Electric field detection device and early warning method under hot-line working condition of ultra-high voltage line

Abstract

The invention relates to the technical field of electric field detection and early warning. The invention aims to overcome the defect of lack of an electric field detection device under the hot-line working condition of an ultra-high-voltage line in the prior art, and relates to an electric field detection device under the hot-line working condition of the ultra-high-voltage line, which is a non-contact electric field detection device and is used for detecting the electric field under the hot-line working condition of the ultra-high-voltage line in the hot-line working condition of the ultra-high-voltage line. The non-contact electric field detection device takes a microprocessor as a core control unit, and is composed of a double-spherical-shell type electric field sensor, a differential amplifier, a filter circuit, a true RMS conversion circuit, a power supply module and a man-machine interaction circuit. And deep association of data support, function collaboration and scene adaptation is carried out through the structure. The problem that traditional equipment is insufficient in stability in a severe environment is solved, continuous and stable operation of the electric field detection equipment under complex working conditions is achieved, it is ensured that reliable electric field intensity data can be continuously output, and a basic guarantee is provided for operation safety evaluation.

Description

Technical Field

[0001] This invention relates to the field of electric field detection and early warning technology, and in particular to an electric field detection device and early warning method for live working conditions on ultra-high voltage lines. Background Technology

[0002] In live-line work on ultra-high voltage (UHV) and extra-high voltage (EHV) lines, conducting on-site personnel behavior early warning is a core requirement for addressing the high-risk nature of the work and ensuring personnel safety and adherence to work procedures. This is because the environment for live-line work on UHV and EHV lines is inherently extremely dangerous, with strong electric fields and high voltages present in the work area, and often involving work at heights. If personnel are too close to live equipment, accidentally enter dangerous areas, or come into contact with excessive electric fields, they may face direct safety risks such as electric shock and induced voltage injuries. Furthermore, deviations in personnel's physiological state and operational procedures during the work process can also lead to accidents such as falls and equipment damage. In addition, live-line work involves various types of equipment, including towers, insulators, and insulating tools, resulting in complex interactions between personnel, equipment, and the environment. Behavioral risks are sudden and cascading. Therefore, it is necessary to use real-time monitoring of multi-source data, including personnel spatial location, surface electric field strength, and physiological characteristics, combined with early warning models to promptly identify abnormal behaviors and prevent accidents.

[0003] In response, the applicant also applied for an invention patent, "Intelligent Early Warning Method and System for Live-Line Workers' On-Site Behavior," with patent number 202211377674.4. This patent provides an intelligent early warning method and system for live-line workers' on-site behavior. The method acquires on-site behavioral characteristic data of the live-line workers through wearable devices. Then, based on the on-site behavioral characteristic data and a preset intelligent early warning algorithm model, the current safety level of the live-line workers is determined. Finally, an early warning is issued based on the current safety level and a preset early warning mechanism. It is evident that by employing a scientifically sound method, establishing a risk perception terminal and intelligent early warning system for live-line work on ultra-high voltage (UHV) lines, and based on a safety evaluation system model for live-line work on UHV / UHV transmission lines, intelligent early warnings are provided for various potential risks. This effectively avoids safety accidents, reduces casualties, and improves the safety of live-line work.

[0004] However, in the actual application of this patent, it was found that the electric field detection step under live-line working conditions on ultra-high voltage and extra-high voltage lines is a neglected step. This leads to the risk of exposure to high electric field environments. Workers cannot know whether the electric field of their environment exceeds the safety threshold, and may accidentally enter high-electric-field risk areas, resulting in direct safety accidents such as electric shock and burns. The risk will be further amplified, especially when the equalizing shielding clothing is not worn correctly or the equipment is not compatible. It also leads to the early warning system lacking quantitative basis, unable to determine the matching relationship between personnel location and electric field distribution, making it difficult to trigger targeted warnings such as boundary crossing warnings and field strength exceeding the standard. The lag and subjectivity of traditional manual monitoring will become prominent, and potential risks are easily missed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to solve the deficiency of the lack of electric field detection device under the working conditions of ultra-high voltage lines, fill the gap of the prior art, and design a corresponding electric field detection and early warning method based on the device.

