KR20200122890A - Apparatus and method for generating a front-view radar image of a vehicle based on a time-domain correlation - Google Patents

Abstract

Disclosed are a front-view observation radar image generating device of a vehicle based on a time-domain correlation technique and a method thereof. The front-view observation radar image generating method comprises the steps of: transmitting a linear frequency modulated signal to the front of a vehicle; receiving a reflected signal reflected from the ground or a target in which the linear frequency modulated signal is located at the edge of the vehicle; generating an image by applying a time domain correlation technique to the reflected signal; and discriminating the left and right of the image by using reflected signals received while the vehicle is moving in a curve.

Description

BACKGROUND OF THE INVENTION [0002] TECHNICAL FIELD [APPARATUS AND METHOD FOR GENERATING A FRONT-VIEW RADAR IMAGE OF A VEHICLE BASED ON A TIME-DOMAIN CORRELATION}

The present invention relates to an apparatus and method using a time domain correlation technique to generate a forward observation radar image of a vehicle moving in a curve.

Vehicle radars have recently begun to be studied, but radar imaging techniques have been widely used in military applications. The existing Synthetic Aperture Radar (SAR) mainly performs image generation through side-looking [1]. The reason is that the resolution of forward-looking is significantly reduced [2]. Therefore, the resolution can be increased by using a bistatic synthetic aperture radar [3] to [9] or scanning to observe the front through mechanical steering with a real aperture radar (RAR) with a narrow beam width. The scanning radar [10] to [15] has been studied. However, due to the characteristics of the scanning radar, the resolution in the distance direction is limited by the bandwidth of the transmitted signal, and the resolution in the direction perpendicular to the distance direction is determined by the beam width.

A scanning radar to search the ground while moving has been used for military use, for example, a brimstone missile using a high-resolution Frequency Modulated Continuous Wave (FMCW) [16]. Again, the distance direction resolution can be improved by adjusting the bandwidth of the FMCW, but the resolution in the direction perpendicular to the distance direction is determined by the azimuth direction beam width of the antenna. Therefore, compared to the distance direction, the resolution in the direction perpendicular to it is significantly inferior.

Accordingly, there is a demand for a method capable of improving the resolution in a direction perpendicular to the distance direction.

The present invention can provide an apparatus and method used in an automatic emergency braking system or assisting in parking by grasping the existence of objects around the vehicle when driving on a curve of a vehicle.

In addition, the present invention can provide a forward observation radar imaging apparatus and method capable of detecting a vehicle crossing at an intersection.

In addition, the present invention can provide an apparatus and method capable of generating a forward observation radar image even in a situation where it is difficult to observe forward due to rain or fog.

A forward observation radar image generation method according to an embodiment of the present invention includes the steps of transmitting a linear frequency modulated signal to the front of a vehicle; Receiving a reflected signal reflected from the ground or a target in which the linear frequency modulated signal is located at the edge of the vehicle; Generating an image by applying a time domain correlation technique to the reflected signal; And discriminating the left and right of the image using reflected signals received while the vehicle is moving in a curve.

According to an embodiment of the present invention, when the vehicle is driving on a curve, the existence of objects around the vehicle can be identified to aid in parking or can be used in an automatic emergency braking system.

In addition, according to an embodiment of the present invention, since vehicles crossing at an intersection can be found, it can be utilized for cross vehicle notification.

In addition, according to an embodiment of the present invention, since it is not affected by the weather compared to a lidar and an optical sensor (camera, etc.), it can operate even in a situation where it is difficult to observe forward due to rain or fog.

