KR101333998B1 - Radar Device and Target Detecting Method Thereof - Google Patents

Abstract

The present invention relates to a radar device and a method for detecting a target of the radar device for reducing the frequency of occurrence of false targets to increase the accuracy and reliability of the target information, the transmission unit for transmitting at least two transmission signals having different frequency changes over time ; A receiver configured to receive a plurality of received signals in which the transmission signal is reflected by a plurality of targets; An amplitude measuring unit measuring amplitudes of the plurality of received signals; An amplitude matching unit for determining a relative amplitude between a plurality of received signals for each transmission signal and searching for received signals for different transmission signals reflected from the same target based on the relative amplitudes; And an information extraction unit for calculating a distance and a relative speed of the target based on the frequency difference between the respective transmission signals and the reception signals with respect to the same target.

Description

Radar Device and Target Detecting Method Thereof}

The present invention relates to a radar device and a target detection method of the radar device, and more particularly, to a radar device and a target detection method of the radar device for reducing the frequency of occurrence of false targets to increase the accuracy and reliability of the target information.

Today, the application of radar-based driver safety systems continues to expand. In particular, adaptive cruise control (ACC) systems are used using radars using frequencies such as 24 GHz and 77 GHz. In such driver safety systems, even in the presence of multiple targets, the distance and speed of each target must be able to be measured simultaneously with high accuracy.

As a radar for measuring a distance and a speed of a target, a frequency modulated continuous wave (FMCW) radar is widely used. Radar of the FMCW method can measure the distance and the speed of the target by using the Up Chirp signal and the Down Chirp signal method.

However, if there are a plurality of targets, false targets or ghost targets may occur in addition to the actual targets. False targets here are errors that do not actually exist but are detected and appear in signal processing.

In order to solve this problem, it may be considered to add a continuous wave signal in addition to the up-modulated signal and the down-modulated signal. However, even in this case, false targets may not be completely eliminated.

An object of the present invention is to provide a radar device and a target detection method of the radar device for reducing the frequency of occurrence of the false target to increase the accuracy and reliability of the target information.

In order to achieve the above object, an embodiment of the present invention, a transmission unit for transmitting at least two transmission signals having different frequency changes with time; A receiver configured to receive a plurality of received signals in which the transmission signal is reflected by a plurality of targets; An amplitude measuring unit measuring amplitudes of the plurality of received signals; An amplitude matching unit for determining a relative amplitude between a plurality of received signals for each transmission signal and searching for received signals for different transmission signals reflected from the same target based on the relative amplitudes; And an information extraction unit configured to calculate a distance and a relative speed of the target based on the frequency difference between the respective transmission signals and the reception signals with respect to the same target.

The at least two transmission signals include an up chirp signal whose frequency increases with time, a down chirp signal whose frequency decreases with time, and a continuous wave modulation whose frequency is constant with time. Can be selected from the signal.

The amplitude matching unit may determine a plurality of received signals having relative amplitudes within a predetermined amplitude region as received signals reflected from the same target.

The information extractor may calculate the distance and the relative speed of the target based on the intersection of the straight lines based on the frequency difference between the transmission signal and the reception signal in the distance and relative velocity planes.

There are three or more different transmission signals, and the information extracting unit is based on the intersection of the straight lines when the straight lines based on the frequency difference between the transmission signal and the reception signal in the distance and relative velocity planes intersect within a predetermined comparison area. To calculate the distance and relative velocity of the target.

Another embodiment of the present invention, a transmission step of transmitting at least two transmission signals having different frequency changes over time; A reception step of receiving a plurality of reception signals in which the transmission signal is reflected on a plurality of targets; An amplitude measuring step of measuring amplitudes of the plurality of received signals; An amplitude matching step of determining relative amplitudes between a plurality of received signals for each transmitted signal and searching for received signals for different transmitted signals reflected from the same target based on the relative amplitudes; And an information extraction step of calculating a distance and a relative velocity of the target based on a frequency difference between each transmission signal and the reception signal with respect to the same target.

