CN112285665B

CN112285665B - Signal detection method and device, millimeter wave radar module, equipment and medium

Info

Publication number: CN112285665B
Application number: CN202011098029.XA
Authority: CN
Inventors: 陈有生
Original assignee: Guangzhou Xaircraft Technology Co Ltd
Current assignee: Guangzhou Xaircraft Technology Co Ltd
Priority date: 2020-10-14
Filing date: 2020-10-14
Publication date: 2023-12-26
Anticipated expiration: 2040-10-14
Also published as: CN112285665A

Abstract

The invention discloses a signal detection method, a device, a millimeter wave radar module, equipment and a medium, comprising the following steps: acquiring a Fourier transformed signal matched with an intermediate frequency measurement signal obtained by detection of the millimeter wave radar module, wherein the Fourier transformed signal comprises a plurality of signal points; clustering all signal points in the signals after Fourier transformation according to the preset cluster number, and obtaining a first detection threshold corresponding to the signals after Fourier transformation according to at least one cluster center obtained after clustering; calculating to obtain second detection thresholds corresponding to all signal points in the signals after Fourier transformation by adopting a preset algorithm; and determining target signal points and noise signal points in the signals after Fourier transformation according to the first detection threshold and the second detection threshold. The technical scheme of the embodiment of the invention can improve the accuracy of the detection result of the millimeter wave radar module on the target signal point.

Description

Signal detection method and device, millimeter wave radar module, equipment and medium

Technical Field

The embodiment of the invention relates to a data signal processing technology, in particular to a signal detection method, a signal detection device, a millimeter wave radar module, millimeter wave radar equipment and a millimeter wave signal medium.

Background

The millimeter wave radar module is a radar working in millimeter wave band detection, has the advantages of strong anti-interference capability, small volume and good concealment, and is widely applied to the unmanned aerial vehicle measurement field. The distance principle of the millimeter wave radar module for detecting the target is shown in fig. 1: the synthesizer transmits the modulated electromagnetic wave to a radar transmitting antenna (TX antenna), the radar transmitting antenna transmits the electromagnetic wave, the target object receives the electromagnetic wave and then reflects the electromagnetic wave to a receiving antenna (RX antenna), and an intermediate frequency measuring signal (intermediate frequency, IF) is obtained after a signal reflected by the target object and a transmitting signal of the transmitting antenna pass through a mixer; after the analog-to-digital converter (Analog Digital Converter, ADC) collects the intermediate frequency measurement signal, the intermediate frequency measurement signal (ADC signal) after the conversion is obtained through analog-to-digital conversion; after the ADC signal is subjected to digital signal processing, such as fourier transform (Fast Fourier Transform, FFT), a processed signal (FFT signal) can be obtained; and then, detecting the FFT signal to obtain the frequency corresponding to the maximum amplitude of the FFT signal, and calculating the distance between the FFT signal and the target object according to the frequency, wherein a set numerical relation exists between the distance and the frequency.

The conventional detection method generally adopts a constant false alarm detection algorithm (Constant False Alarm Rate, CFAR) in the radar field, but the method has the problem of low sensitivity and accuracy, and particularly on the premise that self-coupling signals and noise signals exist, the CFAR algorithm can misdetect unwanted signals almost every time.

Disclosure of Invention

The embodiment of the invention provides a signal detection method, a signal detection device, a millimeter wave radar module, millimeter wave radar equipment and a medium, which can improve the accuracy of a detection result of the millimeter wave radar module on a target signal point.

In a first aspect, an embodiment of the present invention provides a method for detecting a millimeter wave radar signal, including:

acquiring a Fourier transformed signal matched with an intermediate frequency measurement signal obtained by detection of a millimeter wave radar module, wherein the Fourier transformed signal comprises a plurality of signal points;

clustering all signal points in the signals after Fourier transformation according to a preset cluster number, and obtaining a first detection threshold corresponding to the signals after Fourier transformation according to at least one cluster center obtained after clustering;

calculating to obtain second detection thresholds corresponding to all signal points in the Fourier transformed signals respectively by adopting a preset algorithm;

And determining target signal points and noise signal points in the signals after Fourier transformation according to the first detection threshold and the second detection threshold.

Optionally, clustering is performed on each signal point in the signal after fourier transform according to a preset cluster number, and a first detection threshold corresponding to the signal after fourier transform is obtained according to at least one cluster center obtained after clustering, including:

initializing cluster centers respectively corresponding to the clusters according to the preset cluster number;

taking the initialized cluster center as a starting point, carrying out multiple clustering treatment on each signal point in the Fourier transformed signal, and carrying out loop iteration to obtain stable cluster centers respectively corresponding to each cluster;

and determining the first detection threshold according to the stable cluster center with the largest signal value in the stable cluster centers.

Optionally, initializing cluster centers corresponding to each cluster according to the preset cluster number, including:

selecting a maximum signal value from signal values corresponding to all signal points included in the Fourier transformed signal;

acquiring preset proportional coefficients respectively corresponding to the clusters according to the preset cluster number;

taking the product of the maximum signal value and each preset proportional coefficient as the cluster center corresponding to each cluster.

Optionally, determining the first detection threshold according to the largest stable cluster center in the cluster centers includes:

if the maximum stable cluster center is smaller than or equal to a first threshold constant, the first threshold constant is used as a first detection threshold;

if the maximum stable cluster center is larger than a first threshold constant and smaller than a second threshold constant, taking the maximum stable cluster center as a first detection threshold;

if the maximum stable cluster center is larger than or equal to a second threshold constant, the second threshold constant is used as a first detection threshold;

wherein the first threshold constant is less than the second threshold constant.

Optionally, determining the target signal point in the post-fourier-transform signal according to the first detection threshold and the second detection threshold includes:

sequentially acquiring one signal point in the signals after Fourier transformation as a current processing signal point;

if the signal value of the current processing signal point is greater than or equal to the first detection threshold value and greater than or equal to a second detection threshold value matched with the current processing signal point, the current processing signal point is taken as a target signal point;

If the signal value of the current processing signal point is smaller than any one of the first detection threshold value and the second detection threshold value, the current processing signal point is used as a noise signal point;

and returning to execute the operation of sequentially acquiring one signal point in the signals after the Fourier transformation as the current processing signal point until the processing of all the signal points in the signals after the Fourier transformation is completed.

Optionally, obtaining a post-fourier transform signal matched with the intermediate frequency measurement signal detected by the millimeter wave radar module includes:

acquiring a digital signal sequence matched with an intermediate frequency measurement signal obtained by detection of the millimeter wave radar module;

and performing fast Fourier transform on the digital signal sequence to obtain a signal after Fourier transform.

