KR102630235B1 - Apparatus and method for generating a range-doppler map using data correlation in a rader system - Google Patents

Abstract

According to the present disclosure, in a radar system, an apparatus for generating a range-Doppler map using range-aligned signal data generated based on a radar reflection signal including a plurality of pulses is provided to generate a range-Doppler map. A phase compensation determiner for determining phase compensation values corresponding to the plurality of pulses based on entropy of complex data in the signal data, a pattern of a first distance-Doppler map based on the distance-aligned signal data, and , a map pattern determiner for determining a pattern of a second distance-Doppler map based on the distance aligned signal data and the phase compensation values, in the pattern of the first distance-Doppler map and the pattern of the second distance-Doppler map, Based on the correlation between complex data, a movement amount determiner determines a cell movement amount in relation to the distance of the pulse data unit, and a distance-Doppler map based on the pattern of the second distance-Doppler map and the cell movement amount. Contains a map generator that generates maps.

Description

Apparatus and method for generating a range-Doppler map using data correlation in a radar system {APPARATUS AND METHOD FOR GENERATING A RANGE-DOPPLER MAP USING DATA CORRELATION IN A RADER SYSTEM}

This disclosure relates generally to a radar system that generates a range-Doppler map using a radar signal reflected from a target, and more specifically to a range-aligned signal generated based on a radar signal containing a plurality of pulses. An apparatus and method for generating a clear range-Doppler map from data using data correlation.

Radar refers to a device that transmits a radio frequency signal to a target and receives reflected waves reflected from the target to obtain information about the distance between the radar and the target or the shape of the target. Accordingly, radar is widely used as a military device to track targets such as enemy missiles or aircraft.

Radar generally detects and tracks a target using an ultra-high frequency radar sensor in the microwave band based on RF (radio frequency) signals, and obtains information about the target. According to one example, a radar system generates a range-Doppler map (RD map) and obtains information about a target from the range-Doppler map. The radar transmits a radar signal including a plurality of linearly modulated pulses and receives a signal reflected from the target, and obtains distance information to the target from the plurality of pulses of the received signal. Afterwards, the radar collects each pulse signal with equally aligned range information and applies Fourier transform in the Doppler direction to generate a two-dimensional distance-Doppler map. Since the Doppler frequency can be converted to speed, the radar can easily detect and track the target by obtaining the target's distance and speed from the two-dimensional range-Doppler map, and determine the shape according to the two-dimensional range-Doppler map. Through this, you can check the scattering pattern of the target.

To generate a range-Doppler map, the radar's signal processing device compensates for the moving distance of the target that occurs while receiving a plurality of pulses and aligns the position using a range bin. In other words, a clear range-Doppler map can be obtained only after compensating for the phase shift due to velocity for each pulse and target and then performing Doppler processing.

However, since it is realistically impossible to accurately determine the target's distance and speed, an error may occur between the target's actual speed and the speed used for phase compensation. In particular, for aerial targets with relatively high speeds, there is a higher probability that an error will occur between the actual speed and the speed used for phase compensation. To solve this problem, the distance-Doppler map generating device compensates for the phase error between each pulse through entropy minimization to generate a relatively clear distance-Doppler map. However, when using the entropy minimization method, not only the phase compensation value with the minimum entropy value but also other phase compensation values in which the linear phase is added to the phase value also satisfies the minimum entropy value, so the phase compensation value that satisfies the minimum entropy value. There are countless of these. Accordingly, the conventional range-Doppler map generating device had difficulty predicting the speed proportional to the exact Doppler frequency, and there was a problem in that the overall detection and tracking performance of the radar target was deteriorated.

Based on the above discussion, the present disclosure provides an apparatus and method for generating a range-Doppler map using range-aligned signal data generated from a radar signal containing a plurality of pulses.

Additionally, the present disclosure provides an apparatus and method for clearly generating a range-Doppler map by determining a phase value required to compensate for motion caused by the distance and speed of the target through entropy minimization.

Additionally, the present disclosure provides an apparatus and method for clearly generating a distance-Doppler map using data correlation with respect to a blurred distance-Doppler map and a phase-compensated distance-Doppler map.

According to various embodiments of the present disclosure, in a radar system, an apparatus for generating a range-Doppler map using distance-aligned signal data generated based on a radar reflection signal including a plurality of pulses A phase compensation determiner that determines phase compensation values corresponding to the plurality of pulses based on entropy of complex data in the distance-aligned signal data, and a pattern of a first distance-Doppler map based on the distance-aligned signal data. (pattern), a map pattern determiner for determining a pattern of a second distance-Doppler map based on the distance aligned signal data and the phase compensation values, a pattern of the first distance-Doppler map and the second distance-Doppler map In the pattern, a movement amount determiner determines a cell movement amount in relation to the distance in pulse data units, based on correlation between complex data, and a distance based on the pattern of the second distance-Doppler map and the cell movement amount. -May include a map generator that generates a Doppler map.

According to another embodiment, the phase compensation determiner initializes a first phase compensation value, determines an entropy for the distance-aligned signal data based on the complex data and the first phase compensation value, and determines the entropy Determine a second phase compensation value at which is the minimum, identify whether a difference between the second phase compensation value and the first phase compensation value is less than a preset threshold, and If the difference between the first phase compensation values is less than the threshold value, the second phase compensation value may be output.

According to another embodiment, the phase compensation determiner sorts the distance based on the complex data and the second phase compensation value when the difference between the second phase compensation value and the first phase compensation value is greater than or equal to a threshold value. The entropy of the signal data can be determined, and a third phase compensation value at which the entropy is minimized can be determined.

According to another embodiment, the entropy may include Shannon entropy.

According to another embodiment, the pattern of the first distance-Doppler map indicates a pattern of a blurring distance-Doppler map in which Fourier transform is applied to the distance-aligned signal data, and the second distance-Doppler map The pattern of the map may indicate the pattern of a phase compensation distance-Doppler map in which Fourier transform is applied to the distance-aligned signal data to which the phase compensation value is applied.