The at least two transmission signals include an up chirp signal whose frequency increases with time, a down chirp signal whose frequency decreases with time, and a continuous wave modulation whose frequency is constant with time. Can be selected from the signal.

In the amplitude matching step, a plurality of received signals having relative amplitudes within a predetermined amplitude region may be determined as received signals reflected from the same target.

The information extraction step may calculate the distance and the relative speed of the target based on the intersection of the straight lines based on the frequency difference between the transmission signal and the reception signal in the distance and relative velocity plane.

The different transmission signals are three or more, and the information extraction step is performed when the straight lines based on the frequency difference between the transmission signal and the reception signal in the distance and relative velocity planes intersect within a predetermined comparison area. Based on the distance and relative speed of the target can be calculated.

According to the present invention described above, since the distance and the relative speed of the target are extracted by matching the received signals reflected from the same target, it is possible to reduce the frequency of occurrence of the false target to increase the accuracy and reliability of the target information.

1 is a diagram illustrating an example of the transmission and reception waveforms of the radar in the up-modulation and down-modulation of the FMCW radar apparatus.
2 is a diagram illustrating another example of the transmission and reception waveforms of the radar in the up-modulation and down-modulation of the FMCW radar apparatus.
3 shows an example of an f _d - f _r diagram for a target measured in up modulation and down modulation.
4 shows an example of up-modulation, down-modulation and continuous wave modulation in an FMCW apparatus.
5 shows an example of an f _d -f _R diagram for a target measured in up modulation, down modulation and continuous wave modulation.
6 shows a block diagram of a radar device according to one embodiment of the invention.
FIG. 7 shows a flowchart of a target detection method executed in the radar device of FIG. 6.
8 illustrates an example of converting and matching an amplitude of a received signal into a relative amplitude in an embodiment of the present invention.
9 shows an example of an f _d -f _R diagram for a target measured in one embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected," "coupled," or "connected."

A typical frequency modulated continuous wave (FMCW) radar (hereinafter referred to as an "FMCW radar") modulates frequency with time in the form of a triangular wave. That is, the FMCW radar modulates the frequency with time in the form of a triangular wave consisting of Up Chirp, which increases in frequency with time, and Down Chirp, which decreases in frequency with time.

The FMCW radar transmits a triangular wave radar, and receives that the transmitted radio wave is reflected on the target.

FIG. 1 shows an example in which triangular wave radar is reflected to a single target in the frequency-time domain. 1 illustrates the case where the target's relative velocity to the FMCW radar is zero.

Referring to FIG. 1, the transmission signal 101 of the FMCW radar has a triangular wave form of up-modulation and down-modulation, and the received signal 102 also has a triangular wave form of up-modulation and down-modulation. When the relative velocity of the target is zero, the received signal 102 does not move in the frequency direction from the transmission signal 101, but only in the time direction by the path of the signal to the target.

The frequency difference f _b between the transmission signal 101 and the reception signal 102 in the up modulation period or the down modulation period is equal to the frequency change f _R according to the time T _R that the signal takes to round trip to the target. When the difference between the minimum frequency f _min and the maximum frequency f _max of the transmission signal 101 is referred to as 'f _sweep ', and the time for which the up-modulated signal or the down-modulated signal lasts to 'T' The frequency difference f _b between the transmission signal 101 and the reception signal 102 may be expressed by Equation 1 below.

In Equation 1, R is the distance to the target, c is the speed of light. According to Equation 1, when the relative velocity of the target is 0, the distance R from the measured frequency difference f _b to the target can be calculated.

FIG. 2 shows another example where triangular wave radar is reflected to a single target in the frequency-time domain. 1 illustrates the case where the target's relative velocity to the FMCW radar is not zero.