Optionally, before performing fast fourier transform on the digital signal sequence to obtain a post-fourier-transform signal, the method further includes:

dividing the digital signal sequence into a plurality of data packets, each data packet including a plurality of digital signal items;

determining a noise data packet and a valid data packet in each data packet according to the fluctuation degree of each digital signal item in each data packet;

And replacing the digital signal items in the noise data packet according to the digital signal items in at least one effective data packet to obtain a digital signal sequence after interference removal.

Optionally, after obtaining the digital signal sequence after interference removal, the method further includes:

fitting the digital signal sequence after interference removal by adopting a polynomial fitting method to obtain fitting values respectively corresponding to digital signal items in the digital signal sequence after interference removal;

and subtracting the fitting values of the digital signal items from the corresponding fitting values to obtain a digital signal sequence after direct current removal corresponding to the digital signal sequence after interference removal.

Optionally, after determining the target signal point in the post-fourier-transform signal according to the first detection threshold and the second detection threshold, the method further includes:

and calculating the distance between the millimeter wave radar module and the target object according to the position of the target signal point in the Fourier transformed signal.

In a second aspect, an embodiment of the present invention further provides a detection device for millimeter wave radar signals, where the device includes:

the acquisition module is used for acquiring a Fourier transformed signal matched with the intermediate frequency measurement signal detected by the millimeter wave radar module, wherein the Fourier transformed signal comprises a plurality of signal points;

The first detection threshold calculation module is used for carrying out clustering processing on each signal point in the signals after Fourier transformation according to the preset cluster number, and obtaining a first detection threshold corresponding to the signals after Fourier transformation according to at least one cluster center obtained after clustering;

the second detection threshold calculation module is used for calculating to obtain second detection thresholds corresponding to all signal points in the Fourier transformed signals respectively by adopting a preset algorithm;

and the determining module is used for determining a target signal point and a noise signal point in the Fourier transformed signal according to the first detection threshold value and the second detection threshold value.

In a third aspect, an embodiment of the present invention further provides a millimeter wave radar module, including:

the antenna module is used for sending electromagnetic wave signals to the surrounding environment and receiving echo signals matched with the electromagnetic wave signals;

the mixer is used for mixing the electromagnetic wave signal with the echo signal to obtain an intermediate frequency measurement signal;

the analog-to-digital converter is used for performing analog-to-digital conversion on the intermediate frequency measurement signal to obtain a digital signal sequence;

one or more processors; a storage means for storing one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors implement a method for detecting millimeter wave radar signals provided by any embodiment of the present invention.

In a fourth aspect, an embodiment of the present invention further provides a computer readable storage medium, where a computer program is stored, where the program when executed by a processor implements a method for detecting a millimeter wave radar signal provided by any embodiment of the present invention.

In a fifth aspect, an embodiment of the present invention further provides a mobile device, where the mobile device is configured with the millimeter wave radar module provided in any embodiment of the present invention.

According to the technical scheme, through obtaining the Fourier transform signal matched with the intermediate frequency measurement signal obtained by detection of the millimeter wave radar module, clustering is conducted on all signal points in the Fourier transform signal according to the preset cluster number, a first detection threshold corresponding to the Fourier transform signal is obtained according to at least one cluster center obtained after clustering, a second detection threshold corresponding to all signal points in the Fourier transform signal is obtained through calculation by adopting a preset algorithm, and the accuracy of the detection result of the millimeter wave radar module on the target signal point can be improved by determining the target signal point and the noise signal point in the Fourier transform signal according to the first detection threshold and the second detection threshold.

Drawings

FIG. 1 is a schematic diagram of a millimeter wave radar module detecting target distance;

fig. 2 is a flowchart of a method for detecting a millimeter wave radar signal according to a first embodiment of the present invention;

fig. 3a is a flowchart of a method for detecting a millimeter-wave radar signal according to a second embodiment of the present invention;

FIG. 3b is a schematic diagram of a Fourier transformed signal in a second embodiment of the invention;

FIG. 3c is a schematic diagram of a first detection threshold and a second detection threshold calculated from a post-Fourier transform signal according to a second embodiment of the present invention;

fig. 4a is a flowchart of a detection method of a millimeter wave radar signal in the third embodiment of the present invention;

fig. 4b is a schematic diagram of a digital signal sequence of the matching of the interfered intermediate frequency measurement signal in the third embodiment of the present invention;

fig. 4c is a digital signal sequence diagram of the matching of the intermediate frequency measurement signal after interference removal in the third embodiment of the present invention;

fig. 5a is a flowchart of a method for detecting a millimeter-wave radar signal according to a fourth embodiment of the present invention;

FIG. 5b is a schematic diagram of a digital signal sequence without DC component removal in a fourth embodiment of the invention;

FIG. 5c is a schematic diagram of a prior art method for DC removal and Fourier transform of a digital signal sequence;

FIG. 5d is a schematic diagram of a fourth embodiment of the present invention after fitting a digital signal sequence;

fig. 5e is a schematic diagram of a digital signal sequence after dc component removal in a fourth embodiment of the present invention;

FIG. 5f is a schematic diagram of a fourth embodiment of the present invention after performing a Fourier transform on the DC-removed signal sequence;

fig. 6 is a block diagram of a detection device for millimeter wave radar signals in a fifth embodiment of the present invention;

fig. 7 is a schematic structural diagram of a millimeter wave radar module in a sixth embodiment of the present invention;

fig. 8 is a schematic structural view of a mobile device according to a seventh embodiment of the present invention.

Detailed Description

The invention is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present invention are shown in the drawings.

Example 1

Fig. 2 is a flowchart of a method for detecting a millimeter-wave radar signal according to an embodiment of the present invention, where the method may be applied to a case of detecting a post-fourier-transform signal obtained by a millimeter-wave radar module, and the method may be performed by a device for detecting a millimeter-wave radar signal, and the device may be implemented by software and/or hardware and may be generally integrated in the millimeter-wave radar module, and specifically includes the following steps:

Step 110, obtaining a post-fourier-transform signal matched with the intermediate-frequency measurement signal detected by the millimeter wave radar module, wherein the post-fourier-transform signal comprises a plurality of signal points.

