A three-dimensional transient magnetic field monitoring system based on sensor array attitude-position joint correction

Abstract

The application discloses a kind of three-dimensional transient magnetic field monitoring systems based on sensor array posture-position joint correction, comprising: the magnetic field measurement component of M×N×K three-dimensional sensor array is formed, and it is distributed with preset space interval equidistant to real-time acquisition transient magnetic field data;Lower computer is synchronized with IIC bus parallel acquisition original data and uploads;Host computer integrates posture error correction unit and collaborative position compensation unit, respectively based on the uniform magnetic field and gradient magnetic field generated by Helmholtz coil, eliminate sensor posture error by rotation matrix solution, construct global optimization model and compensate position deviation.Data processing module reconstructs continuous magnetic field distribution using cubic spline interpolation, and display module realizes the visualization of vector, scalar space-time distribution and time sequence playback through dynamic rendering technology;The system of the application realizes high-precision monitoring of transient magnetic field through hardware parallel architecture and joint correction algorithm, and is suitable for transient magnetic field dynamic analysis in the fields of power equipment, medical imaging and the like.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic measurement technology, and specifically to a three-dimensional transient magnetic field monitoring system based on sensor array attitude-position joint correction. Background Technology

[0002] Magnetic field monitoring technology, as an important component of modern science and technology, is widely used in numerous fields, such as electromagnetic environment monitoring of power systems, magnetic field sensing of aircraft in the aerospace field, underground magnetic field detection in geological exploration, and biomagnetic field measurement in biomedical engineering. With the continuous advancement of science and technology, various fields are placing increasingly higher demands on the accuracy, efficiency, and data processing capabilities of magnetic field monitoring.

[0003] Existing three-dimensional transient magnetic field monitoring technologies have several problems and shortcomings. Firstly, during actual installation, various factors, such as the complexity of the installation environment and operational errors, cause deviations between the actual and theoretical positions of the sensors. Secondly, sensor orientation errors are unavoidable during installation, meaning there is a rotational deviation between the sensor's measurement coordinate system and the actual magnetic field generating device's coordinate system. Furthermore, transient magnetic field monitoring requires not only accurate acquisition of the sensor's spatial position and orientation information but also real-time, high-precision data acquisition and processing of rapidly changing magnetic fields. Traditional monitoring systems, in the data acquisition stage, are often limited by data transmission rates and synchronous acquisition capabilities, making it difficult to meet the requirements of rapidly changing transient magnetic fields. In terms of data processing, the lack of effective spatial interpolation and data reconstruction algorithms prevents accurate reconstruction of the high-precision spatial magnetic field distribution from discrete sensor data, resulting in insufficient spatiotemporal resolution and an inability to clearly demonstrate the dynamic evolution of the transient magnetic field. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide a three-dimensional transient magnetic field monitoring system based on joint attitude-position correction of sensor array, which solves the problems of insufficient sensor array installation accuracy, large attitude error, and limited transient data acquisition and processing capabilities in existing three-dimensional transient magnetic field monitoring systems.

[0005] Technical Solution: The present invention discloses a three-dimensional transient magnetic field monitoring system based on joint attitude-position correction of a sensor array, comprising: a magnetic field measurement component, consisting of an M×N×K three-dimensional Hall effect sensor array, wherein the sensor array is equally spaced at preset spatial intervals for real-time acquisition of transient magnetic field data; a lower-level computer, connected to the sensor array via an IIC bus, for synchronously acquiring the raw magnetic field data of each sensor using a parallel data reading architecture and transmitting the raw data to the upper-level computer; and an upper-level computer, connected to the lower-level computer via a wired or wireless communication protocol, comprising: an attitude error correction unit, which eliminates sensor installation attitude errors based on a uniform magnetic field generated by a Helmholtz coil through rotation matrix calculation; a collaborative position compensation unit, which constructs a global optimization model based on the gradient magnetic field to compensate for the deviation between the theoretical and actual positions of the sensors; a data processing module, which uses a cubic spline interpolation algorithm to spatially reconstruct the corrected discrete data to generate a continuous magnetic field distribution; and a display module, which displays the spatiotemporal distribution of magnetic field vectors / scalars in layers using dynamic rendering technology and supports dynamic visualization of time series.

