Positioning method and apparatus

Abstract

The application provides a positioning method and device, belongs to the technical field of sensing, and can be used for intelligent driving. The radar comprises a plurality of transmitting antennas and a plurality of receiving antennas for transmitting different carrier frequency signals. The method comprises the following steps: obtaining peak values of a plurality of two-dimensional transformation results, each two-dimensional transformation result being obtained by performing two-dimensional Fourier transformation on echo signals corresponding to a transmitting-receiving channel; performing eigenvalue decomposition on a covariance matrix to determine a noise subspace, each element in the covariance matrix being a peak value; constructing a spatial spectrum according to the noise subspace and a steering vector, the steering vector being determined according to the antenna configuration of the radar and the frequency of each transmitting signal, the steering vector being related to position information, and the position information comprising target distance and target direction of at least one target; and determining the position information, the position information making the spatial spectrum reach a maximum value. The position information is determined in a direction-distance joint estimation mode, and the positioning accuracy is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radar, in particular to a positioning method and device. BACKGROUND

[0002] With the development of society, intelligent transportation devices, intelligent home devices, robots and other intelligent terminals are gradually entering people's daily life. Sensors play a very important role in intelligent terminals. Various sensors installed on intelligent terminals, such as millimeter wave radar, laser radar, camera, ultrasonic radar, etc., perceive the surrounding environment, collect data, identify and track moving objects, and recognize static scenes such as lane lines and signs during the movement of intelligent terminals, and combine with navigation and map data for path planning. The sensors can detect potential dangers in advance and assist or even autonomously take necessary evasive measures, effectively increasing the safety and comfort of intelligent terminals.

[0003] Intelligent driving technology includes perception, decision-making, control and other stages. The perception module is the "eyes" of the intelligent vehicle, which receives surrounding environment information and understands the environment through machine learning technology. The decision-making module uses the information output by the perception module to predict the behavior of traffic participants and make behavior decisions for the ego vehicle. The control module calculates the lateral and longitudinal acceleration of the vehicle according to the output of the decision-making module to control the ego vehicle to pass through.

[0004] Radar can perceive the direction, distance, speed and other information of targets in the environment, and plays an important role in intelligent driving. How to improve the resolution of radar positioning is a problem to be solved at present. SUMMARY

[0005] The present application provides a positioning method and device, which can improve the resolution of positioning.

[0006] In a first aspect, a positioning method is provided, which comprises: obtaining a peak value of each of a plurality of two-dimensional transform results, wherein a difference between corresponding fast time frequency parameters of the plurality of peak values and a difference between corresponding slow time frequency parameters of the plurality of peak values are within a preset difference range, wherein each of the two-dimensional transform results is obtained by performing two-dimensional Fourier transform on an echo signal, the fast time frequency parameter is a frequency domain parameter corresponding to a fast time parameter in the echo signal corresponding to the two-dimensional transform result, the slow time frequency parameter is a frequency domain parameter corresponding to a slow time parameter in the echo signal corresponding to the two-dimensional transform result, the echo signal corresponds to a transceiving channel one-to-one, and each of the transceiving channels comprises one receiving antenna and one transmitting antenna; performing eigenvalue decomposition on a covariance matrix to determine a noise subspace, wherein each element in the covariance matrix is a peak value, each row and each column in the covariance matrix does not include the same peak value, and the noise subspace comprises at least one noise vector, each of the noise vectors is a characteristic vector corresponding to a noise eigenvalue in a plurality of eigenvalues of the covariance matrix, and the noise eigenvalue is determined according to a signal source number estimation; constructing a spatial spectrum according to the noise subspace and a steering vector, wherein the steering vector is determined according to a configuration of a radar, a carrier frequency of each transmitting signal, the steering vector is related to position information, the radar comprises a plurality of transmitting antennas and at least one receiving antenna, the plurality of transmitting antennas are used to transmit a plurality of carrier frequency transmitting signals, and the position information comprises target distance and target direction of at least one target; determining the position information, wherein the position information makes the spatial spectrum reach a maximum value. The transmitting signal is transmitted by a transmitting antenna of a radar.

[0007] The spatial spectrum estimation algorithm is used to jointly estimate the direction and distance of a target according to the peak values in the two-dimensional transform results corresponding to each echo signal received by a radar, so as to avoid introducing the error of direction estimation into the determined distance result, and improve the positioning accuracy.

[0008] In combination with the first aspect, in some possible implementation manners, the method comprises: performing fast time dimension Fourier transform on the echo signal to obtain a first initial distance compression result; when a difference between fast time frequency parameters corresponding to peaks of the initial distance compression result under a plurality of slow time parameters exceeds a first preset difference, replacing the slow time parameter of the echo signal with a first slow time adjustment parameter by using a wedge-shaped transformation; performing fast time dimension Fourier transform on the replaced echo signal to obtain a distance compression result, wherein a difference between fast time frequency parameters corresponding to peaks of the distance compression result under the plurality of first slow time adjustment parameters is within the first preset difference; and performing slow time dimension Fourier transform on the distance compression result to obtain the two-dimensional transform result.

[0009] By adjusting the slow time, correction of the slow time distance migration is realized, and the positioning accuracy is improved.

[0010] With reference to the first aspect, in some possible implementation manners, the method further includes: performing fast time dimension Fourier transform on a plurality of first replacement echo signals corresponding to a first receiving antenna of the at least one receiving antenna and the plurality of transmitting antennas respectively, to obtain a plurality of second initial range compression results, the first replacement echo signals being obtained by replacing the slow time parameter in the echo signal with the first slow time adjustment parameter; when a difference between the fast time frequency parameters corresponding to the wave peaks of the plurality of second initial range compression results under the first slow time parameter exceeds a second preset difference, replacing the fast time parameter in the plurality of first replacement echo signals with a fast time adjustment parameter by using a wedge-shaped transform, to obtain the replacement echo signal, the difference between the fast time frequency parameters corresponding to the wave peaks of the plurality of range compression results under the first slow time parameter being within the second preset difference.

[0011] By adjusting the fast time parameter in the echo signal, correction of the distance migration caused by different transmitting signal frequencies is realized, and the positioning accuracy is improved.

[0012] With reference to the first aspect, in some possible implementation manners, the method further includes: performing slow time dimension Fourier transform on the plurality of range compression results respectively, to obtain a plurality of initial two-dimensional transform results; when a difference between the slow time frequency parameters corresponding to the wave peaks of the plurality of initial two-dimensional transform results under a first fast time frequency parameter exceeds a third preset difference, replacing the first slow time adjustment parameter in the plurality of range compression results with a second slow time adjustment parameter by using a wedge-shaped transform; and the performing slow time dimension Fourier transform on the range compression results to obtain the two-dimensional transform results includes: performing slow time dimension Fourier transform on the plurality of replacement range compression results respectively based on the second slow time adjustment parameter, to obtain a plurality of the two-dimensional transform results, the difference between the slow time frequency parameters corresponding to the wave peaks of the plurality of two-dimensional compression results under the first fast time frequency parameter being within the third preset difference.

[0013] By adjusting the first slow time adjustment parameter, correction of the Doppler migration caused by different transmitting signal frequencies is realized, and the positioning accuracy is improved.

[0014] With reference to the first aspect, in some possible implementation manners, the method further includes: performing fast-time dimension Fourier transform on the plurality of echo signals corresponding to the first receiving antenna among the at least one receiving antenna and the plurality of transmitting antennas respectively to obtain a plurality of initial range compression results; when a difference between fast-time frequency parameters corresponding to peaks of each of the plurality of initial range compression results under a plurality of slow-time parameters is not more than a first preset difference, and a difference between the fast-time frequency parameters corresponding to the peaks of the plurality of initial range compression results under a first slow-time parameter is more than a second preset difference, replacing, by using a wedge-shaped transform, the fast-time parameters in the plurality of echo signals corresponding to the first receiving antenna with fast-time adjustment parameters; performing fast-time dimension Fourier transform on the plurality of echo signals corresponding to the first receiving antenna based on the fast-time adjustment parameters respectively to obtain a plurality of range compression results, the difference between the fast-time frequency parameters corresponding to the peaks of the plurality of range compression results under the first slow-time parameter being within the second preset difference; and performing slow-time dimension Fourier transform on the plurality of replaced range compression results based on the fast-time adjustment parameters respectively to obtain the plurality of two-dimensional transform results.

[0015] For the echo signal without slow-time range migration, by adjusting the fast-time parameters in the echo signal, correction of the range migration caused by different transmitting signal frequencies is achieved, and the positioning accuracy is improved.

[0016] With reference to the first aspect, in some possible implementation manners, the method further includes: performing slow-time dimension Fourier transform on the plurality of range compression results respectively to obtain a plurality of initial two-dimensional transform results; and when a difference between slow-time frequency parameters corresponding to peaks of the plurality of initial two-dimensional transform results under a first fast-time frequency parameter is more than a third preset difference, replacing, by using a wedge-shaped transform, the slow-time parameters in the plurality of range compression results with second slow-time adjustment parameters to obtain the plurality of replaced range compression results.

[0017] For the echo signal without slow-time range migration, by adjusting the slow-time parameters, correction of the Doppler migration caused by different transmitting signal frequencies is achieved, and the positioning accuracy is improved.

[0018] With reference to the first aspect, in some possible implementation manners, the method further includes: performing, respectively, Fourier transform on a fast time dimension on the plurality of echo signals corresponding to a first receiving antenna of the at least one receiving antenna to obtain a plurality of range compression results, a difference between peak corresponding fast time frequency parameters of each range compression result under a plurality of slow time parameters being less than a first preset difference, and a difference between the peak corresponding fast time frequency parameters of the plurality of range compression results under a first slow time parameter being less than a second preset difference; performing, respectively, Fourier transform on a slow time dimension on the plurality of range compression results to obtain a plurality of initial two-dimensional transform results; when a difference between peak corresponding slow time frequency parameters of the plurality of initial two-dimensional transform results under a first fast time frequency parameter exceeds a third preset difference, replacing, by using a wedge-shaped transform, the slow time parameters in the plurality of range compression results with second slow time adjustment parameters; performing, respectively, Fourier transform on a slow time dimension on the plurality of range compression results after the replacement based on the second slow time adjustment parameters to obtain a plurality of two-dimensional transform results, a difference between the peak corresponding slow time frequency parameters of the plurality of two-dimensional transform results under the first fast time frequency parameter range being within the third preset difference.

[0019] For echo signals that neither have range migration of the slow time nor have range migration caused by different transmission signal frequencies, by adjusting the slow time parameters, correction of Doppler migration caused by different transmission signal frequencies is implemented, and the positioning accuracy is improved.

[0020] With reference to the first aspect, in some possible implementation manners, the method further includes: obtaining an initial target distance of a first target of the at least one target, the initial target distance being determined according to the echo signals; and the determining the position information includes: determining a distance range of the first target according to the initial target distance; and determining the target distance of the first target in the distance range.

[0021] By determining the distance range of the first target, when the distance of the first target is traversed to determine the position information that makes the spatial spectrum reach a maximum value, the range of the distance traversal can be reduced, and the processing efficiency is improved.

[0022] With reference to the first aspect, in some possible implementation manners, the method further includes: obtaining an initial target direction of a first target of the at least one target, the initial target direction being determined according to at least two echo signals corresponding to the same transmitting antenna; and the determining the position information includes: determining a direction range of the first target according to the initial target direction; and determining the target direction in the direction range.

[0023] By determining the direction range of the first target, the range of the direction traversal for determining the position information of the maximum value of the spatial spectrum can be reduced, and the processing efficiency can be improved.

[0024] In combination with the first aspect, in some possible implementation manners, the covariance matrix is a skew-symmetric matrix or a symmetric matrix, and elements on a line parallel to a symmetric axis in the covariance matrix are the same.

[0025] By making the covariance matrix a skew-symmetric matrix or a symmetric matrix, and making elements on a line parallel to a symmetric axis in the covariance matrix the same, the number of required peaks can be reduced, that is, the number of two-dimensional transform results is reduced, thereby reducing the number of two-dimensional Fourier transforms in the echo signal processing process, simplifying the processing flow, and reducing the amount of calculation.

[0026] In combination with the first aspect, in some possible implementation manners, the number of the plurality of transmitting antennas is M, the number of the at least one receiving antenna is N, the covariance matrix is an L-dimensional square matrix, L is obtained by rounding up M*N / 2, and different peaks in the covariance matrix correspond to different transceiving channels, where M, N, and L are positive integers.

