Multi-degree-of-freedom automatic obstacle avoidance space magnetic field measurement method and system

Abstract

The invention discloses a multi-degree-of-freedom automatic obstacle avoidance space magnetic field measurement method and system, and the method comprises the steps that an upper computer issues an instruction according to a global coordinate system, a PLC drives a Z-axis module and an R-axis module to move cooperatively, and a rotary detection mechanism is conveyed to a coarse positioning point in a tank; the microcontroller plans an obstacle avoidance path through laser scanning data, and the driving shaft rotating mechanism adjusts a detection posture to a barrier-free position; the internal orthogonal Hall sensor collects a magnetic field component, and the microcontroller performs coordinate transformation operation in combination with a real-time angle to synthesize accurate three-dimensional magnetic field intensity data of a target point. According to the technical scheme, multi-degree-of-freedom automatic obstacle avoidance and flexible detection in a complex closed space are achieved, the problems that a traditional rigid structure is prone to collision and has a measurement blind area are effectively solved, automatic collection of high-precision three-dimensional magnetic field data can be completed without manual intervention, and the measurement safety, efficiency and data accuracy are improved.

Description

Technical Field

[0001] This invention relates to the field of automated detection technology, and in particular to a multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method and system. Background Technology

[0002] Hall effect sensors, as magnetic field detection devices, are widely used in precision fields such as motor magnetic field detection and space magnetic field mapping because their output voltage signal has a linear relationship with the magnetic field strength. In existing space magnetic field measurement technologies, the mainstream solutions are mainly divided into two categories: multi-sensor orthogonal arrangement and single-sensor manual rotation. While the multi-sensor orthogonal scheme achieves simultaneous acquisition of X, Y, and Z axis components by arranging three orthogonal sensors at the same measurement point, it suffers from a large number of sensors, large size, and high cost, making it difficult to adapt to narrow measurement spaces. The single-sensor manual rotation scheme, while reducing costs, has drawbacks such as poor angle adjustment accuracy and inability to automate operation. Existing mechanical transport structures are typically based on standard X, Y, and Z three-dimensional module designs, where sensors are mounted on a slider, and horizontal displacement, ascent, and forward movement are achieved by a three-axis motor. In rigid structures based on a Cartesian coordinate system, the cantilever of the forward axis bears a huge mechanical load during long-distance detection, increasing the risk of structural deformation. Meanwhile, the sensor module can only move along a straight trajectory. This single degree of freedom of motion means that it cannot flexibly adjust its posture when facing complex geometric environments, making it difficult to reach non-direct-view detection target locations, which greatly limits the flexibility and coverage of magnetic field mapping.

[0003] In specific industrial applications such as space plasma experimental equipment, the sealed container interior is not an open environment but contains complex obstacles such as coils that generate magnetic fields and rigid support brackets. Traditional rotary sensors or linear telescopic probes based on 3D modules, lacking flexible obstacle avoidance mechanisms, are highly susceptible to mechanical collisions when obstructed in their path. Even minor collisions can cause probe position shifts, introducing significant measurement errors; severe collisions can lead to rotor jamming, transmission mechanism overload, or even permanent damage to the sensor's core components. Furthermore, in enclosed spaces, the backs of obstacles often create shadow areas for measurement, which traditional linear motion mechanisms cannot bypass to deliver the sensor to, resulting in incomplete magnetic field data acquisition. Currently, there is no mature system in the industry that can simultaneously achieve high-precision rotation angle adjustment and intelligent obstacle avoidance. To obtain complete data, existing solutions often rely on manual pre-clearing of obstacles inside the container or extremely inefficient manual adjustments. This not only significantly increases operational time costs but also poses extremely high safety risks in experimental environments involving high pressure or special gases.

[0004] While some existing technical solutions attempt to address these issues through low-cost, multi-sensor approaches—for example, using an integrated rigid rotating rod made of ABS engineering plastic in conjunction with an STM32 microcontroller and LCD display module to achieve basic 0.5V~4.5V analog voltage signal acquisition and processing—this does not tackle the core mechanical motion challenges. Although similar technical solutions employ anti-interference shielding designs in the signal transmission module and utilize telescopic supports for a degree of positioning, they are essentially rudimentary devices suitable only for static, unobstructed laboratory environments. When facing complex scenarios such as industrial-grade sealed containers, these technologies suffer from three fundamental drawbacks: first, the complete lack of obstacle avoidance capabilities prevents safe operation in unstructured environments; second, low automation hinders path planning and adaptive adjustments; and third, the rigid structure results in signal acquisition blind spots and insufficient positioning accuracy. Therefore, how to achieve high-precision, full-coverage magnetic field measurement in complex environments with sealed enclosures and dense obstacles has become a pressing issue for the industry. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides a multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method and system, which achieves automatic obstacle avoidance through laser scanning and multi-axis linkage, solving the problem of collisions in confined spaces; combined with coordinate transformation algorithms, it realizes high-precision automated measurement of three-dimensional magnetic fields.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for measuring the spatial magnetic field of multi-degree-of-freedom automatic obstacle avoidance is provided, including: S1, the host computer sends a measurement task instruction containing the three-dimensional coordinates of the target point to the PLC control unit according to the preset global coordinate system of the space to be measured. The PLC control unit parses the measurement task instruction and drives the Z-axis lifting module and the R-axis telescopic module to perform coordinated motion, and transports the rotary detection mechanism installed at the end of the R-axis to the predetermined coarse positioning coordinate point inside the tank to be measured, thereby establishing the height reference and radial reference position of the rotary detection mechanism in the cylindrical coordinate system. S2, based on the height and radial reference positions, the microcontroller activates the laser ranging module integrated on the rotating detection mechanism to scan and measure the distance in the forward fan-shaped area, and generates a circumferential rotation control command containing obstacle avoidance path planning based on the distance data obtained from the scan, driving the rotation. The axis rotation mechanism drives the rotating detection mechanism to rotate around the center line of the R-axis and adjusts its attitude until it reaches the target measurement attitude without obstacles; S3, under the condition that the rotating detection mechanism maintains the target measurement posture, three linear Hall sensors arranged orthogonally inside the rotating detection mechanism sense the spatial magnetic field vector at the current position and output the corresponding three analog voltage signals. The microcontroller collects the three analog voltage signals and performs coordinate transformation calculations in combination with the real-time angle value of the target measurement posture to synthesize the accurate three-dimensional magnetic field strength data at the target point.

[0007] Furthermore, in S2, a circumferential rotation control command containing obstacle avoidance path planning is generated based on the distance data obtained from the scan, including: S21, the laser ranging module performs continuous multi-point ranging on the fan-shaped cross section of the rotating detection mechanism in the direction of travel according to a preset angular resolution, and generates environmental depth matrix data containing multiple partition distance values. S22, the microcontroller reads the environmental depth matrix data, compares the distance value of each partition in the matrix with the preset safe distance threshold one by one, filters out the abnormal partition set whose distance value is less than the safe distance threshold, and fits the geometric contour and center position coordinates of the potential obstacle based on the spatial topology relationship of the abnormal partition set. S23, for the fitted geometric contour and center position coordinates of the obstacle, an obstacle avoidance trajectory that can bypass the geometric contour and minimize the path cost function is planned in the preset motion space grid map using the A* path search algorithm, and the obstacle avoidance trajectory is discretized and converted into the time-pulse sequence of the corresponding motor as the circumferential rotation control command.

[0008] Furthermore, in step S23, the obstacle avoidance trajectory is discretized and converted into a time-pulse sequence corresponding to the motor, including: S231, if the fitted obstacle geometry is located directly in front of the current motion trajectory of the rotating detection mechanism and the nearest distance is less than the preset danger distance threshold, the PLC control unit parses the retreat sub-instruction in the obstacle avoidance trajectory and prioritizes driving the R-axis telescopic module to rotate in the opposite direction so that the rotating detection mechanism retreats a preset safety buffer distance along the radial axis. S232, at the safe position after the rotary detection mechanism completes its radial axis retraction, the PLC control unit drives the mechanism according to the detour angle parameters in the obstacle avoidance trajectory. The axis rotation mechanism deflects to a predetermined avoidance angle, and then drives the R-axis telescopic module to resume radial feed until the rotation detection mechanism bypasses the obstacle and resets to the target measurement posture.

[0009] Furthermore, in S1, driving the Z-axis lifting module and the R-axis telescopic module to perform coordinated motion includes: S11, the PLC control unit calculates the target number of pulses for the Z-axis stepper motor according to the height coordinate parameters in the measurement task instruction, and sends the target number of pulses to the Z-axis driver through the pulse output port to drive the ball screw to rotate, thereby driving the load-bearing platform to rise and fall vertically along the linear guide rail to the target height surface aligned with the center axis of the tank. S12, after the load-bearing platform stops stably at the target height surface, the PLC control unit controls the friction wheel drive motor installed on the outer wall of the R-axis to start according to the radial depth parameter in the measurement task instruction. The static friction between the friction wheel and the hollow tube wall of the R-axis drives the hollow tube of the R-axis to extend or retract axially until the end of the R-axis reaches the target radial depth, thus completing the physical positioning of the predetermined coarse positioning coordinate point.