In this embodiment, the millimeter wave radar module is mounted on a mobile device (such as an unmanned aerial vehicle, an unmanned vehicle, and an unmanned ship) for measuring a distance between the mobile device and a target object. For example, in recent years, an agricultural plant protection unmanned aerial vehicle is required to keep a constant distance from a plant all the time in order to ensure that plant protection is successfully completed, and the distance is calculated by a millimeter wave radar module.

In one implementation manner of the embodiment of the present invention, obtaining a fourier transformed signal matched with an intermediate frequency measurement signal detected by a millimeter wave radar module includes: acquiring a digital signal sequence matched with an intermediate frequency measurement signal obtained by detection of the millimeter wave radar module; and performing fast Fourier transform on the digital signal sequence to obtain a signal after Fourier transform.

The intermediate frequency measurement signal is a signal obtained by mixing an electromagnetic wave signal sent by an antenna module in the millimeter wave radar module and a received echo signal through a mixer in the millimeter wave radar module; the digital signal sequence is a signal obtained by processing the intermediate frequency measurement signal through an analog-to-digital converter in the millimeter wave radar module.

And 120, clustering each signal point in the signals after Fourier transformation according to the preset cluster number, and obtaining a first detection threshold corresponding to the signals after Fourier transformation according to at least one cluster center obtained after clustering.

In one implementation manner of the embodiment of the present invention, clustering is performed on each signal point in the post-fourier-transform signal according to a preset cluster number, and a first detection threshold corresponding to the post-fourier-transform signal is obtained according to at least one cluster center obtained after clustering, including: initializing cluster centers respectively corresponding to the clusters according to the preset cluster number; taking the initialized cluster center as a starting point, carrying out multiple clustering treatment on each signal point in the Fourier transformed signal, and carrying out loop iteration to obtain stable cluster centers respectively corresponding to each cluster; and determining the first detection threshold according to the stable cluster center with the largest signal value in the stable cluster centers.

Optionally, initializing cluster centers corresponding to each cluster according to the preset cluster number, including: selecting a maximum signal value from signal values corresponding to all signal points included in the Fourier transformed signal; acquiring preset proportional coefficients respectively corresponding to the clusters according to the preset cluster number; taking the product of the maximum signal value and each preset proportional coefficient as the cluster center corresponding to each cluster.

In a specific embodiment, the largest signal value k can be selected from the signal values corresponding to all the signal points in the signal after fourier transformation, and the cluster center corresponding to each cluster is initialized assuming that the preset cluster number is 3, so as to obtain the cluster center corresponding to the first cluster as k ₁ The cluster center corresponding to the second cluster is k ₂ The cluster center corresponding to the third cluster is k ₃ Wherein each initialized cluster center k ₁ ，k ₂ ，k ₃ Is the product of the maximum signal value k and a plurality of different preset scaling factors, in particular, k ₁ ＝k*0.8，k ₂ ＝k*0.4，k ₃ ＝k*0；

Then calculating Euclidean distance between each signal point in the signals after Fourier transformation and each initialized cluster center, taking the signal point with the shortest Euclidean distance with each initialized cluster center as a center reference point, and marking each center reference point into the cluster where the corresponding initialized cluster center is located; calculating the average value of the signal values of each initialized cluster center and the corresponding center reference point, and replacing each initialized cluster center by using each average value; the above steps are repeatedly performed until each initialized cluster center is unchanged, and when the initialized cluster center is unchanged, the cluster center is taken as a stable cluster center. In the present embodiment, the preset cluster number and the preset scaling factor are set in actual conditions, which is not limited in this embodiment.

After the stable cluster centers corresponding to the clusters are obtained through the method, specifically, the stable cluster center with the largest signal value can be selected as the first detection threshold.

And 130, calculating to obtain second detection thresholds corresponding to the signal points in the Fourier transformed signals respectively by adopting a preset algorithm.

In this embodiment, optionally, a constant false alarm detection algorithm may be used to estimate the background clutter power level of each signal point, and then the estimated value of the background clutter power level corresponding to each signal point is multiplied by a preset value to obtain a second detection threshold value corresponding to each signal point.

And 140, determining a target signal point and a noise signal point in the Fourier transformed signal according to the first detection threshold and the second detection threshold.

In one implementation of the embodiment of the present invention, determining the target signal point in the post-fourier-transform signal according to the first detection threshold and the second detection threshold includes: sequentially acquiring one signal point in the signals after Fourier transformation as a current processing signal point; if the signal value of the current processing signal point is greater than or equal to the first detection threshold value and greater than or equal to a second detection threshold value matched with the current processing signal point, the current processing signal point is taken as a target signal point; if the signal value of the current processing signal point is smaller than any one of the first detection threshold value and the second detection threshold value, the current processing signal point is used as a noise signal point; and returning to execute the operation of sequentially acquiring one signal point in the signals after the Fourier transformation as the current processing signal point until the processing of all the signal points in the signals after the Fourier transformation is completed.

In this embodiment, since the intermediate frequency measurement signal detected by the millimeter wave radar module is a time domain signal with a fixed frequency, after the intermediate frequency measurement signal is subjected to fast fourier transform, the obtained fourier transformed signal will have a signal with a very strong amplitude at a certain frequency point. The conventional constant false alarm detection algorithm generally only compares the signal value of the signal point with a second detection threshold value when determining the target signal point, and takes the signal point as the target signal point when the signal value of the signal point is larger than the corresponding second detection threshold value. In this embodiment, the signal values of the signal points are compared with the first detection threshold and the second detection threshold at the same time, and since the first detection threshold can reflect the clustering level of the signal points and the first detection threshold is greater than the second detection threshold corresponding to most signal points, the accuracy of the detection result of the millimeter wave radar module on the target signal points can be improved by determining the target signal points in the fourier transformed signals according to the first detection threshold and the second detection threshold.

Example two

The embodiment provides a specific implementation manner of determining the first detection threshold corresponding to the signal after fourier transform based on the foregoing embodiment, and the explanation of the terms is the same as or corresponding to the foregoing embodiment, which is not repeated. Fig. 3a is a flowchart of a method for detecting a millimeter wave radar signal according to a second embodiment of the present invention, in this embodiment, the technical solution of this embodiment may be combined with one or more methods in the solution of the foregoing embodiment, and as shown in fig. 3a, the method provided by the embodiment of the present invention may further include:

step 210, obtaining a post-fourier-transform signal matched with the intermediate-frequency measurement signal detected by the millimeter wave radar module, wherein the post-fourier-transform signal comprises a plurality of signal points.

Step 220, initializing cluster centers respectively corresponding to the cluster clusters according to the preset cluster number.