[0027] Different peaks in the covariance matrix correspond to different transceiving channels, and the covariance matrix is set as an L-dimensional square matrix, L is obtained by rounding up M*N / 2, so that the number of required peaks is reduced, and the covariance matrix includes, as much as possible, peaks in two-dimensional transform results corresponding to each transceiving channel, so that the noise subspace determined according to the covariance matrix more accurately reflects noise information in the environment, and positioning is more accurate.

[0028] In combination with the first aspect, in some possible implementation manners, the method further includes that the radar is distributed or centralized.

[0029] By using a distributed radar, the positioning method can be applied more widely, and a virtual aperture can be increased, thereby improving the positioning accuracy.

[0030] In a second aspect, a positioning device is provided, comprising an obtaining module and a processing module. The obtaining module is configured to obtain a plurality of peaks, each of the peaks corresponding to a two-dimensional transform result, wherein a difference between fast time frequency parameters corresponding to the plurality of peaks is within a preset difference range, and a difference between slow time frequency parameters corresponding to the plurality of peaks is within the preset difference range. Each of the two-dimensional transform results is obtained by performing a two-dimensional Fourier transform on an echo signal. The fast time frequency parameter is a frequency domain parameter corresponding to a fast time parameter in the echo signal corresponding to the two-dimensional transform result. The slow time frequency parameter is a frequency domain parameter corresponding to a slow time parameter in the echo signal corresponding to the two-dimensional transform result. The echo signal corresponds to a transceiving channel. Each of the transceiving channels comprises a receiving antenna and a transmitting antenna. The processing module is configured to perform eigenvalue decomposition on a covariance matrix to determine a noise subspace. Each element in the covariance matrix is one of the peaks. Each row and each column in the covariance matrix does not include the same peak. The noise subspace comprises at least one noise vector. Each of the noise vectors is an eigenvector corresponding to a noise eigenvalue in a plurality of eigenvalues of the covariance matrix. The noise eigenvalue is determined according to a signal source number estimation. The processing module is further configured to construct a spatial spectrum according to the noise subspace and a steering vector. The steering vector is determined according to an antenna configuration of a radar and a frequency of each transmitted signal. The radar comprises a plurality of transmitting antennas and at least one receiving antenna. The plurality of transmitting antennas are configured to transmit a plurality of carrier frequency transmitted signals. The steering vector is related to position information. The position information comprises target distance and target direction of at least one target. The processing module is further configured to determine the position information, which makes the spatial spectrum reach a maximum value.

[0031] In some possible implementation manners of the second aspect, the processing module is further configured to perform a fast time dimension Fourier transform on the echo signal to obtain a first initial range compression result. When a difference between fast time frequency parameters corresponding to peaks of the initial range compression result under a plurality of slow time parameters exceeds a first preset difference, the slow time parameter of the echo signal is replaced with a first slow time adjustment parameter by using a wedge-shaped transform. A fast time dimension Fourier transform is performed on the replaced echo signal to obtain a range compression result. A difference between fast time frequency parameters corresponding to peaks of the range compression result under the plurality of first slow time adjustment parameters is within the first preset difference. A slow time dimension Fourier transform is performed on the range compression result to obtain the two-dimensional transform result.

[0032] In some possible implementation manners, in combination with the second aspect, the processing module is further configured to: perform fast time dimension Fourier transform on a plurality of first replacement echo signals corresponding to a first receiving antenna of the at least one receiving antenna respectively to obtain a plurality of second initial range compression results, the first replacement echo signals being obtained by replacing the slow time parameter in the echo signals with the first slow time adjustment parameter; when a difference between the fast time frequency parameters corresponding to the peaks of the plurality of second initial range compression results under at least one first slow time adjustment parameter exceeds a second preset difference, replace the fast time parameter in the plurality of first replacement echo signals with a fast time adjustment parameter by using a wedge-shaped transform to obtain the replacement echo signals, the difference between the fast time frequency parameters corresponding to the peaks of the plurality of range compression results under at least one first slow time parameter being within the second preset difference.

[0033] In some possible implementation manners, in combination with the second aspect, the processing module is further configured to: perform slow time dimension Fourier transform on the plurality of range compression results respectively to obtain a plurality of initial two-dimensional transform results.

[0034] When a difference between the slow time frequency parameters corresponding to the peaks of the plurality of initial two-dimensional transform results under a first fast time frequency parameter range exceeds a third preset difference, replace the first slow time adjustment parameter in the plurality of range compression results with a second slow time adjustment parameter by using a wedge-shaped transform; perform slow time dimension Fourier transform on the plurality of range compression results after replacement based on the second slow time adjustment parameter to obtain a plurality of the two-dimensional transform results, the difference between the slow time frequency parameters corresponding to the peaks of the plurality of two-dimensional compression results under the first fast time frequency parameter range being within the third preset difference.

[0035] With reference to the second aspect, in some possible implementations, the processing module is further configured to: perform fast-time dimension Fourier transform on the plurality of echo signals corresponding to a first receiving antenna of the at least one receiving antenna respectively to obtain a plurality of initial range compression results; when a difference between fast-time frequency parameters corresponding to peaks of each of the plurality of initial range compression results at a plurality of slow-time parameters is not more than a first preset difference, and a difference between the fast-time frequency parameters corresponding to the peaks of the plurality of initial range compression results at a first slow-time parameter is more than a second preset difference, replace, by using a wedge-shaped transform, a fast-time parameter in the plurality of echo signals corresponding to the first receiving antenna with a fast-time adjustment parameter; perform fast-time dimension Fourier transform on the plurality of echo signals corresponding to the first receiving antenna based on the fast-time adjustment parameter respectively to obtain a plurality of range compression results, a difference between the fast-time frequency parameters corresponding to the peaks of the plurality of range compression results at the first slow-time parameter being within the second preset difference; and perform slow-time dimension Fourier transform on the plurality of replaced range compression results based on the fast-time adjustment parameter respectively to obtain the plurality of two-dimensional transform results.

[0036] With reference to the second aspect, in some possible implementations, the processing module is further configured to: perform slow-time dimension Fourier transform on the plurality of range compression results respectively to obtain a plurality of initial two-dimensional transform results; when a difference between slow-time frequency parameters corresponding to peaks of the plurality of initial two-dimensional transform results in a first fast-time frequency parameter range is more than a third preset difference, replace, by using a wedge-shaped transform, a slow-time parameter in the plurality of range compression results with a second slow-time adjustment parameter to obtain the plurality of replaced range compression results.

[0037] With reference to the second aspect, in some possible implementations, the processing module is further configured to: perform fast-time dimension Fourier transform on each of the plurality of echo signals corresponding to a first receiving antenna of the at least one receiving antenna, to obtain a plurality of range compression results, each of the plurality of range compression results having a difference between fast-time frequency parameters corresponding to peaks at a plurality of slow-time parameters that is not more than a first preset difference, and a difference between the fast-time frequency parameters corresponding to the peaks at a first slow-time parameter that is not more than a second preset difference; perform slow-time dimension Fourier transform on the plurality of range compression results, respectively, to obtain a plurality of initial two-dimensional transform results; when a difference between slow-time frequency parameters corresponding to peaks at a first fast-time frequency parameter range of the plurality of initial two-dimensional transform results exceeds a third preset difference, replacing, by using a wedge-shaped transform, the slow-time parameters in the plurality of range compression results with second slow-time adjustment parameters; performing slow-time dimension Fourier transform on the plurality of range compression results after the replacement, respectively, based on the second slow-time adjustment parameters, to obtain a plurality of two-dimensional transform results, the plurality of two-dimensional transform results having a difference between the slow-time frequency parameters corresponding to peaks at the first fast-time frequency parameter range that is within the third preset difference.

[0038] With reference to the second aspect, in some possible implementations, the processing module is further configured to: obtain an initial target distance of a first target of the at least one target, the initial target distance being determined according to at least one of the echo signals; determine a range of distances of the first target according to the initial target distance; and determine the target distance of the first target within the range of distances.

[0039] With reference to the second aspect, in some possible implementations, the processing module is further configured to: obtain an initial target direction of a first target of the at least one target, the initial target direction being determined according to a plurality of echo signals corresponding to a same transmitting antenna; determine a range of directions of the first target according to the initial target direction; and determine the target direction within the range of directions.

[0040] With reference to the second aspect, in some possible implementations, the covariance matrix is a skew-symmetric matrix or a symmetric matrix, and elements in the covariance matrix located on a line parallel to a symmetric axis are the same.

[0041] With reference to the second aspect, in some possible implementations, the number of the plurality of transmitting antennas is M, the number of the at least one receiving antenna is N, the covariance matrix is an L-dimensional square matrix, L is obtained by rounding up M*N / 2, and different peak values in the covariance matrix correspond to different transceiving channels, where M, N, and L are positive integers.

[0042] With reference to the second aspect, in some possible implementations, the radar is distributed or centralized.

[0043] In a third aspect, a positioning apparatus is provided, including at least one memory and at least one processor, the at least one memory is configured to store a program, and the at least one processor is configured to execute the program to implement the method of the first aspect.

[0044] In a fourth aspect, a chip is provided, including at least one processor and an interface circuit, the interface circuit is configured to provide program instructions or data for the at least one processor, and the at least one processor is configured to execute the program instructions to implement the method of the first aspect.

[0045] In a fifth aspect, a computer readable storage medium is provided, the computer readable medium stores program code for execution by a device, and the program code, when executed by the device, implements the method of the first aspect.

[0046] In a sixth aspect, a computer program product is provided, the computer program product includes a computer program, and when the computer program product is executed by a computer, the computer executes the method in the first aspect.

[0047] It should be understood that, in this application, the method of the first aspect can specifically refer to the method in the first aspect and any one of the various implementation manners of the first aspect.

[0048] In a seventh aspect, a terminal is provided, including the positioning apparatus of the second aspect or the third aspect.

[0049] The terminal can further include a radar.

[0050] Further, the terminal can be a smart transportation device (a vehicle or a drone), a smart home device, a smart manufacturing device, or a robot, etc. The smart transportation device can be, for example, an automated guided vehicle (AGV) or a unmanned transport vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 is a functional block diagram of a vehicle to which embodiments of the present application are applicable.

[0052] Figure 2 is a schematic flowchart of a positioning method provided by embodiments of the present application.

[0053] Figure 3 is a schematic flowchart of another positioning method provided by embodiments of the present application.

[0054] Figure 4is a schematic structural diagram of a positioning device provided by an embodiment of the present application.

[0055] Figure 5 is a schematic structural diagram of another positioning device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0056] The technical solutions in the present application will be described below with reference to the drawings.

[0057] The road model construction method and device provided by the embodiments of the present application can be applied to a smart driving vehicle. The technical solutions of the embodiments of the present application will be introduced below with reference to the drawings.

[0058] Figure 1 is a functional block diagram of a vehicle to which the embodiments of the present application are applicable. The vehicle 100 can be a smart driving vehicle, and the vehicle 100 can be configured in a fully or partially autonomous driving mode.

[0059] In one example, the vehicle 100 can control the ego vehicle while in the autonomous driving mode, and can determine a current state of the vehicle and its surrounding environment, determine possible behaviors of at least one other vehicle in the surrounding environment, and determine a confidence level corresponding to a likelihood of the other vehicle performing the possible behavior, based on the determined information to control the vehicle 100. When the vehicle 100 is in the autonomous driving mode, the vehicle 100 can be placed to operate without human interaction.

[0060] The vehicle 100 can include various subsystems, such as a travel system 110, a sensing system 120, and a control system 130.

[0061] Optionally, the vehicle 100 can include more or fewer subsystems, and each subsystem can include multiple elements. In addition, each subsystem and element of the vehicle 100 can be interconnected by wire or wirelessly.

[0062] By way of example, the travel system 110 can include components for providing powered movement to the vehicle 100.

[0063] By way of example, the sensing system 120 can include several sensors that sense information about the environment surrounding the vehicle 100.

[0064] For example, the sensing system 120 can include a radar 123, etc. By way of example, the radar 123 can use radio waves to sense objects within the surrounding environment of the vehicle 100. In some embodiments, in addition to sensing objects, the radar 123 can also be used to sense the speed and / or direction of travel of the objects.

[0065] As Figure 1As shown, the control system 130 controls the operation of the vehicle 100 and its components.

[0066] Exemplarily, the control system 130 can process and analyze the data output by the radar 123 to identify objects and / or features in the environment surrounding the vehicle 100. The objects and / or features can include traffic information, road boundaries, and obstacles. Exemplarily, the control system 130 can also be used to determine a travel route for the vehicle 100. In some embodiments, the control system 130 can determine the travel route for the vehicle 100 in conjunction with data from the sensing system 120.

[0067] Optionally, one or more of the components described above can be installed separately from or associated with the vehicle 100. The components described above can be communicatively coupled together in a wired and / or wireless manner.