According to another embodiment, the movement amount determiner includes at least one first complex data corresponding to the position of the target in the pattern of the first range-Doppler map and the position of the target in the pattern of the second range-Doppler map. A circular correlation between the second complex data corresponding to can be determined, and the cell movement amount of the pulse data unit can be determined based on the size of the circular correlation.

According to another embodiment, the movement amount determiner may determine the distance that maximizes the size of the circular correlation as the cell movement amount.

According to an embodiment of the present disclosure, in a radar system, a device for generating a range-Doppler map using distance-aligned signal data generated based on a radar reflection signal including a plurality of pulses. The operating method includes determining phase compensation values corresponding to the plurality of pulses based on entropy of complex data in the distance-aligned signal data, and determining a first distance-Doppler map based on the distance-aligned signal data. Determining a pattern and a pattern of a second distance-Doppler map based on the distance aligned signal data and the phase compensation values, the pattern of the first distance-Doppler map and the second distance-Doppler map determining, in a pattern, a cell movement amount in relation to a distance in pulse data units, based on a correlation between complex data, and range-Doppler based on the cell movement amount and the pattern of the second range-Doppler map. It may include the step of creating a map.

According to another embodiment, the pattern of the first distance-Doppler map indicates a pattern of a blurring distance-Doppler map in which Fourier transform is applied to the distance-aligned signal data, and the second distance-Doppler map The pattern of the map may indicate the pattern of a phase compensation distance-Doppler map in which Fourier transform is applied to the distance-aligned signal data to which the phase compensation value is applied.

According to another embodiment, the step of determining the cell movement amount includes at least one first complex data corresponding to the location of the target in the pattern of the first distance-Doppler map and the pattern of the second distance-Doppler map. It may include determining a circular correlation between second complex data corresponding to the location of the target, and determining a cell movement amount in units of pulse data based on the size of the circular correlation.

According to another embodiment, determining the cell movement amount may include determining a distance that maximizes the size of the circular correlation as the cell movement amount.

Various respective aspects and features of the invention are defined in the appended claims. Combinations of the features of the dependent claims may be combined with the features of the independent claims as appropriate, not just those explicitly set out in the claims.

Additionally, one or more features selected from any one embodiment described in this disclosure may be combined with one or more features selected from any other embodiments described in this disclosure, and alternatives to these features may be used. A combination of the above may at least partially alleviate one or more technical problems discussed in this disclosure, or at least partially alleviate technical problems that can be discerned by a person skilled in the art from this disclosure, and further provide the features of the embodiments ( Unless such a particular combination or permutation of embodiment features is understood by those skilled in the art to be incompatible, the combination is possible.

In any described example implementation of this disclosure, two or more physically distinct components may alternatively be integrated into a single component if such integration is possible, so forming a single component. If the same function is performed by , integration is possible. Conversely, a single component of any embodiment described in this disclosure may alternatively, where appropriate, be implemented as two or more separate components that achieve the same functionality.

It is an object of certain embodiments of the present invention to solve, alleviate or eliminate, at least in part, at least one of the problems and/or disadvantages associated with the prior art. Certain embodiments aim to provide at least one of the advantages described below.

Apparatus and methods according to various embodiments of the present disclosure enable the generation of a clear range-Doppler map by correcting errors using correlation in a radar system.

The apparatus and method according to various embodiments of the present disclosure determine a clear range-Doppler map pattern for an aerial target for which it is difficult to accurately determine the target's distance and speed, thereby increasing the accuracy of the target's speed estimate value. .

Apparatus and methods according to various embodiments of the present disclosure enable increased detection and tracking performance of a radar target in a radar system.

The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description below. will be.

1 illustrates a radar system according to various embodiments of the present disclosure.
FIG. 2 shows a schematic diagram of a method for generating a range-Doppler map in a radar system according to various embodiments of the present disclosure.
Figure 3 shows a schematic diagram of a method for generating a range-Doppler map by compensating phase through an entropy minimization method in a conventional radar system.
FIG. 4 illustrates the configuration of a signal processor in a radar system according to various embodiments of the present disclosure.
FIG. 5 shows a block diagram of a method of operating a range-Doppler map generating device in a radar system according to various embodiments of the present disclosure.
FIG. 6 illustrates a schematic diagram of a method for generating a range-Doppler map in which errors are compensated using correlation in a radar system according to various embodiments of the present disclosure.
FIG. 7 illustrates a flowchart of a method of operating a range-Doppler map generating device in a radar system according to various embodiments of the present disclosure.
FIG. 8 shows a flowchart of a method for determining a phase compensation value in a radar system according to various embodiments of the present disclosure.
Figure 9 shows an example of target modeling and range-Doppler map for a target in a conventional radar system.
FIG. 10 illustrates an example of a range-Doppler map generated by a range-Doppler map generating device in a radar system according to various embodiments of the present disclosure.
FIG. 11 illustrates an example of a range-Doppler map generated by a range-Doppler map generating device in a radar system according to various embodiments of the present disclosure.

Terms used in the present disclosure are merely used to describe specific embodiments and may not be intended to limit the scope of other embodiments. Singular expressions may include plural expressions, unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as generally understood by a person of ordinary skill in the technical field described in this disclosure. Among the terms used in this disclosure, terms defined in general dictionaries may be interpreted to have the same or similar meaning as the meaning they have in the context of related technology, and unless clearly defined in this disclosure, have an ideal or excessively formal meaning. It is not interpreted as In some cases, even terms defined in the present disclosure cannot be interpreted to exclude embodiments of the present disclosure.

In various embodiments of the present disclosure described below, a hardware approach method is explained as an example. However, since various embodiments of the present disclosure include technology using both hardware and software, the various embodiments of the present disclosure do not exclude software-based approaches.

Hereinafter, the present disclosure relates to an apparatus and method for generating a range-Doppler map in a radar system. Specifically, this disclosure describes a technique for generating a clear range-Doppler map using correlation with respect to range-aligned signal data generated based on a radar signal containing a plurality of pulses.

