A millimeter wave distance monitoring device and monitoring method for distribution network non-stop operation

Abstract

The present invention proposes a millimeter wave distance monitoring device for non-stop power distribution network operation and a monitoring method thereof. The device includes a housing, a control panel, a power supply module and a transceiver antenna arranged inside the housing. The control panel includes a mixer, a low-pass filter, an AD sampling module and a processor connected in sequence, and a waveform generator connected to the mixer, and a communication module connected to the processor. The transceiver antenna includes a transmitting antenna array and a receiving antenna array. The transmitting antenna array is connected to the waveform generator, and the receiving antenna array is connected to the mixer. The transceiver antenna is used to transmit millimeter waves to the target and receive the target reflected echo. The power supply module is connected to the control panel for power supply, and the communication module is connected to an alarm for responding to an alarm notification. The present invention can identify and determine whether the human arms and head are outside the safe distance line, and can regulate the operating behavior of personnel by recording the number of times the moving speed and target distance exceed the limit.

Description

Technical Field

[0001] The present invention relates to the field of millimeter wave radar technology, and in particular to a millimeter wave distance monitoring device for non-stop operation of a distribution network and a monitoring method thereof. Background Art

[0002] Non-stop power supply operation for overhead lines refers to the on-site operators riding in an insulated bucket in the air to the vicinity of the overhead lines to perform maintenance and other operations on the overhead energized cables. Its characteristics are that there is no need to shut down the power supply during the operation, which does not affect the power supply reliability of users, and the operation time is flexible, which can realize all-weather operation.

[0003] During overhead line operations, workers wear insulating protective gear, rise to a suitable height with the insulating bucket, and then use insulating rods to carry out live operations on live objects near the work area. In the insulating rod operation method, the insulating rod is the main insulation between the phase and the ground, and the insulating protective gear is the auxiliary insulation. According to the national standard GB / T18857-2019 "Technical Guidelines for Live Operations on Distribution Lines", when the insulating rod operation method is used on distribution lines, the minimum safe distance between the human body and the live object (excluding the range of human activities) shall comply with the provisions of Table 1, that is, within an altitude of 3000m, the minimum safe distance in 10kV operations shall not be less than 0.4m; within an altitude of 1000m, the minimum safe distance in 20kV operations shall not be less than 0.5m.

[0004] At present, in the existing actual operation process, special observation and command personnel are deployed on the ground. The position area of ​​the operating personnel and their insulating buckets are observed and judged by human eyes. It is impossible to accurately grasp the area range of the specific non-stop operation location in real time, and it is even more impossible to judge the distance between the operator's upper limbs and the live body. Therefore, it is impossible to ensure that the operating personnel and their insulating buckets are in a safe area, which makes the non-stop operation have safety hazards. Summary of the invention

[0005] The purpose of the present invention is to provide a millimeter wave distance monitoring device and a monitoring method for non-stop operation of a distribution network, which solves the problem in the prior art that the distance between the operator's upper limbs and the charged body cannot be accurately determined.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a millimeter wave distance monitoring device for non-stop operation of a distribution network, which can be detachably installed on a three-phase cable, including a shell, a control board, a power supply module and a transceiver antenna arranged inside the shell, the control board includes a mixer, a low-pass filter, an AD sampling module and a processor connected in sequence, and a waveform generator connected to the mixer, and a communication module connected to the processor, the transceiver antenna includes a transmitting antenna array and a receiving antenna array, the transmitting antenna array is connected to the waveform generator, the receiving antenna array is connected to the mixer, the transceiver antenna is used to transmit millimeter waves to a target and receive a reflected echo from the target, the power supply module is connected to the control board for power supply, and the communication module is connected to an alarm for responding to an alarm notification.

[0007] As a preferred solution, the targets include targets A, B and C located on the arms and head of the human body, and the targets A, B and C are made of materials with different reflectivity.

[0008] As a preferred solution, the connection between the monitoring device and the three-phase cable is snap-on, winding or clamping.