[0068] Optionally, the components in each module described above are only an example, and in actual applications, components in each module described above can be added or deleted according to actual needs, Figure 1 It should not be understood as a limitation on the embodiments of the present application.

[0069] Optionally, the vehicle 100 or a computing device associated with the vehicle 100 (such as the sensing system 120, the control system 130 of the vehicle 100) can predict the behavior of the identified object based on the characteristics of the identified object and the state of the surrounding environment (e.g., traffic, rain, ice on the road, etc.). Figure 1

[0070] The vehicle 100 described above can be a car, a truck, a motorcycle, a bus, a ship, an airplane, a helicopter, a lawnmower, an amusement vehicle, an amusement park vehicle, a construction device, a trolley, a golf cart, a train, and a cart, etc., and the embodiments of the present application are not particularly limited.

[0071] The resolution of the radar for the measurement of angle, distance, and speed has an important influence on the safety of driving. The smaller the value of the resolution, the higher the resolution. The radar can use a multiple input multiple output (MIMO) radar. The distance resolution p of the radar can be represented as r where c represents the speed of electromagnetic wave propagation in a vacuum, B

[0072]

[0073] where c represents the speed of electromagnetic wave propagation in a vacuum, B r represents the signal bandwidth.

[0074] ​That is, the range resolution of the radar is limited by the bandwidth of the transmitted signal. In the application of vehicle-mounted millimeter wave radar, achieving a large bandwidth requires a wideband transceiver, which puts higher requirements on the hardware of the radar antenna and increases the cost of the device. When the allocated frequency spectrum range is limited, the range resolution of the radar is limited.

[0075] The angle resolution of the MIMO radar is θ may be expressed as

[0076]

[0077] where D represents the virtual aperture of the radar transceiver antenna, θ represents the angle of the target relative to a certain preset direction with the radar as the center, and λ represents the wavelength. The direction of the target can be represented by the angle θ.

[0078] That is, the angle resolution of the radar is limited by the size of the antenna aperture. Further improvement of the angle resolution is limited by the size of the antenna in the vehicle-mounted radar.

[0079] The MIMO radar system using multiple carrier frequencies, also known as a frequency divided (FD) MIMO radar system, can obtain phase information related to the distance and angle of the target. Different transmitting antennas of the FD-MIMO radar transmit orthogonal signals with different carrier frequencies. By processing the received data formed by receiving the signal transmitted by a certain transmitting antenna by all receiving antennas in the MIMO radar, the angle information of the target in the environment can be obtained. According to the angle information and the received data formed by receiving the signals transmitted by all transmitting antennas by all receiving antennas in the MIMO radar, the distance between the target and the MIMO radar can be determined.

[0080] When determining the angle information of the target, only the received data formed by receiving the signal transmitted by a certain transmitting antenna by all receiving antennas is used, which results in a small virtual aperture size and does not fully utilize the virtual aperture formed by all transceiver channels, and the resolution of the direction is low.

[0081] The angle and the distance are estimated step by step, and the mutual influence between the angle and the distance is not fully considered, which results in that the estimation result of the distance is affected by the estimation result of the angle.

[0082] To solve the above problems, the embodiments of the present application provide a positioning method and device.

[0083] Figure 2 is a schematic flowchart of a positioning method provided by the embodiments of the present application.

[0084] In S310, the peak value of each of a plurality of two-dimensional transformation results is obtained.

[0085] Each of the two-dimensional transform results is obtained by performing two-dimensional Fourier transform on the echo signal.

[0086] The target reflects the transmission signals transmitted by each of the transmission antennas, and the reflected signals are transmitted to each of the reception antennas.

[0087] The echo signal corresponds to one of the transceiving channels. Each of the transceiving channels includes one of the reception antennas and one of the transmission antennas. That is, the echo signal is obtained by receiving, by one of the reception antennas, a reflected signal of a transmission signal transmitted by one of the transmission antennas.

[0088] The radar includes a plurality of transmission antennas for transmitting transmission signals of a plurality of carrier frequencies, and at least one reception antenna. The carrier frequency of a signal is the center frequency of the signal. In some embodiments, the carrier frequencies of the transmission signals are different.

[0089] The echo signal can be a reception signal received by the reception antenna. Alternatively, an intermediate frequency signal obtained by mixing and low-pass filtering a reception signal received by the reception antenna and a transmission signal corresponding to the reception signal can be obtained. Embodiments of the present application do not limit this.

[0090] It should be understood that the data output by the radar can include the reception signals received by each of the reception antennas, or the data output by the radar can include the intermediate frequency signals corresponding to each of the transceiving channels. That is, the echo signal can be the output data of the radar, or it can also be obtained by processing the output data of the radar.

[0091] Each of the two-dimensional transform results includes at least one peak value. In the case where the number of peak values in the two-dimensional transform results is a plurality, the corresponding peak values in each of the two-dimensional transform results can be taken respectively to perform S320 to S340. The corresponding peak values in each of the two-dimensional transform results are the peak values corresponding to the difference between the fast time frequency parameters and the difference between the slow time frequency parameters in each of the two-dimensional transform results within a preset difference range.

[0092] After two-dimensional Fourier transform, the echo signal is transformed into a two-dimensional transform result. In the two-dimensional transform result, the frequency domain parameter corresponding to the fast time parameter in the echo signal is the fast time frequency parameter, and the frequency domain parameter corresponding to the slow time parameter in the echo signal is the slow time frequency parameter.

[0093] In S320, eigenvalue decomposition is performed on the covariance matrix to determine the noise subspace, each element in the covariance matrix being one of the peak values.

[0094] The covariance matrix is constructed such that each row and each column of the covariance matrix does not include the same peak value.

[0095] The covariance matrix is subjected to eigenvalue decomposition to obtain a plurality of eigenvalues. The number of signal eigenvalues corresponding to the targets is determined according to the number of signal sources. The signal eigenvalues are greater than the noise eigenvalues in the plurality of eigenvalues of the covariance matrix, so that at least one noise eigenvalue of the covariance matrix can be determined. Each eigenvalue corresponds to an eigenvector. The eigenvector corresponding to each noise eigenvalue is a noise vector. The noise subspace includes the noise vectors corresponding to the noise eigenvalues.

[0096] That is, the noise subspace includes at least one noise vector. Each noise vector is an eigenvector corresponding to a noise eigenvalue in the plurality of eigenvalues of the covariance matrix. The noise eigenvalue is determined according to the number of signal sources.

[0097] At S330, a spatial spectrum is constructed according to the noise subspace and a steering vector, the steering vector being determined according to the antenna configuration of the radar and the carrier frequencies of each transmitted signal, the steering vector being related to the position information, the position information including the target distance and the target direction of at least one target.

[0098] The steering vector is used to represent the phase difference between the corresponding echo signals between the plurality of transceiver channels in an ideal case. The ideal case is a case where there is no noise interference. In the ideal case, the echo signals are related to the position information, and the antenna configuration of the radar and the carrier frequencies of each transmitted signal. The position information of the target is an unknown quantity. By obtaining the antenna configuration of the radar and the carrier frequencies of each transmitted signal, the steering vector can be expressed as a function of the position information.

[0099] The radar includes at least one receiving antenna and a plurality of transmitting antennas. The antenna configuration of the radar can represent the relative positional relationship between the at least one receiving antenna and the relative positional relationship between the plurality of transmitting antennas. For example, when the plurality of transmitting antennas are linearly arranged, the antenna configuration of the radar can represent the relative distance between the plurality of transmitting antennas.

[0100] At S340, the position information is determined, the position information making the spatial spectrum reach a maximum value.

[0101] A spatial spectrum estimation algorithm such as multiple signal classification (MUSIC) is used to construct the spatial spectrum. The distance and direction are traversed to perform maximum value search on the spatial spectrum, so that the distance and direction making the spatial spectrum reach a maximum value are the target distance and the target direction of a target.

[0102] It should be understood that for each covariance matrix constructed according to the corresponding peak in each two-dimensional transform result, at least one combination can be determined, each combination including a target distance and a target direction, each combination making the spatial spectrum reach a maximum value. Each combination corresponds to a target, that is, a target can be located according to the target distance and the target direction in each combination.

[0103] Through S310 to S340, the direction and distance of the target are jointly estimated according to the peak in the two-dimensional transform result corresponding to each echo signal received by the radar by using a spatial spectrum estimation algorithm, so as to avoid introducing the error of the direction estimation into the determined distance result, and improve the positioning accuracy.

[0104] Before S310, the plurality of echo signals can be processed to obtain a plurality of two-dimensional transform results.

[0105] Due to the movement of the target, slow-time distance migration can be introduced. The slow-time distance migration affects the accuracy of the peak position in the two-dimensional transform result.

[0106] Whether the slow-time distance migration exists can be determined.

[0107] Specifically, the fast-time dimension Fourier transform can be performed on the echo signal to obtain a first initial range compression result.

[0108] When the difference between the peak corresponding to the fast-time frequency parameter under the plurality of slow-time parameters in the initial range compression result exceeds a first preset difference, the slow-time distance migration exists.

[0109] The fast-time frequency parameter can be continuous or discrete. When the fast-time frequency parameter is a discrete value, the first preset difference can be one or more adjacent fast-time frequency parameters.

[0110] The slow-time distance migration can be corrected. The slow-time parameter of the echo signal can be replaced with a first slow-time adjustment parameter by using a wedge-shaped transform.

[0111] Then, the fast-time dimension Fourier transform is performed on the replaced echo signal to obtain a range compression result. After the correction of the slow-time distance migration, the difference between the peak corresponding to the fast-time frequency parameter under the plurality of first slow-time adjustment parameters in the range compression result is within the first preset difference.

[0112] Through the slow-time adjustment, the correction of the slow-time distance migration is realized.

[0113] Because the carrier frequencies of the transmission signals transmitted by different transmission antennas are different, distance migration and Doppler migration can be caused.

[0114] For the echo signals without the range migration of the slow time, or the echo signals after the correction of the range migration of the slow time, it can be judged whether there is the range migration caused by the different transmission signal frequencies. The range migration caused by the different transmission signal frequencies affects the accuracy of the fast time frequency parameter corresponding to the branch in the two-dimensional transform result.

[0115] The plurality of echo signals corresponding to the first receiving antenna in the radar can be respectively subjected to the fast time dimension Fourier transform to obtain a plurality of second initial range compression results.

[0116] When the difference between the fast time frequency parameters corresponding to the peaks of the plurality of second initial range compression results under one or more first slow time parameters exceeds a second preset difference, there is the range migration caused by the different transmission signal frequencies.

[0117] When the fast time frequency parameter is a discrete value, the second preset difference can be one or more adjacent fast time frequency parameters, which can be the same as or different from the first preset difference.

[0118] In the case where there is the range migration caused by the different transmission signal frequencies, the fast time parameters in the plurality of echo signals can be replaced by fast time adjustment parameters by using a wedge-shaped transform to obtain replaced echo signals. Thus, the plurality of range compression results obtained by respectively subjecting the replaced echo signals to the fast time dimension Fourier transform have a difference between the fast time frequency parameters corresponding to the peaks under one or more first slow time adjustment parameters within the second preset difference.

[0119] By adjusting the fast time parameters in the echo signals, the correction of the range migration caused by the different transmission signal frequencies is realized.

[0120] For the plurality of range compression results without the range migration caused by the different transmission signal frequencies, or the range compression results after the correction of the range migration caused by the different transmission signal frequencies, it can be judged whether there is the Doppler migration caused by the different transmission signal frequencies. The Doppler migration caused by the different transmission signal frequencies affects the accuracy of the slow time frequency parameter corresponding to the peak in the two-dimensional transform result.

[0121] The plurality of range compression results corresponding to the first receiving antenna in the radar can be respectively subjected to the slow time dimension Fourier transform to obtain initial two-dimensional transform results.

[0122] It should be understood that for the range compression results after the correction of the range migration of the slow time, the slow time dimension Fourier transform can be based on the first slow time adjustment parameter. For the range compression results without the correction of the range migration of the slow time, the slow time dimension Fourier transform can be based on the slow time parameter.

[0123] When the difference between the slow time frequency parameters corresponding to the peaks of the plurality of initial two-dimensional transform results in the first fast time frequency parameter range exceeds a third preset difference, there is Doppler walk caused by different transmission signal frequencies.

[0124] When the fast time frequency parameter is a discrete value, the first fast time frequency parameter range can include one or more adjacent fast time frequency parameters. When the fast time frequency parameter is a continuous value, the first fast time frequency parameter range can be a continuous range of fast time frequency parameters.

[0125] The slow time frequency parameter can be continuous or discrete. When the slow time frequency parameter is a discrete value, the third preset difference can include one or more adjacent slow time frequency parameters.

