CN114966656A - Positioning method and device based on millimeter wave equipment - Google Patents
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Abstract
The invention provides a positioning method and a positioning device based on millimeter wave equipment, wherein the method comprises the following steps: acquiring the number of targets to be detected and echo signals, and constructing a frequency spectrum signal model based on the number of the targets to be detected and the echo signals; calculating a sampling error value of a target to be detected and a phase difference of adjacent antennas based on a spectrum signal model; calculating a distance value from the target to be detected to the millimeter wave equipment based on the sampling error value, and calculating a reaching angle of the target to be detected based on the phase difference; and generating a positioning result of the target to be detected according to the distance value and the wave arrival angle. The method is based on millimeter wave equipment, utilizes the advantages of short millimeter wave wavelength and high resolution, and accurately calculates the signal frequency by establishing a quantitative analysis model of a frequency spectrum sampling point and the signal frequency aiming at the conditions of different target numbers, thereby completing high-precision distance measurement; the measurement precision of the signal wave arrival angle is improved in the calculation process of the signal frequency, and the high-precision positioning of the target to be measured is further realized.
Description
Technical Field
The invention relates to the technical field of wireless sensing, in particular to a positioning method and device based on millimeter wave equipment.
Background
Accurate target location technology is especially important in daily applications, including safety monitoring, virtual reality, and smart home. Also, high resolution positioning is required for some industrial applications, such as robotic arms, conveyor belts, subway train control systems. In conjunction with these applications, many different device-based object localization techniques are currently emerging, including wearable sensor-based localization as well as visual signal-based localization. However, these positioning technologies all have certain defects, and positioning based on a sensor requires that a target carries a specific device, and is not convenient enough to use in scenes such as security monitoring. Positioning based on visual signals is easy to threaten the privacy of users, and is not suitable for family scenes and important work units; in addition, the camera is greatly influenced by the illumination condition, and in the case of extreme illumination condition, the measurement result will be greatly interfered.
In recent years, wireless signal-based positioning technologies have been attracting attention, and wireless signals mainly include Wi-Fi signals, RFID signals, millimeter wave signals, and the like. In recent years, in addition to their common communication functions, researchers have been searching for techniques for obtaining activity information contained in a wireless signal by using phenomena such as reflection and scattering of the wireless signal, and for realizing perception of a target motion state. The wavelength of millimeter-wave signals is typically on the order of millimeters. The millimeter wave signal has strong penetrating power and large bandwidth, so that the millimeter wave signal has high signal resolution and smoke penetrating capability and is less influenced by the environment. The electromagnetic wave signals are utilized to sense the activities of the personnel, so that the privacy of the personnel can be effectively protected; in addition, the electromagnetic waves can realize activity sensing by utilizing reflected signals of personnel, positioning and tracking can be realized without carrying specific equipment by a target, and the application range is wider.
However, due to the influence of the bandwidth and sampling rate of the device, the existing positioning work based on wireless signals can only reach centimeter accuracy, and it is difficult to achieve higher accuracy positioning for a universal target. In the case of limited hardware conditions, the resolution of the signal is improved, and the following challenges are faced:
(1) the resolution of the ranging is limited. Based on the analytical theory of signal processing, the ranging resolution of a signal is inversely related to the bandwidth. At present, the bandwidth of a common commercial millimeter wave radar is usually about 4GHz, and the distance resolution obtained by calculation is usually about 4 cm. Due to hardware limitations, it is not practical to increase the resolution of the range by increasing the bandwidth of the signal. Current resolutions are also difficult to achieve on the millimeter scale.
(2) The angular resolution is limited. The existing method for calculating the arrival angle of a signal is to calculate according to the phase difference between antennas in an antenna array, and is easily affected by phase noise.
(3) And (4) multi-target positioning. Multiple targets may appear in the monitored area at the same time, and the reflected signals may alias with each other, affecting the accuracy of target positioning.
Disclosure of Invention
The invention provides a positioning method and a positioning device based on millimeter wave equipment, which are used for solving the defects of low distance resolution and poor positioning precision of the millimeter wave equipment in the prior art and realizing high-precision positioning of a target to be measured.