[0006] Furthermore, the attitude error correction unit includes:

[0007] Rotation matrix calculation module: used for calculating the orthogonal rotation matrix between the sensor measurement coordinate system S and the magnetic field generating device coordinate system G. Solving for the true magnetic field vector B th Establish the rotation matrix between the sensor measurement coordinate system S and the magnetic field generating device coordinate system G. Rotation matrix from coordinate system G to S A uniform magnetic field B in three orthogonal directions is generated by a magnetic field generator. th Measure the sensor output value B real Calculate the rotation matrix Elements in the middle:

[0008] When a uniform magnetic field along the Z-axis is applied At that time, sensor data was measured. calculate:

[0009] r 11 =X1 / U,r 21 =Y1 / U,r 31 =Z1 / U

[0010] When a uniform magnetic field along the Y-axis is applied At that time, sensor data was measured. calculate:

[0011] r 12 =X2 / V, r 22 =Y2 / V, r 32 =Z2 / V

[0012] When a uniform magnetic field along the X-axis is applied At that time, sensor data was measured. calculate:

[0013] r 13 =X3 / W, r 23 =Y3 / W, r 33 =Z3 / W

[0014] U, V, and W are all arbitrary magnetic field values.

[0015] matrix Transpose The sensor measurements are transformed to obtain the true magnetic field vector.

[0016]

[0017] The multi-sensor synchronization module uses a parallel processing architecture to calculate the position of the magnetic field data of the sensor array in real time using the attitude matrix. By using the parallel processing architecture, the rotation matrix of all sensors is solved synchronously, eliminating the overall attitude error of the array.

[0018] Furthermore, the cooperative position compensation unit includes: a deviation modeling module, based on the sensor's theoretical position... With actual location residual function Construct a global optimization objective: Suppose there are n sensors in total, and the theoretical position of the i-th sensor is the theoretical position. The actual location is Construct the residual function:

[0019]

[0020] The global optimization module uses the least squares method to iteratively solve for the optimal increment of the sensor position deviation and outputs the compensation parameters:

[0021] ΔP=-(J T J) -1 J T E

[0022] in

[0023]

[0024] When J T When J is irreversible, the compensation parameter is modified by introducing a regularization parameter λ:

[0025] ΔP=-(J T J+λI) -1 J T E

[0026] Where λ is a small positive number and I is the identity matrix.

[0027] The real-time calibration module, based on the compensation parameter Δp i Adjusting the actual spatial coordinate parameters of the digital sensor array

[0028] Furthermore, the data processing module specifically performs the following: The discrete magnetic field data is divided into sub-intervals, and a cubic polynomial function S is constructed for each sub-interval. i (x,y,z)=a i (xx i ) 3 +b i (xx i ) 2 +c i (xx i )+d i ; where a i ,b i ,c i ,d i For the polynomial coefficients, (x i ,y i ,z i () represents the coordinates of the nodes in the sub-interval; the polynomial coefficients are solved by interpolation conditions, derivative continuity constraints, and natural boundary conditions; and the dynamic evolution data of the transient magnetic field is reconstructed by combining spatiotemporal correlation analysis.

[0029] The interpolation algorithm is implemented based on the following steps:

[0030] (1) Divide the discrete magnetic field data points into multiple sub-intervals according to spatial coordinates, and construct a cubic polynomial function in each sub-interval, with the following form:

[0031] S i (x,y,z)=a i (xx i ) 3 +b i (xx i ) 2 +c i (xx i )+d i

[0032] Among them, a i ,b i ,c i ,d i For the polynomial coefficients, (x i ,y i ,z i ) represents the coordinates of the nodes in the sub-interval;

[0033] (2) Ensure that the function value at each node is consistent with the actual measured value by interpolation conditions:

[0034] S i (x i ,y i ,z i ) = B real (x i ,y i ,z i )

[0035] (3) Force the first and second derivatives to be continuous at nodes of adjacent subintervals to ensure smooth interpolation results;

[0036] (4) Use natural boundary conditions, that is, the second derivative at the global boundary is zero;

[0037] (5) Solve the linear equation system using the three-moment algorithm to determine the polynomial coefficients of all subintervals;

[0038] By combining spatiotemporal correlation analysis, the dynamic evolution data of transient magnetic fields are reconstructed.

