KR20200055259A - Apparatus and method for detecting target using radar - Google Patents

Abstract

Disclosed are a target detecting method using a radar and an apparatus thereof. The target detecting method comprises the steps of: generating a bit signal continuously present to a distance bin in which a target is detected by using a transmission radar signal output toward a search area and a reception radar signal in which the transmission radar signal is reflected by the target; extracting discretely present bit signals by sampling the continuously present bit signals based on the size and the delay time for one distance bin; determining a clutter map for a clutter present in the search area using the discretely present bit signal; and detecting a target present in the search area using the determined clutter map.

Description

Target detection method and device using radar {APPARATUS AND METHOD FOR DETECTING TARGET USING RADAR}

The following description relates to a target detection method and apparatus using a radar, and more specifically, to extract a bit signal that exists discretely from a bit signal that continuously exists up to a distance bin where the target is detected, and continuously exists. It relates to a technique for determining a clutter map using a discrete bit signal rather than a bit signal.

In radar systems, clutter is an object other than the target you want to detect where radar signals can be reflected. This clutter is one of the obstacles when detecting a target through a radar system. In general, radar systems use a moving target indicator (MTI) method to remove clutter. However, the MTI method has a disadvantage that it cannot be used when both the target and the clutter are not moving. Therefore, when both the target and the clutter do not move, the clutter component must be removed using the clutter map. In general, the clutter map may be generated by accumulating radar signals received from the clutter.

On the other hand, the radar system can perform a simulation computation using software before actually measuring and generating a clutter map due to safety and cost problems. At this time, when the distance to measure the target is far, or if the detection result requires high accuracy, the radar system generates a beat signal proportional to the number of range bins in a very large amount, and is generated. A clutter map can be determined using a bit signal. In this case, the radar system may have a problem of increasing cost and time due to an increase in calculation amount.

Therefore, recently, a radar system is in need of a method for reducing the amount of computation required to determine a clutter map.

The present invention relates to a method and apparatus for detecting a target using a radar, and more specifically, to extract a bit signal that exists discretely from a bit signal that is continuously present up to a distance bin where a target is detected, and all bits that are continuously present. It is possible to provide a method of reducing the overall computation amount of a clutter map generation algorithm by determining a clutter map using a discrete bit signal rather than a signal.

In the target detection method according to an embodiment of the present invention, the transmission radar signal output toward the search area and the transmission radar signal reflected continuously by the target are continuously present up to the distance bin where the target is detected. Generating a bit signal; Sampling the continuously existing bit signals based on the size and delay time for one distance bin to extract discretely present bit signals; Determining a clutter map for a clutter present in the search area using the discretely present bit signal; And detecting a target existing in the search area using the determined clutter map.

In the target detection method according to an embodiment of the present invention, the transmission radar signal output toward the search area and the transmission radar signal reflected continuously by the target are continuously present up to the distance bin where the target is detected. Generating a bit signal; Extracting discretely present bit signals by applying an Inverse Fast Fourier Transform (IFFT) algorithm to the continuously present bit signals; Determining a clutter map for a clutter present in the search area using the discretely present bit signal; And detecting a target existing in the search area using the determined clutter map.

The target detection apparatus according to an embodiment of the present invention includes a processor that detects a target existing in the search area by using a transmission radar signal and a reception radar signal transmitted and received toward the search area, and the processor detects the search area. The transmitted radar signal output toward the target signal and the received radar signal reflected by the target are used to generate a bit signal continuously present up to a distance bin where the target is detected, and to perform the continuously present bit signal. Sampling is performed based on the size and delay time for the distance bins of the dogs to extract discretely present bit signals, and using the discretely present bit signals, a clutter map for clutters present in the search area is extracted. The target may be determined, and a target existing in the search area may be detected using the determined clutter map.

The present invention relates to a method and apparatus for detecting a target using a radar, and more specifically, to extract a bit signal that exists discretely from a bit signal that is continuously present up to a distance bin where a target is detected, and all bits that are continuously present. By determining the clutter map using a discrete bit signal rather than a signal, the overall computation of the clutter map generation algorithm can be reduced.

1 is a view showing the structure of a target detection apparatus according to an embodiment of the present invention.
2 is a diagram illustrating a target detection method performed by a target detection apparatus according to an embodiment of the present invention.
3 is a diagram comparing a difference between a target detection method according to an embodiment of the present invention and a bit signal for the existing technology.
4 to 5 are diagrams comparing a target detection method according to an embodiment of the present invention with a difference in calculation amount and time required for the existing technology.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, various changes may be made to the embodiments, and the scope of the patent application right is not limited or limited by these embodiments. It should be understood that all modifications, equivalents, or substitutes for the embodiments are included in the scope of rights.

