High-voltage line detection and distance measurement method, system and device based on millimeter wave radar

Abstract

The invention relates to the technical field of radar target detection, in particular to a high-voltage line detection and distance measurement method, system and device based on a millimeter wave radar, and the method comprises the following steps: transmitting a linear frequency modulation pulse signal to a high-voltage line region; obtaining an original echo signal reflected by a target high-voltage line based on the linear frequency modulation pulse signal, and preprocessing the original echo signal to obtain a preprocessed echo signal; performing pulse compression processing on the linear frequency modulation pulse signal and the preprocessed echo signal in a frequency domain to obtain a frequency domain pulse pressure signal; and obtaining a target distance based on the frequency domain pulse pressure signal. The millimeter wave radar technology is utilized, linear frequency modulation pulse signals are transmitted, echoes reflected by the high-voltage line are received, and through the steps of preprocessing, frequency domain pulse compression, moving target detection, non-coherent accumulation and the like, accurate detection and distance measurement of the high-voltage line are achieved.

Description

Technical Field

[0001] The present invention relates to the field of radar target detection technology, and in particular to a high-voltage line detection and ranging method, system and device based on millimeter-wave radar. Background Art

[0002] In the process of performing special operations in the power industry, especially live transmission line operations, operators are limited by on-site conditions and often rely on visual intuitive judgment to determine the safe distance for operations. However, this method may not only introduce errors due to differences in subjective judgment of operators and interference from external environmental factors, but may also increase the risk factor of live operations. In view of this, the development of a space limit alarm system based on transmission lines to prevent large-scale mechanical construction from touching the line is of great significance to improving operation safety.

[0003] At present, the alarm detection technologies adopted in the industry mainly include power frequency electric field measurement, ultrasonic ranging and optical image detection. However, these technologies face certain challenges in practical applications. Specifically, due to the dense lines around high-voltage towers and the complex and changeable electromagnetic field environment, the existing power frequency electric field sensing technology is susceptible to electromagnetic interference in this environment, resulting in large fluctuations in measurement data and insufficient stability. In addition, the wire diameter of high-voltage transmission lines is usually small, which causes the ultrasonic signal to be severely attenuated during propagation and the received signal strength is weak. In addition, the problems of blurring and distortion that may be encountered during image acquisition affect the accuracy of ultrasonic ranging and optical image detection methods to a certain extent. What's more serious is that these two methods are also easily restricted by weather conditions. For example, bad weather such as rain and snow will significantly affect the propagation of ultrasonic waves and the clarity of the image, making it difficult to meet the system's requirements for high precision and high reliability. Summary of the invention

[0004] To this end, the technical problem that the present invention aims to solve is that the traditional visual inspection method is largely limited by the subjective errors of human judgment and the interference of complex and changeable environmental factors, especially in a low signal-to-noise ratio environment, where this influence is particularly prominent, thereby greatly reducing the accuracy of high-voltage line detection distance estimation.

[0005] In order to solve the above technical problems, the present invention uses millimeter-wave radar signal correlation processing technology, clutter cancellation technology, and signal clustering technology to complete the detection and ranging of high-voltage wires, and provides a high-voltage line detection and ranging method, system and device based on millimeter-wave radar, which solves the detection and ranging problems of weak echo signals of wires under low signal-to-noise ratio, and provides technical support for the subsequent transmission line space limiting system to prevent large-scale mechanical construction from touching the line.

[0006] The specific steps of the high-voltage line detection and ranging method based on millimeter-wave radar are as follows:

[0007] S1: Transmits linear frequency modulation pulse signal to the high voltage line area;

[0008] S2: based on the linear frequency modulation pulse signal, obtaining an original echo signal reflected by the target high-voltage line, and preprocessing the original echo signal to obtain a preprocessed echo signal;

[0009] S3: performing pulse compression processing on the linear frequency modulation pulse signal and the preprocessed echo signal in the frequency domain to obtain a frequency domain pulse compression signal;

[0010] S4: Obtaining a target distance based on the frequency domain pulse pressure signal.