[0010] Furthermore, in S3, the three analog voltage signals are acquired, including: S31, the three linear Hall sensors sense the magnetic field under the excitation of the constant voltage source power supply circuit, and each outputs a single-ended analog voltage signal containing magnetic field induction component and common mode interference noise. The single-ended analog voltage signal is transmitted to the front-end signal conditioning circuit through shielded twisted pair cable. S32, the front-end signal conditioning circuit receives the single-ended analog voltage signal, converts the single-ended analog voltage signal into a differential signal through a high common-mode rejection ratio instrumentation amplifier and performs a first-stage gain amplification, and outputs a high signal-to-noise ratio differential analog signal after filtering out power frequency interference during transmission based on a low-pass filter. S33, the analog-to-digital conversion module performs multiple high-frequency trigger samplings on the differential analog signal, and calculates the arithmetic mean of the remaining valid sample values ​​after removing gross error values ​​in the sampling sequence using the 3σ criterion. The arithmetic mean is then provided to the microcontroller as valid voltage sampling data.

[0011] Furthermore, in S3, coordinate transformation calculations are performed based on the real-time angle values ​​of the target's measured attitude, including: S34, during the entire process of the rotating detection mechanism performing the rotation action, with The absolute encoder, which is rigidly connected to the shaft rotation mechanism, monitors the angular displacement of the rotating shaft in real time. When the rotation stops, it locks the current actual physical angle value and feeds it back to the microcontroller. S35, the microcontroller receives the actual physical angle value, calculates the angle deviation between the actual physical angle value and the theoretical target angle, and constructs a rotation compensation matrix for correcting the direction of the magnetic field vector based on the angle deviation. S36, the original magnetic field component vector obtained by converting the three analog voltage signals output by the linear Hall sensor is reverse rotated and corrected according to the rotation compensation matrix, thereby eliminating the magnetic field measurement component offset caused by the mechanical positioning error of the rotating detection mechanism.

[0012] According to a second aspect of the present invention, a multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement system is provided, comprising: The drive module is used by the host computer to send a measurement task instruction containing the three-dimensional coordinates of the target point to the PLC control unit according to the preset global coordinate system of the space to be measured. The PLC control unit parses the measurement task instruction and drives the Z-axis lifting module and the R-axis telescopic module to perform coordinated motion, so as to transport the rotary detection mechanism installed at the end of the R-axis to the predetermined coarse positioning coordinate point inside the tank to be measured, thereby establishing the height reference and radial reference position of the rotary detection mechanism in the cylindrical coordinate system. The adjustment module, based on the height and radial reference positions, activates the laser ranging module integrated on the rotating detection mechanism to scan and measure the distance in the forward fan-shaped area, and generates a circumferential rotation control command containing obstacle avoidance path planning based on the distance data obtained from the scan, driving the rotation. The axis rotation mechanism drives the rotating detection mechanism to rotate around the center line of the R-axis and adjusts its attitude until it reaches the target measurement attitude without obstacles; The synthesis module is used to, under the condition that the rotating detection mechanism maintains the target measurement posture, have three orthogonally arranged linear Hall sensors inside the rotating detection mechanism sense the spatial magnetic field vector at the current position and output corresponding three analog voltage signals. The microcontroller collects the three analog voltage signals and performs coordinate transformation calculations in combination with the real-time angle value of the target measurement posture to synthesize accurate three-dimensional magnetic field strength data at the target point.

[0013] The present invention also provides a multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement system, comprising a processor and a computer-readable storage medium interconnected thereto, wherein the computer-readable storage medium stores a computer program, and the computer program is executed by the processor to implement the steps of the above-described multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method.

[0014] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method.

[0015] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the above-described multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method.

[0016] Compared with the prior art, the advantages of the present invention are as follows: This invention enables multi-degree-of-freedom automatic obstacle avoidance and flexible detection in complex enclosed spaces, effectively solving the problems of easy collision and measurement blind spots in traditional rigid structures. It can automatically acquire high-precision three-dimensional magnetic field data without manual intervention, improving the safety, efficiency and accuracy of measurement. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 A flowchart of a multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method provided for embodiments of the present invention; Figure 2 A flowchart of another multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method provided for embodiments of the present invention; Figure 3 A flowchart of another multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method provided for embodiments of the present invention; Figure 4 A structural diagram of a multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement system provided for an embodiment of the present invention; Figure 5 A structural diagram of a multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement system provided for an embodiment of the present invention; Figure 6 A structural diagram of a multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement system provided for an embodiment of the present invention; Figure 7 A structural diagram of an electronic device provided as an embodiment of the present invention; Figure 8 System coordinate axis diagram of a multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement system provided for embodiments of the present invention; Figure 9 A schematic diagram of an absolute encoder for a multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement system provided for an embodiment of the present invention; Figure 10 A mechanical structure diagram of a multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement system provided for an embodiment of the present invention.

[0019] Explanation of symbols in the attached drawings: 1. Orthogonal Hall sensor module; 2. Rotating rod; 3. Rotating rod angle encoder; 4. Circumferential rotating inner tube; 5. Laser ranging module; 6. Height shaft; 7. Friction wheel; 8. Axial telescopic shaft; 9. Stepper motor; 10. Circumferential rotating inner tube; 11. Transmission disc. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0021] The technical solution adopted in this embodiment is as follows: Figure 1 As shown, it includes the following steps: S1, the host computer sends a measurement task instruction containing the three-dimensional coordinates of the target point to the PLC control unit according to the preset global coordinate system of the space to be measured. The PLC control unit parses the measurement task instruction and drives the Z-axis lifting module and the R-axis telescopic module to perform coordinated motion, and transports the rotary detection mechanism installed at the end of the R-axis to the predetermined coarse positioning coordinate point inside the tank to be measured, thereby establishing the height reference and radial reference position of the rotary detection mechanism in the cylindrical coordinate system. S2, based on the height and radial reference positions, the microcontroller activates the laser ranging module integrated on the rotating detection mechanism to scan and measure the distance in the forward fan-shaped area, and generates a circumferential rotation control command containing obstacle avoidance path planning based on the distance data obtained from the scan, driving the rotation. The axis rotation mechanism drives the rotating detection mechanism to rotate around the center line of the R-axis and adjusts its attitude until it reaches the target measurement attitude without obstacles; S3, under the condition that the rotating detection mechanism maintains the target measurement posture, three linear Hall sensors arranged orthogonally inside the rotating detection mechanism sense the spatial magnetic field vector at the current position and output the corresponding three analog voltage signals. The microcontroller collects the three analog voltage signals and performs coordinate transformation calculations in combination with the real-time angle value of the target measurement posture to synthesize the accurate three-dimensional magnetic field strength data at the target point.

[0022] This embodiment proposes a multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement system. Its hardware architecture adopts a four-layer topology of "host computer - PLC control unit - microcontroller - execution / acquisition terminal," and the mechanical part is based on a cylindrical coordinate system. The system comprises a load-bearing platform, a Z-axis lifting module, an R-axis telescopic module, and... Axis rotation detection mechanism, system coordinate axes such as Figure 8As shown. Further, the Z-axis lifting module is vertically fixed on the load-bearing platform, employing a precision ball screw and linear guide rail, driven by a high-torque stepper motor. Its stroke matches the height of the tank under test, for example, covering the tank's diameter range, to establish a height reference for the measurement system. The R-axis telescopic module is a cantilever beam structure mounted on the Z-axis slide. Its main body is a lightweight, nested hollow tubular structure, driven by a servo motor through a friction wheel transmission mechanism, achieving stepless telescopic extension along the tank's radius. Its stroke is greater than or equal to half the tank's length, thus establishing a radial reference. The shaft rotation detection mechanism is nested inside the R-axis hollow tube and includes an inner tube, a micro stepper motor, and an end rotating arm. The mechanism achieves 360-degree circumferential rotation through an angle encoder. The sensor probe is installed at the top of the rotating arm and is not rigidly connected to the tank, thus forming a three-dimensional motion logic of lifting, telescopic and rotating to adapt to the detection needs of the unstructured environment inside the sealed tank.