1 is a diagram illustrating an apparatus for generating a forward observation radar image according to an embodiment of the present invention.
2 is a diagram showing the operation of the forward observation radar image generating apparatus according to an embodiment of the present invention.
3 is an example of a linear frequency modulated linear frequency modulated signal sequence output from the forward observation radar image generating apparatus according to an embodiment of the present invention.
4 is an example of a simulation experiment according to an embodiment of the present invention.
5 is an example of an image generated according to an embodiment of the present invention when the signal-to-noise ratio is 10 dB.
6 is an example of a comparison result of a point variance function according to an embodiment of the present invention when the signal-to-noise ratio is 10 dB.
7 is an example of an image generated according to an embodiment of the present invention when the signal-to-noise ratio is 0 dB.
8 is an example of an image generated according to an embodiment of the present invention when the signal-to-noise ratio is -10 dB.
9 is a flowchart illustrating a forward observation radar image generation method according to an embodiment of the present invention.

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

The terms used in the examples are used for illustrative purposes only and should not be interpreted as limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiment belongs. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in this 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 the reference numerals, and redundant descriptions thereof will be omitted. In describing the embodiments, when it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the embodiments, the detailed description thereof will be omitted.

The forward observation radar image generation method according to an embodiment of the present invention may be performed by a forward observation radar image generation apparatus.

1 is a diagram illustrating an apparatus for generating a forward observation radar image according to an embodiment of the present invention.

The forward observation radar image generating apparatus 100 may include a transmitting antenna 110, a receiving antenna 120, and a processor 130 as shown in FIG. 1.

The transmission antenna 110 is mounted on the front of the vehicle equipped with the forward observation radar image generating device 100, and transmits a linear frequency modulated signal to the front of the vehicle equipped with the forward observation radar image generating device 100. Can be sent to. In this case, the transmission antenna may transmit the linear frequency modulated signal every pulse repetition interval (PRI). In addition, the beam width of the linear frequency modulated signal may be wide enough to receive signals for all targets while the vehicle is moving.

The reception antenna 120 may receive a reflected signal reflected from the ground or a target in which the linear frequency modulated signal transmitted from the transmission antenna 110 is located at the side of the vehicle.

은 수학식 1과 같이 나타낼 수 있다.The processor 130 may generate a forward observation radar image by applying a time domain correlation (TDC) technique to the reflected signal received by the reception antenna 120. In this case, the time domain correlation technique is a technique in which matched filtering is implemented with correlation rather than convolution for a space-variant system. Position generated by the processor 130 when the linear frequency modulated signal transmitted by the transmitting antenna 110 in the continuous time considering noise is defined as z _p (t) to the ground or the reflected signal reflected on the target Forward observation radar image according to x, y

Can be expressed as in Equation 1.

는 x_k, y_l에 반사율 1을 가진 단일의 점 표적이 존재하는 경우, 수신 안테나(120)가 수신한 반사 신호를 모사한 값일 수 있다. 프로세서(130)는

를 위치 x, y와 켤레 복소수를 취하여 곱하고 시간에 대하여 적분함으로써 모사한 반사 신호와 수신 안테나(120)가 수신한 반사 신호 간의 상관 관계를 계산할 수 있다. 또한, 송신 안테나(110)가 P 개의 선형 주파수 변조 신호들을 송신하고, 수신 안테나(120)는 P 개의 선형 주파수 변조 신호들 각각에 대응하는 반사 신호를 수신하므로, 프로세서(130)는 모사한 반사 신호와 수신 안테나(120)가 수신한 반사 신호들 각각 간의 상관 관계들의 총합을 계산할 수 있다.At this time,

When there is a single point target having a reflectance of 1 at x _k and y _l , may be a value that simulates the reflected signal received by the reception antenna 120. The processor 130 is

A correlation between the simulated reflected signal and the reflected signal received by the reception antenna 120 may be calculated by multiplying and integrating with the positions x and y and a complex conjugate number and integrating over time. In addition, since the transmitting antenna 110 transmits P linear frequency modulated signals, and the receiving antenna 120 receives a reflected signal corresponding to each of the P linear frequency modulated signals, the processor 130 The sum of correlations between each of and reflected signals received by the reception antenna 120 may be calculated.

Accordingly, as the absolute value of the correlation between the simulated reflected signal and the reflected signal reflected from a plurality of targets increases, the processor 130 may determine that a target having a large reflectance exists at x _k and y _l . In addition, when the absolute value of the correlation between the simulated reflected signal and the reflected signal reflected from a plurality of targets is less than or equal to the threshold value, the processor 130 may determine that the target does not exist at x _k and y _l .