[0009] The present invention also provides a monitoring method for a millimeter wave distance monitoring device for non-stop operation of a distribution network as described in any of the above items, comprising the following steps: using an insulating operating rod to install the monitoring device on a three-phase cable, and adjusting the monitoring device to a horizontal state; transmitting a linear frequency modulated continuous millimeter wave to the bottom of the three-phase cable, and receiving a reflected echo in real time, the reflected echo including a human body echo signal, an insulating bucket echo signal and an environmental echo signal; pre-processing the reflected echo, and separating the human body echo signal therefrom; calculating the target distance and the corresponding echo direction angle based on the waveform characteristics of the human body echo signal; obtaining the shortest distance between the target and the three-phase cable based on the target distance and the corresponding echo direction angle, and outputting an alarm notification if the shortest distance is less than the safety distance.

[0010] As a preferred solution, the preprocessing of the reflected echo includes: mixing the reflected echo with a mixer, and obtaining an intermediate frequency signal after processing with a low-pass filter; AD sampling the intermediate frequency signal, and performing an inverse Fourier transform to obtain a time domain signal; and performing digital filtering processing, spatial multipath interference elimination and spatial noise processing on the time domain signal in sequence.

[0011] As a preferred embodiment, the method of separating the human body echo signal therefrom includes: selecting a first threshold value according to the waveform characteristics of the environmental echo signal; filtering out the component of the processed reflected echo at zero frequency according to the first threshold value to obtain a primary processing spectrum; expanding the primary processing spectrum to a two-dimensional plane, sorting all reference points in a reference window of the two-dimensional plane, and selecting the average value of M points around the Kth value as a second threshold value; filtering out the insulation bucket echo signal component according to the second threshold value to obtain a secondary processing spectrum, i.e., the human body echo signal.

[0012] As a preferred solution, the calculation process of the echo direction angle includes: assuming that the human body echo signals received by the two antennas of the receiving antenna array are μ1 and μ2 respectively, the phase difference between the two is φ, and the echo direction angle is θ, then

[0013]

[0014]

[0015]

[0016] In the above formula, Δ is the difference channel of signals μ1 and μ2, ∑ is the sum channel of signals μ1 and μ2, j is the coefficient, φ is the phase difference between signals μ1 and μ2, d is the distance between the two antennas, λ is the wavelength of the radar signal, and θ is the echo direction angle;

[0017] The target distance calculation process includes:

[0018]

[0019] In the above formula, R is the target distance, c is the speed of light, and TR is the delay time.

[0020] As a preferred solution, the obtaining the shortest distance between the target and the three-phase cable includes:

[0021] d i =R i sinθ,i=1L n

[0022] d min =min(d i )

[0023] In the above formula, di is the vertical distance between the i-th target and the three-phase cable, Ri is the distance between the receiving antenna and the i-th target, θ is the echo direction angle, n is the number of targets, and dmin is the shortest distance between the target and the three-phase cable.

[0024] As a preferred solution, the reflectivity of the targets A, B and C is R A >R B >RC After separating the human body echo signal, it also includes: classifying and identifying each target of the human body echo signal, specifically: clustering the frame data of the human body echo signal based on the density clustering algorithm, and outputting the clustering result; calculating the reflection peak value of each class of the clustering result, determining the class with the largest reflection peak value as target A, the class with the middle reflection peak value as target B, and the class with the smallest reflection peak value as target C.

[0025] As a preferred solution, it also includes: obtaining the beat signal frequency after the reflected echo delay, calculating and recording the moving speed of various targets; according to the preset safety speed and safety distance, determining the number of times the moving speed and the shortest distance between the target and the three-phase cable exceed the limit, so as to regulate the operating behavior of personnel.

[0026] Compared with the prior art, the beneficial effects of the present invention include: selecting the first threshold value and the second threshold value according to the waveform characteristics of the environmental echo signal and the insulating bucket echo signal, accurately separating the human body echo signal, and then using the density clustering algorithm to classify and identify the human body echo signal, which can identify and judge whether the human arms and head are outside the safe distance line, and can regulate the operating behavior of personnel by recording the number of times the moving speed and the target distance exceed the limit. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The disclosure of the present invention is described with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. In the accompanying drawings, the same reference numerals are used to refer to the same components. Among them:

[0028] Figure 1 This is a diagram of the implementation environment of the millimeter wave distance monitoring device for non-stop power supply operation of the distribution network according to an embodiment of the present invention;

[0029] Figure 2 for Figure 1 A partial enlarged schematic diagram of

[0030] Figure 3 It is a structural schematic diagram of a millimeter wave distance monitoring device for non-stop power supply operation of a distribution network according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can propose a variety of interchangeable structural modes and implementation modes. Therefore, the following specific implementation modes and drawings are only exemplary descriptions of the technical solution of the present invention, and should not be regarded as the whole of the present invention or as a limitation or restriction to the technical solution of the present invention.