And 230, carrying out multiple clustering treatment on each signal point in the Fourier transformed signal by taking the initialized cluster center as a starting point, and carrying out loop iteration to obtain stable cluster centers respectively corresponding to each cluster.

Step 240, determining a first detection threshold according to the stable cluster center with the largest signal value in the stable cluster centers.

In one implementation manner of the embodiment of the present invention, determining the first detection threshold according to the stable cluster center with the largest signal value in the stable cluster centers includes: if the center of the stable cluster with the maximum signal value is smaller than or equal to a first threshold constant, the first threshold constant is used as a first detection threshold; if the stable cluster center with the maximum signal value is larger than a first threshold constant and smaller than a second threshold constant, the stable cluster center with the maximum signal value is used as a first detection threshold; if the center of the stable cluster with the maximum signal value is larger than or equal to a second threshold constant, the second threshold constant is used as a first detection threshold; wherein the first threshold constant is less than the second threshold constant.

The first threshold constant is a larger preset value, and when the center of the largest stable cluster is smaller than or equal to the first threshold constant, the first threshold constant is used as a first detection threshold, so that the first detection threshold can be prevented from being too small; when the center of the stable cluster with the maximum signal value is larger than or equal to a second threshold constant, the second threshold constant is used as a first detection threshold, and the situation that the target signal point cannot be identified due to the fact that the first detection threshold is too large can be avoided, and therefore accuracy of detection results of the millimeter wave radar module on the target signal point can be improved.

And 250, calculating to obtain second detection thresholds corresponding to the signal points in the Fourier transformed signals respectively by adopting a preset algorithm.

Step 260, determining a target signal point and a noise signal point in the post-fourier-transform signal according to the first detection threshold and the second detection threshold.

FIG. 3b is a schematic diagram of the Fourier transformed signal obtained in this embodiment; fig. 3c is a schematic diagram of a first detection threshold and a second detection threshold calculated for the fourier transformed signal of fig. 3b, wherein the horizontal axis represents frequency and the vertical axis represents signal value. As shown in fig. 3c, curve 1 is the same post-fourier-transform signal as in fig. 3b, curve 2 is the calculated first detection threshold, and curve 3 is the calculated second detection threshold using the constant false alarm detection algorithm. As can be seen in fig. 3c, the abscissa of the first target signal point detected using the constant false alarm detection algorithm is about 20, the abscissa of the first target signal point detected using the first detection threshold in this embodiment is about 445, and the abscissa of the first target signal point detected using the first detection threshold in combination with the second detection threshold is about 447. Therefore, it can be explained that the detection method of the millimeter wave radar signal of the embodiment can improve the detection performance of the constant false alarm detection algorithm, reduce the false detection rate of the constant false alarm detection algorithm, and it can be seen from fig. 3c that a large number of erroneous detection results exist when the constant false alarm detection algorithm is used for detecting the target signal point in the first 400 signal points, and the position of the target signal point can be accurately detected after the clustering processing is added.

And 270, calculating the distance between the millimeter wave radar module and the target object according to the position of the target signal point in the Fourier transformed signal.

In this step, as shown in fig. 3c, according to the position of the target signal point in the signal after fourier transform, the frequency corresponding to the target signal point may be obtained, and according to this frequency, the distance between the millimeter wave radar module and the target object may be calculated, where a set numerical relationship exists between the distance and the frequency.

According to the technical scheme, the cluster centers corresponding to the clustered clusters are initialized according to the preset cluster number and are used as starting points, clustering processing is conducted on the signal points in the signals after the Fourier transform for multiple times, the stable cluster centers corresponding to the clustered clusters are obtained through cyclic iteration, a first detection threshold value is determined according to the stable cluster center with the largest signal value in the stable cluster centers, a second detection threshold value corresponding to the signal points in the signals after the Fourier transform is obtained through calculation according to the preset algorithm, and the target signal points and the noise signal points are determined according to the first detection threshold value and the second detection threshold value, so that accuracy of detection results of the millimeter wave radar module on the target signal points can be improved, detection performance of a constant false alarm detection algorithm is improved, and false detection rate of the constant false alarm detection algorithm is reduced.

Example III

The present embodiment is a further refinement of the foregoing embodiments, and the same or corresponding terms as those of the foregoing embodiments are explained, which are not repeated herein. Fig. 4a is a flowchart of a detection method of a millimeter wave radar signal according to a third embodiment of the present invention, in this embodiment, the technical solution of this embodiment may be combined with one or more methods in the solution of the foregoing embodiment, and as shown in fig. 4a, the method provided by the embodiment of the present invention may further include:

step 310, a digital signal sequence matched with the intermediate frequency measurement signal detected by the millimeter wave radar module is obtained.

Step 320, dividing the digital signal sequence into a plurality of data packets, each data packet including a plurality of digital signal items.

In this step, the digital signal sequence is composed of a plurality of digital signal points, and the digital signal sequence is divided into a plurality of data packets according to the output order of the analog-to-digital converter and a preset packet length, wherein the value of each digital signal point in each data packet is called a digital signal item, and the packet length of each data packet is the same. Assuming that the analog-to-digital converter outputs 440 digital signal points, the preset packet length is 10, the digital signal points are grouped into a group of 10 digital signal points, which can be divided into 44 data packets, the 1 st to 10 th digital signal points are the first packet, the 11 th to 20 th digital signal points are the second packet, and so on. The packet length is preset according to the actual situation, which is not limited in this embodiment.

Step 330, determining a noise data packet and a valid data packet in each data packet according to the fluctuation degree of each digital signal item in each data packet.

In this embodiment, considering that the electromagnetic wave signal emitted by the millimeter wave radar module is a standard sinusoidal signal, the standard sinusoidal signal theoretically does not have a great fluctuation degree, and if the fluctuation degree of a certain section of sinusoidal signal is great, it can be stated that a noise term is introduced into the section of sinusoidal signal. Namely: if the degree of fluctuation of each digital signal item in the data packet is relatively large, the data packet may be determined as a noisy data packet, whereas the data packet is determined as a valid data packet. If the data packet is a valid data packet, it means that each digital signal item in the data packet is valid data required in the process of measuring the distance by the millimeter wave radar module.

In one implementation of the embodiment of the present invention, determining a noise data packet and a valid data packet in each data packet according to a fluctuation degree of each digital signal item in each data packet includes: respectively calculating extremum difference between maximum value and minimum value in each data group, and calculating average extremum difference according to extremum difference of each data group; a noise data packet and a valid data packet are determined in each data packet based on a numerical relationship between the extremum difference and the average extremum difference for each data packet.