[0006] To achieve this objective, the present invention relates to an electric field detection device for live-line working conditions of ultra-high voltage and extra-high voltage lines. The device is a non-contact electric field detection device, which uses a microprocessor as its core control unit and comprises a double-spherical-shell electric field sensor, a differential amplifier, a filter circuit, a true RMS conversion circuit, a power supply module, and a human-machine interface circuit. The output of the double-spherical-shell electric field sensor is connected to the input of the differential amplifier, the output of the differential amplifier is connected to the input of the filter circuit, the output of the filter circuit is connected to the input of the true RMS conversion circuit, and the output of the true RMS conversion circuit is connected to the microprocessor. The power supply module is connected to the double-spherical-shell electric field sensor, the differential amplifier, the filter circuit, the true RMS conversion circuit, the microprocessor, and the human-machine interface circuit to provide power. The human-machine interface circuit is connected to the microprocessor to enable interactive operation. All components form a complete signal transmission, processing, and control link through the above connections.

[0007] Preferably, the differential amplifier circuit includes two input terminals, respectively connected to the two poles of the double-spherical-shell electric field sensor, for receiving the differential signal output by the double-spherical-shell electric field sensor; the chip output pin is AD620_OUT, serving as the output terminal of the processed signal. The circuit includes two current-limiting resistors, each with a resistance of 1MΩ, for limiting the input current; it also includes two DC bias resistors, each with a resistance of 50MΩ, both connected to ground. These two DC bias resistors are connected in parallel with the double-spherical-shell electric field sensor.

[0008] Preferably, the differential amplifier circuit uses an external gain resistor to set the amplification factor. The overall circuit, through the characteristics of the AD620 chip and the configuration of the external resistors, converts the suspended differential signal output by the dual-spherical-shell electric field sensor into a ground-based signal, effectively eliminating common-mode interference from the spatial electromagnetic field.

[0009] Preferably, the core component in the true RMS conversion circuit is a high-precision monolithic true RMS to DC-DC converter chip; its input terminal is connected to the signal output by the filter circuit, the high-precision monolithic true RMS to DC-DC converter chip is externally connected to a polarized capacitor to set the time constant, the power supply terminal is connected to ±5V voltage to adapt to the 0~5V input requirements of the microcontroller A / D module, and the output terminal is connected to the microprocessor to transmit the converted electric field signal RMS value to the microprocessor for subsequent data processing.

[0010] Preferably, the power supply module includes a positive voltage module and a negative voltage module; the positive voltage module and the negative voltage module work together through input association: the positive voltage module takes a 9V rechargeable battery as input and outputs a stable 5V positive voltage. This voltage directly powers components that require positive voltage, such as the microprocessor, the positive power supply terminal of the differential amplifier AD620, and the positive power supply terminal of the filter MCP6402E. On the other hand, it serves as the input voltage of the negative voltage module connected to the ICL7660 chip; the negative voltage module converts this 5V positive voltage to output a stable -5V negative voltage, which powers components that require negative voltage, such as the negative power supply terminal of the AD620 and the negative power supply terminal of the true RMS converter chip AD637.

[0011] Preferably, in the positive pressure module, the P1 interface is connected to a 9V rechargeable battery as the input power source; P5 is the charging port, and the power switch J1 needs to be turned off during charging to avoid circuit conflicts; the input port 1 of the three-terminal voltage regulator integrated chip is connected to the voltage from P1, and the output port 3 outputs a stable 5V DC voltage; capacitors C1 and C3 are connected in parallel between the chip's input and output terminals and ground to filter and stabilize the output voltage; resistor R11 is connected in series with LED2 and then connected between the 5V output terminal and ground to form a power indicator circuit.

[0012] Preferably, the grounding terminal of the negative voltage module is connected to the system common ground, sharing a common ground with the positive voltage module to ensure the potential consistency of the entire power supply system.