The invention provides a positioning method based on millimeter wave equipment, which comprises the following steps:
acquiring the number of targets to be detected and echo signals, and constructing a frequency spectrum signal model based on the number of the targets to be detected and the echo signals;
calculating a sampling error value of the target to be detected and a phase difference of adjacent antennas based on the spectrum signal model;
calculating the distance value from the target to be detected to the millimeter wave equipment based on the sampling error value, and calculating the angle of arrival of the target to be detected based on the phase difference;
and generating a positioning result of the target to be detected according to the distance value and the wave arrival angle.
According to the positioning method based on the millimeter wave device provided by the invention, the establishing of the spectrum signal model based on the number of the targets to be detected and the echo signal specifically comprises the following steps:
extracting a target frequency band signal in the echo signal, and performing discrete sampling on the target frequency band signal to obtain a discrete target frequency band signal;
performing discrete Fourier transform on the discrete target frequency band signal to obtain a processing result, and acquiring a peak sampling point corresponding to the discrete target frequency band signal based on the processing result;
and selecting a plurality of sampling point data within a preset distance of the peak sampling point, and establishing a frequency spectrum signal model by combining the processing result.
According to the positioning method based on the millimeter wave device provided by the invention, when the number of the targets to be detected is single, the discrete target frequency band signal is expressed as follows:
wherein N is a discrete time point of a discrete target frequency band signal, N is a sampling point number of the signal, and N is 0,1, …, N-1; e is the base number of the natural logarithm, and j is the unit of an imaginary number;
According to the positioning method based on the millimeter wave device provided by the invention, the discrete target frequency band signal is subjected to discrete Fourier transform to obtain a processing result, and the method specifically comprises the following steps:
performing discrete Fourier transform on the representation r [ n ] of the discrete target frequency band signal, wherein the processing result is as follows:
wherein m ═ k p -N+1,k p -N+2,…,k p ；W[k p -m]Is w [ n ]]The result of the discrete fourier transform of (a); k is a radical of p The peak sample points.
According to the positioning method based on the millimeter wave equipment, the invention selects a plurality of sampling point data within the preset distance of the peak sampling point, and establishes a spectrum signal model by combining the processing result, specifically comprising the following steps:
selecting three points R [ k ] near the sampling point of the peak value p -1]、R[k p ]、R[k p +1]Establishing a spectrum signal model, and solving the model to obtain the complex amplitude of the discrete intermediate frequency signal
And normalized frequency
Calculating the distance of the target to be measured based on the normalized frequency:
when the number of the targets to be detected is two, the discrete target frequency band signal is represented as:
wherein N is a discrete time point of a discrete target frequency band signal, N is a sampling point number of the signal, and N is 0,1, …, N-1;
and
is the amplitude of the complex signal that is unknown,
and
is the normalized frequency component of the signal, w n]Is white gaussian noise;
for the discrete target frequency band signal t [ n ]]Performing discrete Fourier transform to obtain operation result T [ k ]](ii) a Obtaining two peak sampling points k according to the operation result p1 、k p2 ；
At the two peak sampling points k p1 、k p2 Selecting a plurality of sampling point data and combining the operation result T [ k ]]Establishing the spectrum signal model, and carrying out model pair on unknown parameters A 1 ,A 2 ,θ 1 ,θ 2 ,δ 1 ,δ 2 Solving;
based on two normalized frequencies f 1 、f 2 And respectively calculating the distance of the target to be measured.
According to the positioning method based on the millimeter wave device provided by the invention, the phase difference of the adjacent antennas is calculated based on the spectrum signal model, and the method specifically comprises the following steps:
obtaining the complex signal amplitude in the discrete target frequency band signal model;
and extracting the phase difference of adjacent receiving antennas in the millimeter wave equipment according to the amplitude of the complex signal.
The invention also provides a positioning device based on millimeter wave equipment, which comprises:
the model building module is used for obtaining the number of the targets to be tested and echo signals and building a frequency spectrum signal model based on the number of the targets to be tested and the echo signals;
the first calculation module is used for calculating a sampling error value of the target to be detected and a phase difference of adjacent antennas based on the spectrum signal model;
the second calculation module is used for calculating a distance value from the target to be detected to the millimeter wave equipment based on the sampling error value and calculating a reaching angle of the target to be detected based on the phase difference;
and the result generation module is used for generating a positioning result of the target to be detected according to the distance value and the arrival angle.
The invention also provides an electronic device, which comprises a memory, a processor and a computer program stored on the memory and capable of running on the processor, wherein the processor executes the program to realize the positioning method based on the millimeter wave device.