Below, various embodiments will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement them. However, since the technical idea of the present disclosure can be modified and implemented in various forms, it is not limited to the embodiments described in this specification. In describing the embodiments disclosed in this specification, if it is determined that detailed description of related known technologies may obscure the gist of the technical idea of the present disclosure, detailed descriptions of the known technologies will be omitted. Identical or similar components will be assigned the same reference number and duplicate descriptions thereof will be omitted.

In this specification, when an element is described as being "connected" to another element, this includes not only the case of being "directly connected" but also the case of being "indirectly connected" with another element in between. When an element is said to “include” another element, this means that it does not exclude another element in addition to the other element, but may further include another element, unless specifically stated to the contrary.

Some embodiments may be described in terms of functional block configurations and various processing steps. Some or all of these functional blocks may be implemented as any number of hardware and/or software configurations that perform specific functions. For example, the functional blocks of the present disclosure may be implemented by one or more microprocessors, or may be implemented by circuit configurations for certain functions. Functional blocks of the present disclosure may be implemented in various programming or scripting languages. The functional blocks of this disclosure may be implemented as algorithms running on one or more processors. Functions performed by a functional block in the present disclosure may be performed by a plurality of functional blocks, or functions performed by a plurality of functional blocks in the present disclosure may be performed by a single functional block. Additionally, the present disclosure may employ conventional technologies for electronic environment setup, signal processing, and/or data processing.

In addition, in the present disclosure, the expressions greater than or less than are used to determine whether a specific condition is satisfied or fulfilled, but this is only a description for expressing an example and excludes descriptions of more or less. It's not about doing it. Conditions written as ‘more than’ can be replaced with ‘more than’, conditions written as ‘less than’ can be replaced with ‘less than’, and conditions written as ‘more than and less than’ can be replaced with ‘greater than and less than’.

Hereinafter used ‘…’ wealth', '… Terms such as 'unit' refer to a unit that processes at least one function or operation, and may be implemented as hardware, software, or a combination of hardware and software. The range-Doppler map generating device may include a communication unit, a storage unit, and a control unit. The storage unit, communication unit, and control unit may operate in functional combination with at least one processor.

1 illustrates a radar system 100 according to various embodiments of the present disclosure. Radar system 100 may include a radar sensor 110 and a target 160. According to the radar system 100, the radar sensor 110 can extract target information using a received signal in which an ultra-high frequency signal transmitted from the radar is scattered from the target. Figure 1 shows a case where the radar system has one radar sensor 110 and one target 160, but the number of radar sensors and targets may be plural depending on the situation.

According to the radar system 100, the radar sensor 110 performs a function to detect or track a target. The radar sensor 110 transmits a radio frequency (RF) signal to the target 160 and receives a signal reflected from the target. The radar sensor 110 may obtain information about the distance between the radar sensor 110 and the target 160 or the shape of the target using the reflected received signal.

According to an embodiment of the present disclosure, the radar sensor 110 may perform a conversion function between a base band signal and a bit stream to transmit a radar signal. For example, when transmitting data, the radar sensor 110 may generate complex symbols by encoding and modulating a transmission bit stream. The radar sensor 110 includes a frequency synthesizer 111 that synthesizes frequencies to modulate the phase, a transmitter 113 that upconverts a baseband signal to a radio frequency (RF) band signal, and at least one antenna element. It may include a transmission antenna 115 that transmits a radar signal using an antenna array. Through this, the radar sensor 110 can transmit a radar signal to the target through the transmission antenna 115.

According to an embodiment of the present disclosure, the radar sensor 110 may obtain information about the target by receiving an RF signal reflected from the target. The radar sensor 110 includes a receiving antenna 117 that receives an RF signal reflected from a target using at least one antenna array composed of antenna elements, a receiver 119 that down-converts the RF band signal to a baseband signal, It may include a signal processor 121 that processes the down-converted signal. Through this, the radar sensor 110 can restore the received bit stream by demodulating and decoding the baseband signal.

FIG. 2 shows a schematic diagram 200 of a method for generating a range-Doppler map in a radar system according to various embodiments of the present disclosure.

Referring to FIG. 2, the signal processor 121 acquires the received signal 201, which is a radar signal reflected from the target. The radar sensor 110 may transmit a radar signal including a plurality of linearly modulated pulses to a target and receive a signal reflected from the target. Accordingly, the radar signal may include M pulses, and the signal processor 121 may receive the received signal 201 including M pulses.

Thereafter, the signal processor 121 may process the received signal to obtain signal data 203. The signal processor 121 may apply pulse compression or stretch processing to the received signal 201 to generate signal data 203 related to distance information. Here, the signal data may be expressed as a signal matrix, and the value of the signal data may include a complex value. Additionally, the size of signal data may be determined based on the number M of pulses included in the radar signal and the total number N of range bins. According to an embodiment of the present disclosure, signal data may be determined as a matrix of size M x N.

Thereafter, the signal processor 121 may obtain distance-sorted signal data 205 by performing distance sorting on the signal data 203 by matching the center of the signal data in units of distance bins. The size of complex data including information about the target is larger than the size of complex data not including information about the target. Accordingly, the signal processor 121 can generate distance-aligned signal data by comparing the sizes of complex data included in the signal data and matching the distance information about the target. Accordingly, the distance-aligned signal data can be determined to be M x N in size.

Thereafter, the signal processor 121 may generate a distance-Doppler map 207 by performing Fourier transform on the distance-aligned signal data 205. According to an embodiment of the present disclosure, the signal processor 121 may apply Fourier transform in the Doppler direction to the distance-aligned signal data 205. According to an embodiment of the present disclosure, the signal processor 121 compensates for the error using phase compensation values according to the speed error corresponding to each pulse in the distance-aligned signal data, and then applies Fourier transform in the Doppler direction. can do. A user of a radar sensor can obtain distance and speed information about a target using the generated range-Doppler map.

Figure 3 shows a schematic diagram 300 of a method for generating a range-Doppler map by compensating phase through an entropy minimization method in a conventional radar system.