가 표적의 위치(k,ㅣ)에 따라 변경되지 않으므로, 수학식 1은 콘볼루션으로 표현될 수 있다. 따라서, 프로세서(130)는 공간 불변 시스템(space-invariant system)에 대한 정합 필터링을 적용할 수 있다. In the lateral observation situation

Since is not changed according to the position of the target (k, l), Equation 1 can be expressed as a convolution. Accordingly, the processor 130 may apply matched filtering for a space-invariant system.

On the other hand, in forward observation, since the reflected signal changes according to the position (k, l) of the target, the processor 130 simulates the reflected signal corresponding to the position (k, l) of the target and obtains a correlation to obtain a matching filter. It can be implemented for a space change system.

In addition, if Equation 1 is expressed on the discrete time axis, it can be changed to Equation 2 for calculating the matched filtering result for obtaining the vector g according to Equations 10 to 12.

)^H는 켤레 전치를 의미할 수 있다.At this time, (

) ^H can mean conjugate transpose.

In addition, a time domain correlation technique for obtaining an image by calculating a correlation for each of the reflected signals for each position to generate a forward observation image may also have limitations. For example, when a target exists in a symmetrical left-right direction while observing the front, the reflected signal reflected on the target located on the left side of the vehicle and the reflected signal reflected on the target located on the right side of the vehicle are the same, so the processor 130 Is unable to distinguish between a reflected signal reflected from a target located on the left side of the vehicle and a reflected signal reflected from a target located on the right side of the vehicle.

가 동일하므로, 두 표적은 동일한 상관 관계 값으로 계산될 수 있다.That is, the two targets

Since is equal, the two targets can be calculated with the same correlation value.

On the other hand, when the vehicle performs a curved motion, since the reflected signal reflected on the target located on the left side of the vehicle and the reflected signal reflected on the target located on the right side of the vehicle are different, the processor 130 reflects on the target located on the left side of the vehicle. It is possible to distinguish the reflected signal from the reflected signal reflected from the target located on the right side of the vehicle.

Accordingly, the processor 130 may distinguish the left and right of the forward observation radar image using the reflected signals received while the vehicle is moving in a curve.

In this case, when receiving a path for the curved motion of the vehicle, the processor 130 may generate a matrix A as shown in Equation 10 to generate a forward observation image. In addition, when the vehicle performs a curved motion, the resolution can be improved because it is possible to distinguish left and right of the forward observation image compared to a situation in which the vehicle performs a linear motion.

In addition, the time domain correlation technique can maximize the signal-to-noise ratio after signal processing because matched filtering is applied to a spatial change system.

The forward observation radar image generating apparatus 100 can assist in parking by detecting the existence of objects around the vehicle when driving on a curve of the vehicle, or can be used in an automatic emergency braking (AEB) system.

In addition, since the forward observation radar image generating apparatus 100 may detect vehicles crossing at an intersection, it may be used for a cross traffic alert (CTA).

In addition, since the forward observation radar image generating apparatus 100 is not affected by the weather compared to a lidar and an optical detector (camera, etc.), it can operate even in a situation where it is difficult to observe the forward by rain or fog.

2 is a diagram showing the operation of the forward observation radar image generating apparatus according to an embodiment of the present invention.

When the vehicle 200 equipped with the forward observation radar image generating apparatus 100 performs a curved motion as shown in FIG. 2, the forward observation radar image generating apparatus 100 uses a time domain correlation technique to A 2D image including the ground and targets 210 may be generated. At this time, TDC is a technique that implements matched filtering for a spatial change system, so it can be robust against Gaussian noise.

3 is an example showing an example of a linear frequency modulated signal output by the forward observation radar image generating apparatus according to an embodiment of the present invention on a time-frequency axis. In this case, S may be a width of the linear frequency modulation signal, B may be a bandwidth, and T _s may be a repetition period of the linear frequency modulation signal.