[0032] According to one embodiment of the present invention, Figures 1 to 3Shown. A millimeter wave distance monitoring device for non-stop power distribution network operation can be detachably installed on a three-phase cable, including a shell, a control board, a power supply module and a transceiver antenna arranged inside the shell, the control board includes a mixer, a low-pass filter, an AD sampling module and a processor connected in sequence, and a waveform generator connected to the mixer, and a communication module connected to the processor, the transceiver antenna includes a transmitting antenna array and a receiving antenna array, the transmitting antenna array is connected to the waveform generator, the receiving antenna array is connected to the mixer, the transceiver antenna is used to transmit millimeter waves to the target and receive the target reflected echo, the power supply module is connected to the control board for power supply, and the communication module is connected to an alarm or display for responding to alarm notifications. Specifically, the monitoring device is connected to the alarm or display through wireless methods such as Bluetooth and wifi.

[0033] In the embodiment of the present invention, the above-mentioned targets include targets A, B and C set on the arms and head of the human body, and targets A, B and C are made of materials with different reflectivity, such as metal plates such as copper, iron, aluminum and nickel. Therefore, the peaks presented on the spectrum of the reflected echo are different, which is convenient for distinguishing various types of targets. The connection method between the monitoring device and the three-phase cable is snap-on, winding or clamping, which is convenient for fixing the device on different accessories.

[0034] The present invention also provides a monitoring method of the millimeter wave distance monitoring device for non-stop operation of a distribution network as described in any one of the above items, comprising the following steps:

[0035] (1) Use an insulated operating rod to install the monitoring device on the three-phase cable and adjust the monitoring device to a horizontal state. Specifically, a gyroscope and a rotating motor can be installed on the monitoring device. When monitoring starts, the control board drives the rotating motor to move according to the angle signal of the gyroscope, and automatically adjusts the monitoring device to a horizontal state, which is convenient to operate.

[0036] (2) A linear frequency modulated continuous millimeter wave is transmitted downwards to the three-phase cable, and reflected echoes are received in real time. The reflected echoes include human body echo signals, insulation bucket echo signals, and environmental echo signals.

[0037] (3) Preprocess the reflected echo and separate the human body echo signal from it.

[0038] The reflected echo is preprocessed, including:

[0039] a. Use a mixer to mix the reflected echo and obtain the intermediate frequency signal after processing it with a low-pass filter.

[0040] b. Perform AD sampling on the intermediate frequency signal and perform inverse Fourier transform to obtain the time domain signal.

[0041] c. Perform digital filtering, spatial multipath interference elimination and spatial noise processing on the time domain signal in sequence.

[0042] In the embodiment of the present invention, separating the human body echo signal includes:

[0043] a. Select the first threshold value according to the waveform characteristics of the environmental echo signal.

[0044] b. According to the first threshold value, the component of the reflected echo at zero frequency after processing is filtered out to obtain a processed spectrum.

[0045] c. Expand the once processed spectrum to a two-dimensional plane, sort all reference points in the reference window of the two-dimensional plane, and select the average value of M points around the Kth value as the second threshold value. The K value is related to the waveform characteristics of the insulation bucket (such as power level or power spectrum density). This method can ensure the accuracy and stability of the threshold value, and ultimately improve the ability of target detection.

[0046] d. Filter out the insulating bucket echo signal component according to the second threshold value to obtain a secondary processing spectrum, that is, a human body echo signal.

[0047] Assume the reflectivity of targets A, B and C is R A >R B >R C After separating the human body echo signal, the method further includes: classifying and identifying the targets of the human body echo signal, specifically: clustering the frame data of the human body echo signal based on the density clustering algorithm, and outputting the clustering result; calculating the reflection peak value of each class of the clustering result, determining the class with the largest reflection peak value as target A, the class with the middle reflection peak value as target B, and the class with the smallest reflection peak value as target C.