[0023] In the signal acquisition terminal, this embodiment uses three high-precision linear Hall sensors (preferably model A1363LLUTR-1-T) to construct an orthogonal measurement array. The three sensors are fixed within the probe bracket, corresponding to the X, Y, and Z axes of the Cartesian coordinate system, ensuring that the sensitive axes are perpendicular to each other, thus achieving synchronous decoupled acquisition of the spatial magnetic field vector in three dimensions. To address the potentially strong electromagnetic interference environment inside the tank, the signal transmission circuit employs a differential transmission architecture and multi-stage filtering design. The 0.5V~4.5V single-ended analog voltage signal output by the sensor is first conditioned by an AD8221 instrumentation amplifier integrated within the probe. This amplifier has a high common-mode rejection ratio (CMRR), effectively suppressing power frequency interference. The signal is then transmitted differentially to the main control board via shielded twisted-pair cable. The opposite polarity of the differential signal cancels out common-mode noise coupled during long-distance transmission. Furthermore, the power supply circuit is designed with a voltage regulator and a 100V... F electrolytic capacitor and 0.1 The filter network composed of F ceramic capacitors minimizes the interference of power supply ripple on the microvolt-level magnetic field signal, ensuring that the signal-to-noise ratio of the original signal meets the requirements of high-precision measurement.

[0024] As described in step S1, the measurement process begins with the task being issued by the host computer. The host computer has a pre-set global coordinate system model of the space to be measured, which maps the physical dimensions and theoretical central axis of the tank. Upon receiving a measurement command containing the three-dimensional coordinates (x, y, z) of the target point, the host computer converts it into cylindrical coordinate instructions. The commands are transmitted to the PLC control unit via industrial Ethernet or serial bus. After parsing the commands, the PLC drives the actuators using a time-sharing or linkage control strategy. The stepper motor of the Z-axis lifting module is controlled to move, and the R-axis assembly is raised to the target height level through pulse counting feedback. The friction wheel mechanism of the R-axis telescopic module is driven to radially transport the rotary detection mechanism installed at the end of the R-axis to the predetermined coarse positioning coordinate point. The system coordinate axis diagram is shown below. Figure 8 As shown. During this process, the PLC reads the encoder feedback of the servo motor in real time and corrects the displacement error caused by changes in mechanical load based on the PID algorithm, ensuring that the end of the R-axis accurately stops at a position with a safe margin from the target point, thereby establishing the height and radial reference positions of the rotary detection mechanism in the cylindrical coordinate system.

[0025] After coarse positioning, the system enters the intelligent obstacle avoidance and fine attitude adjustment stage described in step S2. At this point, the microcontroller (based on an STM32F103C8T6) takes over control and activates the laser ranging module integrated at the front of the rotating detection mechanism. This laser ranging module includes a main rangefinder and an auxiliary rangefinder, which scan and measure the forward fan-shaped area along the axial and radial directions, respectively, to acquire an environmental depth data matrix. The microcontroller uses its built-in A* path planning algorithm or Dynamic Window Method (DWA) to process the distance data and identify the outlines of obstacles (such as coils or supports) within the field of view. If an obstacle is detected on the target path, and the distance is less than a preset safety threshold (e.g., 5cm), the microcontroller will generate a circumferential rotation control command containing obstacle avoidance path planning to drive the rotation. The shaft rotation mechanism is activated. The shaft rotation mechanism drives the rotation detection mechanism to rotate precisely around the center line of the R-axis, and works in conjunction with the angle encoder to provide real-time feedback of the rotation angle. This forms a closed-loop control. The system will continuously adjust its attitude, and if necessary, combine the slight retraction and refeed of the R-axis until the detection mechanism bypasses the obstacle and reaches the unobstructed target measurement attitude. At this point, the laser ranging module confirms that there is clear space ahead and that the probe is accurately aligned with the target measurement point.

[0026] Once the system locks onto the target measurement attitude, it executes the data acquisition and processing described in step S3. At this time, the rotating detection mechanism is stationary, and the three linear Hall sensors arranged orthogonally inside sense the spatial magnetic field vector at the current position and output the corresponding three analog voltage signals. The microcontroller's ADC module (configured for 12-bit precision, 16-times oversampling averaging) acquires these three signals and converts them into local magnetic flux density components that have been calibrated for temperature compensation based on the sensor sensitivity coefficient. Because the probe follows The axis rotated by a certain angle Because there is a deflection between the local coordinate system and the global coordinate system, the local coordinate system cannot be directly used as the final data. Therefore, the microcontroller reads the real-time angle value fed back by the angle encoder at this time. The calculation is performed using a coordinate transformation matrix. By performing rotation matrix operations, the magnetic field components in the local coordinate system are mapped back to the global coordinate system, eliminating the directional deviation introduced by the rotation. This synthesizes accurate three-dimensional magnetic field strength data and vector direction at the target point, which is then uploaded to the host computer for display and storage via a communication module.

[0027] After completing a single-point or multi-point continuous measurement task, the system executes a reset logic. The PLC control unit retracts the detection mechanism to its initial safe position in the order of first retracting the R-axis and then lowering the Z-axis to prevent mechanical collisions during retraction. Throughout the implementation process, the system integrates a comprehensive safety protection mechanism. Hardware limit switches are installed at both ends of the R-axis and Z-axis to prevent overtravel; if the laser ranging module detects an obstacle that cannot be bypassed (e.g., distance <3cm), it will trigger an emergency stop and alarm. This embodiment uses the Z-axis, R-axis, and... The organic coordination of axes, combined with laser active obstacle avoidance and coordinate transformation technology, solves the technical problem of traditional rigid measuring rods being unable to "enter" and "measure accurately" in enclosed and complex obstacle environments. This system not only achieves sub-millimeter-level spatial positioning accuracy but also ensures the authenticity and integrity of magnetic field measurement data in highly interfering industrial environments through differential transmission and orthogonal decoupling algorithms, providing a reliable automated solution for magnetic field mapping in high-end fields such as space plasma equipment.

[0028] This system adopts a four-layer architecture: host computer, PLC, microcontroller, and execution / acquisition module. The core components include: a host computer module, a PLC control module, a drive and microcontroller management module, a Hall sensor probe module, an angle feedback module, a differential signal transmission module, and an obstacle detection and positioning module. The host computer sends commands, the PLC drives the rotating mechanism, the encoder provides angle feedback, the obstacle detection module acquires distance signals, the positioning module adjusts the path, the sensor acquires magnetic field signals, differentially transmits these signals to the microcontroller, a compensation algorithm corrects the data, and the data is uploaded back to the host computer. This entire process forms a closed loop.

[0029] 1. Hall sensor module The A1363LLUTR-1-T linear Hall sensor was selected, with the following key parameters: power supply voltage 4.5~5.5V, output voltage 0.5~4.5V, sensitivity 0.6mV / mT~14mV / mT, and its zero drift and linearity error are relatively small, which can meet the requirements of strong magnetic field environment and ensure its measurement accuracy. A constant voltage source is used for power supply, and a voltage regulator is selected. The 3.3V output of the STM32 is regulated to output 5V to power the linear Hall sensor, ensuring voltage stability. A current-limiting resistor is connected in series in the power supply circuit to prevent overcurrent damage to the sensor, and a 100μF electrolytic capacitor and a 0.1μF ceramic capacitor are connected in parallel to filter low-frequency noise and filter high-frequency noise, further reducing the interference of power supply noise on the sensor output. The signal output circuit is a Hall sensor, whose output signal corresponds to magnetic induction intensity from 0.5 to 4.5V. The output terminal is connected to the subsequent signal conditioning circuit.

[0030] This system orthogonally arranges three A1363 sensors in a Cartesian coordinate system: one sensor with its sensing axis along the X-axis in the radial horizontal direction, one along the Y-axis in the axial depth direction, and one along the Z-axis in the radial vertical direction. The sensing axes are perpendicular to each other, enabling synchronous measurement of the three-dimensional magnetic field (Bx, By, Bz) in space. The STM32 calculates the magnitude and direction of the composite magnetic field in space in real time based on the calibrated three-dimensional magnetic field components.

[0031] 2. Signal Conditioning Module The amplifier circuit uses the AD8221 instrumentation amplifier, whose common-mode rejection ratio is within the design requirements, which can effectively suppress power frequency common-mode interference. The gain is adjustable to adapt to the signal amplification requirements under different magnetic field strengths. This design doubles the gain of the sensor signal and, together with the STM32's ADC calibration function, corrects the gain error in real time to ensure amplification accuracy ≤0.5%.

[0032] Meanwhile, a differential output method is adopted (using operational amplifiers to form a differential circuit) to adapt to signal amplification requirements under different magnetic field strengths. The sensor module is encapsulated in a shielded enclosure, which is grounded through a low-impedance wire of less than 1Ω to reduce external electromagnetic radiation interference. The connection between the sensor and the signal conditioning module uses a shielded twisted-pair cable, with one end of the shielding layer grounded to suppress interference during transmission.