The present invention also provides a non-transitory computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements a millimeter wave device-based positioning method as described in any of the above.
The present invention also provides a computer program product comprising a computer program, which when executed by a processor implements the positioning method based on millimeter wave devices as described in any of the above.
According to the positioning method and device based on the millimeter wave equipment, the millimeter wave equipment is used as a basis, the advantages of short millimeter wave wavelength and high resolution are utilized, and the signal frequency is accurately calculated by establishing a quantitative analysis model of a frequency spectrum sampling point and the signal frequency aiming at the conditions of different target numbers, so that high-precision distance measurement is completed; the measurement precision of the signal wave arrival angle is improved in the calculation process of the signal frequency, and then high-precision target positioning is realized.
Drawings
In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
Fig. 1 is one of the flow diagrams of the positioning method based on millimeter wave devices provided by the present invention;
fig. 2 is a second schematic flowchart of the positioning method based on millimeter wave devices according to the present invention;
fig. 3 is a third schematic flowchart of the positioning method based on millimeter wave devices according to the present invention;
fig. 4 is a fourth schematic flowchart of the positioning method based on millimeter wave device according to the present invention;
FIG. 5 is a schematic diagram of a spectral sampling error provided by the present invention;
FIG. 6 is a CDF plot of positioning error using different methods provided by the present invention;
FIG. 7 is a CDF plot of AoA calculation error using different methods provided by the present invention;
fig. 8 is a schematic structural diagram of a positioning apparatus based on millimeter wave devices provided by the present invention;
fig. 9 is a schematic structural diagram of an electronic device provided by the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The positioning method based on millimeter wave devices of the present invention is described below with reference to fig. 1 to 4.
Fig. 1 is a schematic flow chart of a positioning method based on millimeter radar wave equipment according to an embodiment of the present invention.
As shown in fig. 1 and 4, a positioning method based on millimeter wave equipment provided in an embodiment of the present invention includes the following steps:
and step 110, acquiring the number of the targets to be detected and echo signals, and constructing a frequency spectrum signal model based on the number of the targets to be detected and the echo signals. Specifically, the millimeter wave device transmits a detection signal to the target to be detected, and then receives an echo signal reflected by the target to be detected. In the actual using process, the millimeter wave radar realizes high-precision target positioning by transmitting a linear frequency modulation signal and receiving a reflected signal of a target, and the millimeter wave equipment extracts an intermediate frequency signal from an echo signal and then performs discrete sampling on the intermediate frequency signal to obtain an intermediate frequency discrete signal. According to theoretical analysis, the frequency of the intermediate frequency discrete signal read by the millimeter wave device is in direct proportion to the distance from the target to the device, so that the distance from the target to the device can be calculated as long as the frequency of the intermediate frequency signal is obtained, and positioning of the target is achieved.
According to the invention, aiming at different numbers of detection targets, the millimeter wave equipment carries out different processing on echo signals and constructs a spectrum signal model for calculating sampling errors and phase differences.
And step 120, calculating a sampling error value of the target to be measured and a phase difference of adjacent antennas based on the spectrum signal model.
A common method for extracting the frequency of the signal is to perform discrete fourier transform on the signal in the target frequency band, so as to obtain a frequency spectrum of the signal, and a peak in the frequency spectrum represents a frequency component included in the signal. Thus, the spectral resolution of the FMCW signal is:
Δd＝c/2B,
where B is the bandwidth of the signal. The range resolution of millimeter-wave devices is inversely proportional to bandwidth.
The maximum bandwidth of the current common commercial millimeter wave equipment is 4 GHz. In consideration of the bandwidth loss problem in practical application scenarios, the distance resolution is usually about 4cm, so that the millimeter wave device cannot achieve positioning with higher accuracy.
One important cause of range errors is spectral sampling errors. Due to the frequency sampling, there is a difference between the observed signal frequency and the actual signal frequency, which results in a frequency error δ, such that the ranging result is in error.
The present invention calculates the sampling error that is ignored in the prior art.
And step 130, calculating a distance value from the target to be detected to the millimeter wave equipment based on the sampling error value, and calculating the arrival angle of the target to be detected based on the phase difference.
The invention obtains a more accurate frequency calculation value through sampling an error value, thereby obtaining a more accurate distance value, wherein the distance value refers to the distance from a target to be measured to millimeter wave equipment.