[0126] In the case where there is Doppler walk caused by different transmission signal frequencies, the first slow time adjustment parameter (or slow time parameter) in the plurality of range compression results can be replaced with a second slow time adjustment parameter by using a wedge-shaped transform.

[0127] Subsequently, the plurality of range compression results after replacement can be respectively subjected to slow time dimension Fourier transform based on the second slow time adjustment parameter to obtain a plurality of two-dimensional transform results. The difference between the slow time frequency parameters corresponding to the peaks of the plurality of two-dimensional transform results in the first fast time frequency parameter range is within the third preset difference.

[0128] By adjusting the first slow time adjustment parameter or the slow time parameter, correction of Doppler walk caused by different transmission signal frequencies is achieved.

[0129] When there is no Doppler walk caused by different transmission signal frequencies, the plurality of initial two-dimensional transform results can be respectively taken as two-dimensional transform results.

[0130] Before S320, a covariance matrix can be constructed.

[0131] The covariance matrix can or can not include the same peak value.

[0132] The number of rows of the covariance matrix can be less than or equal to M×N, where M is the number of transmitting antennas in the radar and N is the number of receiving antennas in the radar. That is, the number of rows of the covariance matrix can be less than or equal to the number of transceiver channels in the radar.

[0133] The covariance matrix includes a plurality of columns. Generally, the covariance matrix can be a square matrix.

[0134] In some embodiments, each echo signal can be divided according to the fast time parameter or the slow time parameter to obtain a plurality of sub-echo signals. A two-dimensional Fourier transform can be performed on each sub-echo signal to obtain a two-dimensional transform result.

[0135] Thus, a covariance matrix can be constructed according to the peak values of the two-dimensional transform results corresponding to the plurality of sub-echo signals. Each element in the covariance matrix can correspond to a different two-dimensional transform result. Generally, the peak values in the sub-echo signals are not equal. That is, the covariance matrix can not include the same peak values.

[0136] In other embodiments, different two-dimensional transform results can correspond to different echo signals.

[0137] The covariance matrix can be an L-dimensional skew-symmetric matrix or a symmetric matrix, where L is obtained by rounding up MxN / 2. In the covariance matrix, the elements on the line parallel to the symmetry axis are the same, and different peak values in the covariance matrix correspond to different transmit-receive channels.

[0138] Thus, the amount of data required to construct the covariance matrix can be reduced, and the accuracy of the determined noise subspace can be improved by maximizing the use of echo signals corresponding to each transmit-receive channel, thereby improving the accuracy of positioning.

[0139] Before S340, an initial target distance of a first target of the at least one target can be obtained.

[0140] For example, the initial target distance can be determined according to at least one echo signal.

[0141] A fast time dimension Fourier transform is performed on an echo signal to obtain a range-compressed result. Using the fast time frequency parameter corresponding to a certain peak value in the range-compressed result, the initial target distance can be determined. It should be understood that in the range-compressed result, each slow time frequency can include a peak value. Each peak value corresponds to at least one target.

[0142] The fast time frequency parameters corresponding to the peak values within a certain fast time frequency parameter range in a plurality of range-compressed results can be averaged to determine the initial target distance. The peak values within a certain fast time frequency parameter range in a plurality of range-compressed results can be understood as corresponding to the same target.

[0143] The distance range of the first target can be determined according to the initial target distance, and the target distance of the first target can be determined within the distance range.

[0144] The distance range of the first target can be determined according to the resolution of the initial target distance.

[0145] By determining the distance range of the first target, the range of traversing the distance of the first target to determine the position information that makes the spatial spectrum reach the maximum value can be reduced, and the processing efficiency is improved.

[0146] Before S340 is performed, an initial target direction of the first target can be acquired. The initial target direction is determined according to multiple echo signals corresponding to the same transmit antenna.

[0147] The initial target direction can be obtained based on a direction of arrival (DOA) estimation method of spectrum estimation or a spatial dimension Fourier transform processing.

[0148] According to the initial target direction, a direction range of the first target can be determined, and the target direction is determined in the direction range.

[0149] The direction range of the first target can be determined according to the resolution of the initial target direction.

[0150] By determining the direction range of the first target, the range of traversing the direction of the first target to determine the position information that makes the spatial spectrum reach the maximum value can be reduced, and the processing efficiency is improved.

[0151] In the process of constructing the spatial spectrum according to the noise subspace and the steering vector in S330, the number of elements in the steering vector can be determined according to the number of elements of each noise vector in the noise subspace. Each element in the steering vector is used to represent a phase corresponding to a transceiving channel. Each element in the steering vector can be understood as an expression related to position information.

[0152] The direction resolution of radar positioning is inversely proportional to the virtual aperture, and the distance resolution of radar positioning is inversely proportional to the bandwidth.

[0153] The number of transmit antennas sending different carrier frequencies is M, and the number of transmit antennas corresponding to the elements of the steering vector is increased, which can improve the direction accuracy of positioning. That is, in the positioning method provided in the embodiments of the present application, the steering vector includes elements of multiple transmit antennas, the increased frequency bandwidth realizes "frequency splicing", and the direction accuracy of positioning is improved.

[0154] When the number of transmit antennas corresponding to the elements of the steering vector is increased by increasing the elements in the steering vector, the virtual aperture is increased, "aperture splicing" is realized, and the distance accuracy of positioning can be improved.

[0155] In determining the steering vector, the elements in the steering vector can be made to include elements corresponding to the plurality of receiving antennas, and the plurality of elements corresponding to each receiving antenna correspond to the largest virtual aperture (i.e., including the two receiving antennas corresponding to the farthest distance), so that the positioning accuracy can be improved.

[0156] When the radar adopts receiving antennas arranged at equal intervals, the virtual aperture D N Can achieve:

[0157] D N = M (N-1) · d R

[0158] Wherein, M is the number of transmitting antennas in the radar, N is the number of receiving antennas in the radar, d R is the distance interval between two adjacent receiving antennas.

[0159] It should be understood that the radar in which different transmitting antennas send different carrier frequency signals can be referred to as a frequency diversity (FD) radar.

[0160] It should be understood that the radar in the embodiments of the present application can be a centralized radar or a distributed radar.

[0161] The distributed radar is composed of several radar nodes, and each node can be a radar device. In the distributed radar, each radar node includes at least one transmitting antenna and at least one receiving antenna, the transmitting antenna sends signals, and the receiving antenna receives not only the reflection signal formed by the reflection of the target to the transmitting signal corresponding to the receiving node where the receiving antenna is located, but also the reflection signal formed by the reflection of the target to the transmitting signal corresponding to other nodes.

[0162] By arranging a plurality of radar nodes at each position of a terminal such as a vehicle, the virtual aperture can be improved, and thus the positioning accuracy can be improved.

[0163] The centralized radar can be understood as a radar located in one radar node. In the centralized radar, the receiving antenna can only receive the reflection signal corresponding to the radar node where the receiving antenna is located.

[0164] Figure 3 is a schematic flow chart of a positioning method provided by the embodiments of the present application.

[0165] The antenna array of the radar can be a frequency modulated continuous wave (FMCW)-MIMO radar. The antenna array of the MIMO radar includes M transmitting antennas and N receiving antennas, where M and N are positive integers greater than 1. Each transmitting antenna or each receiving antenna can be understood as an array element. Different combinations of transmitting antennas and receiving antennas can be understood as different transmitting-receiving channels.

[0166] At S410, each transmitting antenna transmits an orthogonal signal with a different carrier frequency.

[0167] The signal transmitted by each transmitting antenna can have a frequency that increases linearly over time, i.e., the signal transmitted by each transmitting antenna can be a frequency modulated continuous wave (FMCW). The starting frequency of the signal transmitted by each of the M transmitting antennas is different.

[0168] The frequency interval of the transmitted signals transmitted by the respective transmitting antennas can be the same or different. For example, the center frequency of the mth transmitted signal transmitted by the mth transmitting antenna can be represented as f m = f c + Δf m , where m = 1, 2,..., M, f c is the center frequency of the signal transmitted by a reference transmitting antenna. For a signal whose frequency increases linearly over time, the center frequency of the signal is the frequency of the signal at the time when half of the signal duration has elapsed since the start of signal transmission, i.e., the center frequency of the signal is the average of the maximum frequency and the minimum frequency of the signal. The center frequency of the signal can also be referred to as the carrier frequency of the signal.

[0169] The mathematical representation of the mth transmitted signal transmitted by the mth transmitting antenna in the antenna array of the MIMO radar is:

[0170]

[0171] where t represents time, p represents the label of the transmitted signal (i.e., the serial number of the transmitted signal, i.e., the number of periods of the transmitted signal), T c is the period of the transmitted signal (when the signal is transmitted in the form of a pulse, the period of the transmitted signal can also be referred to as the pulse repeat interval (PRI)), the slow time t a = p · T c , T r represents the signal duration (i.e., the width of the transmitted signal), K r represents the frequency modulation rate of the FMCW signal (i.e., the rate of change of the frequency of the signal transmitted by the transmitting antenna over time). rect[] represents a rectangular gate function, which is equal to 1 when When t does not satisfy When t does not satisfy When t does not satisfy

[0172] For ease of illustration, let the fast time t r = t - p T c Then, we have:

[0173]

[0174] Thus, the signal transmitted by the mthtransmitting antenna is represented by both fast time and slow time dimensions.

[0175] For ease of illustration, it is assumed that the transmitting antennas and the receiving antennas are arranged at equal intervals, the interval between the transmitting antennas is d T , and the interval between the receiving antennas is d R . Taking the virtual position corresponding to the first transmitting antenna and the first receiving antenna as a reference position, it is assumed that the distance from the target to the reference transmitting antenna at the slow time starting time point is r, the angle between the line connecting the target and the reference transmitting antenna and the line connecting the transmitting antennas is angle θ, and the radial velocity of the target is v p .

[0176] The signal transmitted by the mthtransmitting antenna is scattered by the target and transmitted to each receiving antenna for reception. Assuming that the antenna array and the target satisfy the far-field condition (plane wave assumption), the time delay of the received signal received by the nthreceiving antenna in the N receiving antennas with respect to the transmitted signal of the mthtransmitting antenna is τ mn which can be expressed as

[0177]

[0178] where c represents the propagation speed of electromagnetic waves in a vacuum.

[0179] In an ideal case, the received signal of the transmitted signal of the mthtransmitting antenna received by the nthreceiving antenna can be expressed as

[0180]

[0181] The ideal case is that the influence of environmental noise on the received signal is not considered.

[0182] Mixing with , that is, performing down-conversion processing, that is, multiplying with , the mixing result can be expressed as ​where conj(·) denotes taking the conjugate. The above down-conversion processing is also referred to as dechirp processing, and the obtained down-converted signal is referred to as an intermediate frequency signal or beat frequency signal.

[0183] The mixing result is filtered by a low-pass filter to obtain an intermediate frequency component

[0184]

[0185] In general, the sampling frequency of a signal is proportional to the frequency of the signal. For a signal with a frequency of f, the sampling frequency is generally set to be 2f. Mixing and low-pass filtering are performed on the signal, and the obtained intermediate frequency component is processed, which can reduce the frequency of the processed signal component and reduce the difficulty of sampling the signal.

[0186] A two-dimensional Fourier transform is performed on the intermediate frequency component After the two-dimensional Fourier transform, the time-domain variable slow time t a in the intermediate frequency component a is converted into a frequency-domain variable f r , and the time-domain variable fast time t r is converted into a frequency-domain variable f

[0187] As can be seen from the exponential term of the intermediate frequency component , the product of the slow time t a and the fast time t r has an impact on the intermediate frequency component , that is, there is coupling between the slow time t a and the fast time t r . As can be seen from the exponential term of the intermediate frequency component , the product of the fast time t r and the center frequency f m of the transmitted signal sent by the mth transmit antenna has an impact on the intermediate frequency component , that is, there is coupling between the fast time t r and the center frequency f m .

[0188] When the radial velocity v p of the target is small, the exponential term can be ignored, that is, it can be considered that v p t a t r = 0,

[0189] When the radial velocity v p of the target is large, the exponential term ​​​the influence of the intermediate frequency component cannot be ignored. That is, the radial velocity v p of the target the slow time distance walk introduced in the intermediate frequency component

[0190] The coupling between the slow time t a and the fast time t r can be eliminated by using a keystone transform, i.e. a correction of the slow time distance walk. Let

[0191]

[0192] When , the variable transformation of the above formula can be simplified as:

[0193] By using the keystone transform, the slow time t a is replaced by the adjusted slow time t a ′, a scale transform is realized. Thus, there is no product of the adjusted slow time t a ′ and the fast time t r in the exponential term of the intermediate frequency component after the keystone transform, and there is no coupling between the adjusted slow time t a ′ and the fast time t r . The intermediate frequency component after the keystone transform can be expressed as:

[0194]

[0195] There is no coupling between the adjusted slow time t a ′ and the fast time t r .