Accordingly, the signal transmitted to the p-th can be expressed as Equation 3.

는 수학식 4와 같이 나타낼 수 있다.In this case, K is B/S, and f _c may be a carrier frequency. In addition,

Can be expressed as in Equation 4.

In this case, the range of the continuous time variable t can be expressed as in Equation 5 for the p-th linear frequency modulated signal.

When the p-th linear frequency modulated signal is reflected from a plurality of targets, the reflected signal received without noise from the reception antenna 120 may be expressed as in Equation 6.

In this case, g(x _k , y _l ) may be a reflectance according to the x and y positions of the grating, assuming that the ground is made of a grating. In addition, X may be the number of gratings in the x-axis direction of the location where the target is present, and Y may be the number of gratings in the y-axis direction of the location where the target is present. At this time, since x _k and y _l denote the position of the ground divided by the grid, it may not mean the position where the target exists. For example, when a target exists in the corresponding grid, the value of g(x _k , y _l ) may not be 0. On the other hand, when there is no target in the corresponding grid, the value of g(x _k , y _l ) may be 0.

Further, τ may be a time from a time when the linear frequency modulated signal is transmitted from the transmission antenna 110 until a reflected signal reflected from the target of the linear frequency modulated signal is received by the reception antenna 120. Therefore, τ can be expressed as a function for x _k and y _l as shown in Equation 7.

In this case, R(t, x _k , y _l ) may be a distance between the forward observation radar image generating apparatus 100 and the target. When a vehicle equipped with the forward observation radar image generating apparatus 100 performs a curved motion while the target is fixed, the distance between the forward observation radar image generating apparatus 100 and the target may be expressed as a function of time. In addition, the forward observation radar image generating apparatus 100 may obtain the position of the vehicle from an odometer of the vehicle.

The sampled result after the received signal passes through the mixer of the receiving antenna 120 may be expressed as Equation 8.

이고, 이산화된 시간 t_f,p 및 시간 τ는 수학식 9와 같이 나타낼 수 있다.At this time,

, And the discretized time t _f,p and time τ can be expressed as in Equation 9.

In this case, t _f is the discretized fast-time, and may indicate the time of the f-th sample. The time span of t _f is from the start of sampling to the end of the transmitted linear frequency modulated signal, S.

로 정의될 수 있다. 이때, R_max는 영상에서 나타날 가장 먼 표적과의 거리를 나타내며 c는 선형 주파수 변조 신호의 전달 속도일 수 있다. 또한, t_f의 길이는 F라고 가정할 수 있다.The starting point of sampling is to consider the area to create an image

Can be defined as At this time, R _max denotes the distance to the farthest target to appear in the image, and c may be the transmission speed of the linear frequency modulated signal. In addition, it can be assumed that the length of t _f is F.

At this time, since k, l, f, and p are all discrete variables, considering Equation 9 and the noise vector n, it can be expressed as the product and sum of the matrix and the vector as shown in Equation 10.

는 잡음이 더해진 상태의 반사 신호이고, P는 송신 안테나(110)가 송신하는 선형 주파수 변조 신호의 총 개수일 수 있다. 또한, 벡터

는 각각의 위치 격자에 해당하는 반사율일 수 있다. 예를 들어, 만약 격자에 표적이 없는 경우, 벡터g는 0의 값을 가질 수 있다. 그리고, 행렬 A는 수학식 11과 같이 나타낼 수 있다.In this case, the vector

Is a reflected signal with noise added, and P may be the total number of linear frequency modulated signals transmitted by the transmission antenna 110. Also, vector

May be a reflectance corresponding to each position grating. For example, if there is no target in the grid, the vector g may have a value of 0. And, the matrix A can be expressed as in Equation 11.

Therefore, Equation 10 can be transformed into Equation 12.