The terms used in the examples are used for illustrative purposes only and should not be construed as limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, the terms "include" or "have" are intended to indicate the presence of features, numbers, steps, actions, components, parts or combinations thereof described herein, one or more other features. It should be understood that the existence or addition possibilities of fields or numbers, steps, operations, components, parts or combinations thereof are not excluded in advance.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the embodiment belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. Does not.

In addition, in the description with reference to the accompanying drawings, the same reference numerals are assigned to the same components regardless of reference numerals, and redundant descriptions thereof will be omitted. In describing the embodiments, when it is determined that detailed descriptions of related known technologies may unnecessarily obscure the subject matter of the embodiments, detailed descriptions thereof will be omitted.

1 is a view showing the structure of a target detection apparatus according to an embodiment of the present invention.

In general, the target detection device 100 of the FMCW radar may detect a target by considering only the radar signal component reflected by the target existing in the search area. However, if there are clutter components as well as targets in the search area, the FMCW radar needs to consider the clutter components in order to detect the target.

는 거리 빈의 순서를 나타내고,

는 타겟이 탐지되는 영역에 대응하는 마지막 거리 빈을 나타낼 수 있다. 그리고,

은 탐지하고자 하는 타겟의 거리 검출을 위해 사용할 고속 푸리에 변환(Fast Fourier Transform, FFT)의 사이즈를 나타내고,

은 거리 빈의 크기를 나타낼 수 있다.However, the clutter component may be continuously present from the first range bin of the target detection apparatus 100 to the distance bin of the region where the target is detected, as shown in FIG. 1. At this time, here in Figure 1

Denotes the order of distance bins,

May represent the last distance bin corresponding to the area where the target is detected. And,

Indicates the size of a Fast Fourier Transform (FFT) to be used to detect the distance of the target to be detected,

Can represent the size of the distance bin.

를 하기의 식 1과 같이 나타낼 수 있다.Accordingly, the target detection apparatus 100 receives the received radar signal in the same way as when the targets of the number of distance bins present up to the region where the target is detected exist at a distance corresponding to each distance bin in order to extract the clutter component. Modeling is possible. That is, the target detection device 100 is a bit signal excluding noise after the de-chirping step

It can be represented as in Equation 1 below.

<Equation 1>

는

번째 거리 빈에 의한 비트 신호이고,

는 유효한 거리 빈의 개수이며,

는

번째 타겟에서 돌아오는 수신 레이더 신호의 진폭을 나타내고,

는 FMCW 첩(chirp) 신호의 스위프(Sweep) 주파수 대역폭을 나타낸다. 그리고,

는 주파수 변조 주기이고,

는 변조율로서,

이고,

는 FMCW 레이더와

번째 타겟 사이의 왕복 지연 시간을 나타낸다. here

The

Is the bit signal by the first distance bin,

Is the number of valid distance bins,

The

Indicates the amplitude of the received radar signal coming from the target,

Denotes the sweep frequency bandwidth of the FMCW chirp signal. And,

Is the frequency modulation period,

Is the modulation rate,

ego,

With the FMCW radar

It represents the round trip delay time between the second targets.

를 샘플링 할 수 있다. 이때,

의 샘플링 결과를

으로 표기하고, 하기의 식 2와 같이 나타낼 수 있다.The target detection device 100 is a signal processing method for detecting a target, a bit signal through an analog to digital convert (ADC)

Can be sampled. At this time,

The sampling result of

It can be expressed as, and can be expressed as Equation 2 below.

<Equation 2>

는 샘플링 간격이고,

는 총 샘플링 개수를 나타낸다(즉,

). here

Is the sampling interval,

Denotes the total number of samples (ie,

).

The target detection device 100 transmits a bit signal corresponding to the number of distance bins present in the target detection area, that is, the number of distance bins in which the clutter exists in order to extract the clutter component present in the search area. Should be created. Therefore, when the target detection device 100 generates a bit signal, the number of targets to be considered is equal to or less than the total number of distance bins. In addition, since many variables need to be calculated simultaneously, the calculation process takes a long time and memory consumption Severe problems can occur.