[0033] 3. STM32 Control Module Design The STM32F103C8T6 microcontroller was selected, and its rich peripherals and high performance meet the system control requirements. The core circuit design is as follows: The ADC acquisition circuit utilizes the built-in 12-bit SAR ADC of the STM32F103. To improve acquisition accuracy, a "single-ended input + multiple sampling averaging" scheme is adopted. The differential analog signal output from the signal conditioning module is converted into a unipolar signal and then connected to the microcontroller's receiving pin. An external high-precision voltage reference source is used for the ADC reference voltage, replacing the chip's internal reference voltage to reduce the impact of temperature and power supply fluctuations on the ADC. The ADC sampling rate is set to 12MHz (maximum conversion rate 1MHz). For different sampling rate requirements, ADC acquisition is triggered by an STM32 timer. After each trigger acquisition, 16 samples are continuously taken, and the average value is used as the final acquired value. Software algorithms reduce ADC quantization noise, effectively improving the actual acquisition accuracy to 14 bits, meeting the measurement accuracy requirement of ±0.02mT.

[0034] As the core of the system, STM32 is responsible for data processing, peripheral control, and logical judgment functions. The key process is as follows.

[0035] Data preprocessing: The raw data acquired by the ADC is subjected to "outlier removal (3σ criterion) → moving average filtering → error compensation" to ensure data stability; Automatic range switching: Three preset ranges are available, and the system automatically switches between them based on the processed magnetic field strength value. Peripheral control: The OLED screen displays measurement data (magnetic field strength, unit, sampling rate, battery level) via SPI or IIC; it can also read temperature and humidity sensor data by adding an I2C interface to compensate for the drift effect of temperature on the sensor.

[0036] 4. Angle Feedback Module The angle feedback module is the core module for achieving high-precision rotational positioning and measurement error compensation of the sensor probe. This invention has two preset angle feedback methods. The first is a closed-loop design of "encoder hardware acquisition + STM32 decoding + power-on automatic calibration" and the second is an absolute encoder to ensure that the rotation angle measurement resolution and positioning accuracy meet the requirements, providing reliable data support for angle compensation for magnetic field component calculation.

[0037] The encoder is rigidly connected to the rotating rod coaxially. Its core principle is to generate A / B phase quadrature TTL pulse signals through photoelectric sensing. The rotating rod outputs 1024 sets of pulses for each rotation. The STM32 microcontroller configures the timer to quadrature decoding mode and counts the pulses on both edges, achieving a single-rotation count of 4096 times, corresponding to an angular resolution of approximately 0.0879°. At the same time, the rotation direction is determined by the phase difference of the A / B phase pulses. After the system is powered on, it automatically performs 0° reference calibration, clears the counter and locks the reference position, calculates the actual angle of the rotating rod in real time and feeds it back, providing high-precision data support for angle compensation in magnetic field measurement. Combined with filtering and anti-interference design, it ensures stable and reliable angle measurement.

[0038] like Figure 9 The absolute encoder shown uses a laser ranging module to measure the distance between the outer and inner rings of the absolute encoder. The distance difference d is calculated as: outer ring distance (slope) - inner ring distance (platform). By measuring the distance difference for one ring, the distance difference corresponding to each degree can be obtained. This value is the conversion factor k. Therefore, the rotation angle α = distance difference d * conversion factor k.

[0039] 5. Obstacle Avoidance and Sensor Positioning Module The sensor positioning module is the core module for achieving precise positioning and trajectory control of the Hall sensor probe within the tank space. This design innovatively uses a laser rangefinder to replace the traditional mechanical positioning method. Through a multi-dimensional closed-loop design of "laser ranging + angle feedback + coordinate calculation", the three-dimensional spatial positioning accuracy of the probe is ≤1mm, providing underlying support for the precise matching of magnetic field measurement points and the optimization of obstacle avoidance paths.

[0040] The main rangefinder measures the distance between the probe and the target surface along the tank's axial direction, while the auxiliary rangefinder measures the distance to the tank wall radially. Together with the rotation angle data provided by the angle feedback module, the two rangefinders calculate the probe's real-time spatial coordinates (X, Y, Z) using a three-dimensional coordinate system model. They also combine static calibration coefficients with temperature and angle coupling error compensation algorithms to correct deviations. Simultaneously, they support multi-zone ranging to identify obstacle contours and generate avoidance trajectories using the A* path planning algorithm. Ultimately, they achieve a three-dimensional positioning accuracy of ≤1mm and stable and reliable positioning control, providing data support for precise matching of magnetic field measurement points and obstacle avoidance actions.

[0041] The STM32 receives a 256-segment distance matrix from the main laser rangefinder, sets a safe distance threshold of 5cm and a danger distance threshold of 3cm. It iterates through all segments; if a segment's distance is less than the safe threshold, it is marked as an obstacle area. The obstacle's outline and center point coordinates are fitted using distance data from adjacent segments. During the obstacle avoidance maneuver, the positioning module provides real-time probe coordinate feedback, and the STM32 dynamically adjusts the avoidance path to ensure a return to the original measurement trajectory after avoidance. After avoidance, the angle feedback module provides the current rotation angle θ, and an angle compensation algorithm corrects the magnetic field measurement value, eliminating the impact of angular offset caused by avoidance on measurement accuracy.

[0042] 6. PLC control motor module The core principle of PLC control of motors is the collaborative logic of "instruction parsing - pulse drive - closed-loop feedback - safety protection". Using a stepper motor as the execution carrier, it realizes the angle positioning and extension and rotation of the rotating rod through precise electrical signal control, while ensuring the safety and stability of the movement process. The specific functions and principles are as follows.

[0043] As the "command center" for motor motion, the PLC receives instruction signals from the host computer and STM32 microcontroller, converts them into pulse signals that the motor can recognize to control the amount of rotation and the direction of rotation, and drives the stepper motor to move along a preset trajectory. At the same time, it forms a closed loop through angle feedback, limit switches and other signals to correct motion deviations in real time and ensure precise execution of actions.

[0044] The principle of precise angle positioning is based on "pulse equivalent conversion" to achieve angle control. The pulse equivalent of the stepper motor + 1:100 reducer is 0.001125° / pulse. The PLC calculates the number of pulses corresponding to the target angle and outputs precise pulses to drive the motor to rotate. The host computer sends the target angle (e.g., 90°). After receiving it, the PLC calculates the required number of pulses (90° ÷ 0.001125° / pulse = 80000 pulses) and outputs continuous pulses of the corresponding frequency through the PLC port. The port outputs high / low levels to control the rotation direction (counterclockwise / clockwise). At the same time, it reads the encoder angle data uploaded by the STM32 in real time. When the deviation between the actual angle and the target angle is ≤0.01°, the pulse output stops, the motor locks, and the positioning is completed.

[0045] The obstacle avoidance function works by receiving obstacle signals (single-directional / multi-directional obstacles, danger distance) from the STM32 microcontroller, parsing them into corresponding motor action commands, and achieving obstacle avoidance by adjusting the rotation direction, speed, or reversing the direction. When the STM32 detects a single-directional obstacle (e.g., distance < 5cm in the 0° direction), the PLC receives a "radial deflection 30°" command, calculates the number of pulses corresponding to the deflection, and controls the motor to rotate in the direction of the maximum safe distance. If it is a multi-directional obstacle, it outputs pulses in the sequence of "first back (motor reverse, corresponding to a 5mm axial displacement pulse) → then deflect → then forward." After each step is completed, it receives a distance confirmation signal from the STM32 before executing the next step, ensuring accurate obstacle avoidance trajectory.

[0046] 7. Mechanical Structure Design Figure 10(1) is an orthogonal Hall sensor module. By installing three mutually orthogonal Hall sensors, a system in which the sensing axes of the three sensors are mutually orthogonal is obtained, thereby measuring the magnetic field strength in space. (2) is a rotating rod. The rotating rod can rotate around its fulcrum. (3) is a rotating rod angle encoder. The rotating rod angle encoder is responsible for measuring the angle between the rotating rod and the tank axis. (4) is a circumferential rotating inner tube. It can drive the rotating rod to rotate 360 ​​degrees. (5) is a laser ranging module. (6) is a height axis. (7) is a friction wheel. This friction wheel is connected to a motor. The motor drives the friction wheel to control the forward and backward movement of the axial telescopic outer tube. (8) is an axial telescopic shaft. (9) is a stepper motor. It can drive the circumferential rotating inner tube to rotate. (10) is a circumferential rotating inner tube. (11) is a transmission disk. The transmission disk has a motor. The motor drives the transmission disk to drive the measuring friction wheel.

[0047] The motion control logic of this invention is as follows: when it is necessary to adjust the probe to the target measurement point, the height axis (6) is first adjusted to the target height; the friction wheel (7) drives the axial telescopic axis (8) to extend and retract the rotating rod (2) to the target radial position; the stepper motor (9) drives the circumferential rotating axis (4) through the circumferential rotating inner tube (10) to rotate the rotating rod (2) to the target angle; the rotating rod angle encoder (3) provides feedback on the real-time angle, and the laser ranging module (5) monitors the distance to obstacles to ensure safe and accurate positioning during the motion process.

[0048] This mechanical structure, through the combination of multi-axis motion and friction wheel drive, enables the probe to adjust its position in all dimensions within the tank space. It also integrates sensors and ranging modules, providing the hardware foundation for magnetic field measurement and obstacle avoidance functions.