[0013] This invention also includes a method for electric field detection and early warning under live-line working conditions of ultra-high voltage lines. The method achieves deep correlation through the aforementioned structure, supporting data, functional collaboration, and scenario adaptation. The non-contact electric field detection device senses the spatial electric field using a capacitive sensor in a double-spherical electric field sensor layer. Based on dynamic capacitance changes, it outputs a raw signal linearly related to the electric field strength. This raw signal is then processed by a differential amplifier in the signal processing layer to eliminate common-mode interference, a low-pass filter in the filtering circuit to remove noise, and a true RMS conversion chip to convert the alternating signal into an RMS value. Finally, quantitative data proportional to the electric field strength is obtained. This precise electric field data serves as input parameters and is directly incorporated into a multi-dimensional information fusion safety assessment model, providing a quantitative basis for risk assessment.

[0014] Preferably, the embedded structure of the non-contact electric field detection device, combined with a low-power power module, enables real-time acquisition, processing, and transmission of electric field data. By establishing a meta-model library of work scenarios, equipment, and personnel, and combining the surface electric field data output by the non-contact electric field detection device, the device visualizes and overlays the electric field distribution corresponding to the personnel's location in a three-dimensional scene. It also integrates the electric field data with the personnel's physiological characteristics and spatial positioning data, triggers an early warning based on a preset threshold, and achieves closed-loop linkage between data, scenarios, and early warning.

[0015] Preferably, the specific content of establishing a meta-model library for work scenarios, equipment, and personnel includes: reducing inter-class coupling and improving cohesion through abstract class design, constructing a meta-model library covering work scenarios, equipment, tools, and personnel, and establishing a model classification management method and 3D simulation standards.

[0016] This invention employs a capacitive double-spherical-shell electric field sensor. Its probe structure is not limited by the area of ​​the sensing element, and is implemented using a small-area metal sheet, resulting in small size and low power consumption. Based on an embedded system design, it features a compact hardware structure. It boasts good temperature stability and a simple structure, capable of withstanding extreme conditions such as high and low temperatures, strong radiation, and strong magnetic fields. The embedded system design simplifies the device structure and reduces the impact of environmental interference on core components. This invention solves the problem of insufficient stability of traditional equipment in harsh environments, enabling continuous and stable operation of the electric field detection equipment under complex working conditions, ensuring the continuous output of reliable electric field strength data, and providing a fundamental guarantee for operational safety assessment. The environmental adaptability and simplified hardware structure of the double-spherical-shell electric field sensor directly support the reliability of the equipment under extreme conditions.

[0017] Powered by a 5V rechargeable battery, it outputs a stable ±5V voltage through an LM7805 positive voltage module and an ICL7660 negative voltage module, adapting to the needs of various chips. The low-power battery power supply mode improves portability and endurance in field operations, meeting the requirements of long-term continuous detection. The miniaturization of the dual-spherical electric field sensor and the optimization of the power supply solution directly support the device's adaptability to different scenarios.

[0018] Ultimately, a 3D scene meta-model library was constructed. High-precision 3D models of core equipment such as power poles and transmission lines were built using graphical modeling methods. Combined with image modeling, rapid modeling of the surrounding environment was achieved, establishing a standardized meta-model library covering work scenarios, equipment, and tools. Through the fusion of LiDAR and RTK positioning technologies, accurate overlay of 3D point cloud scenes with real-time personnel locations was realized. The risk warning system integrates data such as electric fields, positioning, physiological characteristics, and video, storing it in an SQL Server database and displaying it in 2D / 3D format on a visualization platform. This achieved the digitalization of live-line working scenarios and the integrated management of multi-source data. The 3D meta-model library provides precise virtual scene support for work planning and simulation; the multi-source data fusion and visualization platform intuitively present information throughout the entire work process, transforming scattered data into "graphical and spatial" decision-making basis, significantly improving data management efficiency. The modeling methods and data fusion technology directly promoted the improvement of management efficiency.

[0019] The risk warning system includes real-time monitoring modules for electric fields, location, and vital signs, collecting data on the electric field strength, spatial position, and physiological characteristics of personnel. Preset safety thresholds for electric field strength and physiological parameters are used; when monitored data exceeds limits, real-time alerts are provided through a visual platform, achieving a "data exceeding limits triggers an early warning" response. This overcomes the shortcomings of traditional manual monitoring, such as delayed response and missed risk assessments, enabling real-time perception and early warning of risks during live-line work. The multi-parameter real-time monitoring and threshold warning mechanism can promptly identify risks such as excessive electric fields and personnel crossing boundaries, providing technical support for "pre-event warning and in-event intervention" for work safety. The combination of monitoring modules and the early warning mechanism directly reduces the probability of accidents. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention.