And 140, generating a positioning result of the target to be detected according to the distance value and the wave arrival angle.
Further, as shown in fig. 2, the method for constructing a spectrum signal model based on the number of the targets to be detected and the echo signals specifically includes the following steps:
Specifically, when only a single target to be measured exists in the environment, theoretically, only one frequency component exists in the intermediate frequency signal extracted by the millimeter wave device, and the discrete target frequency band signal may be represented as:
wherein N is a discrete time point of a discrete target frequency band signal, N is a sampling point number of the signal, and N is 0,1, …, N-1; e is the base number of the natural logarithm, and j is the unit of an imaginary number;
As shown in fig. 5 and 6, the conventional frequency estimation scheme usually estimates only k p While δ is ignored. In the invention, a more accurate frequency estimation result is obtained by designing a spectrum peak value reconstruction algorithm.
And step 220, performing discrete Fourier transform on the discrete target frequency band signal to obtain a processing result, and acquiring a peak sampling point corresponding to the discrete target frequency band signal based on the processing result.
Specifically, by pairing r [ n ]]DFT is carried out to obtain a peak sampling point k in a frequency spectrum p . In the original signal r [ n ]]In, there are three real unknowns: a. the 0 、θ 0 And δ. r [ n ]]The result of the DFT operation is as follows:
wherein m ═ k p -N+1,k p -N+2,…,k p ；W[k p -m]Is w [ n ]]The result of the discrete fourier transform of (a); k is a radical of p The peak sample points.
And step 230, selecting a plurality of sampling point data within a preset distance of the peak sampling point, and establishing a frequency spectrum signal model by combining the processing result.
Further, three points near the peak sampling point are selected:
R[k p -1]、R[k p ]、R[k p +1]establishing a spectrum signal model, and solving the model to obtain the complex amplitude of the discrete intermediate frequency signal
And normalized frequency
Calculating the distance of the target to be measured based on the normalized frequency:
Specifically, since the operation result of DFT is complex, the real part and the imaginary part of the two sides of the above formula should be equal to each other. Thus, each DFT sample can provide 2 real equations.
To solve for 3 unknown real numbers, at least 2 sample points of data are needed. Theoretically, more sampling points are used for estimation, and a more accurate estimation result is obtained. However, the sampling points with lower amplitudes are susceptible to noise and have larger errors. According to a spectrum calculation formula, the distance between the peak point k and the peak point k p Closer sample points typically have higher amplitudes. Thus, three points R k around the peak point of the spectrum are used p -1],R[k p ],R[k p +1]To establish a spectrum reconstruction nonlinear equation system, i.e. a spectrum signal model in the invention.
Finally, the common nonlinear equation system solving algorithm Levenberg-Marquardt is used for solving the unknown parameters to obtain the complex amplitude of the signal
And normalized frequency
Then, the distance of the target is calculated from the frequency of the signal:
wherein F s Is the sampling rate of the millimeter wave device.
Compared with the traditional distance measurement method, more accurate frequency information is obtained, and more high-precision distance information is obtained.
Furthermore, the invention judges the number of the targets to be detected, and respectively processes the target frequency band signals according to the number of single or multiple targets.
When the number of the targets to be detected is two, the discrete target frequency band signal is expressed as:
wherein N is a discrete time point of a discrete target frequency band signal, N is a sampling point number of the signal, and N is 0,1, …, N-1;
and
is the amplitude of the complex signal that is unknown,
and
is the normalized frequency component of the signal, w n]Is white gaussian noise;
for discrete target frequency band signal t [ n ]]Performing discrete Fourier transform to obtain operation result T [ k ]](ii) a Obtaining two peak sampling points k according to the operation result p1 、k p2 ；
At two peak sample points k p1 、k p2 Selecting a plurality of sampling point data and combining the operation result T [ k ]]Establishing the spectrum signal model, and carrying out model pair on unknown parameters A 1 ,A 2 ,θ 1 ,θ 2 ,δ 1 ,δ 2 Solving;
based on two normalized frequencies f 1 、f 2 And respectively calculating the distance of the target to be measured.
In practical application scenarios, multiple targets may appear simultaneously, and multiple frequency components will exist in the signal simultaneously. Aliasing may occur between different frequency components, affecting the estimation of the parameters of each component. To cope with these complex cases, a multi-frequency component estimation scheme is proposed.