의 생성 과정과 역 고속 푸리에 변환(Inverse Fast Fourier Transform, IFFT) 연산의 유사성을 활용하여 클러터 맵 생성을 위해 불필요한 계산량을 확연히 줄임으로써, 모의전산실험에 소요되는 시간 및 메모리 사용량을 감소시키고자 한다.Target detection device 100 of the present invention

By using the similarity of the inverse Fast Fourier Transform (IFFT) operation and the generation process of, we intend to reduce the amount of time and memory used for simulation by significantly reducing unnecessary computation for clutter map generation. .

2 is a diagram illustrating a target detection method performed by a target detection apparatus according to an embodiment of the present invention.

In step 210, the target detection apparatus 100 continuously exists to a distance bin where the target is detected by using a transmission radar signal output toward the search area and a reception radar signal in which the transmission radar signal is reflected by the target. Can generate a bit signal. If this is expressed as an equation, it may be as shown in Equation 1 above.

In step 220, the target detection apparatus 100 may extract the discretely present bit signal by sampling the continuously existing bit signal based on the size and delay time for one distance bin.

)을 결정할 수 있다. 타겟 탐지 장치(100)로부터 거리 빈까지의 거리는 정수 배로 멀어질 수 있는데, 거리가 멀어진 만큼 레이더 신호의 왕복에 따른 지연 시간도 늘어날 수 있다. First, when the number of points of the fast Fourier transform is determined according to the distance to detect the target and the distance, the target detection device 100 displays the distance bin

). The distance from the target detection device 100 to the distance bin may be increased by an integer multiple, and as the distance increases, the delay time due to the round trip of the radar signal may also increase.

)의 크기는

이고, 한 개의 거리 빈(

)에 의한 지연시간(

은

가 된다. 이때, 각 거리 빈의 간격은 동일하므로,

는

의 정수배가 되어

가 되므로 상기의 식 2를 다음과 같이 표현할 수 있다.Specifically, one street bin (

) Size

And one street bin (

Delay time by)

silver

Becomes. At this time, since the distance between each bin is the same,

The

Multiplied by

Equation 2 can be expressed as follows.

<Equation 3>

,

이고,

일 때,

의 조건이면 상기의 식 3을 아래와 같이

-point IDFT(Inverse Discrete Fourier Transform) 수식으로 근사화 할 수 있다. Here, the target detection apparatus 100 may obtain information only about an area corresponding to half of the points of the fast Fourier transform. For example, when N-point FFT is performed, since both sides are symmetric about f = 0, the amount of information that the target detection apparatus 100 can acquire may be N / 2. In other words,

,

ego,

when,

If the condition of the equation 3 above

It can be approximated by -point IDFT (Inverse Discrete Fourier Transform) formula.

을

으로 표기하고,

는 하기의 식 4와 같이 나타낼 수 있다.Concretely approximated

of

Denoted by

Can be represented as in Equation 4 below.

<Equation 4>

-point IDFT의 형태이므로, 타겟 탐지 장치(100)은 식 4에 역 고속 푸리에 변환(IFFT) 알고리즘을 적용함으로써 중복된 계산량을 감소시킬 수 있다. 여기서, 식 4를 이용한 역 고속 푸리에 변환의 출력 개수는

이지만, 식 3에서

의 샘플 개수는

보다 작은

이므로, 타겟 탐지 장치(100)는

의 성분 가운데 1부터

번째 성분 만을 사용할 수 있다.At this time, Equation 4

Since it is a form of -point IDFT, the target detection apparatus 100 may reduce the amount of duplicated calculation by applying an inverse fast Fourier transform (IFFT) algorithm to Equation 4. Here, the number of outputs of the inverse fast Fourier transform using Equation 4 is

But in equation 3

The number of samples in

lesser

Therefore, the target detection device 100

From 1 of the ingredients in

Only the first component can be used.

As an example, FIG. 3 is a diagram comparing a difference between a bit signal for a target detection method and an existing technology according to an embodiment of the present invention. When the original bit signal generated using Equation 1 is compared with the bit signal extracted through Equation 4, the present invention applies the inverse fast Fourier transform (IFFT) algorithm to reduce the amount of computation to determine the clutter map. It can be seen that it is similar to the bit signal.

In step 230, the target detection apparatus 100 may determine a clutter map for the clutter existing in the search area using the discretely present bit signal extracted through step 220. That is, the target detection apparatus 100 uses the inverse fast Fourier transform to extract only the discretely present bit signals by using the inverse fast Fourier transform to determine the clutter map. Time and resources can be reduced.