[0021] Figure 1 The diagram shows the overall measurement system of the electric field detection device for live-line operation of ultra-high voltage lines according to the present invention.

[0022] Figure 2 For: For Figure 1 A schematic diagram of the intermediate differential amplifier.

[0023] Figure 3 For: For Figure 1 A detailed circuit diagram of the filter circuit.

[0024] Figure 4 For: For Figure 1A detailed circuit diagram of the true RMS conversion circuit.

[0025] Figure 5 For: For Figure 1 A detailed circuit diagram of the power supply module.

[0026] Figure 6 Here is a flowchart illustrating the electric field detection and early warning method for live-line working conditions of ultra-high voltage lines according to the present invention. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure.

[0028] It should be noted that this invention is a further study based on the prior application "Intelligent Early Warning Method and System for Live-Line Workers' On-Site Behavior" with patent number 202211377674.4. The electric field detection under live-line working conditions of ultra-high voltage lines involved in this patent has several shortcomings: First, the electric field detection indicators are based on static or preset path simulations, which do not fully consider the local electric field abrupt changes caused by the dynamic movements of the workers. The existing model only relies on the membership function of fixed points and does not couple the movement trajectory with field strength changes in real time. Second, the optimal route planning is based on conventional line simulations and does not specifically adapt to the electric field distortion of lines with surge arresters or parallel gaps. The location and type of surge arresters are not included in the electric field calculation, which may lead to the failure of the optimal route under special working conditions. Third, although it mentions analyzing wind force levels through audio and video, it does not include environmental parameters such as humidity and temperature in the electric field detection model, and does not dynamically correct the impact of environmental factors on the electric field distribution and the performance of insulating tools. The existing membership function does not consider environmental interference. Fourth, the electric field detection mainly focuses on the surface field strength and does not establish a correlation mapping between internal defects of composite insulators and human body field strength, making it impossible to infer equipment hazards from the surface field strength.

[0029] To solve these problems, it is necessary to apply the specific technical solutions used in the electric field detection and early warning method for live working conditions of ultra-high voltage lines of this invention.

[0030] like Figure 1As shown, this invention relates to an electric field detection device for live-line working conditions of ultra-high voltage and extra-high voltage lines. The device is a non-contact electric field detection device, which uses a microprocessor as the core control unit and consists of a double-spherical-shell electric field sensor, a differential amplifier, a filter circuit, a true RMS conversion circuit, a power supply module, and a human-machine interface circuit. The output of the double-spherical-shell electric field sensor is connected to the input of the differential amplifier, the output of the differential amplifier is connected to the input of the filter circuit, the output of the filter circuit is connected to the input of the true RMS conversion circuit, and the output of the true RMS conversion circuit is connected to the microprocessor. The power supply module is connected to the double-spherical-shell electric field sensor, the differential amplifier, the filter circuit, the true RMS conversion circuit, the microprocessor, and the human-machine interface circuit to provide power. The human-machine interface circuit is connected to the microprocessor to enable interactive operation.

[0031] Among them, such as Figure 2 As shown, the potentials of the two plates of the double-spherical-shell electric field sensor are floating potentials, and the output voltage is the difference between the two plates. Therefore, when designing the signal processing circuit, a differential input module is needed to convert the differential signal into a signal to ground.

[0032] exist Figure 2 In the diagram, -IN and +IN are the two input terminals of the AD620 chip, connected to the two poles of the dual-sphere type electric field sensor respectively. The chip's output pin is AD620_OUT, and the output voltage is U. O The AD620 is a low-cost, high-precision instrumentation differential amplifier that converts input differential signals into signals to ground and significantly reduces common-mode interference generated in the lead wires by electromagnetic fields in space. The gain is set by a single external gain resistor, with a gain range of 1 to 10000. The gain equation is as follows:

[0033]

[0034] In the formula, R6 is set to 1002, then the magnification is G = 495.

[0035] R1 and R2 are two current-limiting resistors, set to 1MΩ. 22 and R 12 Two DC bias resistors are provided, each set to 50MΩ.