[0048] The steps of the density clustering algorithm include: 1. If the ε neighborhood of a frame data point x in the human echo signal contains extra m objects, create a new cluster with x as the core object; 2. Find and merge objects that are directly density-reachable by the core object; 3. When there are no new points to update the cluster, the algorithm ends.

[0049] (4) According to the waveform characteristics of the human body echo signal, the target distance and the corresponding echo direction angle are calculated.

[0050] Specifically, the calculation process of the echo direction angle includes: assuming that the human body echo signals received by the two antennas of the receiving antenna array are μ1 and μ2 respectively, the phase difference between the two is φ, and the echo direction angle is θ, then

[0051]

[0052]

[0053]

[0054] In the above formula, Δ is the difference channel of signals μ1 and μ2, ∑ is the sum channel of signals μ1 and μ2, j is the coefficient, φ is the phase difference between signals μ1 and μ2, d is the distance between the two antennas, λ is the wavelength of the radar signal, and θ is the echo direction angle;

[0055] The target distance calculation process includes:

[0056]

[0057] In the above formula, R is the target distance, c is the speed of light, and TR is the delay time.

[0058] Get the shortest distance between the target and the three-phase cable, including:

[0059] d i =R i sinθ,i=1L n

[0060] d min =min(d i )

[0061] In the above formula, di is the vertical distance between the i-th target and the three-phase cable, Ri is the distance between the receiving antenna and the i-th target, θ is the echo direction angle, n is the number of targets, and dmin is the shortest distance between the target and the three-phase cable.

[0062] (5) According to the target distance and the corresponding echo direction angle, the shortest distance between the target and the three-phase cable is obtained. If the shortest distance is less than the safety distance, an alarm notification is output.

[0063] In an embodiment of the present invention, the monitoring method further includes: obtaining the beat signal frequency after the reflected echo delay, calculating and recording the moving speed of various targets; and determining the number of times the moving speed and the shortest distance between the target and the three-phase cable exceed the limit according to the preset safety speed and safety distance, so as to regulate the operation behavior of personnel. For example, an operator triggers an alarm 10 times during an operation. After checking the records, it is found that the operator's left arm exceeds the safety distance 8 times, the right arm exceeds the safety distance 2 times, and the moving speed of the left arm exceeds the preset safety speed 25 times. It can be analyzed that the operator's left arm frequently triggers the alarm due to excessive movement. It is recommended to reduce the movement speed of the arm in subsequent operations, regulate the operation behavior, and improve the safety of non-stop operation, which has high practical training value.

[0064] In summary, the beneficial effects of the present invention include: selecting the first threshold value and the second threshold value according to the waveform characteristics of the environmental echo signal and the insulating bucket echo signal, accurately separating the human body echo signal, and then using the density clustering algorithm to classify and identify the human body echo signal, which can identify and judge whether the human arms and head are outside the safe distance line. The monitoring method can ensure a low false alarm probability and missed detection probability, and can standardize the operating behavior of personnel by recording the number of times the moving speed and target distance exceed the limit.

[0065] The technical scope of the present invention is not limited to the contents in the above description. Those skilled in the art can make various deformations and modifications to the above embodiments without departing from the technical idea of ​​the present invention, and these deformations and modifications should all fall within the protection scope of the present invention.

