Seismic detection method and system based on real-time attitude compensation of nine-axis gyroscope

Abstract

The invention discloses an earthquake detection method and system based on real-time attitude compensation of a nine-axis gyroscope, and relates to the technical field of earthquake detection and signal processing. The method comprises the following steps: collecting original vibration signals from X, Y and Z axes, and obtaining attitude information of a seismograph in real time; the method comprises the following steps: combining attitude information with a seismic signal, calculating the influence of attitude change on an original vibration signal, generating a compensation parameter (total rotation matrix), correcting the original vibration signal in real time by using the compensation parameter, and carrying out noise reduction on the corrected signal to obtain the seismic signal. The X-axis, Y-axis and Z-axis vibration deviation caused by attitude change of the seismograph can be compensated in real time by combining data of the nine-axis gyroscope, and the measurement precision of seismic signals is improved. The seismograph can also adapt to various installation environments, and even if the seismograph works on an inclined and unstable ground, the signal accuracy can be ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of earthquake detection and signal processing, and more particularly to an earthquake detection method and system based on real-time attitude compensation of a nine-axis gyroscope. Background Art

[0002] A seismograph is a device used to monitor and record ground vibrations and is widely used in earthquake monitoring and geological research. Existing seismographs are fixedly installed in the field to record vibration information during the propagation of seismic waves. However, since the seismograph is susceptible to continuous changes in the installation position during long-term operation, external environmental influences such as tilt and small displacement, and even large-scale deviations in its posture due to geological events such as earthquakes and landslides, its measurement accuracy may be significantly reduced. What the staff wants to obtain is the vibration signal of the three axes XYZ when the seismograph has no posture deflection, but the actual situation is that the vibration signal of the seismograph has changed its posture. Because the collected vibration signal is a vector, vibration signals in different directions often have different physical characteristics, so it is necessary to manually compensate the seismograph signal after the posture shift.

[0003] Traditional seismograph compensation methods rely on static calibration and lack the ability to adjust dynamically in real time, especially in environments where they cannot be stably installed, where posture changes can easily introduce additional errors. In order to improve the measurement accuracy of seismographs, a compensation method combined with posture sensing is urgently needed, so that the seismograph can still ensure high-precision signal acquisition when its posture changes. Summary of the invention

[0004] In view of this, the present invention provides an earthquake detection method and system based on real-time attitude compensation of a nine-axis gyroscope.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A method for earthquake detection based on real-time attitude compensation of a nine-axis gyroscope comprises the following steps:

[0007] The original vibration signals from the three axes of X, Y, and Z are collected and the attitude information of the seismograph is obtained in real time through the nine-axis gyroscope;

[0008] The posture information is combined with the seismic signal, the impact of the posture change on the original vibration signal is calculated, and the compensation parameters are generated. The original vibration signal is corrected in real time using the compensation parameters, and the corrected signal is denoised to obtain a fully compensated seismic signal.

[0009] Optionally, before combining the attitude information with the seismic signal, the attitude information and the seismic signal are time-aligned.

[0010] Optionally, the vibration signal is compensated using the following rotation matrix:

[0011]

[0012] Where R is the rotation matrix.

[0013] An earthquake detection system based on real-time attitude compensation of a nine-axis gyroscope, comprising:

[0014] Seismic detector: used to collect the original vibration signals from the three axes of X, Y, and Z;

[0015] Nine-axis gyroscope module: used to detect the attitude change information of the seismograph in real time, including angular velocity and acceleration;

[0016] Compensation algorithm module: used to compensate the XYZ axis vibration signal according to the data of the nine-axis gyroscope module;

[0017] Data storage module: used to store compensated seismic signal data.

[0018] It can be seen from the above technical solutions that, compared with the prior art, the present invention provides an earthquake detection method and system based on real-time attitude compensation of a nine-axis gyroscope, which has the following beneficial effects:

[0019] 1. Real-time attitude compensation: By combining the data of the nine-axis gyroscope, the XYZ axis vibration deviation caused by the attitude change of the seismograph can be compensated in real time, thereby improving the measurement accuracy of the seismic signal.