Referring to FIG. 2, the transmission signal 201 of the FMCW radar has a triangular wave form consisting of up modulation and down modulation, and the received signal 202 also has a triangular wave form consisting of up modulation and down modulation. When the relative velocity of the target is not zero, the received signal 202 is moved from the transmission signal 101 in the frequency direction and the time direction.

The frequency difference fb ₁ between the transmission signal 201 and the reception signal 202 in the up-modulation interval depends on the relative speed of the target at a frequency change f _R according to the time T _R that the signal takes to round trip to the target. It can be expressed by adding the frequency change f _d due to the Doppler effect. On the other hand, the frequency difference fb ₂ of the transmission signal 201 and the reception signal 202 in the down-modulation period is the relative speed of the target to the frequency change (f _R ) according to the time (T _R ) that the signal takes to round trip to the target. It can be expressed by subtracting the frequency change (f _d ) due to the Doppler effect. The frequency difference f _b1 in the up modulation period and the frequency difference f _b2 in the down modulation period may be expressed by Equation 2 below.

In Equation 2, v is the relative velocity of the target, λ is the wavelength of the radio wave used in the FMCW radar.

In the f _d -F _R diagram where the horizontal axis is f _R and the vertical axis is f _d , a straight line of f _d = -f _R + f _b1 is drawn for up modulation, and f _d = + f _R + f _b2 for down modulation. A straight line is drawn. F _d and f _R are found from the intersections of the two straight lines. The distance _R to the target and the relative velocity v of the target from the obtained f _d and f _R can be obtained by the following equation (3).

Since the frequency f _R and the frequency f _d correspond one-to-one to the distance and the relative velocity of the target, respectively, the f _d -f _R diagram may be represented by a speed-distance diagram.

On the other hand, the FMCW radar can detect a plurality of targets. However, when detecting a plurality of targets with an FMCW radar, a false target or a ghost target may be detected in addition to the actual target. 3 shows an example of an f _d -f _r diagram for a plurality (three) targets measured in up modulation and down modulation as an example.

Referring to FIG. 3, a false target 302 appears in addition to the actual target 301 on the f _d -f _R diagram. On the f _d -f _R diagram, the actual target 301-1 is located at the intersection of the straight line 303-1 obtained in the uplink modulation and the straight line 304-1 obtained in the downlink modulation, and the actual target 301-2 is It is located at the intersection of the straight line 303-2 obtained from the uplink modulation and the straight line 304-2 obtained from the downlink modulation, and the actual target 301-3 is obtained from the straight line 303-3 obtained from the uplink modulation and the downlink modulation. It is located at the intersection of the straight line 304-3.

However, all nine intersections may exist by the straight lines obtained from three uplink modulations and the straight lines obtained from three downlink modulations, and there may be up to six false targets except three actual targets 301.

When the number of actual targets is N, when N straight lines are obtained from one of up-modulation and down modulation and M (N ≦ M) straight lines are obtained from the other, the number of actual targets among all N × M intersections is obtained. Is N and the number of false targets is N × MN. Therefore, it is difficult to obtain accurate target information.

As an example of a method for accurately obtaining information of an actual target except for a false target, a continuous wave modulated signal may be used in addition to the up modulated signal and the down modulated signal.

4 shows an example of up-modulation, down-modulation and continuous wave modulation in an FMCW radar.

In the example of FIG. 4, the signal transmitted in the FMCW radar is composed of an up-modulated signal 401, a down-modulated signal 402, and a continuous wave modulated signal 403. The up-modulated signal 401 has a frequency increasing from f _min to f _max during time T (f _sweep = f _max -f _min ), and the down-modulating signal 402 has a frequency from f _max during time T. reduced to f _min and a continuous wave modulation signal 403 is held constant at the frequency for a time (T) f _min + f _sweep / 2 (= (f f _max + _min) / 2).

As described above with reference to FIGS. 1 to 3, the straight lines of FIG. 3 may be obtained with respect to the up-modulation signal 401 and the down-modulation signal 402 from the frequency difference between the transmission signal and the reception signal.