Wherein, the maximum value in the group in the data packet is the maximum value in each digital signal item, the minimum value in the group is the minimum value in each digital signal item, and the difference between the maximum value in the group and the minimum value in the group is the extremum difference. Assuming that the digital signal sequence is divided into 44 data packets in step 320, each data packet corresponds to one extremum difference, then there are 44 extremum differences in total, and the 44 extremum differences are averaged to obtain an average extremum difference. Then judging whether each extremum difference is larger than the product of the average extremum difference and the set proportionality coefficient; if yes, determining the data packet corresponding to the extremum difference as a noise data packet; if not, the data packet corresponding to the extremum difference is determined to be a valid data packet. The set proportionality coefficient is associated with the configuration parameters of the millimeter wave radar module and the model of the unmanned aerial vehicle adapted by the millimeter wave radar module, and is an adjustable constant, for example, 30.

And 340, replacing the digital signal items in the noise data packet according to the digital signal items in at least one effective data packet to obtain a digital signal sequence after interference removal.

In one implementation manner of the embodiment of the present invention, replacing the digital signal item in the noise data packet according to the digital signal item in at least one valid data packet to obtain a de-interference signal sequence matched with the digital signal sequence includes: acquiring a digital signal item in an effective data packet, for example, acquiring a digital signal item of an effective data packet adjacent to the noise data packet to the left or right, and taking the digital signal item in the effective data packet as replacement data in the noise data packet to replace the digital signal item in the noise data packet; or alternatively

Performing interpolation calculation according to the maximum value and the minimum value of the digital signal items in one effective data packet, for example, obtaining the maximum value and the minimum value of the digital signal items of the effective data packet adjacent to the left or adjacent to the right of the noise data packet, and interpolating to obtain a plurality of interpolation signal items matched with the number of the digital signal items in the noise data packet; replacing digital signal items in the associated noise data packets using the interpolated signal items; or alternatively

Traversing each noise data packet, and respectively acquiring at least one effective data packet from the left side and the right side of each noise data packet; according to digital signal items in at least one effective data packet on the left side and the right side of each noise data packet and a preset interpolation algorithm, interpolation is carried out to obtain a plurality of interpolation signal items matched with the number of the digital signal items in the noise data packet; and replacing the digital signal item in the associated noise data packet by using the interpolation signal item.

If a plurality of noise data packets are adjacent, the noise data packets can be combined into a new noise data packet, so that interference elimination processing is carried out on the noise data packets, and processing efficiency is improved. If valid data packets exist on the left side and the right side of the noise data packet, interpolation operation is performed on the last digital signal item in the left side data packet of the noise data packet and the first digital signal item in the right side data packet of the noise data packet according to a preset interpolation algorithm to obtain a plurality of interpolation signal items matched with the number of the digital signal items in the noise data packet, and then the digital signal items in the noise data packet are replaced by the plurality of interpolation signal items. The preset interpolation algorithm may be a linear interpolation algorithm or a nonlinear interpolation algorithm, which is not limited in this embodiment.

Therefore, the digital signal items in the noise data packet are close to the digital signal items in the effective data packet by carrying out interpolation operation on the digital signal items in at least one effective data packet on the left side and the right side of the noise data packet and replacing the digital signal items in the noise data packet by the operated interpolation signal items, so that the interference on the signals is eliminated.

In this embodiment, optionally, before replacing the digital signal item in the noise data packet according to the digital signal item in the at least one valid data packet, the method further includes: determining whether the noisy data packet is a first data packet or a last data packet of the plurality of data packets; if yes, all digital signal items in the currently processed noise data packet are set to be preset data values; if not, replacing the digital signal items in the noise data packet according to the digital signal items in at least one effective data packet.

Wherein if the currently processed noise data packet does not have a left adjacent data packet, the noise data packet may be determined to be a first data packet of the plurality of data packets; if there is no right-adjacent data packet in the currently processed noise data packet, it may be determined that the noise data packet is the last data packet of the plurality of data packets. If the noise data packet is the first data packet or the last data packet of the plurality of data packets, each digital signal item in the currently processed noise data packet is all set to a preset data value.

Where the millimeter wave radar module generally needs to truncate the digital signal sequence using a window function before processing (e.g., fourier transform) the digital signal sequence, the digital signal entries at the beginning and end of the digital signal sequence have little effect on the processed result, so if there is no valid data packet that is left-adjacent or valid data packet that is right-adjacent to the currently processed noise data packet, all of the digital signal entries in the currently processed noise data packet may be set to zero.

Fig. 4b is a schematic diagram of a digital signal sequence matched with the interfered intermediate frequency measurement signal in the present embodiment, where the abscissa is the serial number of each digital signal point output by the analog-to-digital converter, and the ordinate is a digital signal item. As shown in fig. 4b, the digital signal sequence between the 350 th digital signal point and the 400 th digital signal point is severely disturbed. According to the interference elimination method of the embodiment, the digital signal sequence in fig. 4b is processed, so that fig. 4c is obtained, as shown in fig. 4c, each digital signal item in the digital signal sequence fluctuates around a stable constant value, the fluctuation degree of each digital signal item is smaller, and the interference elimination effect on the intermediate frequency measurement signal in fig. 4b is achieved.

And 350, performing fast Fourier transform on the digital signal sequence to obtain a signal after Fourier transform.

And 360, clustering each signal point in the signals after Fourier transformation according to the preset cluster number, and obtaining a first detection threshold corresponding to the signals after Fourier transformation according to at least one cluster center obtained after clustering.

And 370, calculating to obtain second detection thresholds corresponding to the signal points in the Fourier transformed signals respectively by adopting a preset algorithm.

Step 380, determining a target signal point and a noise signal point in the post-fourier-transform signal according to the first detection threshold and the second detection threshold.

According to the technical scheme, the digital signal sequences which are obtained by detecting the millimeter wave radar module and are matched with the intermediate frequency measurement signals are grouped, noise data groups and effective data are determined according to the fluctuation degree of each digital signal item in each data group, the digital signal items in the noise data groups are replaced according to the digital signal items in at least one effective data group, fast Fourier transform is carried out on the replaced digital signal sequences, clustering processing is carried out on each signal point according to the preset cluster number, a first detection threshold value corresponding to the signals after Fourier transform is obtained according to the cluster center calculated after clustering, a second detection threshold value corresponding to each signal point in the signals after Fourier transform is obtained by adopting a preset algorithm, the target signal point and the noise signal point in the signals after Fourier transform are determined according to the first detection threshold value and the second detection threshold value, interference signals in the intermediate frequency measurement signals can be effectively eliminated, the accuracy of the detection result of the target signal point by the millimeter wave radar module is improved, the detection performance of a constant false alarm detection algorithm is improved, and the false alarm detection rate of the constant false alarm detection algorithm is reduced.