[0011] In one embodiment of the present invention, the linear frequency modulation pulse signal r(t',n) is:

[0012]

[0013] Among them, t′=t-nT represents the intra-pulse time, that is, the fast time, in seconds, rect represents the rectangular function operation, t is the acquisition time, n=0,...,N-1, N is the number of accumulated pulses, Tp is the pulse width, T is the pulse repetition period, k is the transmission signal modulation frequency, and fc is the carrier frequency.

[0014] In one embodiment of the present invention, the original echo signal s(t',n) is expressed as:

[0015] s(t',n)=A r r[t'-τ(t),n]+w(t',n)

[0016] in, v is the lifting speed of the vehicle arm, A r represents the echo amplitude in volts, w(t′,n) represents Gaussian white noise with a mean of 0, R(t) represents the distance between the radar and the target high-voltage line at time t in meters, R0 represents the distance between the radar and the target high-voltage line at the initial time t0, and c represents the electromagnetic wave propagation speed, which is 3×10 8 Meters / second.

[0017] In one embodiment of the present invention, in S2, the step of obtaining the preprocessed echo signal is as follows:

[0018] S21: performing pulse cancellation processing on the original echo signal to obtain an echo signal after the pulse cancellation processing;

[0019] S22: performing interference suppression on the echo signal after the pulse cancellation processing to obtain an interference suppressed echo signal, that is, the pre-processed echo signal.

[0020] In one embodiment of the present invention, the echo signal s after the pulse cancellation processing MTI (t',n) is:

[0021] s MTI (t',n)=s(t',n)-2s(t'-T,n)+s(t'-2T,n).

[0022] In one embodiment of the present invention, the preprocessed echo signal S(f',n) is:

[0023] S(f',n)=FFT[s MTI (t',n)]

[0024] Among them, f'∈[-f d ,f d ], v is the lifting speed of the working vehicle arm, in m / s, θ is the radar line of sight angle; FFT[·] represents the fast Fourier transform function.

[0025] In one embodiment of the present invention, the frequency domain pulse pressure signal s pc (t',n) is:

[0026] s pc (t',n)=IFFT[FFT[r(t',n)]S * (f',n)]

[0027] Among them, S * (f',n) represents the conjugate of the preprocessed echo signal S(f',n), and IFFT[·] represents an inverse fast Fourier transform function.

[0028] In one embodiment of the present invention, in S4, the step of obtaining the target distance is as follows:

[0029] S41: after performing moving target detection processing on the frequency domain pulse pressure signal, setting a first iteration number and a second iteration number;

[0030] S42: Determine whether the first number of iterations has been reached:

[0031] If not, return to step S2 to perform non-coherent accumulation to obtain the non-coherent accumulation value calculated in each iteration;

[0032] If yes, filter out the maximum value among the multiple non-coherent accumulation values ​​to obtain the target distance information corresponding to the maximum value;

[0033] S43: Determine whether the second number of iterations has been reached:

[0034] If not, return to step S2 to obtain the target distance information corresponding to the maximum value in each non-coherent accumulation iterative calculation process;

[0035] If so, cluster the target distance information corresponding to multiple maximum values ​​to obtain the target distance.

[0036] In one embodiment of the present invention, in S41, the non-coherent accumulation value s obtained by each iteration calculation is obtained. Q (t',n) is:

[0037]

[0038] Among them, s Q (t',n) represents the non-coherent accumulation value, MTD[·] represents the moving target detection function, and Q is the first iteration number.

[0039] In one embodiment of the present invention, in S41, the target distance information R1 corresponding to the maximum value is obtained as follows:

[0040]

[0041] Among them, s Q (t',n) represents the non-coherent accumulation value, T s Indicates the collection time interval in seconds.