For the continuous wave modulated signal 403, the frequency variation of the transmitted signal and the received signal is not affected by the horizontal movement (due to the time the signal travels back and forth to the target) and only by the vertical movement (due to the relative speed of the target). If the frequency change amount is f _b3 in the continuous wave modulation period, it may be expressed by Equation 4 below.

In the f _d -F _R diagram where the horizontal axis is f _R and the vertical axis is f _d , as described above, a straight line f _d = -f _R + f _b1 is drawn for up-modulation and f _d = + for down-modulation. A straight line of f _R + f _b2 is drawn, and a straight line of f _d = f _b3 is drawn for continuous wave modulation. When three straight lines intersect at one intersection, or when three intersections at which two of the three straight lines intersect are within a predetermined area, f _d and f _R are obtained from the coordinates of the intersection. The distance _R to the target and the relative speed v of the target from the obtained f _d and f _R can be obtained by the above equation (3).

However, even in this case, false targets may occur.

FIG. 5 shows an example of an f _d -f _R diagram for a plurality (three) targets measured in up modulation, down modulation and continuous wave modulation.

Referring to FIG. 5, a false target 502 appears in addition to the actual target 501 on the f _d -f _R diagram. On the f _d -f _R diagram, the actual target 501-1 is the intersection of the straight line 503-1 obtained in the uplink modulation and the straight line 504-1 obtained in the downlink modulation and the straight line 505-1 obtained in the continuous wave modulation. And the actual target 501-2 is located at the intersection of the straight line 503-2 obtained from the uplink modulation and the straight line 504-2 obtained from the downlink modulation and the straight line 505-2 obtained from the continuous wave modulation. The target 501-3 is located at the intersection of the straight line 503-3 obtained from the uplink modulation, the straight line 504-3 obtained from the downlink modulation and the straight line 505-3 obtained from the continuous wave modulation.

However, the straight line 503-3 obtained in uplink modulation with respect to the actual target 501-3 and the straight line 504-1 and real target 501-2 obtained in downlink modulation with respect to the real target 501-1. The straight line 505-2 obtained in continuous wave modulation by chance intersects at one intersection, and a false target 502 may occur. In particular, if the resolution of the speed is not enough, it is possible to increase the probability of false targets.

6 is a block diagram of a radar apparatus according to an embodiment of the present invention.

The radar device illustrated in FIG. 6 includes a transmitter 610 for transmitting a radar signal, a receiver 620 for receiving a radar signal reflected on a target, an amplitude measuring unit 630 for measuring the amplitude of the received radar signal, and a measurement. An amplitude matching unit 640 for matching the radar signals reflected and received from the same target based on the amplitude of the received radar signal, and transmitting the transmission unit 610 based on the received radar signals matched by the amplitude matching unit 640. Matching of the _{d d} -f _R matching unit 650 and the f _d -f _R matching unit 650 matching in the f _d -f _R space from the frequency difference between the radar signal and the radar signal received by the receiving unit 620 And an information extracting unit 660 that extracts information such as a distance and a speed of the target based on the result.

The transmitter 610 transmits a plurality of modulated signals. In the following embodiments, the plurality of modulated signals is illustrated as including, but not limited to, up chirp, down chirp, and continuous wave modulation. The plurality of modulation signals may include two or more of the three signals described above. In addition to the above three modulation signals, a plurality of modulation signals different in frequency change over time may be used. The transmitter 610 may continuously transmit the plurality of modulated signals.

The receiver 620 receives the radar signal reflected by the target after transmitting from the transmitter 610. When there are a plurality of targets, a plurality of received signals may exist with respect to one modulated signal transmitted by the transmitter 610, and the receiver 620 may receive each received signal.

The amplitude measuring unit 630 measures the amplitude of each received radar signal.