[0039] Furthermore, the sensor array is deployed in an M×N×K three-dimensional orthogonal structure, where M, N, and K are positive integers, and each sensor is connected in groups via an IIC bus, with each group of buses carrying a sensor with a unique address.

[0040] Furthermore, the display module is specifically as follows: based on piecewise cubic spline interpolation and the reconstructed magnetic field data, a scalar spatiotemporal distribution of the transient magnetic field is generated; based on the corrected discrete magnetic field data, the total magnetic field vector and X / Y / Z components are assigned to independent layers through dynamic rendering technology and superimposed to display as a synthetic image, generating a vector spatiotemporal distribution map of the transient magnetic field; an integrated time axis control interface is provided to support time series playback and analysis of the spatiotemporal distribution of the transient magnetic field.

[0041] Furthermore, it also includes a data storage unit for storing raw data, correction parameters, and magnetic field distribution images, and supports offline data playback.

[0042] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) The present invention eliminates sensor installation errors and significantly improves the accuracy of magnetic field measurement by using attitude-position joint correction technology. (2) It adopts a parallel data acquisition architecture, supports parallel acquisition of multiple sensors and high-speed data processing, greatly improves the sampling rate, and meets the real-time monitoring requirements of transient magnetic fields. (3) It adopts cubic spline interpolation algorithm and dynamic rendering technology, enabling users to clearly observe the vector spatiotemporal distribution and scalar spatiotemporal distribution of transient magnetic fields, as well as the changes in magnetic fields at different time points. (4) The sensor array adopts an M×N×K three-dimensional structure, which can flexibly adjust the number and layout of sensors according to actual monitoring needs. It is suitable for three-dimensional transient magnetic field monitoring scenarios of different scales and complexities, and has wide applicability and good scalability. Attached Figure Description

[0043] Figure 1 This is a block diagram of the three-dimensional transient magnetic field monitoring system architecture of the present invention;

[0044] Figure 2 This is a schematic diagram of the M×N×K three-dimensional Hall sensor array of the present invention;

[0045] Figure 3 This is a physical diagram of the M×N×K three-dimensional Hall sensor array of the present invention;

[0046] Figure 4 This is a physical diagram of the lower-level machine module of the present invention;

[0047] Figure 5 This is a schematic diagram showing the positional relationship between the sensor measurement coordinate system and the magnetic field generating device coordinate system of the present invention;

[0048] Figure 6 The rotation matrix solution and magnetic field vector correction calculation steps for attitude error correction in this invention are as follows;

[0049] Figure 7 This is a flowchart of the global optimization algorithm for collaborative position compensation of the present invention;

[0050] Figure 8 This is a flowchart of the data reconstruction process for the piecewise cubic spline interpolation algorithm of the present invention;

[0051] Figure 9 This is a flowchart illustrating the dynamic rendering process of the display module of the present invention.

[0052] Figure 10 This is a real-time three-dimensional magnetic field map dynamically rendered according to the present invention;

[0053] Figure 11 This is a layer-by-layer real-time distribution map of the three-dimensional magnetic field dynamically rendered according to the present invention.

[0054] Figure 12This is a rendering of the transient magnetic field vector / scalar layered dynamic rendering effect of the present invention. Detailed Implementation

[0055] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0056] like Figure 1 As shown, this embodiment of the invention provides a three-dimensional transient magnetic field monitoring system based on sensor array attitude-position joint correction, comprising three parts: a three-dimensional sensor array, a lower-level computer, and a higher-level computer.

[0057] Figure 2 and Figure 3 In this system, the sensor array adopts a 4×4×4 three-dimensional orthogonal structure, comprising 64 three-dimensional Hall effect sensors 1. The sensors are soldered onto a multi-layer PCB board 2 with 5mm equal spacing, each PCB layer corresponding to a different height along the Z-axis. Each sensor 1 communicates with the lower-level machine via the software IIC protocol, and its IIC address is configured with four independent addresses through hardware pins. To support parallel data acquisition, the system uses 16 IIC buses, each bus connecting four sensors (with unique addresses), forming independent communication channels for the 4×4×4 array. The PCB board 2 is fixed with a non-magnetic bracket to ensure the spatial positioning accuracy of the array.