Referring to FIG. 3, the signal processor 121 may generate distance-aligned signal data 301 based on the radar signal reflected from the target. The distance-aligned signal data 301 may be generated according to the same method as the method in which the signal processor 121 generates the distance-aligned signal data 205 in FIG. 2 . Accordingly, distance-aligned signal data may be expressed as a signal matrix, and values of the signal data may include complex values. Additionally, the size of signal data may be determined based on the number M of pulses included in the radar signal and the total number N of distance bins. According to one embodiment, signal data may be determined as a matrix of size M x N.

The signal processor 121 determines a phase compensation value ϕ (303) to compensate for the phase error regarding speed. The signal processor 121 may determine phase compensation values corresponding to each of a plurality of pulses in the distance-aligned signal data 301. According to one embodiment, the signal processor 121 may determine the phase compensation value ϕ (303) based on the size of complex data corresponding to the intensity of the signal. Here, the phase compensation value ϕ (303) may include M complex data corresponding to each of the M pulses.

Thereafter, the signal processor 121 may generate phase-compensated signal data 305 based on the distance alignment signal data 301 and the phase compensation value ϕ (303). The signal processor 121 applies phase compensation values to the distance-aligned signal data 301 to generate phase-compensated signal data 305. That is, the signal processor 121 may determine M phase compensation values that have the minimum entropy value and apply the phase compensation values to the signal of the distance-aligned signal data to compensate for the phase. According to one embodiment, the signal processor 121 may compensate the phase by applying the phase compensation value ϕ (303) to the distance-aligned signal data 301 by element-wise multiplication.

Thereafter, the signal processor 121 may process the phase-compensated signal data 305 to generate a phase-compensated range-Doppler map 307. According to one embodiment, the signal processor 121 may generate a phase-compensated distance-Doppler map 307 by applying Fourier transform in the Doppler direction to the phase-compensated signal data 305. A user of a radar sensor can obtain distance and speed information about a target using the generated range-Doppler map.

Referring to FIG. 3, the signal processor 121 can generate a range-Doppler map with high clarity by compensating the signal data for the phase related to the distance and speed of the target. Here, the signal processor 121 may use an entropy minimization method to determine a phase value at which the absolute value of the signal size satisfies the minimum entropy value in order to determine the phase compensation value ϕ (303).

When the phase compensation value is determined according to a general entropy minimization method, the phase value obtained by adding the linear phase to the determined phase compensation value also satisfies the minimum value of entropy. In other words, there may be an infinite number of phase compensation values that satisfy entropy minimization. Differences in linear phase cause the image quality to be the same, but cause a circular shift in the vertical (cross range) direction, and the speed proportional to the clear Doppler frequency cannot be predicted, so the radar can detect and track the target. Performance may deteriorate.

FIG. 4 illustrates a configuration 400 of the signal processor 121 in a radar system according to various embodiments of the present disclosure.

Referring to FIG. 4, when the radar sensor 110 receives a radar signal reflected from a target, the signal processor 121 processes the received signal to obtain information about the target. That is, the signal processor 121 can process radar signals to generate signal data and obtain information about the target from the signal data. At this time, signal data can be expressed as a signal matrix. According to an embodiment of the present disclosure, the signal processor 121 may include a signal data generating device 411 and a range-Doppler map generating device 461.

As shown in FIG. 4, the following example illustrates the case where the signal processor 121 includes the signal data generating device 411 and the distance-Doppler map generating device 461. However, the signal data generating device 411 and the distance -The Doppler map generating device 461 is composed of a separate device that is separate from the signal processor 121, and can operate in connection with the signal processor 121.

The signal data generating device 411 performs a function of generating distance-aligned signal data from radar signals. According to an embodiment of the present disclosure, the signal data generating device 411 generates signal data by applying a pulse compression method or stretch processing to a radar signal including a plurality of pulses, and the center of the signal data in distance bin units. You can perform distance sorting to match . At this time, the signal data can be expressed as a signal matrix, and the size of the signal matrix can be determined based on the number of pulses and the number of distance bins included in the radar signal. The signal data generating device 411 outputs the generated distance-aligned signal data to the distance-Doppler map generating device 461.

The distance-Doppler map generating device 461 performs a function of generating a distance-Doppler map using distance-sorted signal data. The distance-Doppler map generating device 461 may generate a distance-Doppler map by performing Fourier transform on distance-aligned signal data generated by collecting a plurality of pulse signals in the Doppler direction. At this time, the distance-Doppler map generating device 461 may generate a distance-Doppler map using an entropy minimization technique from distance-sorted signal data. According to an embodiment of the present disclosure, the distance-Doppler map generating device 461 includes a phase compensation determiner 471, a map pattern determiner 473, a movement amount determiner 475, and a map generator 477.

The phase compensation determiner 471 performs a function of determining phase compensation values corresponding to each of a plurality of pulses, based on distance-aligned signal data. According to an embodiment of the present disclosure, the phase compensation determiner 471 determines a phase compensation value according to the speed error using complex data regarding each pulse in all distance bins. Accordingly, the phase compensation determiner 471 can determine phase compensation values corresponding to the number of pulses.

The map pattern determiner 473 performs a function of determining a pattern of a distance-Doppler map using distance-aligned signal data and phase compensation values. According to an embodiment of the present disclosure, the map pattern determiner 473 may determine the pattern of the first distance-Doppler map by applying Fourier transform to the distance-aligned signal data. Here, the first range-Doppler map indicates a blurred map. Additionally, the map pattern determiner 473 may determine the pattern of the second distance-Doppler map by applying Fourier transform to the phase compensation values and the distance-aligned signal data. The map pattern determiner 473 may determine the pattern of the second distance-Doppler map by multiplying and applying the determined phase compensation values to the distance-aligned signal data generated by collecting the plurality of pulse signals and compensating them. Here, the second range-Doppler map indicates an auto-focused map.