For ease of understanding, consider first a signal having two frequency components:
wherein,
and
is the amplitude of the complex signal that is unknown,
and
is the normalized frequency component of the signal, N is the number of sampling points of the signal, w [ N ]]Is gaussian white noise.
From the derivation of the single target distance measurement, t [ n ] is calculated]DFT operation result T [ k ]]Obtaining a frequency component k of the signal p1 ,k p2 . In both frequency component signals, there are 6 unknown parameters: a. the 1 ,A 2 ,θ 1 ,θ 2 ,δ 1 ,δ 2 。
In a single frequency component signal, the information of 3 DFT samples is used to calculate the unknown parameters. In the two-frequency component signal, k is not set p1 ≤k p2 Then use T [ k ] p1 -1]To T [ k ] p2 +1]The unknown parameters are solved by the sampling information. The number of the sampling points in the part is not less than 3, which is enough to solve 6 unknown parameters of two components.
If the signal contains more frequency components, it is solved in a system of non-linear equations using the method described above. In order to solve a system of equations containing u frequency components, i.e. 3u unknown parameters, at least 3u non-linear equations are required, i.e. 3u non-linear equations are required
Information of the individual sampling points.
As shown in fig. 3, in step 120, the calculating a phase difference between adjacent antennas based on the spectrum signal model specifically includes the following steps:
and 320, extracting the phase difference of adjacent linear receiving antennas in the millimeter wave equipment according to the amplitude of the complex signal.
Specifically, in order to acquire two-dimensional coordinates of the target, the arrival angle (AoA) of the signal needs to be known. The AoA is solved using a linear receive antenna array of millimeter wave devices.
The spacing between antennas in a linear array is d 0 . Taking into account the distance d of the target to the device>>d 0 The reflected signals may be considered approximately parallel when they reach the antennas. The phase difference of adjacent antennas can be expressed as:
where λ is the wavelength of the signal and θ is the AoA of the signal. From the above equation, AoA can be solved according to the phase difference of different antennas.
As shown in fig. 3 and 7, in practical applications, the AoA directly solved by using the phase difference usually has a large error due to the influence of random noise and multi-target reflection. It is observed that the initial phase of each frequency component can be extracted by DFT. In the signal modeling of a single target, the influence of frequency deviation delta and white Gaussian noise w [ n ] is ignored, and the phases of DFT sampling points are as follows:
wherein k is p Is the peak point of DFT, θ 0 Is the initial phase of the corresponding frequency component. According to the above equation, if frequency is ignoredAnd due to the influence of the rate deviation delta, the initial phase of each antenna can be extracted according to the sampling point information of DFT.
But in most cases the frequency deviation δ ≠ 0. The corresponding phases of the peak points in the DFT spectrum are as follows:
angle(R[k p ])＝θ 0 +angle(F(δ)),
wherein
The phase of the DFT peak no longer corresponds to the initial phase of the antenna due to the influence of F (δ), and therefore, the calculation of AoA using the phase of the DFT peak will generate a large systematic error.
In order to reduce the occurrence of system errors and improve the accuracy of AoA calculation, it is necessary to accurately calculate the initial phase θ corresponding to each frequency component 0 . In the foregoing description, while solving the parameter δ of each frequency component, the complex amplitude thereof is also obtained
Therefore, the initial phase of each frequency component has been solved. Therefore, the parameter information obtained by spectrum reconstruction can be directly used for directly obtaining the initial phase of each frequency component, and the more accurate AoA is obtained by using the solving result of each receiving antenna, so that the distortion removal measurement of the AoA is realized.
The positioning apparatus based on millimeter wave devices provided by the present invention is described below, and the positioning apparatus based on millimeter wave devices described below and the positioning method based on millimeter wave devices described above may be referred to correspondingly.
The invention takes millimeter wave equipment as a basis, utilizes the advantages of short millimeter wave wavelength and high resolution, and designs and realizes a spectrum peak value reconstruction algorithm by establishing a quantitative analysis model of a spectrum sampling point and a signal frequency aiming at the conditions of different target numbers, thereby completing high-precision distance measurement; and the measurement precision of the signal wave arrival angle is improved through the amplitude information of the signal, so that a high-precision target positioning system is realized.