[0049] The mechanical motion system designed in this embodiment breaks through the limitations of past magnetic field measuring devices, which could only move along a preset rigid path, endowing it with a high degree of spatial intelligence and environmental adaptability. Specifically, based on precise three-dimensional positioning, the system innovatively introduces a dynamic obstacle avoidance function based on sensor feedback. When the sensor probe installed at the end of the rotating arm detects unexpected obstacles such as internal supports or coils in real time through laser ranging or proximity switches during scanning, the system can immediately interrupt the preset path. More importantly, the control core PLC will drive the circumferential rotation axis (θ axis) and the axial telescopic axis (R axis) to coordinate their movements based on real-time data, executing a flexible swing arm or detour command, enabling the probe to intelligently bypass obstacles and autonomously find a new, collision-free path to continue to the target measurement point. This greatly improves the system's survivability and measurement success rate in complex, unstructured industrial environments (such as inside reaction tanks and pipeline networks). The coordinated control logic of "obstacle avoidance action - angle compensation - magnetic field measurement" ensures that the measurement accuracy is not reduced after obstacle avoidance; the coordinates of the target point are determined to determine the path selection; after reaching the target point, the angle of the rotating arm is recorded by the angle encoder; by calculating the angle with the R axis, the distance the rotating node moves forward, and the rotation angle of the θ axis, the coordinate position of the sensor in space can be obtained, thereby measuring the magnetic field strength at that coordinate position.

[0050] The beneficial effects of the technical solution in this embodiment are as follows: 1. Improved measurement efficiency: Autonomous obstacle avoidance eliminates the need for manual obstacle clearing or sensor position adjustment. The target position coordinates can be preset through the control module, allowing the measurement module to reach the destination autonomously, thereby reducing the time required for a single measurement and improving measurement efficiency. 2. High environmental adaptability: Since the mechanical structure of the system is independent of the test environment, it can be adapted to the test environment by presetting the spatial structural coordinates of the test environment. It can be extended to other complex spaces without modifying the test environment. 3. Signal transmission advantages: The present invention adopts a differential signal transmission architecture, which can effectively cancel the common-mode noise generated by motors and other equipment in the tank environment, as well as the interference introduced by ground potential difference in long-distance transmission. The differential signal is transmitted through shielded twisted pair cable, and the two core wires are twisted together to cancel the coupling interference of external electromagnetic radiation and adapt to the strong electromagnetic environment around the tank.

[0051] 4. High positioning accuracy: This invention builds a full range of positioning advantages around "precise angle, intelligent obstacle avoidance, environmental adaptation, and data closed loop", which can meet the high-precision and high-reliability positioning requirements of sensor probes in complex scenarios such as sealed tanks.

[0052] The technical solution in this embodiment has flexible obstacle avoidance and automated detection capabilities, achieved through the Z-axis, R-axis, and... The coordinated linkage of axes and laser scanning path planning enable multi-degree-of-freedom automatic obstacle avoidance and flexible detection in complex and enclosed spaces, effectively solving the problems of easy collision and measurement blind spots in traditional rigid structures. Combined with orthogonal Hall sensors and coordinate transformation algorithms, high-precision three-dimensional magnetic field data can be automatically acquired without manual intervention, improving the safety, efficiency and accuracy of measurements.

[0053] Preferred, such as Figure 2 As shown, in step S2, a circumferential rotation control command containing obstacle avoidance path planning is generated based on the distance data obtained from the scan, including the following steps S21-S23: S21, the laser ranging module performs continuous multi-point ranging on the fan-shaped cross section of the rotating detection mechanism in the direction of travel according to a preset angular resolution, and generates environmental depth matrix data containing multiple partition distance values. S22, the microcontroller reads the environmental depth matrix data, compares the distance value of each partition in the matrix with the preset safe distance threshold one by one, filters out the abnormal partition set whose distance value is less than the safe distance threshold, and fits the geometric contour and center position coordinates of the potential obstacle based on the spatial topology relationship of the abnormal partition set. S23, for the fitted geometric contour and center position coordinates of the obstacle, an obstacle avoidance trajectory that can bypass the geometric contour and minimize the path cost function is planned in the preset motion space grid map using the A* path search algorithm, and the obstacle avoidance trajectory is discretized and converted into the time-pulse sequence of the corresponding motor as the circumferential rotation control command.

[0054] In one embodiment, at the specific execution level of the automatic obstacle avoidance function, the system performs environmental perception and data preprocessing according to steps S21 and S22. When the rotating detection mechanism enters the area to be measured, the microcontroller activates the laser ranging module via command. This laser ranging module performs a high-frequency continuous scan of the fan-shaped cross-section in front of the rotating detection mechanism's current direction of travel, based on a preset angular resolution, for example, acquiring data every 0.5°. This process maps the discrete physical space into digitized environmental depth matrix data, where each matrix element corresponds to a measured distance value at a specific azimuth angle. The microcontroller reads this matrix data through a high-speed communication interface and initiates the built-in threshold discrimination logic, comparing the distance value of each zone with a preset safe distance threshold, the optimal value of which is 50mm. Any area with a distance value less than this safe distance threshold is identified by the system as a potential collision risk zone and marked as an abnormal zone. The microcontroller uses clustering analysis algorithms to process these sets of anomalous partitions. Based on their adjacency relationships and spatial topology in the matrix index, discrete noise interference is eliminated, and continuous anomalous partitions are aggregated. Then, through fitting algorithms such as least squares, the closed geometric contours of potential obstacles and the coordinates of their geometric center positions are calculated, thereby completing the digital reconstruction from the original sensor data to the physical obstacle model.

[0055] After completing the digital modeling of the obstacles, the system executes the intelligent path planning and execution control described in step S23. The microcontroller maps the fitted geometric contours of the obstacles onto a preset motion space grid map, marking the grid nodes covered by the obstacles as impassable areas, i.e., the obstruction layer. Based on this, the system calls the A* (A-Star) heuristic path search algorithm, setting the current detection position as the starting node and the target's obstacle-free measurement posture as the ending node. This algorithm calculates the path cost function. ,in, The actual cost of moving from the starting point to the current node. To estimate the cost from the current node to the destination, an iterative search is performed on the grid map to plan an obstacle avoidance trajectory that safely bypasses the geometric contour while minimizing the total path cost (i.e., the shortest path or lowest energy consumption). To translate this theoretical trajectory into physical motion, the microcontroller's motion control unit further discretizes and analyzes the obstacle avoidance trajectory, converting it into a time-pulse sequence containing a specific frequency, direction, and number of pulses based on the motor's step angle and transmission ratio. This time-pulse sequence is then sent to the motor driver as the final circumferential rotation control command, driving the motor... The shaft rotation mechanism precisely drives the detection probe along the planned path to avoid obstacles until it reaches the target position.

[0056] Preferred, such as Figure 3As shown, in step S23, the obstacle avoidance trajectory is discretized and converted into a time-pulse sequence of the corresponding motor, including the following steps S231-S232: S231, if the fitted obstacle geometry is located directly in front of the current motion trajectory of the rotating detection mechanism and the nearest distance is less than the preset danger distance threshold, the PLC control unit parses the retreat sub-instruction in the obstacle avoidance trajectory and prioritizes driving the R-axis telescopic module to rotate in the opposite direction so that the rotating detection mechanism retreats a preset safety buffer distance along the radial axis. S232, at the safe position after the rotary detection mechanism completes its radial axis retraction, the PLC control unit drives the mechanism according to the detour angle parameters in the obstacle avoidance trajectory. The axis rotation mechanism deflects to a predetermined avoidance angle, and then drives the R-axis telescopic module to resume radial feed until the rotation detection mechanism bypasses the obstacle and resets to the target measurement posture.

[0057] When executing the emergency obstacle avoidance procedure described in step S231, the system enters the near-field risk assessment and dynamic response phase. The microcontroller monitors the local environment model constructed by the laser ranging module in real time. Once it determines that the fitted obstacle's geometric contour is directly in front of the current motion trajectory of the rotating detection mechanism, i.e., on the extension line of the detection vector, and that the Euclidean distance of its nearest surface is less than a preset danger distance threshold, such as 30mm, the system will immediately trigger the highest priority safety interruption mechanism. At this time, the microcontroller's motion planning unit no longer executes the regular continuous feed instructions, but instead parses an independent retreat sub-instruction from the pre-generated obstacle avoidance trajectory data package. After this retreat sub-instruction is transmitted to the PLC control unit, the PLC, based on the mechanical transmission ratio of the R-axis telescopic module (i.e., pulse equivalent, e.g., 0.01mm / pulse), discretizes the physical space length to be retreated (i.e., the preset safety buffer distance, e.g., 50mm) into the specific number of pulses required for the corresponding servo motor to reverse, through the high-speed pulse output port of the PLC. The PLC drives the R-axis motor to perform a reverse rotation action, causing the rotating detection mechanism to retract rapidly along the radial axis. This retraction action creates a sufficiently wide safety corridor for the front probe of the detection mechanism, preventing the probe's rotational scanning envelope from accidentally scraping against the obstacle when performing large-scale rotational avoidance maneuvers, thus ensuring the safety of obstacle avoidance maneuvers at the physical level.