Example IV

The present embodiment is a further refinement of the foregoing embodiments, and the same or corresponding terms as those of the foregoing embodiments are explained, which are not repeated herein. Fig. 5a is a flowchart of a method for detecting a millimeter wave radar signal according to a fourth embodiment of the present invention, in this embodiment, the technical solution of this embodiment may be combined with one or more methods in the solution of the foregoing embodiment, and as shown in fig. 5a, the method provided by the embodiment of the present invention may further include:

step 401, acquiring a digital signal sequence matched with an intermediate frequency measurement signal detected by the millimeter wave radar module.

Step 402, dividing the digital signal sequence into a plurality of data packets, wherein the data packets comprise a plurality of digital signal items.

Step 403, determining a noise data packet and a valid data packet in each data packet according to the fluctuation degree of each digital signal item in each data packet.

Step 404, replacing the digital signal item in the noise data packet according to the digital signal item in at least one effective data packet, so as to obtain a digital signal sequence after interference removal.

And step 405, fitting the digital signal sequence after interference removal by using a polynomial fitting method to obtain fitting values respectively corresponding to the digital signal items in the digital signal sequence after interference removal.

The millimeter wave radar module is usually required to remove a direct current component in the digital signal sequence in the distance measurement process, if the direct current component exists in the digital signal sequence, a large low-frequency component easily exists in data after the digital signal sequence is subjected to Fourier transform by the millimeter wave radar module, and the low-frequency component can mask a real low-frequency signal. The existing method for removing the direct current component comprises the following steps: and subtracting the average value of the whole digital signal items from each digital signal item to obtain a DC-free signal sequence. However, if the mean value of the integral digital signal item is not a straight line, the low-frequency interference data exists in the data obtained by performing fourier transformation on the direct current signal sequence in the existing method.

Fig. 5b is a schematic diagram of a digital signal sequence without dc component removal in the present embodiment, fig. 5c is a schematic diagram after dc removal processing is performed on the digital signal sequence in fig. 5b by a conventional method, and fourier transformation is performed, and the abscissa in fig. 5c represents frequency and the ordinate represents signal value. As can be seen from fig. 5c, the data after fourier transforming the dc-removed signal sequence in the conventional method has low-frequency interference data.

The embodiment proposes an implementation manner of subtracting the fitting values corresponding to each digital signal item from each digital signal item to remove the direct current component. In a specific embodiment, a 5-order polynomial fitting method may be used to fit the digital signal sequence, or a fitting result of the interference-free signal sequence may be obtained by calling a polyfit function in matrix laboratory software (Matrix Laboratory, MATLAB). As shown in fig. 5d, curve 1 is a digital signal sequence from which a direct current component is not removed, and curve 2 is a curve obtained by fitting a digital signal sequence from which a direct current component is not removed.

Step 406, subtracting the fitting value from each digital signal item to obtain a digital signal sequence after direct current removal corresponding to the digital signal sequence after interference removal.

As shown in fig. 5d, the dc-removed signal sequence, i.e., curve 3, is obtained by subtracting curve 1 from curve 2.

Step 407, performing fast fourier transform on the digital signal sequence after direct current removal to obtain a signal after fourier transform.

Fig. 5e is a schematic diagram of the dc component removal process of fig. 5b, the curve in fig. 5e is the same as curve 3 in fig. 5d, and fig. 5f is a schematic diagram of the dc signal removal sequence of fig. 5e after fourier transformation. As can be seen from fig. 5f and fig. 5c, the low frequency amplitude in fig. 5f is smaller than the amplitude of the following real signal, and the low frequency amplitude in fig. 5c is larger than the amplitude of the following real signal, so that it can be explained that the dc component removing method proposed in the present embodiment has better dc component removing effect than the existing dc component removing method.

And 408, clustering each signal point in the signals after Fourier transformation according to the preset cluster number, and obtaining a first detection threshold corresponding to the signals after Fourier transformation according to at least one cluster center obtained after clustering.

And 409, calculating to obtain second detection thresholds corresponding to the signal points in the Fourier transformed signals respectively by adopting a preset algorithm.

Step 410, determining a target signal point and a noise signal point in the post-fourier-transform signal according to the first detection threshold and the second detection threshold.

According to the technical scheme, the digital signal sequences matched with the intermediate frequency measurement signals detected by the millimeter wave radar module are grouped, and noise data groups and effective data are determined according to the fluctuation degree of each digital signal item in each data group; according to the digital signal item in at least one effective data packet, replacing the digital signal item in the noise data packet to obtain a digital signal sequence after interference removal; then, a polynomial fitting method is adopted to fit the digital signal sequence, and each digital signal item is subtracted from the corresponding fitting value to obtain a digital signal sequence after DC removal; performing fast Fourier transform on the digital signal sequence after DC removal, performing clustering processing on each signal point in the signal after Fourier transform according to a preset cluster number, obtaining a first detection threshold according to a cluster center calculated after clustering, calculating to obtain a second detection threshold corresponding to each signal point in the signal after Fourier transform by adopting a preset algorithm, and determining a target signal point and a noise signal point in the signal after Fourier transform according to the first detection threshold and the second detection threshold. The technical scheme of the embodiment of the invention can effectively eliminate the interference signal in the intermediate frequency measurement signal, eliminate the direct current component in the digital signal sequence matched with the intermediate frequency measurement signal, improve the accuracy of the detection result of the millimeter wave radar module on the target signal point and reduce the false detection rate of the constant false alarm detection algorithm.

Example five

Fig. 6 is a block diagram of a detection device for millimeter wave radar signals according to a fifth embodiment of the present invention, where the device includes: an acquisition module 610, a first detection threshold calculation module 620, a second detection threshold calculation module 630, and a determination module 640, wherein:

an obtaining module 610, configured to obtain a post-fourier-transform signal that matches the intermediate frequency measurement signal detected by the millimeter wave radar module, where the post-fourier-transform signal includes a plurality of signal points;

the first detection threshold calculation module 620 is configured to perform clustering processing on each signal point in the post-fourier-transform signal according to a preset cluster number, and obtain a first detection threshold corresponding to the post-fourier-transform signal according to at least one cluster center obtained after clustering;

a second detection threshold calculation module 630, configured to calculate, using a preset algorithm, a second detection threshold corresponding to each signal point in the fourier transformed signal;

and the determining module 640 is configured to determine a target signal point and a noise signal point in the post-fourier-transform signal according to the first detection threshold and the second detection threshold.