[0020] 2. Strong environmental adaptability: The system can adapt to a variety of installation environments and can ensure the accuracy of the signal even if the seismograph works on tilted and unstable ground. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0022] Figure 1 is a flow chart of the vibration signal compensation of the seismograph of the present invention;

[0023] Figure 2 A seismograph in ideal posture;

[0024] Figure 3 A seismograph with attitude shift. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] The embodiment of the present invention discloses an earthquake detection method based on real-time attitude compensation of a nine-axis gyroscope, comprising the following steps:

[0027] The original vibration signals from the X, Y, and Z axes are collected through the 3-axis seismometer and the 9-axis gyroscope, and the attitude information of the seismometer is obtained in real time;

[0028] The posture information is combined with the seismic signal, the impact of the posture change on the original vibration signal is calculated, and the compensation parameters are generated. The original vibration signal is corrected in real time using the compensation parameters, and the corrected signal is denoised to obtain a fully compensated seismic signal.

[0029] More specifically, the present invention comprises the following steps:

[0030] Step 1: Vibration signal acquisition: The seismic detector collects the original vibration signals from the three axes of X, Y, and Z, and transmits these signals to the compensation algorithm module.

[0031] Step 2: Acquisition of nine-axis attitude data: The nine-axis gyroscope module acquires the attitude information of the seismograph in real time, including three-axis acceleration, three-axis angular velocity, and three-axis magnetic field strength. These data are used to describe the attitude changes that may occur in the seismograph during the measurement process. After being processed by the DMP module (an embedded digital motion processor), the Euler angles of the three axes are output to the compensation algorithm module.

[0032] Step 3: Attitude compensation calculation: Use the compensation algorithm module to combine the attitude data provided by the nine-axis gyroscope with the seismic signal. According to the Euler angles of the three axes obtained in step 2, generate the rotation matrix of the three axes XYZ. Multiply the three in the order of ZYX to get the total rotation matrix. Perform matrix multiplication on it with the three-dimensional column vector formed by the vibration signal detected by the three-axis vibration detector to obtain the compensated three-axis vibration signal three-dimensional column vector. The above process is completed in the MCU. The specific calculation steps include:

[0033] Attitude data time matching: synchronize the nine-axis gyroscope data with the seismic vibration signal data to ensure the consistency of the data timing.

[0034] Application of compensation parameters: Use the calculated compensation parameters (i.e., the total rotation matrix R) to perform real-time correction on the XYZ axis vibration signals.

[0035] Step 4: Signal storage and post-processing: The compensated signal is transmitted to the data storage module. The data can be further transmitted to the PC for more sophisticated noise reduction processing through Matlab to obtain the final high-precision seismic signal.

[0036] like Figure 2 and Figure 3 As shown in the figure, when the attitude of the seismograph shifts, the directions of the three coordinate axes of the seismograph are completely different, and the corresponding Figure 2 The three-axis vibration signal and Figure 3 The seismic signals measured in the state are completely different, and what we want is Figure 2 The seismic signal of the attitude is Figure 3 The vibration signal of the posture is compensated and inverted back Figure 2 The state of the seismograph needs to be known, and this requires the ability to know the attitude changes of the seismograph, so a nine-axis gyroscope chip is needed, which includes a three-axis angular velocity meter, a three-axis accelerometer, and a three-axis magnetometer. Through the internal attitude solution algorithm Kalman filter, complementary filter and Madgwick / Mahony filter, these algorithms are integrated in the DMP (an embedded digital motion processor). After the attitude solution is completed by the DMP, three attitude angles can be obtained, which are:

[0037] Yaw angle (ψ): The rotation angle around the Z axis.

[0038] Pitch angle (θ): The rotation angle around the Y axis.

[0039] Roll angle (Φ): The rotation angle around the X axis.

[0040] By obtaining these three Euler angles, we can know the specific posture of the seismograph. Figure 2 The vibration signals of the three axes XYZ under the state need to be transformed by the rotation matrix R Figure 3 The signals in the three directions of X, Y, and Z are measured and converted back Figure 2 The signals of the three axes XYZ in the state. Assume Figure 3 The vibration signals of the three axes in the state are [S X ,S Y ,S Z ] T , Figure 2 The vibration signals of the three axes under the state are [S X.orig ,S Y,orig ,S Z,orig ] T ,The rotation matrix R transforms the signal in the original coordinate system to the coordinate system of the current posture, which is recorded as:

[0041]

[0042] S X , S Y , S Z ——Vibration speed of XYZ three-axis vibration signal before compensation

[0043] S X,orig , S Y,orig , S Z,orig ——Vibration velocity of XYZ three-axis vibration signal after compensation

[0044] To transform from the current coordinate system back to the original coordinate system, you need to use the inverse of the rotation matrix R -1 ,

[0045]

[0046] Since R is an orthogonal matrix, R T =R -1 , just use the transpose of the rotation matrix.

