction scale in the infrastructure field such as expressways, high-speed railways, urban subways, large reservoirs, and slope management, the monitoring demands on the geological stability and structural safety around foundation pit engineering are increasingly urgent. The deep horizontal displacement monitoring of the foundation pit, abbreviated as inclinometry, is used as a key item for evaluating the stability of a foundation pit supporting structure or a peripheral soil body, and has important significance for preventing landslide and structural instability of the soil body and ensuring construction safety. At present, a sliding inclinometer is generally adopted in the field of foundation pit deep horizontal displacement monitoring to measure, and although the deformation form of an inclinometer can be accurately depicted, the deformation is accurately positioned to a specific depth coordinate, and the accuracy of a mileage value provided by an odometer is completely relied on. However, due to the slip, the stretching and the transmission errors of the traction rope, errors exist in mileage data and the measurement is inconsistent, so that the deformation depth cannot be accurately positioned, and the back-to-back measurement and multi-period deformation data cannot be effectively aligned and compared, so that the accurate analysis of the deformation trend and the effective evaluation of engineering safety are severely restricted. Disclosure of Invention The invention aims to provide a depth positioning method of a foundation pit inclinometer based on magnetic field feature matching, which aims to solve the problems that the deformation depth of the conventional mechanical odometer mentioned in the background art cannot be accurately positioned, and the conventional back-measuring and multi-stage deformation data cannot be effectively aligned and compared. The method comprises the steps of controlling an inclinometer carrying an inertial measurement unit IMU, an odometer and a magnetometer to move in an inclinometer pipe, synchronously collecting IMU data, triaxial magnetic field data and odometer data marked in unified time, fusing the IMU data and the odometer data by adopting a filtering algorithm to restrain drift errors solved by the IMU so as to obtain an inclinometer motion state estimation sequence, carrying out space resampling on the triaxial magnetic field data based on the odometer data, converting the triaxial magnetic field data into magnetic field feature sequences distributed along the mileage direction, carrying out matching on the magnetic field feature sequences and a pre-built background magnetic field feature database to obtain a matching mileage value, wherein the background magnetic field feature database comprises magnetic field feature data of the inclinometer pipe in a reference state, constructing the inclinometer motion state estimation sequence and the matching mileage value by taking depth coordinates as indexes, carrying out correlation on the matching mileage value as the unified depth reference, calibrating each point again, and calculating deformation depth of each point in the same depth coordinate in the same time period accurately. The method comprises the steps of carrying out a calculation process on IMU data, calculating attitude, speed and position information of the inclinometer through inertial navigation mechanics arrangement, fusing a calculation result of inertial navigation with the odometer data through a Kalman filtering algorithm, compensating an error calculated by the IMU data, generating a high-precision depth coordinate sequence through a reverse smoothing algorithm, and extracting magnetic field characteristics of triaxial magnetic field data corresponding to each depth coordinate by taking the depth coordinate sequence as an index to form a structured background magnetic field characteristic database in incremental depth arrangement. Optionally, the reference state comprises a data acquisition state which is performed under the working condition that the inclinometer pipe is not deformed after being installed and no magnetic interference equipment works, and the magnetic field characteristics comprise triaxial magnetic field intensity, total magnetic field intensity and triaxial magnetic field gradient. Optionally, the magnetometer is fixedly installed on the inclinometer body, and measures the installation distance of the magnetometer relative to the measurement front end of the inclinometer, and compensates the installation distance as a deviation when recali