[0058] Once the rotating detection mechanism successfully retracts to the safe position determined in step S231, the system immediately transitions to the attitude reconstruction and obstacle avoidance phase described in step S232. At this time, the rotating detection mechanism is in a temporary stationary hovering state. The PLC control unit reads the obstacle avoidance trajectory data stream's obstacle avoidance angle parameter. This angle parameter is the optimal deflection angle calculated based on the A* algorithm to bypass the obstacle edge with minimal cost; this optimal deflection angle can be selected as 45°. The PLC uses its built-in motion control library to map this optimal deflection angle to... The target pulse sequence required by the axis stepper motor is superimposed with an S-shaped acceleration / deceleration curve to prevent mechanism jitter. In the drive... After the axis rotation mechanism precisely deflects to the predetermined avoidance angle, the detection mechanism has successfully avoided the obstructing section of the obstacle. At this point, the PLC reactivates the R-axis telescopic module, but this time it performs a restored radial feed action. Based on the geometric constraints of the planned path, the system drives the R-axis to transport the detection mechanism forward again, allowing it to travel along the new unobstructed radius vector until the axial position of the probe exceeds the depth coverage range of the obstacle.

[0059] After completing the aforementioned "retreat-deflection-progress" composite action sequence, the rotating detection mechanism has effectively bypassed the physical obstacle in space. However, at this point, a deviation still exists between its attitude and the originally set target measurement attitude introduced by the avoidance action. Therefore, at the end of step S232, the system executes attitude reset logic. The microcontroller combines the current R-axis extension length with... The axis deflection angle is calculated in real time, and the actual position of the probe in the cylindrical coordinate system is compared with the coordinates of the target measurement point. Based on the comparison result, the PLC control unit generates a corrected time-pulse sequence again to drive the probe. The axis rotates in the opposite direction to compensate for the previous avoidance angle, while the extension and retraction of the R-axis are finely adjusted. This allows the rotating detection mechanism to accurately return to center and lock onto the preset target measurement posture after passing behind the obstacle. The entire process is verified in real time through dual closed-loop feedback from an angle encoder and laser rangefinder, ensuring that the mechanical reset error is controlled at the sub-millimeter level.

[0060] Preferred, such as Figure 4 As shown, in step S1, driving the Z-axis lifting module and the R-axis telescopic module to perform coordinated motion includes the following steps S11-S12: S11, the PLC control unit calculates the target number of pulses for the Z-axis stepper motor according to the height coordinate parameters in the measurement task instruction, and sends the target number of pulses to the Z-axis driver through the pulse output port to drive the ball screw to rotate, thereby driving the load-bearing platform to rise and fall vertically along the linear guide rail to the target height surface aligned with the center axis of the tank. S12, after the load-bearing platform stops stably at the target height surface, the PLC control unit controls the friction wheel drive motor installed on the outer wall of the R-axis to start according to the radial depth parameter in the measurement task instruction. The static friction between the friction wheel and the hollow tube wall of the R-axis drives the hollow tube of the R-axis to extend or retract axially until the end of the R-axis reaches the target radial depth, thus completing the physical positioning of the predetermined coarse positioning coordinate point.

[0061] During the vertical positioning process described in step S11, the digitized spatial coordinates need to be accurately converted into the physical displacement of the mechanical actuator. Specifically, the PLC control unit first receives the measurement task instruction from the host computer and extracts the height coordinate parameters. Based on the preset mechanical transmission ratio parameters, namely the ball screw lead (e.g., 5mm / rev) corresponding to one revolution of the stepper motor and the microstepping setting of the stepper driver (e.g., 3200 pulses / revolution), the high-speed computing unit inside the PLC calculates the total target number of pulses and frequency curve required for the Z-axis stepper motor to reach the target height using the pulse equivalent formula. Subsequently, the PLC sends a pulse sequence containing S-shaped acceleration and deceleration control logic to the Z-axis motor driver through its high-speed pulse output port (PTO). The driver amplifies the weak electrical pulse signal into a strong electrical drive current, driving the high-torque Z-axis stepper motor to rotate. The motor shaft is connected to the precision ball screw pair through a flexible coupling, converting the rotational motion of the motor into the linear motion of the screw and nut pair, thereby driving the load-bearing platform to smoothly rise and fall along the vertically set linear guide rail. During this process, the linear guide rail bears the lateral torque and ensures the linearity of the motion, while the self-locking characteristic of the ball screw or the additional brake mechanism ensures that the platform can overcome gravity and remain absolutely stationary after reaching the target height plane aligned with the central axis of the tank.

[0062] Once the load-bearing platform has mechanically locked at the target height and its stability has been confirmed by sensors, the system enters the radial coarse positioning stage described in step S12. Unlike the Z-axis lead screw drive, the R-axis telescopic module employs an innovative friction wheel drive scheme to meet the requirements of long-stroke, lightweight cantilever detection. The PLC control unit calculates the required extension stroke of the R-axis based on the radial depth parameter in the measurement task command and controls the drive motor mounted on the R-axis outer wall bracket to start. This motor drives a specially designed friction wheel (usually covered with a high-friction coefficient rubber material) to rotate via a reduction mechanism. The friction wheel is in close contact with the outer wall of the R-axis hollow tube, using the static friction generated at their contact surface as the feed power to drive the R-axis hollow tube axially into the tank. The R-axis hollow tube is typically made of lightweight, high-rigidity materials such as ABS engineering plastic or carbon fiber, and contains a drive mechanism for rotating the probe. Shaft assembly. During the extension and retraction process, the PLC dynamically adjusts the clamping force or speed of the friction wheel by monitoring the load current of the servo motor and the encoder feedback in real time to prevent slippage or jamming. When the cumulative displacement feedback from the encoder equals the target radial depth, the PLC controls the motor to brake and stop, so that the end of the R-axis is precisely stopped at the predetermined coarse positioning coordinate point, completing the physical positioning of the detection mechanism deep inside the tank.

[0063] The coordinated motion of the Z-axis and R-axis described above is a closed-loop control process involving multiple safety checks. Throughout the execution of steps S11 and S12, the PLC control unit continuously reads the feedback signals from the limit switches and grating rulers of each axis. If abnormal resistance (such as current overload) is detected during the Z-axis lifting process, or if the friction wheel experiences a step loss abnormality during the R-axis extension and retraction, the system will immediately trigger an emergency stop logic. In addition, to ensure the physical accuracy of the predetermined coarse positioning coordinates, the system adopts a segmented approximation strategy. In the last 5% of the stroke approaching the target position, the PLC automatically switches to a low-speed jogging mode to eliminate overshoot errors caused by mechanical inertia. The composite motion structure of lead screw lifting combined with friction extension and retraction not only effectively solves the problem of traditional rigid connecting rods being difficult to deploy in narrow spaces, but also ensures that the rotary detection mechanism still has sufficient end stiffness in the long cantilever state through a transmission design that combines rigidity and flexibility.

[0064] Preferred, such as Figure 5 As shown, the acquisition of the three analog voltage signals in step S3 includes the following steps S31-S33: S31, the three linear Hall sensors sense the magnetic field under the excitation of the constant voltage source power supply circuit, and each outputs a single-ended analog voltage signal containing magnetic field induction component and common mode interference noise. The single-ended analog voltage signal is transmitted to the front-end signal conditioning circuit through shielded twisted pair cable. S32, the front-end signal conditioning circuit receives the single-ended analog voltage signal, converts the single-ended analog voltage signal into a differential signal through a high common-mode rejection ratio instrumentation amplifier and performs a first-stage gain amplification, and outputs a high signal-to-noise ratio differential analog signal after filtering out power frequency interference during transmission based on a low-pass filter. S33, the analog-to-digital conversion module performs multiple high-frequency trigger samplings on the differential analog signal, and calculates the arithmetic mean of the remaining valid sample values ​​after removing gross error values ​​in the sampling sequence using the 3σ criterion. The arithmetic mean is then provided to the microcontroller as valid voltage sampling data.