Finally, in step 240, the target detection device 100 may detect a target existing in the search area using the determined clutter map.

4 to 5 are diagrams comparing a target detection method according to an embodiment of the present invention with a difference in calculation amount and time required for the existing technology.

번의 곱셈이 필요하기 때문이다. 하지만 본 발명과 같이 역 고속 푸리에 변환 알고리즘을 활용하면 클러터 맵을 결정하기 위해

번의 곱셈이 필요하게 된다. When the target detection apparatus 100 generates a clutter map in the simulation, the multiplication process may take up most of the time. When generating bit signals for all distance bins

This is because multiplication is required. However, using the inverse fast Fourier transform algorithm as in the present invention, to determine the clutter map

Multiplication of times is required.

을 만족하기 때문에, 타겟 탐지 장치(100) 역 고속 푸리에 변환 알고리즘을 활용하였을 때 전체적인 계산량이 줄어들게 된다. 이때 탐지해야 할 탐색 영역의 거리가 증가하거나, 거리 빈의 간격이 감소할 경우 그 효과는 더욱 증가할 수 있다. Generally

Because it satisfies, the overall amount of computation is reduced when the inverse fast Fourier transform algorithm of the target detection apparatus 100 is used. At this time, if the distance of the search area to be detected increases or the distance between the distance bins decreases, the effect may further increase.

Referring to Figure 4, shows the multiplication amount required according to the size and distance of the various distance bins. It can be seen that the present invention using the inverse fast Fourier transform algorithm reduces the multiplication amount about 10 times compared to the previous method.

Also, referring to FIG. 5, it is a result of comparing the time required for generating a clutter map according to the number of points of the fast Fourier transform. It can be seen that the present invention using an inverse fast Fourier transform algorithm reduces the time required by more than 100 times compared to the previous method.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, or the like alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiments or may be known and usable by those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs, DVDs, and magnetic media such as floptical disks. -Hardware devices specifically configured to store and execute program instructions such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language code that can be executed by a computer using an interpreter, etc., as well as machine language codes produced by a compiler. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

The software may include a computer program, code, instruction, or a combination of one or more of these, and configure the processing device to operate as desired, or process independently or collectively You can command the device. Software and / or data may be interpreted by a processing device, or to provide instructions or data to a processing device, of any type of machine, component, physical device, virtual equipment, computer storage medium or device. , Or may be permanently or temporarily embodied in the transmitted signal wave. The software may be distributed over networked computer systems, and stored or executed in a distributed manner. Software and data may be stored in one or more computer-readable recording media.

As described above, although the embodiments have been described with limited drawings, those skilled in the art can apply various technical modifications and variations based on the above. For example, the described techniques are performed in a different order than the described method, and / or the components of the described system, structure, device, circuit, etc. are combined or combined in a different form from the described method, or other components Alternatively, even if substituted or substituted by equivalents, appropriate results can be achieved.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

100: target detection device

Claims (4)

Generating a bit signal continuously present up to a distance bin at which the target is detected by using a transmission radar signal output toward the search area and a reception radar signal in which the transmission radar signal is reflected by a target;
Sampling the continuously existing bit signals based on the size and delay time for one distance bin to extract discretely present bit signals;
Determining a clutter map for a clutter present in the search area using the discretely present bit signal; And
Detecting a target existing in the search area using the determined clutter map
Target detection method using a radar including.
Generating a bit signal continuously present to a distance bin at which the target is detected by using a transmission radar signal output toward the search area and a reception radar signal in which the transmission radar signal is reflected by a target;
Extracting discretely present bit signals by applying an Inverse Fast Fourier Transform (IFFT) algorithm to the continuously present bit signals;
Determining a clutter map for a clutter present in the search area using the discretely present bit signal; And
Detecting a target existing in the search area using the determined clutter map
Target detection method using a radar including.
A computer-readable recording medium in which a program for executing the method of any one of claims 1 to 2 is recorded.
Processor for detecting a target existing in the search area by using a transmission radar signal and a reception radar signal transmitted and received toward the search area
Including,
The processor,
The transmission radar signal output toward the search area and the reception radar signal where the transmission radar signal is reflected by the target are used to generate a bit signal continuously present up to a distance bin where the target is detected,
The continuously existing bit signal is sampled based on the size and delay time for one distance bin to extract discretely present bit signals,
A clutter map for a clutter present in the search area is determined using the discretely present bit signal,
A target detection device using a radar that detects a target existing in the search area using the determined clutter map.

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