Claims

1. A monitoring method for a millimeter wave distance monitoring device for non-stop operation of a distribution network, characterized in that: The millimeter wave distance monitoring device for non-stop power supply operation of the distribution network can be detachably installed on a three-phase cable, and includes a shell, a control board, a power supply module and a transceiver antenna arranged inside the shell, the control board includes a mixer, a low-pass filter, an AD sampling module and a processor connected in sequence, and a waveform generator connected to the mixer, and a communication module connected to the processor, the transceiver antenna includes a transmitting antenna array and a receiving antenna array, the transmitting antenna array is connected to the waveform generator, the receiving antenna array is connected to the mixer, the transceiver antenna is used to transmit millimeter waves to the target and receive the target reflected echo, the power supply module is connected to the control board for power supply, and the communication module is connected to an alarm for responding to an alarm notification; The monitoring method comprises the following steps: installing a monitoring device on a three-phase cable by using an insulating operating rod, and adjusting the monitoring device to be in a horizontal state; transmitting a linear frequency modulated continuous millimeter wave to the bottom of the three-phase cable, and receiving a reflected echo in real time, wherein the reflected echo comprises a human body echo signal, an insulating bucket echo signal and an environmental echo signal; pre-processing the reflected echo, and separating the human body echo signal therefrom; calculating a target distance and a corresponding echo direction angle according to waveform characteristics of the human body echo signal; obtaining the shortest distance between the target and the three-phase cable according to the target distance and the corresponding echo direction angle, and outputting an alarm notification if the shortest distance is less than a safe distance; The method of separating the human body echo signal from the environmental echo signal comprises: selecting a first threshold value according to the waveform characteristics of the environmental echo signal; filtering out the component of the processed reflected echo at zero frequency according to the first threshold value to obtain a primary processing spectrum; extending the primary processing spectrum to a two-dimensional plane, sorting all reference points in a reference window of the two-dimensional plane, and selecting the average value of M points around the Kth value as a second threshold value; filtering out the insulation bucket echo signal component according to the second threshold value to obtain a secondary processing spectrum, i.e., the human body echo signal; The targets include targets A, B and C located on the arms and head of the human body, and the targets A, B and C are made of materials with different reflectivity; the reflectivity of the targets A, B and C is , after separating the human body echo signal, it also includes: classifying and identifying each target of the human body echo signal, specifically: clustering the frame data of the human body echo signal based on the density clustering algorithm, and outputting the clustering result; calculating the reflection peak value of each class of the clustering result, determining the class with the largest reflection peak value as target A, the class with the middle reflection peak value as target B, and the class with the smallest reflection peak value as target C; The steps of the density clustering algorithm include: if the ε neighborhood of a frame data point x in the human echo signal contains redundant m objects, then create a new cluster with x as the core object; find and merge objects that are directly density-reachable by the core object; when there are no new points to update the cluster, the algorithm ends.

2. The monitoring method of the millimeter wave distance monitoring device for non-stop operation of distribution network according to claim 1 is characterized in that: The connection between the monitoring device and the three-phase cable is a snap-on, winding or clamping type.

3. The monitoring method of the millimeter wave distance monitoring device for non-stop operation of distribution network according to claim 1 is characterized in that: The preprocessing of the reflected echo comprises: A mixer is used to mix the reflected echo, and an intermediate frequency signal is obtained after being processed by a low-pass filter; Perform AD sampling on the intermediate frequency signal and perform inverse Fourier transform to obtain a time domain signal; The time domain signal is subjected to digital filtering processing, spatial multipath interference elimination and spatial noise processing in sequence.

4. The monitoring method of the millimeter wave distance monitoring device for non-stop operation of distribution network according to claim 1 is characterized in that: The calculation process of the echo direction angle comprises: Assume that the human body echo signals received by the two antennas of the receiving antenna array are μ1 and μ2 respectively, and the phase difference between the two is , the echo direction angle is θ, then ； ； ； In the above formula, is the difference channel of signals μ1 and μ2, is the sum channel of signals μ1 and μ2, j is the coefficient, is the phase difference between signals μ1 and μ2, λ is the wavelength of radar signal, and θ is the echo direction angle; The target distance calculation process includes: ； In the above formula, R is the target distance, c is the speed of light, and TR is the delay time.

5. The monitoring method of the millimeter wave distance monitoring device for non-stop operation of distribution network according to claim 1 is characterized in that: The obtaining of the shortest distance between the target and the three-phase cable comprises: ； In the above formula, di is the vertical distance between the i-th target and the three-phase cable, Ri is the distance between the receiving antenna and the i-th target, θ is the echo direction angle, n is the number of targets, and dmin is the shortest distance between the target and the three-phase cable.

6. The monitoring method of the millimeter wave distance monitoring device for non-stop operation of distribution network according to claim 1 is characterized in that: Also includes: Obtain the beat signal frequency after the reflected echo delay, calculate the moving speed of various targets and record it; According to the preset safety speed and safety distance, the number of times the moving speed and the shortest distance between the target and the three-phase cable exceed the limit is determined to regulate the operating behavior of personnel.

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