The movement amount determiner 475 performs a function of determining the cell movement amount based on the correlation between complex data in the pattern of the first distance-Doppler map and the pattern of the second distance-Doppler map. According to an embodiment of the present disclosure, the movement amount determiner 475 determines the cell movement amount for which the maximum value of the circular correlation in the vertical direction between images in the patterns of two distance-Doppler maps is calculated. Here, the cell movement amount may indicate the distance in pulse data units. The movement amount determiner 475 determines the correlation in the vertical distance direction between the pattern of the first distance-Doppler map and the second distance-Doppler map pattern received from the map pattern determiner 473. The movement amount determiner 475 uses the determined correlation as a matching score and determines the movement amount corresponding to the largest matching score as the cell movement amount.

The map generator 477 performs a function of generating a distance-Doppler map by applying the cell movement amount to the pattern of the second distance-Doppler map. According to one embodiment of the present disclosure, the map generator 477 generates the final distance-Doppler map by applying the cell movement amount to the pattern of the second distance-Doppler map.

Referring to FIG. 4, the range-Doppler map generating device 461 determines a pattern of a second range-Doppler map in which the phase error regarding speed is compensated. That is, the pattern of the second distance-Doppler map may have clear image quality with focus adjusted through phase compensation values, but includes an error regarding clarity. Here, the distance-Doppler map generating device 461 according to the present disclosure determines and reflects the cell movement amount from the correlation between complex data in the pattern of the second distance-Doppler map and the pattern of the blurred first distance-Doppler map. By doing so, it is possible to generate a final range-Doppler map that is clear and at the same time has reduced errors in clarity.

FIG. 5 shows a block diagram 500 of a method of operating the range-Doppler map generating device 461 in a radar system according to various embodiments of the present disclosure. Figure 5 illustrates a method of operating the range-Doppler map generating device 461.

Referring to FIG. 5, the signal data generating device 411 may generate distance-aligned signal data and output it to the distance-Doppler map generating device 461. Here, the distance-sorted signal data may include matrix data of size M x N. At this time, M may indicate the number of pulses and N may indicate the total number of distance bins. Additionally, the value of each signal data may be expressed as complex values. The distance-aligned signal data is input to the phase compensation determiner 471 and the map pattern determiner 473.

The phase compensation determiner 471 determines phase compensation values corresponding to a plurality of pulses in units of total distance bins from the distance-aligned signal data. The phase compensation determiner 471 may determine a phase compensation value for each of a plurality of pulses through entropy minimization using complex data included in the distance-aligned signal data. According to an embodiment of the present disclosure, the entropy used to determine phase compensation may include at least one of Tsallis entropy and Shannon entropy. Hereinafter, the phase compensation determiner 471 determines the phase compensation value at which the entropy value is minimum using Shannon entropy, but the phase compensation value may be determined using another entropy value.

Distance-aligned signal data including M pulses can be expressed as matrix data. Here, if the matrix data is f(x,n), the complex image signal matrix z(m,n), in which Fourier transform is applied to the matrix data f(x,n) in the Doppler direction, can be determined as <Equation 1>. .

Referring to <Equation 1>, z(m,n) is complex image signal matrix data, f(x,n) is signal data including M pulses, M is the number of pulses, and ϕ is the phase compensation value. Instruct.

If Shannon entropy is calculated with respect to the size of the absolute value of such complex image signal matrix data, the Shannon entropy value can be determined as shown in Equation 2.

Referring to <Equation 2>, E _shannon is the Shannon entropy value, z(m,n) is the complex image signal matrix related to the distance-aligned signal data, M is the number of pulses of the radar return signal, and N is the distance bin. Indicate the size.

The phase compensation determiner 471 may determine M phase compensation values that minimize the Shannon entropy value determined through Equation 2. Thereafter, the phase compensation determiner 471 outputs the determined phase compensation value to the map pattern determiner 473.

The map pattern determiner 473 generates a pattern of the range-Doppler map. According to an embodiment of the present disclosure, the map pattern determiner 473 may generate a pattern of the first distance-Doppler map based on distance-aligned signal data. Here, the first range-Doppler map contains accurate information about the target's location, but the phase is not compensated for speed, indicating a blurred map. Additionally, the map pattern determiner 473 may generate a pattern of a second distance-Doppler map based on the phase compensation value and the distance-aligned signal data. Here, the second range-Doppler map indicates an auto-focused map with a phase compensation value applied. The map pattern determiner 473 outputs the pattern of the first distance-Doppler map to the movement amount determiner 475, and outputs the pattern of the second distance-Doppler map to the movement amount determiner 475 and the map generator 477.

The movement amount determiner 475 performs a function of determining the cell movement amount based on the correlation between complex data in the pattern of the first distance-Doppler map and the second distance-Doppler map. According to an embodiment of the present disclosure, the movement amount determiner 475 identifies the distance bin where the target is located based on the size of complex data in the patterns of the range-Doppler map. Thereafter, the movement amount determiner 475 determines circular correlation values in the vertical direction between images in the pattern of the first distance-Doppler map and the pattern of the second distance-Doppler map with respect to the identified distance bin. That is, the movement amount determiner 475 uses the circular correlation values as the matching score, and determines the movement amount that produces the largest matching score as the cell movement amount.

According to another embodiment of the present disclosure, in order to increase the accuracy of the matching score, the movement amount determiner 475 does not use the complex data itself regarding the pattern of the first distance-Doppler map, but slides in the vertical direction. complex data can be used. The movement amount determiner 475 may determine the correlation between complex data of the pattern of the first distance-Doppler map slid by a preset number of cells in the vertical direction and complex data of the pattern of the second distance-Doppler map. Thereafter, the movement amount determiner 475 may determine the cell movement amount based on the size of the determined correlation. The movement amount determiner 475 transmits the determined cell movement amount to the map generator 477.

The map generator 477 performs a function of generating a final distance-Doppler map using the pattern of the second distance-Doppler map and the cell movement amount. The map generator 477 may apply the cell movement amount to the auto-focused second distance-Doppler map pattern to generate a distance-Doppler map in which positional errors are compensated.

FIG. 6 illustrates a schematic diagram 600 of a method for generating a range-Doppler map in which errors are compensated using correlation in a radar system according to various embodiments of the present disclosure. Figure 6 illustrates a method of operating the range-Doppler map generating device 461.