[0036] exist Figure 2 In the chip, the -IN and +IN terminals are connected to an operational amplifier internally, therefore the output current is zero, and R... 12 and R 22 Both are connected to ground, so these two resistors are essentially in series, and connected to R. 11 R 12 And a double-spherical-shell type electric field sensor connected in parallel. Combined with... Figure 2Equivalent circuit diagram of a double-spherical shell electric field sensor, output voltage U O It can be represented as:

[0037]

[0038] Furthermore, the effective value U of the output voltage O_ms It can be represented as:

[0039]

[0040] The effective electric field E can be obtained. O_rms With the effective value U of the output voltage O_rms The relationship is:

[0041]

[0042] It can be seen that the original electric field in space is proportional to the measured voltage.

[0043] Due to noise interference in the space, the signal from the preamplifier circuit needs to be processed, and one common method is filtering. Filtering techniques are generally divided into software filtering and hardware filtering. Since the subsequent circuits in this invention use a true RMS conversion chip, software filtering cannot be used; therefore, hardware filtering technology is chosen.

[0044] Depending on the filtering circuit, the filters used in the filtering circuit are generally divided into three types: LC passive filters, RC passive filters, and RC active filters. LC passive filters are passive reactive networks composed of inductors and capacitors, possessing advantages such as low energy loss, low noise, and high sensitivity. However, due to the large size of inductors, they are rarely used in integrated circuits. RC passive filters are composed of resistors and capacitors, but the presence of resistors consumes energy, resulting in significant signal attenuation. Therefore, they are typically only used in applications with lower filtering performance requirements. RC active filters overcome the shortcomings of RC passive filters, enabling RC networks to possess high filtering performance similar to LC networks. This invention uses the MCP6402E chip to construct an active filtering network. This chip contains two independent operational amplifiers (Op-amp A and Op-amp B). Op-amp B forms a voltage follower circuit, and Op-amp A forms the filtering circuit. Figure 3 In the middle, operational amplifiers B and R 38 R 39 R 40 R 41This circuit forms a voltage follower, which acts as a buffer and isolation stage, improving the circuit's load-carrying capacity. In the diagram, AD620_OUT is the output of the preamplifier circuit, i.e., the input of the voltage follower circuit; AD620_OUT2 is the input of the voltage follower, connected to the input of the post-filter circuit. Based on the virtual short and virtual open principles of operational amplifiers, the input-output relationship can be derived as follows:

[0045]

[0046] Substituting the resistor parameters into the diagram, we can determine that the turns ratio of the voltage follower is 1. The introduction of a voltage follower increases the input resistance of the circuit and decreases the output resistance, thereby isolating the preceding and following stages, improving the circuit's load-carrying capacity, and reducing interference to the filter circuit.

[0047] Figure 3 In the middle, operational amplifiers A and R 30 R 31 R 32 C 13 A filter circuit is constructed, with AD620_OUT2 as its input and AD637_IN as its output, which connects to subsequent processing circuits. Based on the virtual short and virtual open principles of operational amplifiers, the input-output relationship of this filter circuit can be derived as follows:

[0048]

[0049] Therefore, it can be seen that this filter circuit is a low-pass filter circuit. Substituting... Figure 3 The values ​​of resistance and capacitance can be obtained from:

[0050]

[0051] As can be seen, this filter module is a low-pass filter with a calculated cutoff frequency of 281Hz. This filter module amplifies signals with a frequency of 50Hz and has a phase lag of approximately 23°.

[0052] In true RMS conversion circuits, the electric field measurement signal is an analog signal, requiring an A / D module to convert it into a digital signal recognizable by the microcontroller. This invention uses a 12-bit, 15-channel high-speed A / D converter integrated within the microcontroller, with an input requirement of 0-5V. However, the electric field measurement signal is a sinusoidal waveform, necessitating signal processing. There are typically two processing methods:

[0053] ① The electric field measurement signal is level-up using a level-up circuit to make its minimum value greater than 0. Then, the influence of the level-up circuit is eliminated through program design. This method can preserve all the original information of the electric field signal, but it increases the complexity of the program. More importantly, due to the influence of level-up, the amplitude of the electric field measurement signal cannot exceed 2.5V, which is equivalent to reducing the electric field measurement range by half.