As shown in fig. 8, a positioning apparatus based on millimeter wave devices according to an embodiment of the present invention includes the following modules: a model building module 810, a first calculation module 820, a second calculation module 830, and a result generation module 840.
Specifically, the model building module 810 is configured to obtain the number of the targets to be detected and the echo signals, and build a spectrum signal model based on the number of the targets to be detected and the echo signals. The first calculating module 820 is configured to calculate a sampling error value of the target to be measured and a phase difference between adjacent antennas based on the spectrum signal model. The second calculating module 830 is configured to calculate a distance value from the target to be measured to the millimeter wave device based on the sampling error value, and calculate a reaching angle of the target to be measured based on the phase difference. The result generating module 840 is configured to generate a positioning result of the target to be detected according to the distance value and the arrival angle.
Fig. 9 illustrates a physical structure diagram of an electronic device, and as shown in fig. 9, the electronic device may include: a processor (processor)910, a communication Interface (Communications Interface)920, a memory (memory)930, and a communication bus 940, wherein the processor 910, the communication Interface 920, and the memory 930 communicate with each other via the communication bus 940. Processor 910 may invoke logic instructions in memory 930 to perform a millimeter wave device based positioning method comprising the steps of: acquiring the number of targets to be detected and echo signals, and constructing a frequency spectrum signal model based on the number of the targets to be detected and the echo signals; calculating a sampling error value of a target to be detected and a phase difference of adjacent antennas based on a spectrum signal model; calculating a distance value from the target to be detected to the millimeter wave equipment based on the sampling error value, and calculating a reaching angle of the target to be detected based on the phase difference; and generating a positioning result of the target to be detected according to the distance value and the wave arrival angle.
Furthermore, the logic instructions in the memory 930 may be implemented in software functional units and stored in a computer readable storage medium when the logic instructions are sold or used as independent products. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
In another aspect, the present invention further provides a computer program product, where the computer program product includes a computer program, the computer program may be stored on a non-transitory computer readable storage medium, and when the computer program is executed by a processor, a computer can execute a positioning method based on a millimeter wave device provided by the above methods, where the method includes the following steps: acquiring the number of targets to be detected and echo signals, and constructing a frequency spectrum signal model based on the number of the targets to be detected and the echo signals; calculating a sampling error value of a target to be detected and a phase difference of adjacent antennas based on a spectrum signal model; calculating a distance value from the target to be detected to the millimeter wave equipment based on the sampling error value, and calculating a reaching angle of the target to be detected based on the phase difference; and generating a positioning result of the target to be detected according to the distance value and the wave arrival angle.
In yet another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored, the computer program being implemented by a processor to execute the method for positioning based on millimeter wave devices provided by the above methods, the method comprising the following steps: acquiring the number of targets to be detected and echo signals, and constructing a frequency spectrum signal model based on the number of the targets to be detected and the echo signals; calculating a sampling error value of a target to be detected and a phase difference of adjacent antennas based on a spectrum signal model; calculating a distance value from the target to be detected to the millimeter wave equipment based on the sampling error value, and calculating a reaching angle of the target to be detected based on the phase difference; and generating a positioning result of the target to be detected according to the distance value and the wave arrival angle.
The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A positioning method based on millimeter wave equipment is characterized by comprising the following steps:
acquiring the number of targets to be detected and echo signals, and constructing a frequency spectrum signal model based on the number of the targets to be detected and the echo signals;
calculating a sampling error value of the target to be detected and a phase difference of adjacent antennas based on the frequency spectrum signal model;
calculating the distance value from the target to be detected to the millimeter wave equipment based on the sampling error value, and calculating the angle of arrival of the target to be detected based on the phase difference;
and generating a positioning result of the target to be detected according to the distance value and the wave arrival angle.
2. The positioning method based on the millimeter wave device according to claim 1, wherein the constructing a spectrum signal model based on the number of the targets to be measured and the echo signals specifically comprises:
extracting a target frequency band signal in the echo signal, and performing discrete sampling on the target frequency band signal to obtain a discrete target frequency band signal;
performing discrete Fourier transform on the discrete target frequency band signal to obtain a processing result, and acquiring a peak sampling point corresponding to the discrete target frequency band signal based on the processing result;
and selecting a plurality of sampling point data within a preset distance of the peak sampling point, and establishing a frequency spectrum signal model by combining the processing result.