The range-Doppler map generating device 461 may obtain a first range-Doppler map pattern 601 and a second range-Doppler map pattern 603 using the map pattern determiner 473. As shown in FIG. 6, the pattern 601 of the first range-Doppler map contains accurate information about the location of the target by indicating the location of the target using a plurality of vertical distance bins, but has no phase difference with respect to speed. This is not compensated for and is blurred. In addition, the pattern 603 of the second range-Doppler map delivers information about the location of the target with clear image quality by applying the phase compensation value determined through entropy minimization to the signal data, but there is an error.

Correspondingly, the distance-Doppler map generating device 461 uses the correlation between the pattern 601 of the first distance-Doppler map and the pattern 603 of the second distance-Doppler map to determine the final distance in which the error is compensated. -A Doppler map 605 can be generated. According to an embodiment of the present disclosure, the range-Doppler map generating device 461 may generate a distance bin regarding the location of the target from the pattern 601 of the first range-Doppler map and the pattern 603 of the second range-Doppler map. Identify the location of the unit. Thereafter, the range-Doppler map generating device 461 generates a circular correlation in the vertical direction between the complex data of the pattern of the first range-Doppler map with respect to complex data regarding the position of the target in the pattern of the second range-Doppler map. Determine the values. The distance-Doppler map generating device 461 determines the determined circular correlation values as a matching score, and determines the movement amount that produces the largest matching score as the cell movement amount. The range-Doppler map generating device 461 may generate a final range-Doppler map 605 similar to an actual target by applying the determined cell movement amount to the pattern of the auto-focused second range-Doppler map.

Referring to the first distance-Doppler map pattern 601, the size of the first complex data arranged in 4 rows and 3 columns and the second complex data arranged in 3 rows and 5 columns are the largest. Accordingly, referring to the first range-Doppler map, it is identified that the positions of the 4th row and 3rd column and the positions of the 3rd row and 5th column contain signals related to the target. However, the pattern 601 of the first distance-Doppler map does not compensate for the phase, so blurring may occur in the vertical direction of the first complex data and the second complex data, which is determined to be large in size.

Referring to the pattern 603 of the second distance-Doppler map, the size of the third complex data arranged in the 2nd row and 3rd column and the fourth complex data arranged in the 1st row and 5th column are the largest. That is, referring to the second range-Doppler map, it is identified that the positions of the 2nd row and 3rd column and the positions of the 1st row and 5th column contain signals related to the target.

The distance-Doppler map generating device 461 determines a circular correlation with the complex data in the first distance-Doppler map pattern with respect to the third and fourth complex data of the second distance-Doppler map pattern. Accordingly, 2, which is the movement amount at which the circular correlation is the largest, is determined as the cell movement amount, and the distance-Doppler map generating device 461 applies the determined cell movement amount to the pattern 603 of the second distance-Doppler map. A final range-Doppler map 605 may be generated.

FIG. 7 illustrates a flowchart 700 of a method of operating the range-Doppler map generating device 461 in a radar system according to various embodiments of the present disclosure.

Referring to FIG. 7 , in step 701, the distance-Doppler map generating device 461 determines phase compensation values corresponding to a plurality of pulses based on entropy regarding complex data in the distance-aligned signal data. According to an embodiment of the present disclosure, the distance-Doppler map generating device 461 may determine phase compensation values that minimize the entropy value of complex data from distance-aligned signal data. Here, the phase compensation values may correspond to a plurality of pulses of the radar signal. According to an embodiment of the present disclosure, the entropy used to determine phase compensation values may include at least one of Shannon entropy and Thesalis entropy.

In step 703, the distance-Doppler map generating device 461 generates a pattern of a first distance-Doppler map based on the distance-aligned signal data and a second distance based on the distance-aligned signal data and phase compensation values. -Determine the pattern of the Doppler map. The distance-Doppler map generating device 461 may generate a pattern of the first distance-Doppler map by applying Fourier transform to the distance-sorted signal data. Additionally, the distance-Doppler map generating device 461 may multiply the distance-aligned signal data by element-by-element phase compensation values and then apply Fourier transform to generate a pattern of the second distance-Doppler map.

In step 705, the distance-Doppler map generating device 461 determines the distance of the pulse data unit based on the correlation between the complex data in the pattern of the first distance-Doppler map and the pattern of the second distance-Doppler map. Determine the cell movement amount. The range-Doppler map generating device 461 identifies the distance bin where the target is located based on the size of complex data in the patterns of the range-Doppler map. Thereafter, the distance-Doppler map generating device 461 generates circular correlation values in the vertical direction between images in the pattern of the first distance-Doppler map and the pattern of the second distance-Doppler map with respect to the identified distance bin. Then, the movement amount corresponding to the value that maximizes the circular correlation can be determined as the cell movement amount.

According to an embodiment of the present disclosure, the distance-Doppler map generating device 461 generates at least one first complex data corresponding to the location of the target in the pattern of the first distance-Doppler map and the pattern of the second distance-Doppler map. A circular correlation between the second complex data corresponding to the position of the target may be determined, and a cell movement amount in a unit of pulse data may be determined based on the size of the circular correlation. Here, the distance-Doppler map generating device 461 may determine the distance that maximizes the size of the circular correlation as the cell movement amount.

In step 707, the distance-Doppler map generating device 461 generates a distance-Doppler map based on the pattern of the second distance-Doppler map and the cell movement amount. According to an embodiment of the present disclosure, the distance-Doppler map generating device 461 may generate the final distance-Doppler map by applying the cell movement amount to the pattern of the second distance-Doppler map.

FIG. 8 shows a flowchart 800 of a method for determining a phase compensation value in a radar system according to various embodiments of the present disclosure. Figure 8 illustrates a method of operating the range-Doppler map generating device 461.

Referring to FIG. 8, in step 801, the range-Doppler map generating device 361 initializes the phase compensation value. The distance-Doppler map generating device 361 initializes M phase compensation values to determine phase compensation values corresponding to a plurality of pulses. According to an embodiment of the present disclosure, phase compensation values may be determined as randomly generated values based on a random number generator.