[0196] Similarly, when the radial velocity v p of the target is small, the exponential term

[0197] When the radial velocity v p of the target is large, the influence of the exponential term on the intermediate frequency component cannot be ignored. That is, the distance walk between different transceiver antennas in the intermediate frequency component cannot be ignored due to different carrier frequencies.

[0198] The coupling between the fast time t r and the center frequency f m can be eliminated by using a keystone transform, thereby realizing a correction of the distance walk between different transceiver antennas.

[0199] It can make

[0200]

[0201] Under normal circumstances, v p << c, r≥d T , r≥d R The above formula can be simplified to:

[0202]

[0203] Using the Keystone transformation, the fast time t r Replace with the adjusted fast time t r This achieves scaling. Therefore, the intermediate frequency components after the keystone transform... The adjusted fast time t is not present in the exponential term. r ′ and center frequency f m The product of the adjusted fast time t r ′ and center frequency f m There is no coupling. The intermediate frequency component after Keystone transform. It can be represented as:

[0204]

[0205] For the replaced intermediate frequency components A fast time-dimensional Fourier transform is performed to achieve distance compression. That is, for Based on fast time t r Perform a Fourier transform, for example, a Fast Fourier Transform (FFT). Based on a fast time t... r Performing a Fourier transform can also be understood as performing a fast time-dimensional Fourier transform.

[0206] Let τ be the time difference between the maximum time delay of the transmitted signal from the transmitting antenna to the receiving antenna and the start time of the next period signal. max .

[0207] When the transmitting antennas do not transmit signals continuously, τ max =0.

[0208] When each transmitting antenna transmits signals continuously, τ needs to be considered. max The impact of fast time t. r When performing the Fourier transform of τ′, it can be done by considering the signal within each signal period from τ′. max Start to signal duration T rThe fast time dimension Fourier transform is performed on the intermediate frequency signal, so that the intermediate frequency signal in the period in which the one period of the transmitted signal coincides with the received signal corresponding to the last period of the transmitted signal is avoided to affect the processing result.

[0209] The fast time t r ' based on the fast time dimension Fourier transform can obtain the distance compression result in the ideal case:

[0210]

[0211] Wherein, f r is the frequency domain parameter corresponding to the fast time t r ' after the fast time dimension Fourier transform.

[0212] When the value of is 1, S mn (t a ', f r ) reaches the peak value. The position where S mn (t a ', f r ) reaches the peak value is:

[0213]

[0214] The frequency f mn that makes S a (t r ', f r ) reach the peak value corresponds to the distance where the target exists.

[0215] The product of the adjusted slow time t mn ' and the center frequency f a of the transmitted signal is included in the exponential term of S r (t a ', f m ), that is, there is coupling between the adjusted slow time t a ' and the center frequency f m of the transmitted signal.

[0216] When the radial velocity v p of the target is small, the exponential term can be ignored, and the slow time dimension Fourier transform can be performed on S mn (t a ', f r ).

[0217] When the radial velocity v p of the target is large, the exponential term affects S mn (t a ', f rThe influence of the coupling between the adjusted slow time t m and the center frequency f a of the transmitted signal cannot be ignored.

[0218] The coupling between the adjusted slow time t m ′ and the center frequency f m of the transmitted signal can be eliminated by a keystone transformation.

[0219] represents the wavelength of the signal with the center frequency f a . During the radial movement of the target, the phase and frequency will change due to the difference in the wave propagation distance, which is usually referred to as Doppler shift. The elimination of the coupling between the adjusted slow time t m ′ and the center frequency f a of the transmitted signal can be understood as the elimination of the Doppler shift.

[0220] Let

[0221]

[0222] In general, Simplify the above equation, let

[0223]

[0224] Using the keystone transformation, the adjusted slow time t a ′ is replaced by the adjusted slow time t m , so that S mn (t a ′, f r ) can be represented as S mn (t a ″, f r ). In the exponential term of S mn (t a ″, f r ), there is no product of the adjusted slow time t a ″ and the center frequency f m of the transmitted signal, i.e., there is no coupling between the adjusted slow time t a ″ and the center frequency f m of the transmitted signal. After the keystone transformation, S mn (t a ″, f r ) can be represented as:

[0225]

[0226] Based on the adjusted slow time t″ a For S mn (t″ a ,f r Performing a slow-time Fourier transform yields the ideal two-dimensional transform result:

[0227]

[0228] The ideal two-dimensional transformation result S obtained through the two-dimensional Fourier transform mn (f a ,f r In ), f a It is the adjusted slow time t″ a The corresponding frequency domain parameters.

[0229] S is satisfied when the following conditions are met. mn (f a ,f r Reaching peak value:

[0230]

[0231] Therefore, in S mn (f a ,f r At the peak of ), and Therefore, based on f at the peak point a f r The value of can be used to make a rough estimate of the target's distance and speed.

[0232] S mn (f a ,f r The expression at the peak is:

[0233]

[0234] When the center frequencies of the transmitting antennas are evenly spaced, the center frequency of the transmitted signal from the m-th transmitting antenna is:

[0235] f m =f c +Δf m =f c +(m-1)Δf, m=1,2,...,M

[0236] At the peak S mn (f a ,f r ) can be represented as

[0237]

[0238] The signal center frequency f c Corresponding wavelength λ0is expressed as S mn (f a ,f r ) is denoted as The remaining index terms are denoted as a mn . That is, a mn can be expressed as

[0239]

[0240] In general, c >> d R sinθ, and c >> d T sinθ, a mn simplification, then:

[0241]

[0242] A receiving antenna receives a combination corresponding to a transmitting antenna, and is understood as a transceiver combination. Then the peak expression S mn (f a ,f r ) of all transceiver combinations can be written in matrix form:

[0243]

[0244] Where the steering vector A(θ, r) is:

[0245] A(θ, r) = [a 11 (θ, r) a 21 (θ, r) … a M1 (θ, r) a 12 (θ, r) … a M2 (θ, r) … a MN (θ, r)] T .

[0246] In actual cases, there is noise in the received signal received by the receiving antenna. In actual cases, the matrix form can be expressed as

[0247]

[0248] Where, is used to represent the influence of noise on each S mn (f a ,f r ).

[0249] In actual situation, there can be multiple targets around the MIMO radar, then there can be multiple peaks in the two-dimensional transform result S mn (f a ,f r ) of each transceiver combination. a Each peak corresponding to the same f r , f c can constitute a matrix X.

[0250] At S420, the received signal is processed to determine the noise subspace.

[0251] Specifically, the following steps can be performed.

[0252] At S4201, for each transceiver combination of the MxN transceiver combinations, the transmitted signal transmitted by the transmitting antenna and the actually received signal received by the receiving antenna are mixed and low-pass filtered to obtain the intermediate frequency signal corresponding to the transceiver combination.

[0253] The m-n transceiver combination includes the m transmitting antenna and the n receiving antenna, and the intermediate frequency signal corresponding to the m-n transceiver combination is denoted as the m-n intermediate frequency component.

[0254] Each intermediate frequency component is represented by two dimensions of fast time and slow time. The slow time represents the product of the index of the transmitted signal transmitted by the transmitting antenna and the signal transmission period T c , and the fast time is used to represent the time within the number of periods of each transmitted signal. Each fast time can correspond to a sampling point.

[0255] At S4202, it is determined whether there is a slow-time distance walk of each intermediate frequency component.

[0256] The m-n intermediate frequency component is subjected to fast-time dimension Fourier transform based on the fast-time parameter to obtain the m-n initial range compression result.

[0257] It is determined whether the peak value of the m-n initial range compression result corresponding to the fast-time frequency parameter f r of each slow time is within the first preset range.

[0258] The fast-time frequency parameter f r is the frequency domain parameter corresponding to the fast-time parameter after the fast-time dimension Fourier transform.

[0259] If the peak value of the m-n initial range compression result corresponding to the fast-time frequency parameter of each slow time is not within the first preset difference, it indicates that the m-n intermediate frequency component has a slow-time distance walk, and S4203 is performed on the m-n intermediate frequency component.

[0260] If the fast time frequency parameter corresponding to the peak value of the m-n initial distance compression result under each slow time is within the first preset difference, it indicates that the m-n intermediate frequency component does not exist the slow time distance migration, and the m-n intermediate frequency component is no longer subjected to S4203.

[0261] In S4203, the slow time is adjusted by Keystone transformation to eliminate the coupling between the fast time and the slow time in the m-n intermediate frequency component.

[0262] The slow time t a The adjustment manner can be:

[0263]

[0264] The adjustment manner can be: a

[0265]

[0266] The adjusted slow time t a ′ in the intermediate frequency component is not coupled with the fast time t r by Keystone transformation, so as to correct the slow time distance migration.

[0267] After the judgment of S4202 whether the slow time distance migration exists in each intermediate frequency component of the M*N and the execution of S4203 to the intermediate frequency component with the slow time distance migration, S4204 is performed.

[0268] In S4204, it is judged whether the distance migration between different receiving and transmitting antennas exists.

[0269] For the M intermediate frequency components corresponding to the M receiving and transmitting channels of the M transmitting antennas and a receiving antenna, fast time dimension Fourier transformation is respectively performed to obtain M initial distance compression results. The fast time frequency parameter corresponding to the peak value of each initial distance compression result in the M initial distance compression results is within the first preset difference. That is, the M initial distance compression results do not exist the intermediate frequency component with the slow time distance migration, or are subjected to the slow time distance migration correction.

[0270] One of the slow time parameters is selected as a first slow time parameter, and it is judged whether the fast time corresponding to the peak value of the M initial distance compression results under the first slow time is within a second preset difference.

[0271] ​If the fast-time frequency parameters corresponding to the peak values of the M initial range-compression results at the first slow time are not within the second preset difference, it indicates that the difference in the center frequency of the transmission signals of the respective transmitting antennas causes the range walk between the transmitting and receiving antennas, and the S4205 is performed on the m-th intermediate frequency component.

[0272] If the fast-time frequency parameters corresponding to the peak values of the M initial range-compression results at the first slow time are within the second preset difference, it indicates that there is no range walk between different transmitting and receiving antennas, and the S4205 is not performed on the M intermediate frequency components.

[0273] In the S4205, the Keystone transformation is used to adjust the fast time so as to eliminate the coupling between the fast time and the center frequency of the transmission signal in the intermediate frequency component.

[0274] The fast time t r is adjusted in the following manner:

[0275]

[0276] Alternatively, the fast time t r is adjusted in the following manner:

[0277]

[0278] Through the Keystone transformation, the adjusted fast time t r ′ in the intermediate frequency component is not coupled with the center frequency f m .

[0279] For each receiving antenna, it can be determined whether there is a range walk between different transmitting and receiving antennas. For a certain receiving antenna, when there is a range walk between different transmitting and receiving antennas, the S4205 is performed on the respective intermediate frequency components corresponding to the receiving antenna.

[0280] In the S4206, the range-compression result is determined.

[0281] When the S4204 is performed, if the fast-time frequency parameters corresponding to the peak values of the M initial range-compression results at the first slow time are within the second preset difference, each of the initial range-compression results is taken as the range-compression result.

[0282] When the S4204 is performed, if the fast-time frequency parameters corresponding to the peak values of the M initial range-compression results at the first slow time are not within the second preset difference, the S4205 is performed, and in the S4206, the fast-time dimension Fourier transform is performed on the replaced M intermediate frequency components based on the adjusted fast time t r ′ respectively.

[0283] That is, for the intermediate frequency component whose fast time t r is adjusted to fast time t r ′, the range compression result is obtained by performing fast time dimension Fourier transform based on the adjusted fast time t r ′.

[0284] For the intermediate frequency component whose fast time t r is not subjected to Keystone transform, the range compression result is obtained by performing fast time dimension Fourier transform based on the fast time t r .

[0285] At S4207, it is judged whether there is Doppler walk.

[0286] The M range compression results corresponding to the M transmitting antennas for a receiving antenna are respectively subjected to slow time dimension Fourier transform to obtain M initial two-dimensional transform results.

[0287] It is judged whether the difference between the fast time frequency parameters corresponding to the peaks in the M initial two-dimensional transform results in the same first slow time frequency parameter range is within a third preset difference.

[0288] The slow time frequency parameter is the frequency domain parameter corresponding to the slow time parameter after the slow time dimension Fourier transform.