[0054] ② As the foregoing analysis shows, the information required in this invention is the effective value of the electric field measurement signal. Therefore, the effective value of the electric field measurement signal can be directly calculated by an external circuit before being input as a signal. This method not only avoids the halving of the measurement range caused by the level-up circuit, but also reduces the complexity of the program. This invention uses the AD637 chip to complete the design of the true RMS conversion circuit for the signal.

[0055] The AD637 chip can be conveniently used to calculate the effective value of an input signal. Its schematic circuit is shown below. Figure 4 As shown:

[0056] Figure 4 In this circuit, AD637_IN is the circuit input, which can be a DC or AC signal; in this invention, it is a sine wave signal. AD637_OUT is the circuit output, and its value is the effective value of the input signal. The AD637 chip requires only one external polarized capacitor C6 to set the time constant, and this capacitor is related to the conversion error at low frequencies. When C is set to 4μF and the frequency is 10Hz, the conversion error is 0.1%; when C is set to 4uF and the frequency is 3Hz, the conversion error is 1%. The double-sphere type electric field sensor of this invention is used in a 50Hz electric field environment, so the conversion accuracy requirement can be met. The output voltage range of the AD637 chip is a function of the supply voltage.

[0057] Since the input voltage requirement of the A / D module of the microcontroller used in this invention is no higher than 5V, the power supply voltage of the AD637 chip is selected to be ±5V, so the maximum output voltage is about 4.5V.

[0058] The measurement system designed in this invention is powered by a 5V rechargeable battery. The voltages used by each chip in the circuit are 5V and -5V. The power conversion circuit is as follows: Figure 5 As shown:

[0059] in Figure 5 (a) shows the positive voltage module. P1 is connected to a 9V battery, and P5 is the charging port. J1 is the power switch, which needs to be turned off during charging. P2 is an LM7805 chip. When the input voltage at port 1 is higher than 7V, its output port 3 can output a stable 5V DC voltage. It contains overcurrent, overheat, and regulating transistor protection circuits, making it convenient and reliable to use.

[0060] Figure 5 (b) is a negative voltage conversion circuit that uses the ICL7660 chip to convert positive voltage to the corresponding negative voltage in the range of 1.5 to 10V.

[0061] Simultaneously, an AD620 differential amplifier is used to eliminate common-mode interference from spatial electromagnetic fields, and an external gain resistor is used to effectively amplify the signal. An RC active low-pass filter circuit is constructed using an MCP6402E chip to amplify the 50Hz electric field signal with a phase lag of only about 23°, filtering out high-frequency noise. An AD637 true RMS converter chip is used to convert the sine wave signal into an RMS value, avoiding the problem of halving the measurement range caused by level rise. This significantly reduces the impact of spatial electromagnetic interference and noise on the signal, achieving high-precision measurement of electric field strength. Optimization of the signal processing link ensures that the output signal has a linear relationship with the measured electric field strength, providing accurate quantitative data for risk assessment. The signal processing measures at each stage directly improve the measurement accuracy.

[0062] Based on the aforementioned equipment, methods for electric field detection and early warning under live-line working conditions on ultra-high voltage and extra-high voltage lines can be developed. This involves visualization and linkage early warning management technology through the overlay of 3D point cloud scenes and personnel RTK positions. A 3D visualization environment is constructed, displaying the 3D digital scene of the live-line working site, the planned trajectory, and real-time high-precision personnel positioning data according to a unified coordinate system. This data is then incorporated into a multi-dimensional information fusion safety assessment model, providing a quantitative basis for risk assessment.

[0063] Taking a multi-sensor fusion system as an example, the first step is to solve the calibration problem and determine the coordinate relationship between the lidar and RTK. This invention collects the pose coordinates of the lidar and RTK over a continuous time period for calibration. The lidar coordinates are obtained using the Lego-LOAM algorithm, while the RTK coordinates are obtained by subtracting the first frame coordinates (0,0,0) from the initial coordinates (0,0,0) of the first frame.