In step 803, the distance-Doppler map generating device 361 determines the entropy of the distance-aligned signal data based on the complex data and the phase compensation value. According to an embodiment of the present disclosure, the distance-Doppler map generating device 361 may calculate an entropy value using a phase compensation value and complex data of distance-aligned signal data. According to an embodiment of the present disclosure, entropy may include Shannon entropy.

In step 805, the distance-Doppler map generating device 361 determines a second phase compensation value that minimizes entropy. According to an embodiment of the present disclosure, the distance-Doppler map generating device 361 may determine M phase compensation values that minimize the entropy value. Accordingly, the distance-Doppler map generating device 361 may update the phase compensation values.

In step 807, the distance-Doppler map generating device 361 identifies whether the difference between the current phase compensation value and the previous phase compensation value is less than a preset threshold. The distance-Doppler map generating device 361 may compare the difference between the current phase compensation value and the previous phase compensation value with respect to the M phase compensation values with a threshold value. According to an embodiment of the present disclosure, the distance-Doppler map generating device 361 determines the phase compensation value with the largest difference in phase compensation values as the reference phase compensation value, and calculates the difference between the phase compensation values from the reference phase compensation value. It can be compared to a preset threshold. According to an embodiment of the present disclosure, when the difference between the phase compensation values is less than a preset threshold, the distance-Doppler map generating device 361 may determine the current phase compensation value as the final phase compensation value. According to another embodiment of the present disclosure, if the difference between the phase compensation values is greater than or equal to a preset threshold, the distance-Doppler map generating device 361 proceeds to step 803 and generates the data based on the complex data and the current phase compensation value. , entropy regarding distance-aligned signal data can be determined.

Figure 9 shows an example 900 of target modeling and range-Doppler map for a target in a conventional radar system.

FIG. 9 shows an example of a modeled target signal 901 when a radar sensor transmits a radar signal including a plurality of pulses to a target and receives a signal reflected from the target. As a radar sensor uses a radar signal including a plurality of pulses, a target can be modeled as a plurality of point scatterers corresponding to each of the plurality of pulses. Referring to the modeled target signal 901, the horizontal and vertical axes indicate distance.

The range-Doppler map generating device may generate a range-Doppler map based on the modeled target signal 901. Referring to FIG. 9, an accurate distance-Doppler map 903 is shown when phase compensation is performed based on accurate speed, and a first distance-Doppler map 905 is shown when phase compensation for speed is not applied. Additionally, in each of the distance-Doppler maps of FIG. 9, the horizontal axis indicates a horizontal distance bin on a linear scale, and the vertical axis indicates a vertical distance bin on a linear scale.

The accurate distance-Doppler map 903 illustrates the result of forming a distance-Doppler map after performing phase compensation based on the center position of the target using the exact speed of the target. The accurate range-Doppler map 903 is the result of generating a range-Doppler map based on the exact speed of the target, so there is little error regarding the focus of the image.

The first range-Doppler map 905 illustrates a case in which Fourier transform is applied without applying a phase compensation value related to the speed of the target. Referring to the first range-Doppler map 905, blurring occurs in the range-Doppler map due to speed error, and as a result, the error regarding the focus of the image is large.

FIG. 10 illustrates an example 1000 of a range-Doppler map generated by a range-Doppler map generating device in a radar system according to various embodiments of the present disclosure. FIG. 10 indicates a range-Doppler map corresponding to the target modeled in FIG. 9. Additionally, in FIG. 10, the horizontal axis indicates horizontal distance bins in a log scale, and the vertical axis indicates vertical distance bins in log scale.

Referring to FIG. 10, an accurate distance-Doppler map 1001 when phase is compensated based on accurate speed, a second distance-Doppler map 1003 using an entropy minimization method, and a distance-Doppler map generating device according to the present disclosure. The final range-Doppler map 1005 generated is shown.

The distance-Doppler map generating device 461 may generate the second distance-Doppler map 1003 using an entropy minimization method. The second range-Doppler map 1003 may have autofocus and clear image quality as the phase error related to speed is reflected. However, the second range-Doppler map 1003 has a large error regarding the location of the target compared to the accurate range-Doppler map 1001.

The distance-Doppler map generating device 461 may generate the final distance-Doppler map 1005 using the correlation of complex data in the first distance-Doppler map and the second distance-Doppler map 1003. The distance-Doppler map generating device 461 uses correlation values between complex data as a matching score and compensates for the cell movement amount that maximizes the matching score. Therefore, the final distance-Doppler map 1005 generated by the distance-Doppler map generating device 461 according to the present disclosure is similar to the accurate distance-Doppler map 1001 in which phase compensation is determined using the actual speed. That is, the final range-Doppler map 1005 has a smaller error regarding the location of the target compared to the second range-Doppler map 1003.

FIG. 11 illustrates an example 1100 of a range-Doppler map generated by a range-Doppler map generating device in a radar system according to various embodiments of the present disclosure. FIG. 11 indicates a range-Doppler map corresponding to the target modeled in FIG. 9. Additionally, in FIG. 11, the horizontal axis indicates horizontal distance bins on a linear scale, and the vertical axis indicates vertical distance bins on a linear scale.

Referring to FIG. 11, when the phase is compensated based on accurate speed, an accurate distance-Doppler map 1101 and a distance-Doppler map 1103 generated by the distance-Doppler map generating device according to the present disclosure are shown. FIG. 11 changes the units of the horizontal and vertical axes from dB scale to linear scale in FIG. 10. Therefore, as shown in FIG. 10, the distance-Doppler map generating device 461 according to the present disclosure can generate a distance-Doppler map with less error compared to the accurate distance-Doppler map 1101 in which phase compensation is determined using the actual speed. there is.