1 이고, A의 크기는 FP

XY이며, 벡터 x 의 크기는 XY

1일 수 있다. 또한, 프로세서(130)는 믹서를 통과한 반사 신호를 벡터와 행렬의 꼴로 나타냄으로써, 벡터z를 이용하여 벡터 g를 추정할 수 있다.Therefore, the size of vector z is FP

1, and the size of A is FP

XY, and the size of vector x is XY

May be 1. In addition, the processor 130 may estimate the vector g by using the vector z by representing the reflected signal passing through the mixer in the form of a vector and a matrix.

5 to 8 show a case where the forward observation radar image generating apparatus 100 arranges four point targets 430 around the vehicle as shown in FIG. 4 and then the vehicle travels in a straight line (410) and the vehicle is curved. This is an example of forward observation radar images generated when driving (420). In this case, since the images shown in FIGS. 5 and 7 to 8 are normalized images, the pixel value having the largest value may be 1. Therefore, a larger value close to 1 indicates that the target exists in that part, and a value close to 0 indicates that there is no target in that part.

In this case, the x-axis is an axis that faces to the right at the moment the vehicle operates the radar, the y-axis is defined as the direction the vehicle is facing, and the z-axis may be a direction that penetrates the ground.

In addition, it is assumed that the position of the forward observation radar image generating device 100 is defined as (0, 0, 0) and that the targets are placed on the floor when the mounting height of the forward observation radar image generating device 100 is h. In this case, the position of the point targets 430 in the z-axis direction may be -h. In FIG. 4, positions of the point targets 430 may be (0,3), (1,4), (4,5), and (0.6), respectively.

In addition, parameters for the experiment of FIG. 4 may be as shown in Table 1.

Parameter Value Carrier frequency 77 GHz Height of the radar 0.5 m Speed of the vehicle 4 m/s Yaw rate (only for curved motion)

Bandwidth 300 MHz Sampling frequency f _s 50 kHz PRI 10 ms Pulse width 1 ms The number of fast-time samples F 50 The number of pulses P 64 The number of grids in direction of x X 101 The number of grids in direction of y Y 51

In this case, according to Table 1, the number F of fast-time samples and the number P of linear frequency modulated signals transmitted from the transmission antenna 110 may be determined.

The image 510 is a forward observation radar image generated by the forward observation radar image generating apparatus 100 mounted on a vehicle in linear motion when the signal-to-noise ratio of the measured value is 10 dB, and the image 520 is the signal to the measured value. When the noise ratio is 10 dB, it is a forward observation radar image generated by the forward observation radar image generating apparatus 100 mounted on a vehicle moving in a curve.

When the vehicle is in a linear motion, the left and right cannot be distinguished because the left and right targets have the same distance change. Accordingly, as shown in the image 510, the image appears bright as there is no point target on the left side, and the image may appear symmetrically left and right. On the other hand, when the vehicle performs a curved motion, as shown in the image 520, the target may be displayed only on the right side where the target exists.

In addition, when comparing the image 510 and the image 520, the forward observation radar image generating apparatus 100 is generated for the target existing at (0, 6) when the vehicle performs a curved movement than when performing a linear movement. It can be seen that the resolution of the forward observation radar image increases.

6 is an example of Point Spread Functions (PSFs) in the x-axis direction calculated by the forward observation radar image generating apparatus 100 mounted on a vehicle when a target exists only in (0, 6). In this case, since the resolution is determined by the distance resolution in the y-axis direction, even if the vehicle movement method is changed, the two point dispersion functions may be similar.

The point variance function 610 calculated by the forward observation radar image generating device 100 mounted on a vehicle in linear motion and the point variance function 620 calculated by the forward observation radar image generating device 100 mounted on a curved vehicle. When comparing ), it can be seen that the thickness of the main-lobe decreases and the resolution is improved when the vehicle performs a curved motion, but the size of the side-lobe increases.

In addition, the -3 dB width of the main lobe is 0.24 m when the vehicle is in a linear motion, but can be improved to 0.015 m in a curved motion.

In addition, as the vehicle rotates to the left, the point variance function 620 may have different correlation values between the left and right, and thus may have an asymmetric shape as illustrated in FIG. 6.