[0064] P = {p1, ..., p} n}, P′={p1′,...,p n ′}

[0065] For two sets of coordinate points, where P represents the lidar coordinates and P' represents the RTK coordinates, we need rotation matrices R and t such that:

[0066]

[0067] First, define the error term for the i-th pair of points:

[0068] e i =p i -(Rp i ′+t)

[0069] Construct a least squares problem, R,t, that minimizes the sum of squared errors.

[0070]

[0071] The centroid coordinates of each point were calculated.

[0072] q i =p i -p,q i ′=p i ′-p′

[0073] The objective function is simplified, and the rotation matrix is ​​calculated using optimization methods:

[0074]

[0075] Finally, t is calculated based on R:

[0076] t * =p-Rp'

[0077] At this point, the coordinate transformation matrix T between the lidar and RTK can be obtained:

[0078]

[0079] After completing the calibration of the LiDAR and RTK, the LiDAR and RTK are fused using a factor graph based on the LeGO-LOAM algorithm. The program flow is as follows: Figure 6 As shown, the 3D LiDAR publishes point cloud data at a frequency of 10Hz; the PointCloudRegistration node calculates the curvature of the point cloud data and extracts feature lines and feature surfaces according to the following formula:

[0080]

[0081] The LidarOdometry node uses the nearest iteration point (ICP) method to register the extracted feature lines and feature surfaces into a point cloud to obtain the radar pose estimate. The LidarMapping node re-registers the point cloud of the current frame with the entire point cloud map at a frequency of 2Hz to optimize the odometry pose estimate. It also subscribes to RTK data and adds it to the factor graph for optimization, publishing the optimized pose estimate at a frequency of 2Hz. The TransformInfegration node fuses the pose estimates from the LidarOdometry and LidarMapping nodes, publishing the final accurate pose estimate at a frequency of 10Hz. The accurate pose estimate published at 10Hz has a core data fusion correlation with electric field detection and early warning: this result provides real-time position and attitude information of personnel or equipment in three-dimensional space, enabling precise spatiotemporal matching with the spatial electric field intensity data output by non-contact electric field detection devices. By overlaying 10Hz high-frequency updated pose data and electric field data in a three-dimensional scene, the early warning system can determine in real time whether personnel have entered high electric field risk areas, whether equipment posture has caused local field strength to exceed the standard, and other situations. Based on the "position-electric field" linkage relationship, it triggers targeted early warnings, ensuring the real-time and accurate nature of the early warning response, and providing dual data support for live-line work safety monitoring.

[0082] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the scope of the invention. Any person skilled in the art can make modifications without departing from the scope of the invention; all equivalent modifications made in accordance with the invention should be covered by the scope of the invention. In the description of this specification, references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Moreover, without contradiction, those skilled in the art can combine and integrate different embodiments / modes or examples and features of different embodiments / modes or examples described in this specification.

[0083] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0084] Those skilled in the art should understand that the above embodiments are merely for illustrating the present disclosure and are not intended to limit the scope of the disclosure. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present disclosure.

Claims

1. An electric field detection device for live-line working conditions of ultra-high voltage and extra-high voltage lines, characterized in that, The device is a non-contact electric field detection device. The non-contact electric field detection device uses a microprocessor as the core control unit and consists of a double-spherical-shell electric field sensor, a differential amplifier, a filter circuit, a true RMS conversion circuit, a power supply module, and a human-machine interaction circuit. The output terminal of the double-spherical-shell electric field sensor is connected to the input terminal of the differential amplifier, the output terminal of the differential amplifier is connected to the input terminal of the filter circuit, the output terminal of the filter circuit is connected to the input terminal of the true RMS conversion circuit, and the output terminal of the true RMS conversion circuit is connected to the microprocessor. The power supply module is connected to the double-spherical electric field sensor, differential amplifier, filter circuit, true RMS conversion circuit, microprocessor and human-machine interaction circuit to provide power. The human-machine interaction circuit is connected to the microprocessor to realize interactive operation.

2. The electric field detection device for live-line working conditions of ultra-high voltage and extra-high voltage lines as described in claim 1, characterized in that, The differential amplifier circuit includes two input terminals, which are respectively connected to the two poles of the double-spherical-shell electric field sensor to receive the differential signal output by the double-spherical-shell electric field sensor; the circuit is equipped with two current-limiting resistors; and also includes two DC bias resistors, which are connected in parallel with the double-spherical-shell electric field sensor.