[0065] During the magnetic field induction and primary transmission stage described in step S31, the system employs a highly stable power supply network and a shielded transmission architecture to ensure the purity of the signal source. Specifically, three orthogonally arranged linear Hall sensors (preferably Allegro A1363LLUTR-1-T model) are driven by a constant voltage source power supply circuit. This circuit includes a low dropout linear regulator (LDO) that steps down and regulates the system voltage to 5.0V, providing a precise excitation voltage for the sensors; simultaneously, a 100V AC voltage regulator is connected in parallel at the power supply pin. F electrolytic capacitor and 0.1 A complex-frequency filter network composed of F-type ceramic capacitors filters out low-frequency power supply ripple and high-frequency switching noise. Under magnetic field excitation, the sensor outputs a single-ended analog voltage signal linearly related to the magnetic induction intensity, ranging from 0.5V to 4.5V. Considering the strong electromagnetic interference that may be generated by the motor drive inside the sealed tank, high-specification shielded twisted-pair cable is selected as the signal transmission medium. The two signal core wires are twisted together to cancel the magnetic flux coupling of the external alternating magnetic field. The external metal shielding layer is connected to the system common ground through a single-point grounding method, effectively shielding electrostatic interference and ensuring that the waveform distortion and common-mode noise of the weak analog signal are controlled to a minimum during transmission from the end of the long cantilever to the front-end conditioning circuit.

[0066] Regarding the signal conditioning process described in step S32, the core task of the front-end circuit is to improve the signal-to-noise ratio (SNR) and match the ADC input range. The received single-ended analog voltage signal first enters the signal conditioning module built based on the AD8221 instrumentation amplifier. This instrumentation amplifier has an extremely high common-mode rejection ratio (CMRR), which can accurately eliminate power frequency interference (50Hz / 60Hz) superimposed on the signal transmission line and common-mode noise introduced by ground potential difference. In the circuit design, by configuring an external gain resistor, the weak Hall voltage signal is amplified by a first-stage gain, and the single-ended input is converted into a differential signal output with stronger anti-interference capability. With the second-order active low-pass filter integrated in the subsequent stage, the cutoff frequency is set to the upper limit of the sensor bandwidth to further filter out high-frequency thermal noise and digital circuit radiation noise that exceed the measurement frequency band. This not only achieves standardized scaling of the voltage amplitude, but also outputs a high signal-to-noise ratio, low-impedance differential analog signal through dual processing of single-ended to differential and frequency domain filtering.

[0067] Step S33 details the sophisticated processing logic in the digital domain, aiming to break through the physical accuracy limits of the hardware ADC. The microcontroller (STM32F103C8T6) utilizes its built-in 12-bit SAR analog-to-digital converter (ADC) to execute a continuous high-frequency triggered sampling strategy on the input differential analog signal. The system is configured with an ADC sampling rate of 12MHz, performing 16 consecutive oversamples for each discrete measurement moment to form an instantaneous sampling sequence. The processor runs a digital filtering algorithm, applying 3... The criteria involve statistical analysis of the sampled sequences to identify and remove gross error values ​​(outliers deviating from the mean by more than three standard deviations) caused by random impulse interference; the arithmetic mean of the remaining valid sampled values ​​is then calculated. This oversampling combined with statistical averaging effectively utilizes the statistical characteristics of white noise, logically increasing the original 12-bit hardware resolution to an equivalent 14-bit precision. This reduces the impact of quantization noise and random fluctuations, thereby providing stable and accurate voltage sampling data to the upper layers of the system, ensuring that the synthesized magnetic field strength resolution meets the requirements. The design specification is 0.02 mT.

[0068] Preferred, such as Figure 6 As shown, in step S3, coordinate transformation calculation is performed based on the real-time angle value of the target's measured attitude, including the following steps S34-S36: S34, during the entire process of the rotating detection mechanism performing the rotation action, with The absolute encoder, which is rigidly connected to the shaft rotation mechanism, monitors the angular displacement of the rotating shaft in real time. When the rotation stops, it locks the current actual physical angle value and feeds it back to the microcontroller. S35, the microcontroller receives the actual physical angle value, calculates the angle deviation between the actual physical angle value and the theoretical target angle, and constructs a rotation compensation matrix for correcting the direction of the magnetic field vector based on the angle deviation. S36, the original magnetic field component vector obtained by converting the three analog voltage signals output by the linear Hall sensor is reverse rotated and corrected according to the rotation compensation matrix, thereby eliminating the magnetic field measurement component offset caused by the mechanical positioning error of the rotating detection mechanism.

[0069] During the angle monitoring process described in step S34, the system eliminates the uncertainties caused by mechanical transmission backlash through a precise closed-loop design at the hardware level. Specifically, A high-resolution absolute encoder, such as a 17-bit or higher precision magnetoelectric / photoelectric encoder, is rigidly connected coaxially to the rotating shaft of the shaft rotation mechanism. Throughout the entire process of the rotating detection mechanism rotating from its initial position to the target posture, this absolute encoder acts as the core of angle sensing, providing real-time angular displacement data to the microcontroller via a high-speed SSI or BiSS serial interface. This absolute encoder, as... Figure 9 As shown. Unlike incremental encoders, absolute encoders do not require power-off to zeroing and can directly reflect a unique absolute code value of the current physical position. When the PLC control unit issues a motion stop command, and the rotary detection mechanism completes mechanical braking at the target position and enters a steady state, the microcontroller immediately triggers a data latch interrupt to read the current encoder value. This value represents the actual physical angle value of the rotating axis in physical space. It includes the step loss error that the stepper motor may have, the tooth backlash of the reduction gear set, and all mechanical positioning deviations caused by flexible deformation, and feeds this real angle value back to the computing unit as the sole reference for subsequent algorithm correction.

[0070] In the data processing stage described in step S35, the microcontroller (such as the STM32F103 series) compares the received actual physical angle value with the preset theoretical target angle. (i.e., the desired angle in path planning) is compared differentially to calculate the angular deviation between the two. , Depend on Calculations show that, although mechanical control pursues… While approaching zero, in sub-millimeter level high-precision measurements, even minute angular deviations can lead to significant projection errors in the orthogonally decomposed magnetic field components. Therefore, microcontrollers do not mandate absolute zero error in mechanical position but compensate using mathematical methods. The processor bases the error on the actual physical angle value. Construct a rotation compensation matrix for coordinate system transformation. This rotation compensation matrix is ​​based on two-dimensional or three-dimensional rotation group theory and is typically expressed as containing... and The orthogonal matrix of the elements. The geometric significance of this orthogonal matrix lies in constructing an accurate mapping model from the probe's local moving coordinate system to the tank's global fixed coordinate system, ensuring that subsequent processing can perform vector reconstruction based on the actual orientation of the detector.

[0071] In step S36, the system performs the core vector correction operation to achieve high-precision measurement of the target by compensating for mechanical errors. At this time, the three analog voltage signals output by the linear Hall sensor, after analog-to-digital conversion, have been converted into the original magnetic field component vectors in the local coordinate system of the detector. Because the probe has a rotation angle, the original magnetic field component vector does not directly represent the magnetic field direction in the global coordinate system. The microcontroller calls the previously constructed rotation compensation matrix to... Perform the reverse rotation correction operation, i.e., matrix multiplication. Through this calculation, the system accurately projects the measurement data from the moving sensor coordinate system back to the stationary global coordinate system of the tank, thus mathematically eliminating the offset of the magnetic field measurement components caused by mechanical positioning errors of the rotating detection mechanism (such as incomplete rotation or overshoot). The output three-dimensional magnetic field strength data is calculated entirely based on the probe's actual physical attitude, ensuring that the spatial directivity and numerical accuracy of the magnetic field mapping results are not limited by mechanical precision under complex mechanical motion conditions.

[0072] In one embodiment, Figure 7This is a block diagram of a multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement system according to an exemplary embodiment. Figure 7 As shown, the multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement system includes a drive module 71, an adjustment module 72, and a synthesis module 73.

[0073] The drive module 71 is used by the host computer to send a measurement task instruction containing the three-dimensional coordinates of the target point to the PLC control unit according to the preset global coordinate system of the space to be measured. The PLC control unit parses the measurement task instruction and drives the Z-axis lifting module and the R-axis telescopic module to perform coordinated motion, so as to transport the rotating detection mechanism installed at the end of the R-axis to the predetermined coarse positioning coordinate point inside the tank to be measured, thereby establishing the height reference and radial reference position of the rotating detection mechanism in the cylindrical coordinate system. The adjustment module 72 is used to activate the laser ranging module integrated on the rotating detection mechanism to scan and measure the distance in the forward fan-shaped area based on the height and radial reference positions, and to generate a circumferential rotation control command containing obstacle avoidance path planning based on the distance data obtained from the scan, thereby driving the rotation. The axis rotation mechanism drives the rotating detection mechanism to rotate around the center line of the R-axis and adjusts its attitude until it reaches the target measurement attitude without obstacles; The synthesis module 73 is used to, under the condition that the rotating detection mechanism maintains the target measurement posture, have three orthogonally arranged linear Hall sensors inside the rotating detection mechanism sense the spatial magnetic field vector at the current position and output corresponding three analog voltage signals. The microcontroller collects the three analog voltage signals and performs coordinate transformation calculations in combination with the real-time angle value of the target measurement posture to synthesize accurate three-dimensional magnetic field strength data at the target point.

[0074] The drive module 71, adjustment module 72, and synthesis module 73 included in the block diagram of the multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement system are controlled to execute the multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method described in any of the above embodiments.