The amplitude matching unit 640 converts the amplitude (or power) of the received radar signal for each transmission modulated signal into a relative amplitude. For example, when the amplitudes of the three reception radar signals r1 to r3 are A1 to A3 and the amplitude A2 of the radar signal r2 is the largest with respect to the up-modulated signal, each radar signal r1 to r3 ), The relative amplitudes are A1 / A2, A2 / A2 (= 1), A3 / A2 and they have values of 0 to 1.

The amplitude matching unit 640 compares the relative amplitudes of the received radar signals with respect to each transmit modulated signal, and when the difference is within a predetermined threshold range, the received radar signal for one transmit modulated signal for the other transmit modulated signal. Match the received radar signal.

The f _d -f _R matching unit 650 determines whether the intersections of the straight lines are matched by the received radar signals determined to be matched by the amplitude matching unit 640 in the f _d -f _R diagram. For example, when the amplitude matching unit 640 determines that one reception radar signal for the up-modulated signal and one reception radar signal for the down-modulated signal and one reception radar signal for the continuous wave modulated signal are determined to match. , Three straight lines due to signals matched with each other are shown in the diagram f _d -f _R , three intersection points with three straight lines are shown in the f _d -f _R diagram, and the f _d -f _R matching unit 650 is an intersection point. It is determined whether three are located in a predetermined area. If three intersections are located within a predetermined area, this will be determined as the actual target; if three intersections are not located within the predetermined area, this will be determined as a false target.

The information extractor 660 may extract the distance and the relative velocity of the target from the data of the position matched by the f _d -f _R matching unit 650.

The operation of the radar device described above will be described in more detail below.

FIG. 7 shows a flowchart of a target detection method executed in the radar device of FIG. 6.

First, the transmitter 610 transmits a radar signal as a modulation signal whose frequency changes with time (S710). As illustrated in FIG. 4, the modulated signal may be one of an up-modulated signal, a down-modulated signal, and a continuous wave modulated signal.

The receiver 620 receives the radar signal reflected by the radar signal transmitted from the transmitter 610 (S720). The radar signal received by the receiver 620 has a waveform in which the radar signal transmitted from the transmitter 610 is moved in the time direction according to the distance to the target and in the frequency direction according to the relative speed of the target. When there are a plurality of targets, the receiver 620 may receive a plurality of radar signals having different amounts of time direction movements and / or frequencies.

The amplitude measuring unit 630 receives a plurality of radar signals received for one modulation signal (uplink modulation signal, down modulation signal or continuous wave modulation signal), that is, one modulation section (uplink modulation section, down modulation section or continuous wave modulation section). In operation S730, amplitudes of the plurality of radar signals received are measured.

It is determined whether the reception of the radar signal and the measurement of the amplitude of each radar signal are completed in all sections, that is, in the up modulation section, the down modulation section, and the continuous wave modulation section (S740). If not completed in all sections (NO in S740), steps S710 to S730 are repeated until completion in all sections.

When all the sections are completed (YES in S740), the amplitude matching unit 640 performs matching between the received signals based on the amplitude measured in each section (S750).

8 illustrates an example of converting and matching an amplitude of a received signal into a relative amplitude in an embodiment of the present invention.

Referring to FIG. 8, radar signals reflected from three targets r1 to r3 are received in an up modulation period, a down modulation period, and a continuous wave modulation period CW. In FIG. 8, although r1 to r3 are displayed for each received radar signal, this is for convenience of description and is unknown when the radar signal is received by the receiver 620. In this case, matching may be performed using the amplitude (intensity) of the radar signal in each modulation section. However, in each modulation section, the amplitude may change according to the change of the radar transmission / reception environment, so that matching using the amplitude of the radar signal may be inaccurate.

The amplitude matching unit 640 changes the amplitude of the radar signal received in each modulation section to the relative amplitude. In the example of FIG. 8, since the radar signal reflected from the target r2 has the largest amplitude, the amplitude of the received signal is converted to the relative amplitude based on the radar signal.