[0042] Based on the same inventive concept, the present invention also provides a high-voltage line detection and ranging system based on millimeter-wave radar, which includes the following modules:

[0043] A pulse signal transmitting module, used for transmitting a linear frequency modulation pulse signal to a high voltage line area;

[0044] An echo signal acquisition and preprocessing module, used to acquire an original echo signal reflected by the high-voltage line based on the linear frequency modulation pulse signal, and preprocess the original echo signal to obtain a preprocessed echo signal;

[0045] A signal-to-noise ratio enhancement module, used for performing pulse compression processing on the linear frequency modulation pulse signal and the preprocessed echo signal in the frequency domain to obtain a frequency domain pulse compression signal;

[0046] The target distance calculation module is used to obtain the target distance based on the frequency domain pulse pressure signal.

[0047] The present invention also provides a power transmission line alarm device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that when the processor executes the program, the steps of the high-voltage line detection and ranging method based on millimeter-wave radar are implemented to obtain the target distance between the operator and the target high-voltage line, and obtain the working safety distance based on the target distance.

[0048] The above technical solution of the present invention has the following advantages compared with the prior art:

[0049] 1. High-precision ranging: This technology transmits linear frequency-modulated pulse signals and receives the reflected echoes, and cleverly uses pulse compression technology to process them in the frequency domain, thereby greatly improving the accuracy of ranging.

[0050] 2. Strong anti-interference ability: With the strong anti-interference ability of millimeter wave radar technology, it can work stably in complex climate environments. In addition, through pulse cancellation processing and interference suppression in the pre-processing step, the influence of noise and interference can be further reduced, and the reliability of ranging can be improved.

[0051] 3. Strong adaptability and real-time performance: This technical solution is not only suitable for static high-voltage line detection, but also can perform real-time dynamic monitoring and precise ranging of dynamic targets through technical means such as dynamic target detection processing and non-coherent accumulation, which is of great significance for timely discovery and warning of potential safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

[0053] Figure 1 is a flow chart of a high-voltage line detection and ranging method based on millimeter-wave radar provided in Embodiment 1 of the present invention;

[0054] Figure 2 This is a specific flow chart of a high-voltage line detection and ranging method based on millimeter-wave radar provided in Embodiment 1 of the present invention;

[0055] Figure 3 is a flow chart of a method for obtaining a preprocessed echo signal provided in Embodiment 1 of the present invention;

[0056] Figure 4 The waveform diagram of the target's distance position when the non-coherent accumulation number Q is 2 and the result comparison number H is 1;

[0057] Figure 5The waveform diagram of the target’s distance position when the non-coherent accumulation number Q is 3 and the result comparison number H is 1;

[0058] Figure 6 The waveform diagram of the target’s distance position when the non-coherent accumulation number Q is 2 and the result comparison number H is 3;

[0059] Figure 7 is a structural diagram of a high-voltage line detection and ranging system based on millimeter-wave radar provided in Embodiment 2 of the present invention;

[0060] Description of the accompanying drawings in the specification: 100, pulse signal transmission module; 200, echo signal acquisition and preprocessing module; 300, signal-to-noise ratio enhancement module; 400, target distance calculation module. DETAILED DESCRIPTION

[0061] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0062] Embodiment 1

[0063] Reference Figure 1 and Figure 2 As shown, the present invention provides a method for high-voltage line detection and ranging based on millimeter-wave radar, the steps of which are as follows:

[0064] S1: Transmitting linear frequency modulation pulse signal (also called LFM signal) to the high voltage line area;

[0065] S2: based on the linear frequency modulation pulse signal, obtaining an original echo signal reflected by the target high-voltage line, and preprocessing the original echo signal to obtain a preprocessed echo signal;

[0066] S3: performing pulse compression processing on the linear frequency modulation pulse signal and the preprocessed echo signal in the frequency domain to obtain a frequency domain pulse compression signal;

[0067] S4: Obtaining a target distance based on the frequency domain pulse pressure signal, including:

[0068] S41: in order to distinguish between stationary targets and moving targets, after performing moving target detection (MTD) processing on the frequency domain pulse pressure signal, setting a first iteration number for non-coherent accumulation and a second iteration number for clustering processing of target distance information;