[0075] This embodiment also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method.

[0076] This embodiment also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the above-described multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method.

[0077] Compared with the prior art, the advantages of this embodiment are: This embodiment achieves multi-degree-of-freedom automatic obstacle avoidance and flexible detection in complex enclosed spaces through the coordinated linkage of the Z-axis, R-axis and other axes and laser scanning path planning. It effectively solves the problems of easy collision and measurement blind spots in traditional rigid structures. Combined with orthogonal Hall sensors and coordinate transformation algorithms, it can automatically acquire high-precision three-dimensional magnetic field data without manual intervention, improving the safety, efficiency and accuracy of measurement.

[0078] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-readable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The functions specified in one or more boxes. These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable apparatus for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0079] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for measuring the spatial magnetic field of multi-degree-of-freedom automatic obstacle avoidance, characterized in that, include: S1, the host computer sends a measurement task instruction containing the three-dimensional coordinates of the target point to the PLC control unit according to the preset global coordinate system of the space to be measured. The PLC control unit parses the measurement task instruction and drives the Z-axis lifting module and the R-axis telescopic module to perform coordinated motion, and transports the rotary detection mechanism installed at the end of the R-axis to the predetermined coarse positioning coordinate point inside the tank to be measured, thereby establishing the height reference and radial reference position of the rotary detection mechanism in the cylindrical coordinate system. S2, based on the height and radial reference positions, the microcontroller activates the laser ranging module integrated on the rotating detection mechanism to scan and measure the distance in the forward fan-shaped area, and generates a circumferential rotation control command containing obstacle avoidance path planning based on the distance data obtained from the scan, driving the rotation. The axis rotation mechanism drives the rotating detection mechanism to rotate around the center line of the R-axis and adjusts its attitude until it reaches the target measurement attitude without obstacles; S3, under the condition that the rotating detection mechanism maintains the target measurement posture, three linear Hall sensors arranged orthogonally inside the rotating detection mechanism sense the spatial magnetic field vector at the current position and output the corresponding three analog voltage signals. The microcontroller collects the three analog voltage signals and performs coordinate transformation calculations in combination with the real-time angle value of the target measurement posture to synthesize the accurate three-dimensional magnetic field strength data at the target point.

2. The multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method as described in claim 1, characterized in that, In step S2, a circumferential rotation control command containing obstacle avoidance path planning is generated based on the distance data obtained from the scan, including: S21, the laser ranging module performs continuous multi-point ranging on the fan-shaped cross section of the rotating detection mechanism in the direction of travel according to a preset angular resolution, and generates environmental depth matrix data containing multiple partition distance values. S22, the microcontroller reads the environmental depth matrix data, compares the distance value of each partition in the matrix with the preset safe distance threshold one by one, filters out the abnormal partition set whose distance value is less than the safe distance threshold, and fits the geometric contour and center position coordinates of the potential obstacle based on the spatial topology relationship of the abnormal partition set. S23, for the fitted geometric contour and center position coordinates of the obstacle, an obstacle avoidance trajectory that can bypass the geometric contour and minimize the path cost function is planned in the preset motion space grid map using the A* path search algorithm, and the obstacle avoidance trajectory is discretized and converted into the time-pulse sequence of the corresponding motor as the circumferential rotation control command.

3. The multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method as described in claim 2, characterized in that, In step S23, the obstacle avoidance trajectory is discretized and converted into a time-pulse sequence corresponding to the motor, including: S231, if the fitted obstacle geometry is located directly in front of the current motion trajectory of the rotating detection mechanism and the nearest distance is less than the preset danger distance threshold, the PLC control unit parses the retreat sub-instruction in the obstacle avoidance trajectory and prioritizes driving the R-axis telescopic module to rotate in the opposite direction so that the rotating detection mechanism retreats a preset safety buffer distance along the radial axis. S232, at the safe position after the rotary detection mechanism completes its radial axis retraction, the PLC control unit drives the mechanism according to the detour angle parameters in the obstacle avoidance trajectory. The axis rotation mechanism deflects to a predetermined avoidance angle, and then drives the R-axis telescopic module to resume radial feed until the rotation detection mechanism bypasses the obstacle and resets to the target measurement posture.

4. The multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method as described in claim 1, characterized in that, In S1, the Z-axis lifting module and the R-axis telescopic module are driven to perform coordinated motion, including: S11, the PLC control unit calculates the target number of pulses for the Z-axis stepper motor according to the height coordinate parameters in the measurement task instruction, and sends the target number of pulses to the Z-axis driver through the pulse output port to drive the ball screw to rotate, thereby driving the load-bearing platform to rise and fall vertically along the linear guide rail to the target height surface aligned with the center axis of the tank. S12, after the load-bearing platform stops stably at the target height surface, the PLC control unit controls the friction wheel drive motor installed on the outer wall of the R-axis to start according to the radial depth parameter in the measurement task instruction. The static friction between the friction wheel and the hollow tube wall of the R-axis drives the hollow tube of the R-axis to extend or retract axially until the end of the R-axis reaches the target radial depth, thus completing the physical positioning of the predetermined coarse positioning coordinate point.

5. The multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method as described in claim 1, characterized in that, In S3, the three analog voltage signals are acquired, including: S31, the three linear Hall sensors sense the magnetic field under the excitation of the constant voltage source power supply circuit, and each outputs a single-ended analog voltage signal containing magnetic field induction component and common mode interference noise. The single-ended analog voltage signal is transmitted to the front-end signal conditioning circuit through shielded twisted pair cable. S32, the front-end signal conditioning circuit receives the single-ended analog voltage signal, converts the single-ended analog voltage signal into a differential signal through a high common-mode rejection ratio instrumentation amplifier and performs a first-stage gain amplification, and outputs a high signal-to-noise ratio differential analog signal after filtering out power frequency interference during transmission based on a low-pass filter. S33, the analog-to-digital conversion module performs multiple high-frequency trigger samplings on the differential analog signal, and calculates the arithmetic mean of the remaining valid sample values ​​after removing gross error values ​​in the sampling sequence using the 3σ criterion. The arithmetic mean is then provided to the microcontroller as valid voltage sampling data.

6. The multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method as described in claim 1, characterized in that, In S3, coordinate transformation calculations are performed using the real-time angle values ​​of the target's measured attitude, including: S34, throughout the entire process of the rotating detection mechanism performing its rotational action, with The absolute encoder, which is rigidly connected to the shaft rotation mechanism, monitors the angular displacement of the rotating shaft in real time. When the rotation stops, it locks the current actual physical angle value and feeds it back to the microcontroller. S35, the microcontroller receives the actual physical angle value, calculates the angle deviation between the actual physical angle value and the theoretical target angle, and constructs a rotation compensation matrix for correcting the direction of the magnetic field vector based on the angle deviation. S36, the original magnetic field component vector obtained by converting the three analog voltage signals output by the linear Hall sensor is reverse rotated and corrected according to the rotation compensation matrix, thereby eliminating the magnetic field measurement component offset caused by the mechanical positioning error of the rotating detection mechanism.

7. A multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement system, characterized in that, include: The drive module is used by the host computer to send a measurement task instruction containing the three-dimensional coordinates of the target point to the PLC control unit according to the preset global coordinate system of the space to be measured. The PLC control unit parses the measurement task instruction and drives the Z-axis lifting module and the R-axis telescopic module to perform coordinated motion, so as to transport the rotary detection mechanism installed at the end of the R-axis to the predetermined coarse positioning coordinate point inside the tank to be measured, thereby establishing the height reference and radial reference position of the rotary detection mechanism in the cylindrical coordinate system. The adjustment module, based on the height and radial reference positions, activates the laser ranging module integrated on the rotating detection mechanism to scan and measure the distance in the forward fan-shaped area, and generates a circumferential rotation control command containing obstacle avoidance path planning based on the distance data obtained from the scan, driving the rotation. The axis rotation mechanism drives the rotating detection mechanism to rotate around the center line of the R-axis and adjusts its attitude until it reaches the target measurement attitude without obstacles; The synthesis module is used to, under the condition that the rotating detection mechanism maintains the target measurement posture, have three orthogonally arranged linear Hall sensors inside the rotating detection mechanism sense the spatial magnetic field vector at the current position and output corresponding three analog voltage signals. The microcontroller collects the three analog voltage signals and performs coordinate transformation calculations in combination with the real-time angle value of the target measurement posture to synthesize accurate three-dimensional magnetic field strength data at the target point.

8. The multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement system as described in claim 7, characterized in that: The drive module, the adjustment module, and the synthesis module are controlled to execute the multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method according to any one of claims 2 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method according to any one of claims 1 to 6.

10. A computer program product, characterized in that, The method includes a computer program that, when executed by a processor, implements the steps of the multi-degree-of-freedom automatic obstacle avoidance spatial magnetic field measurement method according to any one of claims 1 to 6.

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