[0047] The rotation matrix R is the result of this rotation around the ZYX axis:

[0048] R=R Z (ψ)R Y (θ)R X (Φ)(3)

[0049] The rotation matrix around the X-axis (roll angle φ):

[0050]

[0051] Rotation matrix around the Y axis (pitch angle θ):

[0052]

[0053] Rotation matrix around the Z axis (yaw angle ψ):

[0054]

[0055] The positive directions of the above three angles are all viewed from the positive direction of the corresponding coordinate axis to the negative direction, and the clockwise direction is positive. After processing, according to formula (3), the total rotation matrix is:

[0056]

[0057] And because:

[0058]

[0059] You can pass Figure 3 The vibration signals of the three axes are obtained under the condition of Figure 2 It should be noted that when the Euler angle of the axis in the middle of the rotation sequence is 90°, the universal joint will be locked and one degree of freedom will be lost. However, the attitude change of the seismometer rarely causes the middle rotation axis (here is the Y axis) to deflect by more than 90°.

[0060] To compensate for vibration signals in different directions, we need to know the vibration signals of the three axes after the attitude transformation, that is, the vibration signals collected in real time by the three axes of the seismograph, and also know the values ​​of the three Euler angles on the same time axis. Figure 1 , the vibration signals in three directions are collected through the three-axis vibration detector, op amp and ADC, and then transmitted through I 2 C communication protocol transmits data to the microcontroller. At the same time, the attitude sensing module also transmits the Euler angle information of the three axes to the MCU (note: the directions of the three axes of the gyroscope must be consistent with the three directions of the detector). According to formulas (2) and (8), the vibration signal and attitude information can be collected and compensated in real time in the MCU (algorithm compensation module), and then uploaded to the PC for other more complex signal processing.

[0061] This embodiment also discloses an earthquake detection system based on real-time attitude compensation of a nine-axis gyroscope, comprising:

[0062] Seismic detector: used to collect the original vibration signals from the three axes of X, Y, and Z;

[0063] Nine-axis gyroscope module: used to detect the attitude change information of the seismograph in real time, including angular velocity and acceleration, and output Euler angle;

[0064] Compensation algorithm module: used to compensate the XYZ axis vibration signal according to the data of the nine-axis gyroscope module, which is implemented by the MCU;

[0065] Data storage module: used to store compensated seismic signal data.

[0066] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0067] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for earthquake detection based on real-time attitude compensation of a nine-axis gyroscope, characterized in that: The following steps are involved: Collect the original vibration signals from the three axes of X, Y, and Z and obtain the attitude information of the seismograph in real time; The posture information is combined with the seismic signal, the impact of the posture change on the original vibration signal is calculated, and the compensation parameters are generated. The original vibration signal is corrected in real time using the compensation parameters, and the corrected signal is denoised to obtain a fully compensated seismic signal.

2. The earthquake detection method based on real-time attitude compensation of a nine-axis gyroscope according to claim 1, characterized in that: Before combining the attitude information with the seismic signal, the attitude information and the seismic signal are time-aligned.

3. The earthquake detection method based on real-time attitude compensation of a nine-axis gyroscope according to claim 1, characterized in that: The following rotation matrix is ​​used to compensate the vibration signal and attitude information: Where R is the rotation matrix.

4. An earthquake detection system based on real-time attitude compensation of a nine-axis gyroscope, characterized in that: include: Seismic detector: used to collect the original vibration signals from the three axes of X, Y, and Z; Nine-axis gyroscope module: used to detect the attitude change information of the seismograph in real time, including three-axis angular velocity, three-axis acceleration, and three-axis magnetometer; Compensation algorithm module: performs attitude compensation on XYZ axis vibration signals based on the data of the nine-axis gyroscope module; Data storage module: used to store compensated seismic signal data.

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