[0069] S42: Determine whether the first number of iterations has been reached:

[0070] If not, return to step S2 to perform non-coherent accumulation to improve the detection capability of weak targets and obtain the non-coherent accumulation value calculated in each iteration;

[0071] If yes, filter out the maximum value among multiple non-coherent accumulation values, and obtain the target distance information corresponding to the maximum value, which is the optimal estimate of the current iteration round;

[0072] S43: Determine whether the second number of iterations has been reached:

[0073] If not, return to step S2 to obtain the target distance information corresponding to the maximum value in each non-coherent accumulation iterative calculation process;

[0074] If so, cluster the target distance information corresponding to multiple maximum values ​​to remove false targets and duplicate targets and obtain the target distance.

[0075] It can be seen from the above technical solutions that the present invention realizes accurate detection and ranging of high-voltage lines by transmitting linear frequency modulation pulse signals, acquiring and preprocessing original echo signals, performing pulse compression processing in the frequency domain, and clustering processing of moving target detection and target distance information based on frequency domain pulse compression signals. This method has the advantages of high resolution, high signal-to-noise ratio, and strong anti-interference ability, and is suitable for high-voltage line detection and ranging tasks in various complex environments.

[0076] Furthermore, in step S1, a linear frequency modulation pulse signal is transmitted to the high voltage line area, wherein the linear frequency modulation pulse signal r(t',n) is:

[0077]

[0078] Among them, t′=t-nT represents the intra-pulse time, that is, the fast time, in seconds, rect represents the rectangular function operation, t is the acquisition time, n=0,...,N-1, N is the number of accumulated pulses, Tp is the pulse width, T is the pulse repetition period, k is the transmission signal modulation frequency, and fc is the carrier frequency.

[0079] The original echo signal reflected from the high-voltage line contains information such as the position and speed of the target (high-voltage line), but usually contains noise and interference. The original echo signal s(t',n) is expressed as:

[0080] s(t',n)=A r r[t'-τ(t),n]+w(t',n)

[0081] in, v is the lifting speed of the vehicle arm, A rrepresents the echo amplitude in volts, w(t′,n) represents Gaussian white noise with a mean of 0, R(t) represents the distance between the radar and the target high-voltage line at time t in meters, R0 represents the distance between the radar and the target high-voltage line at the initial time t0, and c represents the electromagnetic wave propagation speed, which is 3×10 8 Meters / second.

[0082] like Figure 3 As shown, in step S2, based on the linear frequency modulation pulse signal, the original echo signal reflected by the target high-voltage line is obtained, and the original echo signal is preprocessed to improve the signal quality and facilitate subsequent pulse compression and target detection. Specifically, the steps of obtaining the preprocessed echo signal are as follows:

[0083] S21: Perform pulse cancellation processing on the original echo signal to obtain an echo signal s after pulse cancellation processing MTI (t',n):

[0084] s MTI (t',n)=s(t',n)-2s(t'-T,n)+s(t'-2T,n);

[0085] S22: performing interference suppression on the echo signal after the pulse cancellation processing to obtain an interference suppressed echo signal, that is, the pre-processed echo signal S(f',n) is:

[0086] S(f',n)=FFT[s MTI (t',n)]

[0087] Among them, f'∈[-f d ,f d ], v is the lifting speed of the vehicle arm, v∈[-1,1], in m / s, f d ∈[-200,200], in Hz, θ is the radar line of sight angle, in radians; FFT[·] represents the fast Fourier transform function.

[0088] In order to improve the resolution and signal-to-noise ratio of the radar system, so as to more accurately extract target information, the linear frequency modulation pulse signal and the pre-processed echo signal obtained in the above steps are pulse compressed in the frequency domain to obtain the frequency domain pulse compression signal s pc (t',n) is:

[0089] s pc (t',n)=IFFT[FFT[r(t',n)]S * (f',n)]

[0090] Among them, S *(f',n) represents the conjugate of the preprocessed echo signal S(f',n), and IFFT[·] represents an inverse fast Fourier transform function.