[0289] If the fast time frequency parameters corresponding to the peaks of the M initial two-dimensional transform results in the first slow time frequency parameter range are not within the third preset difference, it is indicated that the different center frequencies of the signals transmitted by the respective transmitting antennas result in Doppler shift, and S4208 is performed on the m-n intermediate frequency component.

[0290] If the fast time frequency parameters corresponding to the peaks of the M initial two-dimensional transform results in the first slow time frequency parameter range are within the third preset range, it is indicated that there is no Doppler shift between different transmitting and receiving antennas, and S4208 is not performed on the M range compression results.

[0291] At S4208, Keystone transform is used to adjust the slow time to eliminate the coupling between the slow time in the range compression result and the center frequency of the transmitted signal.

[0292] It should be understood that the slow time in the range compression result can be the slow time t a , or the adjusted slow time t a ′. The adjustment of the slow time is illustrated by taking the adjusted slow time t a ′ as an example. If the slow time in the range compression result is the slow time t a , the slow time t a ′ in the adjustment is replaced by the slow time t aThat's all.

[0293] For slow time t a The adjustment can be made in the following ways:

[0294]

[0295] Under normal circumstances, Then for slow time t a The adjustment can also be made in the following ways:

[0296]

[0297] For each receiving antenna, it can be determined whether Doppler shift exists. For a given receiving antenna, if Doppler shift exists, S4208 is executed on the distance compression results for that antenna.

[0298] In S4209, determine the two-dimensional transformation result corresponding to each distance compression result.

[0299] When performing S4207, if the fast time frequency parameter corresponding to the peak value of the M initial two-dimensional transformation results is within the third preset range under the first slow time frequency parameter range, the M initial two-dimensional transformation results can also be used as the M two-dimensional transformation results.

[0300] If the fast time frequency parameter corresponding to the peak value of the M initial two-dimensional transformation results is not within the third preset difference range under the first slow time frequency parameter range, after performing S4208, the distance compression result obtained after performing Keystone transformation on the slow time is based on the slow time parameter t″. a Perform a slow-time Fourier transform.

[0301] For those who have already adjusted slow time to slow time t a ′ or slow time t″ a The distance compression result is then subjected to a slow-time Fourier transform based on the adjusted slow-time dimension.

[0302] For the unconstrained slow time t a Distance compression results after Keystone transform, based on slow time t a Perform a slow-time Fourier transform.

[0303] In S430, the MUSIC algorithm is used to locate the target.

[0304] In S4301, the covariance matrix is ​​constructed based on the peak values ​​in each two-dimensional transformation result.

[0305] Each of the two-dimensional transform results includes at least one peak value, and for each corresponding peak value, a covariance matrix is constructed. The corresponding peak value is a peak value whose difference in fast time frequency parameter and difference in slow time frequency parameter in the M×N two-dimensional transform results correspond.

[0306] The covariance matrix can be expressed as: R XX =YY H , wherein Y H represents the transpose of Y.

[0307] The covariance matrix can be constructed in the form of a Toeplitz matrix or a Hankle matrix. Taking the Toeplitz matrix as an example for description. The elements on the main diagonal of the Toeplitz matrix are equal, and the elements on the lines parallel to the main diagonal are also equal; the elements in the Toeplitz matrix are symmetric about the secondary diagonal, that is, the Toeplitz matrix is a secondary symmetric matrix. The following Toeplitz matrix is constructed using the compressed peak value data:

[0308]

[0309] , wherein fix() is a floor function. x1 to x MN are the corresponding peak values in the M×N two-dimensional transform results, respectively.

[0310] The covariance matrix is: R XX =YY H .

[0311] At S4302, the covariance matrix is eigen-decomposed to determine a noise subspace.

[0312] The frequency domain covariance matrix R XX is eigen-decomposed to obtain a plurality of eigenvalues, each of which corresponds to an eigenvector.

[0313] The number of signal eigenvalues corresponding to signals in the plurality of eigenvalues can be determined by signal source number estimation. The plurality of eigenvalues of the covariance matrix are arranged in order of size, and the signal eigenvalue is at least one eigenvalue that satisfies the maximum number of signal eigenvalues. The eigenvalues other than the signal eigenvalues are noise eigenvalues.

[0314] The signal source number estimation can be performed by an information theory method, a smooth rank method, a matrix decomposition method, a Gerschgorin circle method, etc.

[0315] Each eigenvalue corresponds to an eigenvector. The eigenvector corresponding to the noise eigenvalue is a noise vector.

[0316] The noise subspace U can be determined according to the noise vector N :

[0317] U N = [u1, u2, …, u p ]

[0318] wherein u1, u2, …, u p are noise vectors respectively, and the number of noise eigenvalues is p.

[0319] At S4303, a spatial spectrum is constructed according to the noise subspace and the steering vector.

[0320] The spatial spectrum P MUSIC may be expressed as:

[0321]

[0322] At S4303, the position of the target is determined.

[0323] The combination of the angle θ and the distance r is traversed, so that the spatial spectrum P MUSIC The combination where the spatial spectrum P appears a maximum value is the position of the target.

[0324] The covariance matrix constructed by the Toeplitz matrix or the Hankle matrix is dimensional matrix, the noise vector is an L-dimensional vector. Therefore, when constructing the spatial spectrum, L elements a mn in the steering vector A(θ, r) can be selected to form a vector A1, and the vector A1 can also be understood as a steering vector.

[0325] The L elements a mn may correspond to M transmitting antennas and N receiving antennas, so that the determined target position has high resolution.

[0326] In some embodiments, at S4201, for each intermediate frequency signal corresponding to each transceiving channel pair, the slow time can be divided to obtain a plurality of sub-intermediate frequency signals corresponding to different slow time ranges. For each sub-intermediate frequency signal, S4202-S4209 can be performed. When performing S4210, the corresponding peak value in the two-dimensional transform result corresponding to each sub-intermediate frequency signal can be taken as an element in the covariance matrix. The covariance matrix can be an M×N dimensional matrix. Then, at S4211, the covariance matrix is subjected to eigenvalue decomposition, and an M×N dimensional noise vector can be obtained.

[0327] When constructing the spatial spectrum at S430, the vector A1 can be the steering vector A(θ, r).

[0328] To reduce the range of combinations of traversal angle θ and distance r, an initial direction can be determined before performing S430. and initial distance Determine the initial distance This involves making a rough estimate of the distance to the target and determining the initial direction. That is, to make a rough estimate of the direction of the target.

[0329] The slow-time frequency parameter f at the peak point of the distance compression is obtained from the fast-time Fourier transform. a Fast time frequency f r The value of can be used to make a rough estimate of the target's distance and speed. At the peak point, and With reference transmitting antenna m=1 and reference receiving antenna n=1, the initial distance of the target relative to the reference transmitting antenna and the reference receiving antenna can be determined.

[0330] initial distance The resolution is B represents the bandwidth of the signal transmitted by the transmitting antenna. In the spatial spectrum P... MUSIC When determining the precise distance to a target, one can... The search is performed within the range of distance r. This reduces the search area for distance r when determining the target's location, thus improving efficiency.

[0331] Using the results transmitted by the m-th transmitting antenna and received by multiple receiving antennas, the initial direction can be obtained through spectral estimation of the angle of arrival (DOA) or spatial Fourier transform processing.

[0332] The initial angle can be determined by using the difference in the initial distances corresponding to the two slow-time-dimensional FFT results, and the distance between the receiving antennas corresponding to the two slow-time-dimensional FFT results. The distance between the two receiving antennas is d R The distance difference between the transmitted signal from the m-th transmitting antenna and the distance received by the two receiving wires is d. R sinθ. Based on the phase difference of the transmitted signal actually received by the two receiving antennas, the initial direction can be obtained. Of course, the initial direction Alternatively, it can be determined based on the average value of the directions determined by each of the multiple sets of receiving antennas.

[0333] By performing spatial Fourier transform processing, the received signals corresponding to N transmit / receive combinations for a given transmit antenna can be subjected to FFT, thereby determining the initial angle.

[0334] initial angle is obtained according to the actual received signals of the transmitted signals of a certain transmitting antenna by a plurality of receiving antennas, so the initial angle has a resolution of D N is used to represent the size of the virtual aperture. Assuming that N receiving antennas are arranged at equal intervals, the interval between two adjacent receiving antennas is d R , then D N = (N-1)·d R . When the accurate angle of the target is determined by using the spatial spectrum P MUSIC , the angle θ can be traversed within the range of . Thus, the range of searching the angle θ when the position of the target is determined is reduced, and the efficiency is improved.

[0335] The method embodiments of the embodiments of the present application are described above in combination with Figures 1 to 3 . The device embodiments of the embodiments of the present application are described below in combination with Figures 4 to 5 . It should be understood that the description of the method embodiments and the description of the device embodiments correspond to each other, and thus, the parts not described in detail can be referred to the foregoing method embodiments.

[0336] Figure 4 is a schematic structural diagram of a positioning device provided by the embodiments of the present application.

[0337] The positioning device 2000 includes an acquisition module 2010 and a processing module 2020.

[0338] The peak value of each of a plurality of two-dimensional transform results is acquired, and the difference between the fast time frequency parameters corresponding to the plurality of peak values and the difference between the slow time frequency parameters corresponding to the plurality of peak values are within a preset difference range, wherein each of the two-dimensional transform results is obtained by two-dimensional Fourier transform on an echo signal, the fast time frequency parameter is a frequency domain parameter corresponding to a fast time parameter in the echo signal corresponding to the two-dimensional transform result, the slow time frequency parameter is a frequency domain parameter corresponding to a slow time parameter in the echo signal corresponding to the two-dimensional transform result, the echo signal corresponds to a transceiving channel in one-to-one correspondence, and each of the transceiving channels includes one receiving antenna and one transmitting antenna.

[0339] The processing module 2020 is configured to perform eigen decomposition on a covariance matrix to determine a noise subspace, each element in the covariance matrix being one of the peaks, each row and each column in the covariance matrix not including the same peak, the noise subspace including at least one noise vector, each noise vector being a feature vector corresponding to a noise eigenvalue in a plurality of eigenvalues of the covariance matrix, the noise eigenvalue being determined according to a number of signal sources estimation.

[0340] The processing module 2020 is further configured to construct a spatial spectrum according to the noise subspace and a steering vector, the steering vector being determined according to an antenna configuration of a radar and a carrier frequency of each transmitted signal, the radar including a plurality of the transmitting antennas and at least one of the receiving antennas, the plurality of the transmitting antennas being configured to transmit the transmitted signals with a plurality of carrier frequencies, the steering vector being associated with position information, the position information including a target distance and a target direction of at least one target.

[0341] The processing module 2020 is further configured to determine the position information, the position information making the spatial spectrum reach a maximum value.

[0342] Optionally, the processing module 2020 is further configured to perform fast-time dimension Fourier transform on the echo signal to obtain a first initial range compression result.

[0343] The processing module 2020 is further configured to replace, when a difference between fast-time frequency parameters corresponding to peaks of the initial range compression result under a plurality of slow-time parameters exceeds a first preset difference, a slow-time parameter of the echo signal with a first slow-time adjustment parameter by using a wedge-shaped transform.

[0344] The processing module 2020 is further configured to perform fast-time dimension Fourier transform on the replaced echo signal to obtain a range compression result, a difference between fast-time frequency parameters corresponding to peaks of the range compression result under the plurality of first slow-time adjustment parameters being within the first preset difference.

[0345] The processing module 2020 is further configured to perform slow-time dimension Fourier transform on the range compression result to obtain the two-dimensional transform result.

[0346] Optionally, the processing module 2020 is further configured to perform fast-time dimension Fourier transform on a plurality of first replaced echo signals corresponding to a first receiving antenna in the at least one receiving antenna respectively to obtain a plurality of second initial range compression results, the first replaced echo signal being obtained by replacing the slow-time parameter in the echo signal with the first slow-time adjustment parameter.

[0347] The processing module 2020 is further configured to, when a difference between the fast time frequency parameters corresponding to the peaks of the plurality of second initial distance compression results under at least one first slow time adjustment parameter exceeds a second preset difference, replace the fast time parameters in the plurality of first replacement echo signals with fast time adjustment parameters by using a wedge-shaped transformation to obtain the replacement echo signals, a difference between the fast time frequency parameters corresponding to the peaks of the plurality of distance compression results under at least one first slow time parameter being within the second preset difference.

[0348] Optionally, the processing module 2020 is further configured to perform slow time dimension Fourier transform on the plurality of distance compression results respectively to obtain a plurality of initial two-dimensional transformation results.

[0349] The processing module 2020 is further configured to, when a difference between the slow time frequency parameters corresponding to the peaks of the plurality of initial two-dimensional transformation results under a first fast time frequency parameter range exceeds a third preset difference, replace the first slow time adjustment parameters in the plurality of distance compression results with second slow time adjustment parameters by using a wedge-shaped transformation.