3. The electric field detection device for live-line working conditions of ultra-high voltage and extra-high voltage lines as described in claim 2, characterized in that, The differential amplifier circuit uses an external gain resistor to set the amplification factor.

4. The electric field detection device for live-line working conditions of ultra-high voltage and extra-high voltage lines as described in claim 1, characterized in that, The core component of the true RMS conversion circuit is a high-precision monolithic true RMS to DC-DC converter chip. Its input terminal is connected to the signal output by the filter circuit. The high-precision monolithic true RMS to DC-DC converter chip is connected to an external polarized capacitor to set the time constant. The power supply terminal is connected to ±5V voltage to adapt to the 0~5V input requirements of the microcontroller A / D module. The output terminal is connected to the microprocessor to transmit the RMS value of the converted electric field signal to the microprocessor for subsequent data processing.

5. The electric field detection device for live-line working conditions of ultra-high voltage and extra-high voltage lines as described in claim 1, characterized in that, The power module includes a positive voltage module and a negative voltage module; the positive voltage module and the negative voltage module work together through input association: the positive voltage module takes a 9V rechargeable battery as input and outputs a stable 5V positive voltage; the negative voltage module converts this 5V positive voltage to output a stable -5V negative voltage.

6. The electric field detection device for live-line working conditions of ultra-high voltage and extra-high voltage lines as described in claim 5, characterized in that, In the positive pressure module, the P1 interface is connected to a 9V rechargeable battery as the input power; P5 is the charging port; the input port 1 of the three-terminal voltage regulator integrated chip is connected to the voltage from P1, and the output port 3 outputs a stable 5V DC voltage; capacitors C1 and C3 are connected in parallel between the input and output terminals of the three-terminal voltage regulator integrated chip and ground to filter and stabilize the output voltage; resistor R11 is connected in series with LED2 and then connected between the 5V output terminal and ground to form a power indicator circuit.

7. The electric field detection device for live-line working conditions of ultra-high voltage and extra-high voltage lines as described in claim 5 or 6, characterized in that, The grounding terminal of the negative voltage module is connected to the system common ground, sharing a common ground with the positive voltage module to ensure the potential consistency of the entire power supply system.

8. A method for detecting and warning of electric fields under live-line working conditions on ultra-high voltage and extra-high voltage lines, characterized in that, The electric field detection device described in any one of claims 1-7 achieves deep correlation in terms of data support, functional synergy, and scenario adaptation: The non-contact electric field detection device senses the spatial electric field through a capacitive sensor in a double-spherical electric field sensor layer. Based on dynamic capacitance changes, it outputs a raw signal that is linearly related to the electric field strength. Then, the signal processing layer's differential amplifier eliminates common-mode interference, the low-pass filter in the filtering circuit filters out noise, and the true RMS conversion chip converts the alternating signal into an RMS value, ultimately obtaining quantitative data that is in a fixed proportion to the electric field strength. This precise electric field data is used as input parameters and directly incorporated into the multi-dimensional information fusion security assessment model, providing a quantitative basis for risk assessment.

9. The electric field detection and early warning method for live-line working conditions of ultra-high voltage and extra-high voltage lines as described in claim 8, characterized in that, The embedded structure of the non-contact electric field detection device, combined with a low-power power module, enables real-time acquisition, processing, and transmission of electric field data. By establishing a meta-model library of work scenarios, equipment, and personnel, and combining it with the surface electric field data output by the non-contact electric field detection device, the device visualizes and overlays the electric field distribution corresponding to the personnel's location in a three-dimensional scene. It also integrates the electric field data with the personnel's physiological characteristics and spatial positioning data, triggers early warnings based on preset thresholds, and achieves closed-loop linkage between data, scenarios, and early warnings.

10. The electric field detection and early warning method for live-line working conditions of ultra-high voltage and extra-high voltage lines as described in claim 8, characterized in that, The specific content of establishing a meta-model library for work scenarios, equipment, and personnel includes: reducing inter-class coupling and improving cohesion through abstract class design, constructing a meta-model library covering work scenarios, equipment, tools, and personnel, and establishing a model classification management method and 3D simulation standards.

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