[0091] like Figure 2 As shown, the specific steps of obtaining the target distance include:

[0092] S41: in order to distinguish between stationary targets and moving targets, after performing moving target detection (MTD) processing on the frequency domain pulse pressure signal, setting a first iteration number Q for non-coherent accumulation and a second iteration number H for clustering processing of target distance information;

[0093] The larger the value of Q is, the stronger the interference suppression capability is, but the longer the operation time is. In practical applications, a compromise should be made between the processing time and the estimation accuracy. In this embodiment, considering that the operation time is less than 200ms, the value of Q is 3;

[0094] The larger the value of H is, the higher the stability of the target distance information is, but the target result will have a greater delay. In this embodiment, considering that the calculation time is less than 200ms, the value of H is 3;

[0095] S42: Determine whether the first iteration number Q is reached:

[0096] If not, return to step S2 to perform non-coherent accumulation to improve the detection capability of weak targets and obtain the non-coherent accumulation value s obtained by each iteration calculation. Q (t',n) is:

[0097]

[0098] Among them, s Q (t',n) represents the non-coherent accumulation value, MTD[·] represents the moving target detection function, and Q is the first iteration number;

[0099] If yes, select the maximum value among multiple non-coherent accumulation values, and obtain the target distance information corresponding to the maximum value, which is the optimal estimate R1 of the current iteration round:

[0100]

[0101] Among them, s Q (t',n) represents the non-coherent accumulation value, T s Indicates the collection time interval in seconds;

[0102] S43: Determine whether the second iteration number H is reached:

[0103] If not, return to step S2 to obtain the target distance information R2, R3...R corresponding to the maximum value in each non-coherent accumulation iterative calculation process.h ;

[0104] If so, cluster the target distance information corresponding to multiple maximum values ​​to remove false targets and duplicate targets, and obtain the target distance R T :

[0105]

[0106] Among them, R h+1 is the target distance information corresponding to the maximum value obtained in the h+1th iteration, R h is the target distance information corresponding to the maximum value obtained in the hth iteration, |R h+1 -R h |≤ΔR, ΔR represents the difference in distance between two adjacent tests, which is generally set within 30 cm, h∈[1,H].

[0107] When H = 3, the target distance R T It is expressed as the following situations:

[0108] When R2-R1≤ΔR,

[0109] When |R3-R2|≤ΔR,

[0110] When |R2-R1|≤ΔR and |R3-R2|≤ΔR,

[0111] In order to verify the effectiveness of the high-voltage line detection and distance measurement method of the present invention, different values ​​of the actual target distance, the number of non-coherent accumulation times Q and the number of result comparison times H are set, and the distance estimation results are obtained accordingly, and then the error between the target distance estimation value and the actual target distance is compared. Specifically, Figures 4 to 6 The experimental results are shown when the actual target distance is set to 4 meters, 6.5 meters, and 7 meters. The straight line represents the amplitude of the noise floor, the curve represents the actual amplitude of the tested signal, and the horizontal axis corresponding to the position of the maximum amplitude is the target distance value of the test.

[0112] Depend on Figure 4 It can be seen that the target distance estimation value is highly consistent with the actual value, which fully verifies the accuracy of the method of the present invention in estimating the high-voltage line distance. Figure 4 The processing result, Figure 5 Although the target amplitude shown is reduced, a high signal-to-noise ratio is still maintained. By comparing the target distance estimate with the actual target distance, it is found that the accuracy of the estimate is still very high, which further confirms the effectiveness of the method of the present invention in detecting and estimating the distance of high-voltage lines in a low signal-to-noise ratio environment.

[0113] Figure 6 The distance estimation result is shown when the target distance is 7 meters. Figure 4 and Figure 5 In comparison, the echo intensity is further weakened at this time, and the signal-to-noise ratio of target detection is also reduced. However, by comparing the estimated target distance with the actual target distance, it can still be concluded that the estimated value is accurate. This result once again verifies the effectiveness of the method of the present invention in detecting and estimating the distance of high-voltage lines under low signal-to-noise ratio conditions.