On the basis of the above embodiments, the first detection threshold calculation module 620 includes:

the initialization unit is used for initializing cluster centers corresponding to the cluster clusters respectively according to the preset cluster number;

the clustering unit is used for carrying out multiple clustering treatment on each signal point in the signals after Fourier transformation by taking the initialized cluster center as a starting point, and carrying out loop iteration to obtain stable cluster centers respectively corresponding to each cluster;

a first detection threshold determining unit, configured to determine the first detection threshold according to a stable cluster center with a maximum signal value in the stable cluster centers;

the first detection threshold determining unit is specifically configured to take a first threshold constant as a first detection threshold when a center of a stable cluster with a maximum signal value is smaller than or equal to the first threshold constant; when the stable cluster center with the maximum signal value is larger than a first threshold constant and smaller than a second threshold constant, the stable cluster center with the maximum signal value is used as a first detection threshold; when the center of the stable cluster with the maximum signal value is larger than or equal to a second threshold constant, the second threshold constant is used as a first detection threshold; wherein the first threshold constant is less than the second threshold constant;

The maximum signal value selecting unit is used for selecting the maximum signal value from the signal values corresponding to all the signal points included in the Fourier transformed signal;

the preset proportional coefficient acquisition unit is used for acquiring preset proportional coefficients corresponding to each cluster according to the preset cluster number;

and the cluster center determining unit is used for taking the product of the maximum signal value and each preset proportional coefficient as the cluster center corresponding to each cluster.

The determining module 640 includes:

the current processing signal point acquisition unit is used for sequentially acquiring one signal point in the signals after Fourier transformation as a current processing signal point;

the target signal point determining unit is used for determining that the signal value of the current processing signal point is larger than or equal to the first detection threshold value and larger than or equal to the second detection threshold value matched with the current processing signal point, and taking the current processing signal point as a target signal point;

and the all-signal-point processing unit is used for returning to execute the operation of sequentially acquiring one signal point in the signals after the Fourier transformation as the current processing signal point until the processing of all the signal points in the signals after the Fourier transformation is completed.

The acquisition module 610 includes:

the digital signal sequence acquisition unit is used for acquiring a digital signal sequence matched with the intermediate frequency measurement signal detected by the millimeter wave radar module;

the transformation unit is used for carrying out fast Fourier transformation on the digital signal sequence to obtain a signal after Fourier transformation;

a grouping unit for dividing the digital signal sequence into a plurality of data packets, each data packet including a plurality of digital signal items therein;

a noise data packet determination unit configured to determine a noise data packet and a valid data packet in each data packet based on a degree of fluctuation of each digital signal item in each data packet;

a replacing unit, configured to replace the digital signal item in the noise data packet according to the digital signal item in at least one effective data packet, so as to obtain a digital signal sequence after interference removal;

the fitting unit is used for fitting the digital signal sequence after interference removal by adopting a polynomial fitting method to obtain fitting values respectively corresponding to the digital signal items in the digital signal sequence after interference removal;

and the direct current signal removing unit is used for subtracting the fitting value corresponding to each digital signal item to obtain a digital signal sequence after direct current removal corresponding to the digital signal sequence after interference removal.

The detection device of millimeter wave radar signals further comprises:

and the distance calculation module is used for calculating the distance between the millimeter wave radar module and the target object according to the position of the target signal point in the Fourier transformed signal.

The detection device for the millimeter wave radar signal provided by the embodiment of the invention can execute the detection method for the millimeter wave radar signal provided by any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the execution method.

Example six

Fig. 7 is a schematic structural diagram of a millimeter wave radar module according to a sixth embodiment of the present invention, as shown in fig. 7, the millimeter wave radar module includes a processor 710, a memory 720, an input device 730, an output device 740, an antenna module 750, a mixer 760 and an analog-to-digital converter 770.

An antenna module 750 for transmitting electromagnetic wave signals to the surrounding environment and receiving echo signals matched with the electromagnetic wave signals;

a mixer 760 for mixing the electromagnetic wave signal with the echo signal to obtain an intermediate frequency measurement signal;

analog-to-digital converter 770, which is configured to perform analog-to-digital conversion on the intermediate frequency measurement signal to obtain a digital signal sequence;

The number of processors 710 in the millimeter wave radar module may be one or more, one processor 710 being taken as an example in fig. 7; processor 710, memory 720, input device 730, output device 740, antenna module 750, mixer 760, and analog-to-digital converter 770 in the millimeter wave radar module may be connected by a bus or other means, for example in fig. 7.

The memory 720 is a computer readable storage medium, and may be used to store a software program, a computer executable program, and modules, such as program instructions/modules corresponding to the detection method of the millimeter wave radar signal in the embodiment of the present invention (for example, the acquisition module 610, the first detection threshold calculation module 620, the second detection threshold calculation module 630, and the determination module 640 in the detection device of the millimeter wave radar signal). Processor 710 executes various functional applications and data processing of the millimeter wave radar module by executing software programs, instructions and modules stored in memory 720, i.e., implements the detection method of millimeter wave radar signals described above. That is, the program, when executed by the processor, implements:

Memory 720 may include primarily a program storage area and a data storage area, wherein the program storage area may store an operating system, at least one application program required for functionality; the storage data area may store data created according to the use of the terminal, etc. In addition, memory 720 may include high-speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid-state storage device. In some examples, memory 720 may further include memory remotely located relative to processor 710, which may be connected to millimeter wave radar modules via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The input device 730 may be used to receive information such as the model number of the unmanned aerial vehicle entered by the user. The output device 740 may include various information output interfaces, such as a CAN bus interface or an RS232 interface, etc., to output measured position information of the target object.

Example seven

Fig. 8 is a schematic structural diagram of a mobile device according to a seventh embodiment of the present invention, where the mobile device includes an unmanned aerial vehicle, an unmanned vehicle, and an unmanned ship.

As shown in fig. 8, the mobile device 801 is configured with a millimeter wave radar module 802 provided by any embodiment of the present invention. In this embodiment, the millimeter wave radar module 802 performs clustering processing on each signal point in the signal after fourier transform according to a preset cluster number by acquiring a signal after fourier transform matched with the intermediate frequency measurement signal detected by the millimeter wave radar module, obtains a first detection threshold corresponding to the signal after fourier transform according to at least one cluster center obtained after clustering, calculates to obtain a second detection threshold corresponding to each signal point in the signal after fourier transform by adopting a preset algorithm, and determines a target signal point and a noise signal point in the signal after fourier transform according to the first detection threshold and the second detection threshold, so that accuracy of a detection result of the millimeter wave radar module on the target signal point can be improved.