[0350] The processing module 2020 is further configured to, based on the second slow time adjustment parameters, perform slow time dimension Fourier transform on the plurality of distance compression results respectively to obtain a plurality of two-dimensional transformation results, a difference between the slow time frequency parameters corresponding to the peaks of the plurality of two-dimensional compression results under the first fast time frequency parameter range being within the third preset difference.

[0351] Optionally, the processing module 2020 is further configured to perform fast time dimension Fourier transform on the plurality of echo signals corresponding to a first receiving antenna in the at least one receiving antenna respectively to obtain a plurality of initial distance compression results.

[0352] The processing module 2020 is further configured to, when a difference between the fast time frequency parameters corresponding to the peaks of each of the plurality of initial distance compression results under a plurality of slow time parameters does not exceed a first preset difference, and a difference between the fast time frequency parameters corresponding to the peaks of the plurality of initial distance compression results under a first slow time parameter exceeds a second preset difference, replace fast time parameters in the plurality of echo signals corresponding to the first receiving antenna with fast time adjustment parameters by using a wedge-shaped transformation.

[0353] The processing module 2020 is further configured to perform fast time dimension Fourier transform on the plurality of echo signals corresponding to the first receiving antenna based on the fast time adjustment parameters respectively to obtain a plurality of distance compression results, a difference between the fast time frequency parameters corresponding to the peaks of the plurality of distance compression results under the first slow time parameter being within the second preset difference.

[0354] The processing module 2020 is further configured to perform a slow-time dimension Fourier transform on each of the plurality of distance compressed results based on the fast-time adjustment parameter to obtain a plurality of two-dimensional transform results.

[0355] Optionally, the processing module 2020 is further configured to perform a slow-time dimension Fourier transform on each of the plurality of distance compressed results to obtain a plurality of initial two-dimensional transform results.

[0356] The processing module 2020 is further configured to replace, when a difference between slow-time frequency parameters corresponding to wave crests of the plurality of initial two-dimensional transform results in a first fast-time frequency parameter range exceeds a third preset difference, a slow-time parameter in the plurality of distance compressed results with a second slow-time adjustment parameter by using a wedge-shaped transform to obtain a plurality of distance compressed results after replacement.

[0357] Optionally, the processing module 2020 is further configured to perform a fast-time dimension Fourier transform on each of the plurality of echo signals corresponding to a first receiving antenna of the at least one receiving antenna to obtain a plurality of distance compressed results, a difference between fast-time frequency parameters corresponding to wave crests of each of the plurality of distance compressed results does not exceed a first preset difference, and a difference between the fast-time frequency parameters corresponding to the wave crests of the plurality of distance compressed results in a first slow-time parameter does not exceed a second preset difference.

[0358] The processing module 2020 is further configured to perform a slow-time dimension Fourier transform on each of the plurality of distance compressed results to obtain a plurality of initial two-dimensional transform results.

[0359] The processing module 2020 is further configured to replace, when a difference between slow-time frequency parameters corresponding to wave crests of the plurality of initial two-dimensional transform results in a first fast-time frequency parameter range exceeds a third preset difference, a slow-time parameter in the plurality of distance compressed results with a second slow-time adjustment parameter by using a wedge-shaped transform.

[0360] The processing module 2020 is further configured to perform a slow-time dimension Fourier transform on each of the plurality of distance compressed results after replacement based on the second slow-time adjustment parameter to obtain a plurality of two-dimensional transform results, a difference between the slow-time frequency parameters corresponding to the wave crests of the plurality of two-dimensional compressed results in the first fast-time frequency parameter range is within the third preset difference.

[0361] Optionally, the processing module 2020 is further configured to obtain an initial target distance of a first target of the at least one target, the initial target distance being determined according to at least one of the echo signals.

[0362] The processing module 2020 is further configured to determine a distance range of the first target according to the initial target distance.

[0363] The processing module 2020 is further configured to determine the target distance of the first target within the distance range.

[0364] Optionally, the processing module 2020 is further configured to obtain an initial target direction of a first target in the at least one target, the initial target direction being determined according to a plurality of echo signals corresponding to the same transmitting antenna.

[0365] The processing module 2020 is further configured to determine a direction range of the first target according to the initial target direction.

[0366] The processing module 2020 is further configured to determine the target direction within the direction range.

[0367] Optionally, the covariance matrix is a skew-symmetric matrix or a symmetric matrix, and elements in the covariance matrix located on a line parallel to a symmetric axis are the same.

[0368] Optionally, the number of the plurality of transmitting antennas is M, the number of the at least one receiving antenna is N, the covariance matrix is an L-dimensional square matrix, L is obtained by rounding up M*N / 2, and different peak values in the covariance matrix correspond to different transceiving channels, M, N, and L are all positive integers.

[0369] Optionally, the radar is distributed or centralized.

[0370] Figure 5 FIG. 1 is a schematic structural diagram of a positioning device provided by an embodiment of the present application.

[0371] The positioning device 3000 of the radar comprises at least one memory 3010 and at least one processor 3020, the at least one memory 3010 is configured to store a program, and the at least one processor 3020 is configured to run the program to implement the method described above.

[0372] The positioning device 2000 and the positioning device 3000 can be a vehicle with a positioning function or other components with a positioning function. The positioning device includes but is not limited to a vehicle terminal, a vehicle controller, a vehicle module, a vehicle module, a vehicle component, a vehicle chip, a vehicle unit, a vehicle radar or other sensors. The vehicle can pass through the vehicle terminal, the vehicle controller, the vehicle module, the vehicle module, the vehicle component, the vehicle chip, the vehicle unit, or the vehicle radar, and the positioning device is used to implement the method provided by the present application.

[0373] That is, the positioning apparatus 2000, 3000 can be located in the radar. Alternatively, the positioning apparatus 2000, 3000 can be located outside the radar and process data output by the radar.

[0374] The positioning apparatus can also be or be arranged in or in a component of a smart terminal having a positioning function other than a vehicle. The smart terminal can be a smart transportation device, a smart home device, a robot, or other terminal device. The positioning apparatus includes but is not limited to the smart terminal or a controller, a chip, or other sensors such as a radar, and other components in the smart terminal.

[0375] The positioning apparatus 2000, 3000 can be a general-purpose device or a special-purpose device. In a specific implementation, the apparatus can also be a desktop computer, a laptop computer, a network server, a personal digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, an embedded device, or other devices having processing functions. The embodiments of the present application do not limit the type of the positioning apparatus.

[0376] The positioning apparatus 2000, 3000 can also be a chip or a processor having processing functions, and the positioning apparatus can include multiple processors. The processor can be a single-CPU processor or a multi-CPU processor. The chip or processor having processing functions can be arranged in a sensor or not arranged in a sensor but arranged at a receiving end of a sensor output signal.

[0377] It should be understood that the processor in the embodiments of the present application can be a central processing unit (CPU), and the processor can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0378] It should also be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically EPROM (EEPROM) or a flash memory. The volatile memory can be a random access memory (RAM) used as an external cache. By way of example, but not by way of limitation, many forms of random access memory (RAM) are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM) and direct rambus RAM (DR RAM).

[0379] The description of the flow corresponding to each of the above figures has its own emphasis, and the part not described in detail in a certain flow can be referred to the related description of other flows.

[0380] The embodiments of the present application also provide a computer readable storage medium, characterized in that the computer readable storage medium has program instructions, when the program instructions are executed directly or indirectly, the method in the foregoing is realized.

[0381] The embodiments of the present application also provide a computer program product containing instructions, when it runs on a computing device, the computing device executes the method in the foregoing, or the computing device realizes the function of the device in the foregoing.

[0382] The embodiments of the present application also provide a chip system, characterized in that the chip system includes at least one processor, when the program instructions are executed in the at least one processor, the method in the foregoing is realized.

[0383] The embodiments of the present application also provide a radar system for providing positioning function for a vehicle. The system comprises at least one positioning device mentioned in the above embodiments of the present application. At least one positioning device in the system can be integrated into one machine or device, or at least one positioning device in the system can be independently arranged as an element or device.

[0384] The embodiments of the present application also provide a sensor system for providing positioning function for a vehicle. The system comprises at least one positioning device mentioned in the above embodiments of the present application, and other sensors such as radars. At least one sensor device in the system can be integrated into one machine or device, or at least one sensor device in the system can be independently arranged as an element or device.

[0385] The embodiments of the present application also provide a system applied to unmanned driving or intelligent driving. The system comprises at least one positioning device mentioned in the above embodiments of the present application, and other sensors such as radars. At least one device in the system can be integrated into one machine or device, or at least one device in the system can be independently arranged as an element or device.

[0386] Further, any of the above systems can interact with a central controller of a vehicle, and provide detection and / or fusion information for decision or control of driving of the vehicle.

[0387] The embodiments of the present application also provide a vehicle comprising at least one positioning device mentioned in the above embodiments of the present application or any of the above systems.

[0388] The embodiments of the present application also provide a terminal comprising the positioning device mentioned above.

[0389] Further, the terminal can be an intelligent transportation device (vehicle or unmanned aerial vehicle), an intelligent home device, an intelligent manufacturing device or a robot, etc. The intelligent transportation device can be an automated guided vehicle (AGV) or an unmanned transportation vehicle, for example.

[0390] The above-described embodiments can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented by software, the above-described embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the processes or functions described in the embodiments of the present application are wholly or partially generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center through a wired (for example, infrared, wireless, microwave, etc.) manner. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server, data center, etc. containing one or more available medium collections. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state disk.

[0391] It should be understood that the term "and / or" herein merely describes an association relationship of associated objects, which means that there can be three relationships, for example, A and / or B can represent three cases of A alone, A and B together, and B alone, where A and B can be singular or plural. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after it, but it can also represent an "and / or" relationship, which can be understood in the context before and after it.

[0392] In this application, "at least one" means one or more, and "multiple" means two or more. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can represent a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

[0393] It should be understood that in various embodiments of the present application, the size of the sequence number of the above-described processes does not mean the order of execution, and the execution order of the processes should be determined by their functions and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0394] As used in this specification, the terms "component," "module," "system," etc., are used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. As illustrated, applications running on computing devices and computing devices can both be components. One or more components may reside in a process and / or an execution thread, and components may be located on a single computer and / or distributed among two or more computers. Furthermore, these components can be executed from various computer-readable media on which various data structures are stored. Components can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system, and / or a network, such as the Internet interacting with other systems via signals).

[0395] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0396] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0397] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0398] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0399] In addition, each function unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0400] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the parts of the technical solutions that essentially contribute to the prior art can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0401] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A positioning method, characterized by, The method comprises: obtaining a plurality of peak values corresponding to a plurality of two-dimensional transform results, wherein a difference between fast time frequency parameters corresponding to the plurality of peak values and a difference between slow time frequency parameters corresponding to the plurality of peak values are within a preset difference range, each of the two-dimensional transform results is obtained by performing two-dimensional Fourier transform on an echo signal, the fast time frequency parameter is a frequency domain parameter corresponding to a fast time parameter in the echo signal corresponding to the two-dimensional transform result, the slow time frequency parameter is a frequency domain parameter corresponding to a slow time parameter in the echo signal corresponding to the two-dimensional transform result, the echo signal corresponds to a transceiving channel one-to-one, and each of the transceiving channels comprises one receiving antenna and one transmitting antenna; performing eigenvalue decomposition on a covariance matrix to determine a noise subspace, each element in the covariance matrix is one of the peak values, each row and each column in the covariance matrix does not include the same peak value, and the noise subspace comprises at least one noise vector, each of the noise vectors is an eigenvector corresponding to a noise eigenvalue in a plurality of eigenvalues of the covariance matrix, and the noise eigenvalue is determined according to a signal source number estimation; constructing a spatial spectrum according to the noise subspace and a steering vector, the steering vector is determined according to an antenna configuration of a radar and a carrier frequency of each transmitted signal, the radar comprises a plurality of transmitting antennas and at least one receiving antenna, the plurality of transmitting antennas are used to transmit a plurality of carrier frequency transmitted signals, the steering vector is related to position information, and the position information comprises target distance and target direction of at least one target. The position information is determined, and the position information makes the spatial spectrum reach a maximum value.

2. The method of claim 1, wherein, The method comprises: performing fast time dimension Fourier transform on the echo signal to obtain a first initial range compression result; when a difference between fast time frequency parameters corresponding to wave crests of the first initial range compression result under a plurality of slow time parameters exceeds a first preset difference, replacing the slow time parameter of the echo signal with a first slow time adjustment parameter by using a wedge-shaped transformation; performing fast time dimension Fourier transform on the replaced echo signal to obtain a range compression result, wherein a difference between fast time frequency parameters corresponding to wave crests of the range compression result under a plurality of first slow time adjustment parameters is within the first preset difference; performing slow time dimension Fourier transform on the range compression result to obtain the two-dimensional transform result.