[0114] In summary, the high-voltage line detection and ranging method proposed in the present invention has shown good performance and accuracy under different conditions, providing strong technical support for high-voltage line safety monitoring.

[0115] Embodiment 2

[0116] Based on the same inventive concept, the present invention also provides a high-voltage line detection and ranging system based on millimeter-wave radar, such as Figure 7 As shown, the system includes the following modules:

[0117] The pulse signal transmitting module 100 is used to transmit a linear frequency modulation pulse signal to a high voltage line area;

[0118] The echo signal acquisition and preprocessing module 200 is used to acquire the original echo signal reflected by the high-voltage line based on the linear frequency modulation pulse signal, and preprocess the original echo signal to obtain a preprocessed echo signal;

[0119] The signal-to-noise ratio enhancement module 300 is used to perform pulse compression processing on the linear frequency modulation pulse signal and the preprocessed echo signal in the frequency domain to obtain a frequency domain pulse compression signal;

[0120] The target distance calculation module 400 is used to obtain the target distance based on the frequency domain pulse pressure signal.

[0121] A high-voltage line detection and ranging system based on millimeter-wave radar proposed in this embodiment is used to implement the aforementioned high-voltage line detection and ranging method based on millimeter-wave radar. Therefore, the specific implementation method of the high-voltage line detection and ranging system based on millimeter-wave radar can be seen in the embodiment part of the aforementioned high-voltage line detection and ranging method based on millimeter-wave radar. For example, the pulse signal transmission module 100, the echo signal acquisition and preprocessing module 200, the signal-to-noise ratio enhancement module 300 and the target distance calculation module 400 are respectively used to correspond to the implementation of steps S1, S2, S3 and S4 in the high-voltage line detection and ranging method based on millimeter-wave radar in embodiment one. Therefore, its specific implementation method can refer to the description of the corresponding embodiments of each part. In order to avoid redundancy, it will not be repeated here.

[0122] Embodiment 3

[0123] The present invention also provides a power transmission line alarm device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the high-voltage line detection and ranging method based on millimeter-wave radar described in Example 1 when executing the program, so as to obtain the target distance between the operator and the target high-voltage line, and obtain the safe working distance according to the target distance.

[0124] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0125] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0126] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0127] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0128] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A high-voltage line detection and ranging method based on millimeter-wave radar, characterized in that: The following steps are involved: S1: Transmits linear frequency modulation pulse signal to the high voltage line area; S2: based on the linear frequency modulation pulse signal, obtaining an original echo signal reflected by the target high-voltage line, and preprocessing the original echo signal to obtain a preprocessed echo signal; S3: performing pulse compression processing on the linear frequency modulation pulse signal and the preprocessed echo signal in the frequency domain to obtain a frequency domain pulse compression signal; S4: Obtaining a target distance based on the frequency domain pulse pressure signal.

2. The high-voltage line detection and ranging method based on millimeter-wave radar according to claim 1 is characterized in that: The linear frequency modulation pulse signal r(t',n) is: Among them, t′=t-nT represents the intra-pulse time, that is, the fast time, in seconds, rect represents the rectangular function operation, t is the acquisition time, n=0,...,N-1, N is the number of accumulated pulses, Tp is the pulse width, T is the pulse repetition period, k is the transmission signal modulation frequency, and fc is the carrier frequency.

3. The high-voltage line detection and ranging method based on millimeter-wave radar according to claim 1 is characterized in that: The original echo signal s(t',n) is expressed as: s(t',n)=A r r[t'-τ(t),n]+w(t',n) in, v is the lifting speed of the vehicle arm, A r represents the echo amplitude in volts, w(t′,n) represents Gaussian white noise with a mean of 0, R(t) represents the distance between the radar and the target high-voltage line at time t in meters, R0 represents the distance between the radar and the target high-voltage line at the initial time t0, and c represents the electromagnetic wave propagation speed, which is 3×10 8 Meters / second.