Methods according to embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

When implemented as software, a computer-readable storage medium that stores one or more programs (software modules) may be provided. One or more programs stored in a computer-readable storage medium are configured to be executable by one or more processors in an electronic device (configured for execution). One or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

These programs (software modules, software) may include random access memory, non-volatile memory, including flash memory, read only memory (ROM), and electrically erasable programmable ROM. (electrically erasable programmable read only memory, EEPROM), magnetic disc storage device, compact disc-ROM (CD-ROM), digital versatile discs (DVDs), or other types of disk storage. It can be stored in an optical storage device or magnetic cassette. Alternatively, it may be stored in a memory consisting of a combination of some or all of these. Additionally, multiple configuration memories may be included.

In addition, the program may be distributed through a communication network such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), or a storage area network (SAN), or a combination thereof. It may be stored on an attachable storage device that is accessible. This storage device can be connected to a device performing an embodiment of the present disclosure through an external port. Additionally, a separate storage device on a communication network may be connected to the device performing an embodiment of the present disclosure.

In the specific embodiments of the present disclosure described above, elements included in the disclosure are expressed in singular or plural numbers depending on the specific embodiment presented. However, singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components, and even components expressed in plural may be composed of singular or singular. Even expressed components may be composed of plural elements.

Meanwhile, in the detailed description of the present disclosure, specific embodiments have been described, but of course, various modifications are possible without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be determined not only by the scope of the patent claims described later, but also by the scope of this patent claim and equivalents.

Claims (12)

In a radar system, an apparatus for generating a range-Doppler map using range-aligned signal data generated based on a radar return signal containing a plurality of pulses,
a phase compensation determiner that determines phase compensation values corresponding to the plurality of pulses based on entropy of complex data in the distance-aligned signal data;
a map pattern determiner that determines a pattern of a first distance-Doppler map based on the distance-aligned signal data and a pattern of a second distance-Doppler map based on the distance-aligned signal data and the phase compensation values;
a movement amount determiner that determines a cell movement amount with respect to a distance in pulse data units based on a correlation between complex data in the pattern of the first distance-Doppler map and the pattern of the second distance-Doppler map; and
A distance-Doppler map generating device including a map generator that generates a distance-Doppler map based on the pattern of the second distance-Doppler map and the cell movement amount.
In claim 1,
The phase compensation determiner is,
Initialize the first phase compensation value,
Based on the complex data and the first phase compensation value, determine an entropy for the distance aligned signal data,
Determine a second phase compensation value at which the entropy is minimized,
Identify whether the difference between the second phase compensation value and the first phase compensation value is less than a preset threshold,
A distance-Doppler map generating device that outputs a second phase compensation value when the difference between the second phase compensation value and the first phase compensation value is less than a threshold value.
In claim 2,
The phase compensation determiner is,
When the difference between the second phase compensation value and the first phase compensation value is greater than or equal to a threshold value,
Based on the complex data and the second phase compensation value, determine an entropy for the distance aligned signal data,
A distance-Doppler map generating device that determines a third phase compensation value at which the entropy is minimized.
In claim 2,
The entropy includes Shannon entropy,
The phase compensation determiner is a distance-Doppler map generating device that determines Shannon entropy based on the equation below.
[Equation]

(Here, Eshannon is the Shannon entropy value, z(m,n) is the complex image signal matrix related to the distance-aligned signal data, M is the number of pulses of the radar return signal, and N indicates the size of the distance bin.)
In claim 1,
The pattern of the first distance-Doppler map indicates a pattern of a blurring distance-Doppler map in which Fourier transform is applied to the distance-aligned signal data,
The pattern of the second distance-Doppler map indicates a pattern of a phase-compensated distance-Doppler map in which Fourier transform is applied to distance-aligned signal data to which the phase compensation value is applied.
In claim 5,
The movement amount determiner is,
Circular correlation between at least one first complex data corresponding to the position of the target in the pattern of the first range-Doppler map and second complex data corresponding to the position of the target in the pattern of the second range-Doppler map Determine (circular correlation),
A distance-Doppler map generating device that determines a cell movement amount in pulse data units based on the size of the circular correlation.
In claim 6,
The movement amount determiner is,
A distance-Doppler map generating device that determines the distance at which the size of the circular correlation is maximized as the cell movement amount.
In a radar system, a method of operating a device for generating a range-Doppler map using range-aligned signal data generated based on a radar return signal including a plurality of pulses,
determining phase compensation values corresponding to the plurality of pulses based on entropy of complex data in the distance-aligned signal data;
determining a pattern of a first distance-Doppler map based on the distance-aligned signal data and a pattern of a second distance-Doppler map based on the distance-aligned signal data and the phase compensation values;
determining a cell movement amount with respect to a distance in pulse data units based on a correlation between complex data in the pattern of the first distance-Doppler map and the pattern of the second distance-Doppler map; and
A method of operating a distance-Doppler map generating device comprising generating a distance-Doppler map based on the pattern of the second distance-Doppler map and the cell movement amount.
In claim 8,
The entropy includes Shannon entropy,
The step of determining the phase compensation values is
A method of operating a distance-Doppler map generating device including determining Shannon entropy based on the equation below.
[Equation]

(Here, Eshannon is the Shannon entropy value, z(m,n) is the complex image signal matrix related to the distance-aligned signal data, M is the number of pulses of the radar return signal, and N indicates the size of the distance bin.)
In claim 8,
The pattern of the first distance-Doppler map indicates a pattern of a blurring distance-Doppler map in which Fourier transform is applied to the distance-aligned signal data,
The pattern of the second distance-Doppler map indicates a pattern of a phase-compensated distance-Doppler map in which Fourier transform is applied to distance-aligned signal data to which the phase compensation value is applied. A method of operating a distance-Doppler map generating device.
In claim 10,
The step of determining the cell movement amount is
Circular correlation between at least one first complex data corresponding to the position of the target in the pattern of the first range-Doppler map and second complex data corresponding to the position of the target in the pattern of the second range-Doppler map determining (circular correlation); and
A method of operating a distance-Doppler map generating device comprising the step of determining a cell movement amount in pulse data units based on the size of the circular correlation.
In claim 11,
The step of determining the cell movement amount includes determining a distance at which the size of the circular correlation is maximized as the cell movement amount. A method of operating a distance-Doppler map generating device.

Images