The image 710 is a forward observation radar image generated by the forward observation radar image generating apparatus 100 mounted on a vehicle in linear motion when the signal-to-noise ratio of the measured value is 0 dB, and the image 720 is the signal-to-noise ratio of the measured value. When the noise ratio is 0 dB, it is a forward observation radar image generated by the forward observation radar image generating apparatus 100 mounted on a vehicle moving in a curve.

Since the time domain correlation is a matched filter, the signal-to-noise ratio after filtering can be maximized. Therefore, since the time domain correlation is robust to noise, FIG. 7 may be an image having a shape similar to that of FIG. 5 in which the signal-to-noise ratio is 10 dB even though the signal and noise are at the same level.

The image 810 is a forward observation radar image generated by the forward observation radar image generating apparatus 100 mounted on a vehicle in linear motion when the signal-to-noise ratio of the measured value is -10 dB, and the image 820 is a signal of the measured value. When the to-noise ratio is -10 dB, this is a forward observation radar image generated by the forward observation radar image generating apparatus 100 mounted on a curved vehicle.

Comparing the image 810 and the image 820, the resolution of the image in the case of a curved motion is improved compared to that in the case of the linear motion, and the left and right can be distinguished. However, in a situation where the noise is greater than the signal, it can be seen that the effect of the noise is greater in the image formed during the curve motion.

In other words, when the vehicle travels on a curve, the thickness of the main lobe that appears after matching filtering is small, so the resolution is improved, but the size of the side lobe has a slightly higher level than that in the case of linear motion. The deterioration of video performance is more pronounced. However, even if the signal-to-noise ratio of the measured value is -5 dB or more, this problem is greatly alleviated, so even in the case of a curved motion, it can be said that it is still robust to noise.

9 is a flowchart illustrating a forward observation radar image generation method according to an embodiment of the present invention.

In step 910, the transmission antenna 110 may transmit a linear frequency modulated signal to the front of the vehicle.

In step 920, the receiving antenna 120 may receive a reflected signal reflected from the ground or target in which the linear frequency modulated signal transmitted in step 910 is located at the side of the vehicle.

In step 930, the processor 130 may generate a forward observation radar image by applying a time domain correlation technique to the reflected signal. In addition, the processor 130 may distinguish the left and right of the forward observation radar image by using reflected signals received while the vehicle is moving in a curve.

The present invention can assist in parking by grasping the existence of objects around the vehicle when driving on a curve of the vehicle or can be used in an automatic emergency braking system. In addition, the present invention can be used for cross vehicle notification because it is possible to find a vehicle crossing at an intersection. In addition, the present invention is not affected by the weather compared to a lidar and an optical detector (camera, etc.), and thus it can operate even in a situation where it is difficult to observe forward due to rain or fog.

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 in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiment, or may be known and usable to 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 and DVDs, and magnetic media such as floptical disks. -A hardware device specially 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 not only machine language codes such as those produced by a compiler but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operation of the embodiment, and vice versa.

The software may include a computer program, code, instructions, or a combination of one or more of these, configuring the processing unit to behave as desired or processed 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 embodyed in a 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 on one or more computer-readable recording media.

As described above, although the embodiments have been described by the limited drawings, a person of ordinary skill 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 from the described method, and/or components such as a system, structure, device, circuit, etc. described are combined or combined in a form different from the described method, or other components Alternatively, even if substituted or substituted by an equivalent, an appropriate result can be achieved.

Therefore, other implementations, other embodiments and claims and equivalents fall within the scope of the following claims.

110: transmitting antenna
120: receiving antenna
130: processor

Claims (1)

Transmitting a linear frequency modulated signal to the front of the vehicle;
Receiving a reflected signal reflected from the ground or a target in which the linear frequency modulated signal is located at the edge of the vehicle;
Generating an image by applying a time domain correlation technique to the reflected signal; And
Distinguishing the left and right of the image using reflected signals received while the vehicle is moving in a curve
Forward observation radar image generation method comprising a.

Images