3. The millimeter wave device based positioning method according to claim 2,
when the number of the targets to be detected is single, the discrete target frequency band signal is expressed as:
wherein N is a discrete time point of a discrete target frequency band signal, N is a sampling point number of the signal, and N is 0,1, …, N-1; e is the base number of the natural logarithm, and j is the unit of an imaginary number;
4. The millimeter wave device-based positioning method according to claim 3, wherein the discrete target frequency band signal is subjected to discrete Fourier transform to obtain a processing result, specifically:
performing discrete Fourier transform on the representation r [ n ] of the discrete target frequency band signal, wherein the processing result is as follows:
wherein m ═ k p -N+1,k p -N+2,…,k p ；W[k p -m]Is w [ n ]]The result of the discrete fourier transform of (a); k is a radical of p Is a peak sampling point;
selecting a plurality of sampling point data within a preset distance of the peak sampling point, and establishing a frequency spectrum signal model by combining the processing result, wherein the specific steps are as follows:
selecting three points R [ k ] p -1]、R[k p ]、R[k p +1]Establishing a spectrum signal model, and solving the model to obtain the complex amplitude of the discrete intermediate frequency signal
And normalized frequency
Calculating the distance of the target to be measured based on the normalized frequency:
F s is the sampling rate of the millimeter wave device.
5. The millimeter wave device based positioning method according to claim 2,
when the number of the targets to be detected is two, the discrete target frequency band signal is represented as:
wherein N is a discrete time point of a discrete target frequency band signal, N is a sampling point number of the signal, and N is 0,1, …, N-1;
and
is the amplitude of the complex signal that is unknown,
and
is the normalized frequency component of the signal, w n]Is white gaussian noise;
for the discrete target frequency band signal t [ n ]]Performing discrete Fourier transform to obtain operation result T [ k ]](ii) a Obtaining two peak sampling points k according to the operation result p1 、k p2 ；
At the two peak sampling points k p1 、k p2 Selecting a plurality of sampling point data and combining the operation result T [ k ]]Establishing the spectrum signal model, and carrying out model pair on unknown parameters A 1 ,A 2 ,θ 1 ,θ 2 ,δ 1 ,δ 2 Solving;
based on two normalized frequencies f 1 、f 2 And respectively calculating the distance of the target to be measured.
6. The millimeter wave device-based positioning method according to claim 5, wherein calculating the phase difference between adjacent antennas based on the spectrum signal model specifically comprises:
obtaining the complex signal amplitude in the discrete target frequency band signal model;
and extracting the phase difference of adjacent receiving antennas in the linear antenna array of the millimeter wave equipment according to the amplitude of the complex signal.
7. A positioning apparatus based on millimeter wave devices, the apparatus comprising:
the model building module is used for obtaining the number of the targets to be tested and echo signals and building a frequency spectrum signal model based on the number of the targets to be tested and the echo signals;
the first calculation module is used for calculating a sampling error value of the target to be detected and a phase difference of adjacent antennas based on the spectrum signal model;
the second calculation module is used for calculating a distance value from the target to be detected to the millimeter wave equipment based on the sampling error value and calculating a reaching angle of the target to be detected based on the phase difference;
and the result generation module is used for generating a positioning result of the target to be detected according to the distance value and the arrival angle.
8. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements a positioning method based on millimeter wave devices according to any of claims 1 to 6 when executing the program.
9. A non-transitory computer-readable storage medium, on which a computer program is stored, wherein the computer program, when executed by a processor, implements the millimeter wave device-based positioning method according to any one of claims 1 to 6.
10. A computer program product comprising a computer program, wherein the computer program when executed by a processor implements a millimeter wave device based positioning method according to any of claims 1 to 6.
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| WO2024060790A1 (en) * | 2022-09-21 | 2024-03-28 | 加特兰微电子科技(上海)有限公司 | Method and apparatus for improving target detection precision, and electronic device |
| CN118152763A (en) * | 2024-05-11 | 2024-06-07 | 北京智芯微电子科技有限公司 | Distribution network data sampling method and device and electronic equipment |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2024060790A1 (en) * | 2022-09-21 | 2024-03-28 | 加特兰微电子科技(上海)有限公司 | Method and apparatus for improving target detection precision, and electronic device |
| CN118152763A (en) * | 2024-05-11 | 2024-06-07 | 北京智芯微电子科技有限公司 | Distribution network data sampling method and device and electronic equipment |
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