Example eight

An eighth embodiment of the present invention further provides a computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the method according to any embodiment of the present invention. Of course, the computer readable storage medium provided by the embodiments of the present invention may perform the related operations in the detection method of the millimeter wave radar signal provided by any embodiment of the present invention. That is, the program, when executed by the processor, implements:

From the above description of embodiments, it will be clear to a person skilled in the art that the present invention may be implemented by means of software and necessary general purpose hardware, but of course also by means of hardware, although in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art in the form of a software product, which may be stored in a computer readable storage medium, such as a floppy disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a FLASH Memory (FLASH), a hard disk or an optical disk of a computer, etc., and include several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method according to the embodiments of the present invention.

It should be noted that, in the embodiment of the detection device for millimeter wave radar signals, each unit and module included in the detection device are only divided according to the functional logic, but are not limited to the above-mentioned division, so long as the corresponding functions can be implemented; in addition, the specific names of the functional units are also only for distinguishing from each other, and are not used to limit the protection scope of the present invention.

Note that the above is only a preferred embodiment of the present invention and the technical principle applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, while the invention has been described in connection with the above embodiments, the invention is not limited to the embodiments, but may be embodied in many other equivalent forms without departing from the spirit or scope of the invention, which is set forth in the following claims.

Claims

1. A method of detecting a millimeter wave radar signal, comprising:

clustering the signal points in the signals after Fourier transformation according to the preset cluster number, and obtaining a first detection threshold corresponding to the signals after Fourier transformation according to at least one cluster center obtained after clustering, wherein the first detection threshold comprises the following steps: initializing cluster centers respectively corresponding to the clusters according to the preset cluster number; taking the initialized cluster center as a starting point, carrying out multiple clustering treatment on each signal point in the Fourier transformed signal, and carrying out loop iteration to obtain stable cluster centers respectively corresponding to each cluster; determining the first detection threshold according to the stable cluster center with the largest signal value in the stable cluster centers;

Calculating to obtain second detection thresholds corresponding to all signal points in the signals after Fourier transformation by adopting a preset algorithm, wherein the second detection thresholds comprise: calculating an estimated value of the background clutter power level corresponding to each signal point by adopting a constant false alarm detection algorithm, and multiplying the estimated value of the background clutter power level corresponding to each signal point by a preset value to obtain a second detection threshold value corresponding to each signal point respectively;

determining a target signal point and a noise signal point in the Fourier transformed signal according to the first detection threshold and the second detection threshold;

wherein the determining a target signal point in the post-fourier-transform signal according to the first detection threshold and the second detection threshold includes:

2. The method for detecting a millimeter wave radar signal according to claim 1, wherein initializing cluster centers respectively corresponding to each cluster according to a preset number of clusters comprises:

3. The method of detecting a millimeter wave radar signal according to claim 1, wherein determining the first detection threshold value based on a stable cluster center having a largest signal value among the stable cluster centers comprises:

if the center of the stable cluster with the maximum signal value is smaller than or equal to a first threshold constant, the first threshold constant is used as a first detection threshold;

if the stable cluster center with the maximum signal value is larger than a first threshold constant and smaller than a second threshold constant, taking the stable cluster center with the maximum signal value as a first detection threshold;

If the stable cluster center with the maximum signal value is larger than or equal to a second threshold constant, the second threshold constant is used as a first detection threshold;

4. The method for detecting a millimeter wave radar signal according to claim 1, wherein acquiring a post fourier transform signal matching an intermediate frequency measurement signal detected by the millimeter wave radar module comprises:

5. The method for detecting millimeter wave radar signals according to claim 4, wherein before performing fast fourier transform on the digital signal sequence to obtain a post-fourier-transform signal, further comprising:

6. The method for detecting a millimeter wave radar signal according to claim 5, further comprising, after obtaining the digital signal sequence after interference removal:

7. The method of detecting a millimeter wave radar signal according to claim 1, further comprising, after determining a target signal point in the post-fourier-transform signal according to the first detection threshold and the second detection threshold:

8. A detection device for millimeter wave radar signals, comprising:

the first detection threshold calculation module is configured to perform clustering processing on each signal point in the post-fourier-transform signal according to a preset cluster number, and obtain a first detection threshold corresponding to the post-fourier-transform signal according to at least one cluster center obtained after clustering, where the first detection threshold includes: the initialization unit is used for initializing cluster centers corresponding to the cluster clusters respectively according to the preset cluster number; the clustering unit is used for carrying out multiple clustering treatment on each signal point in the signals after Fourier transformation by taking the initialized cluster center as a starting point, and carrying out loop iteration to obtain stable cluster centers respectively corresponding to each cluster; a first detection threshold determining unit, configured to determine the first detection threshold according to a stable cluster center with a maximum signal value in the stable cluster centers;

the second detection threshold calculation module is configured to calculate, by using a preset algorithm, a second detection threshold corresponding to each signal point in the fourier transformed signal, where the second detection threshold calculation module includes: calculating an estimated value of the background clutter power level corresponding to each signal point by adopting a constant false alarm detection algorithm, and multiplying the estimated value of the background clutter power level corresponding to each signal point by a preset value to obtain a second detection threshold value corresponding to each signal point respectively;

The determining module is used for determining a target signal point and a noise signal point in the Fourier transformed signal according to the first detection threshold and the second detection threshold;

wherein the determining module comprises:

a target signal point determining unit, configured to take the current processing signal point as a target signal point if the signal value of the current processing signal point is greater than or equal to the first detection threshold and greater than or equal to a second detection threshold that is matched with the current processing signal point; if the signal value of the current processing signal point is smaller than any one of the first detection threshold value and the second detection threshold value, the current processing signal point is used as a noise signal point;

9. A millimeter wave radar module, the millimeter wave radar module comprising:

one or more processors;

a storage means for storing one or more programs;

when executed by the one or more processors, causes the one or more processors to implement a method of detecting millimeter wave radar signals as recited in any one of claims 1-7.

10. A computer-readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements a method for detecting a millimeter-wave radar signal according to any one of claims 1-7.

11. A mobile device having the millimeter wave radar module of claim 9 disposed thereon.