[0058] Figure 4 In the lower-level system, a 32-bit high-performance microcontroller with built-in IIC driver software is used. IIC timing is simulated via GPIO to achieve parallel control of 16 IIC bus groups. The lower-level software is configured to synchronously read data from the 16 IIC bus groups; the raw magnetic field data is encapsulated into data packets according to the sensor register format (00H-05H); and the data packets are uploaded to the upper-level system in real time via a UART serial port (baud rate 230400).

[0059] The three-dimensional Helmholtz coil consists of three pairs of orthogonal loop coils. The sensor array is positioned in the uniform magnetic field region at the center of the coil (error <1mm) for attitude error correction.

[0060] like Figure 5 The diagram shows the positional relationship between the sensor measurement coordinate system S and the magnetic field generator coordinate system G caused by installation attitude error.

[0061] like Figure 6 The diagram shown illustrates the attitude error correction process, which includes the following steps:

[0062] (1) Align the sensor array with the Helmholtz coil coaxially and apply uniform magnetic fields in the X / Y / Z axis directions in sequence;

[0063] (2) Collect the output values ​​B of each sensor real Calculate the rotation matrix using the following formula. (Taking a single sensor as an example):

[0064] When a uniform magnetic field along the Z-axis is applied At that time, sensor data was measured. calculate:

[0065] r 11 =X1 / U=6.12 / 6.53=0.937

[0066] r 21 =Y1 / U=0.32 / 6.53=0.049

[0067] r 31 =Z1 / U=-0.15 / 6.53=-0.023

[0068] When a uniform magnetic field along the Y-axis is applied At that time, sensor data was measured. calculate:

[0069] r 12 =X² / V = 0.25 / 6.4² = 0.039

[0070] r 22 =Y² / V = 6.08 / 6.4² = 0.947

[0071] r 32 =Z² / V = 0.41 / 6.4² = 0.064

[0072] When a uniform magnetic field along the X-axis is applied At that time, sensor data was measured. calculate:

[0073] r 13 =X3 / W=-0.18 / 6.71=-0.027

[0074] r 23 =Y3 / W=0.27 / 6.71=0.040

[0075] r 33 =Z3 / W=6.45 / 6.71=0.961

[0076] Finally, the rotation matrix is ​​obtained:

[0077]

[0078] (3) By transpose matrix Transform the sensor measurements to the device coordinate system:

[0079]

[0080] For example, the sensor measurement value Convert to

[0081]

[0082] like Figure 7 The diagram shown illustrates the process of collaborative position compensation according to the present invention, which includes the following steps:

[0083] (1) Apply a gradient magnetic field through a Helmholtz coil. Taking the same sensor as an example, the theoretical position is:

[0084] (2) Theoretical magnetic field The sensor measures the magnetic field after attitude correction.

[0085] (3) Construct the residual and Jacobian matrices:

[0086]

[0087] The Jacobian matrix J1 is composed of the partial derivatives of the magnetic field with respect to position, for example:

[0088]

[0089] Similarly, for the remaining components, we get:

[0090]

[0091] (4) Solve for the position deviation increment:

[0092] Assuming the global residual vector E = e1 and the Jacobian matrix J = J1, the following can be obtained through iterative calculation using the least squares method:

[0093] Δp1=(0.18mm,-0.22mm,0.08mm) T

[0094] The actual location is updated after compensation as follows:

[0095] Extending the above process to all sensors allows for coordinated position compensation of the array.

[0096] The host computer is developed based on MATLAB. It receives data packets from the slave computer via serial port, parses them, and stores them as an array, which includes the sensor position, XYZ magnetic field components, and measurement time.

[0097] like Figure 8 As shown, a piecewise cubic spline interpolation algorithm is used on the corrected discrete data (4×4×4 array) to generate a continuous magnetic field distribution with a resolution of 0.5 mm.

[0098] like Figure 9 The diagram shows the workflow of the display module, which generates a spatiotemporal distribution image of transient magnetic field strength based on interpolated data. Figure 10 , Figure 11 Thick black arrows represent the 3D vector direction, while the X / Y / Z components are displayed independently using thin red / green / blue arrows. The arrow length is linearly related to the magnetic field strength, ensuring that the component arrows are aligned with the total vector space to generate a spatiotemporal distribution image of the transient magnetic field vector. Dynamic updates are achieved through fast graphics rendering technology, supporting fast forward / slow motion control, such as... Figure 12 As shown.