4. The high-voltage line detection and ranging method based on millimeter-wave radar according to claim 3 is characterized in that: In S2, the steps of obtaining the preprocessed echo signal are as follows: S21: performing pulse cancellation processing on the original echo signal to obtain an echo signal after the pulse cancellation processing; S22: performing interference suppression on the echo signal after the pulse cancellation processing to obtain an interference suppressed echo signal, that is, the pre-processed echo signal.

5. The high-voltage line detection and ranging method based on millimeter-wave radar according to claim 4 is characterized in that: The echo signal s after the pulse cancellation process MTI (t',n) is: s MTI (t',n)=s(t',n)-2s(t'-T,n)+s(t'-2T,n)。 6. The high-voltage line detection and ranging method based on millimeter-wave radar according to claim 5 is characterized in that: The preprocessed echo signal S(f',n) is: S(f',n)=FFT[s MTI (t',n)] Among them, f'∈[-f d ,f d ], v is the lifting speed of the working vehicle arm, in m / s; FFT[·] represents the fast Fourier transform function.

7. The high-voltage line detection and ranging method based on millimeter-wave radar according to claim 6 is characterized in that: The frequency domain pulse pressure signal s pc (t',n) is: s pc (t',n)=IFFT[FFT[r(t',n)]S * (f',n)] Among them, S * (f',n) represents the conjugate of the preprocessed echo signal S(f',n), and IFFT[·] represents an inverse fast Fourier transform function.

8. The high-voltage line detection and ranging method based on millimeter-wave radar according to claim 7 is characterized in that: In S4, the steps to obtain the target distance are as follows: S41: after performing moving target detection processing on the frequency domain pulse pressure signal, setting a first iteration number and a second iteration number; S42: Determine whether the first number of iterations has been reached: If not, return to step S2 to perform non-coherent accumulation to obtain the non-coherent accumulation value calculated in each iteration; If yes, filter out the maximum value among the multiple non-coherent accumulation values ​​to obtain the target distance information corresponding to the maximum value; S43: Determine whether the second number of iterations has been reached: If not, return to step S2 to obtain the target distance information corresponding to the maximum value in each non-coherent accumulation iterative calculation process; If so, cluster the target distance information corresponding to multiple maximum values ​​to obtain the target distance.

9. The high-voltage line detection and ranging method based on millimeter-wave radar according to claim 8, characterized in that: In S42, the non-coherent accumulation value s obtained by each iteration calculation is obtained. Q (t',n) is: Wherein, MTD[·] represents a moving target detection function, and Q is the first iteration number.

10. The high-voltage line detection and ranging method based on millimeter-wave radar according to claim 8, characterized in that: In S42, the target distance information R1 corresponding to the maximum value is obtained as: Among them, s Q (t',n) represents the non-coherent accumulation value, T s Indicates the collection time interval in seconds.

11. A high-voltage line detection and ranging system based on millimeter-wave radar, characterized in that: Includes the following modules: A pulse signal transmitting module, used for transmitting a linear frequency modulation pulse signal to a high voltage line area; An echo signal acquisition and preprocessing module, used to acquire an original echo signal reflected by the high-voltage line based on the linear frequency modulation pulse signal, and preprocess the original echo signal to obtain a preprocessed echo signal; A signal-to-noise ratio enhancement module, used for performing pulse compression processing on the linear frequency modulation pulse signal and the preprocessed echo signal in the frequency domain to obtain a frequency domain pulse compression signal; The target distance calculation module is used to obtain the target distance based on the frequency domain pulse pressure signal.

12. A transmission line alarm device, characterized in that: It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the high-voltage line detection and ranging method based on millimeter-wave radar as described in any one of claims 1 to 10 are implemented to obtain the target distance between the operator and the target high-voltage line, and obtain the working safety distance according to the target distance.

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