3. The method of claim 2, wherein, The method further comprises: performing fast time dimension Fourier transform on a plurality of first replaced echo signals corresponding to a first receiving antenna in the at least one receiving antenna to obtain a plurality of second initial range compression results, wherein the first replaced echo signal is obtained by replacing the slow time parameter in the echo signal with the first slow time adjustment parameter. when a difference between the peak corresponding fast time frequency parameters of the plurality of second initial distance compressed results under at least one first slow time adjustment parameter exceeds a second preset difference, replacing the fast time parameters in the plurality of first replacement echo signals with fast time adjustment parameters by using a wedge-shaped transformation to obtain the replacement echo signals; the step of performing the fast time dimension Fourier transform on the replacement echo signals to obtain the distance compressed results comprises: performing the fast time dimension Fourier transform on the replacement echo signals to obtain a plurality of distance compressed results, a difference between the peak corresponding fast time frequency parameters of the plurality of distance compressed results under at least one first slow time adjustment parameter is within the second preset difference.

4. The method of claim 3, wherein the method further comprises: performing the fast time dimension Fourier transform on the plurality of distance compressed results respectively to obtain a plurality of initial two-dimensional transform results; when a difference between the peak corresponding slow time frequency parameters of the plurality of initial two-dimensional transform results under a first fast time frequency parameter range exceeds a third preset difference, replacing the first slow time adjustment parameter in the plurality of distance compressed results with a second slow time adjustment parameter by using a wedge-shaped transformation; the step of performing the slow time dimension Fourier transform on the distance compressed results to obtain the two-dimensional transform results comprises: performing the slow time dimension Fourier transform on the plurality of distance compressed results respectively based on the second slow time adjustment parameter to obtain a plurality of the two-dimensional transform results, a difference between the peak corresponding slow time frequency parameters of the plurality of two-dimensional transform results under the first fast time frequency parameter range is within the third preset difference. the method further comprises:

5. The method of claim 1, wherein, performing the fast time dimension Fourier transform on the plurality of echo signals corresponding to a first receiving antenna in the at least one receiving antenna respectively to obtain a plurality of initial distance compressed results; when a difference between the peak corresponding fast time frequency parameters of each of the plurality of initial distance compressed results under a plurality of slow time parameters does not exceed a first preset difference, and a difference between the peak corresponding fast time frequency parameters of the plurality of initial distance compressed results under a first slow time parameter exceeds a second preset difference, replacing the fast time parameters in the plurality of echo signals corresponding to the first receiving antenna with fast time adjustment parameters by using a wedge-shaped transformation; performing the fast time dimension Fourier transform on the plurality of echo signals corresponding to the first receiving antenna respectively based on the fast time adjustment parameters to obtain a plurality of distance compressed results, a difference between the peak corresponding fast time frequency parameters of the plurality of distance compressed results under the first slow time parameter is within the second preset difference; performing the slow time dimension Fourier transform on the plurality of replacement distance compressed results respectively based on the fast time adjustment parameters to obtain a plurality of the two-dimensional transform results. the method further comprises:

6. The method of claim 5, wherein, performing the fast time dimension Fourier transform on the plurality of distance compressed results respectively to obtain a plurality of initial two-dimensional transform results; ​ When a difference between slow time frequency parameters corresponding to peaks of the plurality of initial two-dimensional transform results in a first fast time frequency parameter range exceeds a third preset difference, the slow time parameters in the plurality of distance compressed results are replaced with second slow time adjustment parameters by using a wedge-shaped transform to obtain a plurality of replaced distance compressed results.

7. The method of claim 1, wherein, The method further comprises: performing fast time dimension Fourier transform on each of the plurality of echo signals corresponding to a first receiving antenna of the at least one receiving antenna to obtain a plurality of distance compressed results, a difference between fast time frequency parameters corresponding to peaks of each of the plurality of distance compressed results does not exceed a first preset difference, and a difference between the fast time frequency parameters corresponding to the peaks of the plurality of distance compressed results in a first slow time parameter does not exceed a second preset difference; performing slow time dimension Fourier transform on each of the plurality of distance compressed results to obtain a plurality of initial two-dimensional transform results; When a difference between slow time frequency parameters corresponding to peaks of the plurality of initial two-dimensional transform results in a first fast time frequency parameter range exceeds a third preset difference, the slow time parameters in the plurality of distance compressed results are replaced with second slow time adjustment parameters by using a wedge-shaped transform to obtain a plurality of replaced distance compressed results. performing slow time dimension Fourier transform on each of the plurality of distance compressed results based on the second slow time adjustment parameters to obtain a plurality of two-dimensional transform results, a difference between the slow time frequency parameters corresponding to the peaks of the plurality of two-dimensional transform results in the first fast time frequency parameter range is within the third preset difference.

8. The method according to any one of claims 1-7, characterized in that, The method further comprises: obtaining an initial target distance of a first target of the at least one target, the initial target distance being determined according to at least one of the echo signals; determining a distance range of the first target according to the initial target distance; The determining the position information comprises: determining the target distance of the first target within the distance range.

9. A positioning device, characterized in that The apparatus comprises an obtaining module and a processing module; The obtaining module is configured to obtain a plurality of peaks of each of a plurality of two-dimensional transform results, a difference between fast time frequency parameters corresponding to the plurality of peaks and a difference between slow time frequency parameters corresponding to the plurality of peaks being within a preset difference range, wherein each of the two-dimensional transform results is obtained by performing two-dimensional Fourier transform on an echo signal, the fast time frequency parameter is a frequency domain parameter corresponding to a fast time parameter in the echo signal corresponding to the two-dimensional transform result, the slow time frequency parameter is a frequency domain parameter corresponding to a slow time parameter in the echo signal corresponding to the two-dimensional transform result, the echo signal corresponds to a transceiving channel one-to-one, and each of the transceiving channels comprises a receiving antenna and a transmitting antenna. The processing module is configured to perform eigen-decomposition on a covariance matrix to determine a noise subspace, each element in the covariance matrix being one of the peaks, each row and each column in the covariance matrix not including the same peak, the noise subspace including at least one noise vector, each noise vector being a eigenvector corresponding to a noise eigenvalue in a plurality of eigenvalues of the covariance matrix, the noise eigenvalue being determined according to a number of signal sources estimation; The processing module is further configured to construct a spatial spectrum according to the noise subspace and a steering vector, the steering vector being determined according to an antenna configuration of a radar and a carrier frequency of each transmitted signal, the radar including a plurality of the transmitting antennas and at least one receiving antenna, the plurality of transmitting antennas being configured to transmit a plurality of carrier frequencies of the transmitted signals, the steering vector being related to position information, the position information including target distance and target direction of at least one target; The processing module is further configured to determine the position information, the position information making the spatial spectrum reach a maximum value.

10. The apparatus of claim 9, wherein, The processing module is further configured to: perform fast-time dimension Fourier transform on the echo signal to obtain a first initial range compression result; when a difference between fast-time frequency parameters corresponding to wave crests of the first initial range compression result under a plurality of slow-time parameters exceeds a first preset difference, replace slow-time parameters of the echo signal with first slow-time adjustment parameters by using a wedge-shaped transform; perform fast-time dimension Fourier transform on the replaced echo signal to obtain a range compression result, a difference between fast-time frequency parameters corresponding to wave crests of the range compression result under a plurality of first slow-time adjustment parameters being within the first preset difference; perform slow-time dimension Fourier transform on the range compression result to obtain the two-dimensional transform result.

11. The apparatus of claim 10, wherein, The processing module is further configured to: perform fast-time dimension Fourier transform on a plurality of first replaced echo signals corresponding to a first receiving antenna of the at least one receiving antenna respectively to obtain a plurality of second initial range compression results, the first replaced echo signal being obtained by replacing the slow-time parameters in the echo signal with the first slow-time adjustment parameters; when a difference between fast-time frequency parameters corresponding to wave crests of the plurality of second initial range compression results under at least one first slow-time adjustment parameter exceeds a second preset difference, replace the fast-time parameters in a plurality of the first replaced echo signals with fast-time adjustment parameters by using a wedge-shaped transform to obtain the replaced echo signal; perform the fast-time dimension Fourier transform on the replaced echo signal to obtain a plurality of range compression results, a difference between fast-time frequency parameters corresponding to wave crests of the plurality of range compression results under at least one first slow-time adjustment parameter being within the second preset difference.

12. The apparatus of claim 11, wherein, The processing module is further configured to: perform slow-time dimension Fourier transform on the plurality of range compression results respectively to obtain a plurality of initial two-dimensional transform results; when a difference between slow time frequency parameters corresponding to peaks of the multiple two-dimensional transform results in a first fast time frequency parameter range exceeds a third preset difference, replacing, by using a wedge-shaped transform, the first slow time adjustment parameter in the multiple distance compression results with a second slow time adjustment parameter; performing, based on the second slow time adjustment parameter, slow time dimension Fourier transform on the multiple distance compression results after replacement respectively to obtain multiple two-dimensional transform results, a difference between slow time frequency parameters corresponding to peaks of the multiple two-dimensional transform results in the first fast time frequency parameter range being within the third preset difference.

13. The apparatus of claim 9, wherein, The processing module is further configured to: perform fast time dimension Fourier transform on the multiple echo signals corresponding to the first receiving antenna respectively to obtain multiple initial distance compression results; when a difference between fast time frequency parameters corresponding to peaks of the multiple initial distance compression results in multiple slow time parameters does not exceed a first preset difference, and a difference between the fast time frequency parameters corresponding to peaks of the multiple initial distance compression results in a first slow time parameter exceeds a second preset difference, replacing, by using a wedge-shaped transform, a fast time parameter in the multiple echo signals corresponding to the first receiving antenna with a fast time adjustment parameter; perform fast time dimension Fourier transform on the multiple echo signals corresponding to the first receiving antenna based on the fast time adjustment parameter respectively to obtain multiple distance compression results, a difference between the fast time frequency parameters corresponding to peaks of the multiple distance compression results in the first slow time parameter being within the second preset difference; perform slow time dimension Fourier transform on the multiple distance compression results after replacement respectively based on the fast time adjustment parameter to obtain multiple two-dimensional transform results.

14. The apparatus of claim 13, wherein, The processing module is further configured to: perform slow time dimension Fourier transform on the multiple distance compression results respectively to obtain multiple initial two-dimensional transform results; when a difference between slow time frequency parameters corresponding to peaks of the multiple initial two-dimensional transform results in a first fast time frequency parameter range exceeds a third preset difference, replacing, by using a wedge-shaped transform, a slow time parameter in the multiple distance compression results with a second slow time adjustment parameter to obtain the multiple distance compression results after replacement.

15. The apparatus of claim 9, wherein, The processing module is further configured to: perform fast time dimension Fourier transform on the multiple echo signals corresponding to the first receiving antenna respectively to obtain multiple distance compression results, a difference between fast time frequency parameters corresponding to peaks of each distance compression result in multiple slow time parameters does not exceed a first preset difference, and a difference between the fast time frequency parameters corresponding to peaks of the multiple distance compression results in a first slow time parameter does not exceed a second preset difference; perform slow time dimension Fourier transform on the multiple distance compression results respectively to obtain multiple initial two-dimensional transform results; when a difference between slow time frequency parameters corresponding to wave crests of the plurality of initial two-dimensional transform results in a first fast time frequency parameter range exceeds a third preset difference, replacing, by using a wedge-shaped transform, slow time parameters in the plurality of range compressed results with second slow time adjustment parameters; performing, based on the second slow time adjustment parameters, slow time dimension Fourier transform on the plurality of range compressed results after replacement respectively to obtain a plurality of the two-dimensional transform results, a difference between slow time frequency parameters corresponding to wave crests of the plurality of two-dimensional transform results in the first fast time frequency parameter range being within the third preset difference.

16. The apparatus of any one of claims 9-15, wherein, The processing module is further configured to: obtain an initial target distance of a first target in the at least one target, the initial target distance being determined according to at least one of the echo signals; determine a distance range of the first target according to the initial target distance; determine the target distance of the first target in the distance range.

17. A computer-readable storage medium, characterized in that, The computer readable storage medium is configured to execute program codes for a device, and the program codes, when executed by the device, implement the method according to any one of claims 1-8.

18. A terminal, characterized by The positioning device according to any one of claims 9-16. The positioning device according to any one of claims 9-16.

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