Claims

1. A three-dimensional transient magnetic field monitoring system based on sensor array attitude-position joint correction, characterized in that, include: The magnetic field measurement component consists of an M×N×K three-dimensional Hall effect sensor array. The sensor array is distributed at equal intervals according to a preset spatial interval and is used to collect transient magnetic field data in real time. The lower-level computer is connected to the sensor array via the IIC bus. It is used to synchronously acquire the raw magnetic field data of each sensor using a parallel data reading architecture and transmit the raw data to the upper-level computer. The host computer, connected to the slave computer via wired or wireless communication protocols, includes: an attitude error correction unit that eliminates sensor installation attitude errors based on a uniform magnetic field generated by a Helmholtz coil and by solving a rotation matrix; a collaborative position compensation unit that constructs a global optimization model based on the gradient magnetic field to compensate for the deviation between the theoretical and actual sensor positions; a data processing module that uses a cubic spline interpolation algorithm to spatially reconstruct the corrected discrete data and generate a continuous magnetic field distribution; and a display module that uses dynamic rendering technology to display the spatiotemporal distribution of magnetic field vectors / scalars in layers and supports dynamic visualization of time series. The attitude error correction unit includes a rotation matrix calculation module, used to calculate the orthogonal rotation matrix between the sensor measurement coordinate system S and the magnetic field generating device coordinate system G. Solve for the true magnetic field vector The multi-sensor synchronization module performs real-time attitude matrix calculations on the magnetic field data of the sensor array using a parallel processing architecture. The rotation matrix calculation module's specific process is as follows: It uses a preset magnetic field vector in the coordinate system of the magnetic field generator. Sensor output value Solve for the rotation matrix Each element is achieved through the following steps: First, apply a uniform magnetic field along the X / Y / Z axes. Obtain sensor output value ; Next, calculate the rotation matrix. Elements in the middle: ； ； ； Rotation matrix transpose As a correction matrix, coordinate transformation is performed on the sensor measurements to output the true magnetic field vector: ； Where U, V, and W are all arbitrary magnetic field values; The collaborative position compensation unit includes: a position deviation modeling module, based on the sensor's theoretical position... With actual location residual function Construct a global optimization objective, in which, The theoretical magnetic field vector represents the i-th sensor; This represents the actual measured magnetic field vector of the i-th sensor; the global optimization module uses the least squares method to iteratively solve for the position deviation increment. Where J is a block diagonal matrix composed of Jacobian matrices. For regularization parameters; real-time calibration module, based on compensation parameters The actual spatial coordinates of the sensor are dynamically adjusted; I represents the identity matrix.

2. The three-dimensional transient magnetic field monitoring system based on sensor array attitude-position joint correction according to claim 1, characterized in that, The data processing module works as follows: The discrete magnetic field data is divided into sub-intervals, and a cubic polynomial function is constructed for each sub-interval. ;in, For polynomial coefficients, The coordinates of the sub-interval nodes are used; the polynomial coefficients are solved by interpolation conditions, derivative continuity constraints and natural boundary conditions; and the dynamic evolution data of the transient magnetic field are reconstructed by combining spatiotemporal correlation analysis.

3. The three-dimensional transient magnetic field monitoring system based on sensor array attitude-position joint correction according to claim 1, characterized in that, The display module is as follows: it assigns the total magnetic field vector and X / Y / Z components to independent layers and displays them through dynamic rendering and overlay; it integrates a time axis control interface to support time series playback of spatiotemporal distribution.

4. The three-dimensional transient magnetic field monitoring system based on sensor array attitude-position joint correction according to claim 1, characterized in that, The sensor array is deployed in a three-dimensional orthogonal structure of M×N×K, where M, N, and K are positive integers, and each sensor is connected in groups via an IIC bus, with each group of buses carrying a sensor with a unique address.

5. A three-dimensional transient magnetic field monitoring system based on sensor array attitude-position joint correction according to claim 1, characterized in that, It also includes a data storage unit for storing raw data, correction parameters, and magnetic field distribution images, and supports offline data playback.

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