The relative amplitudes of the signals received in one modulation period are compared with the relative amplitudes of the signals received in another modulation period to find signals that match each other. For example, the relative amplitude of one receive radar signal to the up-modulated signal is 0.80, the relative amplitude of one receive radar signal to the down-modulated signal is 0.79, and the relative amplitude of one radar signal to the continuous wave modulated signal. Is 0.81 and the threshold range is 0.05, they can be matched with a signal reflected from one target (eg r3). This is based on that radar signals reflected from the same target will have a similar amplitude.

Next, the f _d -f _R matching unit 660 executes matching on the f _d -f _R diagram (S760).

A straight line is located on the f _d -f _R diagram based on the frequency difference between the received signal in each modulation period and the transmission signal in each modulation period determined in step S750, and the intersection of the straight lines is located within a predetermined range. In that case, the position can be extracted from the position of the intersection on the f _d -f _R diagram of the actual target.

In FIG. 8, the matching signal may determine a received signal in an uplink modulation period, a downlink modulation period, and a continuous wave modulation period for each target r1, r2, r3. When the received signal in each modulation section for the matched received signal, for example, the target r1, is determined, the difference between the transmitted signal and the received signal (f _b1 ) in the uplink modulation section, and the transmitted signal and the received signal in the downlink modulation section The difference f _b2 , the difference f _b3 between the transmitted signal and the received signal in the continuous wave modulation section is obtained.

9 shows an example of an f _d -f _R diagram for a target measured in one embodiment of the present invention.

On the f _d -f _R diagram, a straight line 903-1 is derived in the up modulation period with respect to the target r1, a straight line 904-1 is derived in the down modulation period, and a straight line 905-in the continuous wave modulation period. 1) is induced. The intersection of the straight line 903-1 and the straight line 904-1, the intersection of the straight line 904-1 and the straight line 905-1, and the intersection of the straight line 905-1 and the straight line 903-1 are predetermined When located within the range of, the actual target 901-1 is obtained. In the same way, a straight line 903-2, a straight line 904-2, a straight line 905-2 are derived with respect to the target r2, and the actual target 901-2 can be obtained, and the target r3 A straight line 903-3, a straight line 904-3, and a straight line 905-3 are derived with respect to the actual target 901-3.

In the example of FIG. 9, straight lines 903-3, straight line 904-1, and straight line 905-2 are shown to intersect at one point 906, but these straight lines 903-3, 904-1, 905-2) are straight lines derived from received signals that do not match each other in step S750, so their intersection 906 may be excluded from the actual target. In this way, false targets may not occur.

Next, by using Equation 3, the information extracting unit 660 uses the targets r1, r2, and r3 from the coordinates of the actual targets 901-1, 901-2, and 901-3 in the f _d -f _R diagram. Information such as distance and relative velocity is extracted (S770).

In the above-described embodiment, the case of three modulation signals (up-modulation signal, down-modulation signal and continuous wave modulation signal) has been described, but the number of modulation signals may be two or more. However, when the number of modulation signals is two, only one intersection point of straight lines exists on the f _d -f _R diagram, and a determination as to whether the intersection points are within a predetermined range may be omitted. However, the accuracy of the actual target and false target judgment, the accuracy of the coordinates of the actual target may be degraded.

For example, since a plurality of targets have similar distances, when there are a plurality of received signals having similar values of amplitude (strength) in one modulation period, matching between signals is not performed only in step S750, but in S750. It may be determined considering both the step and the step S760. For example, in FIG. 8, when the signal reflected and received by the target r1 and the signal received by the target r3 are similar in amplitude, in step S750, the target signal r1 and the target r3 are distinguished from each other. Cannot match them. However, in the example of FIG. 9, the straight line 905-1 or the straight line 905-3 does not pass at the point where the straight line 903-1 and the straight line 904-3 intersect, and the straight line 903-1 does not pass. The straight line 905-1 passes through the point 901-1 where the straight line 904-1 intersects. Further, at the point where the straight line 903-3 and the straight line 904-1 intersect, the straight line 905-1 or the straight line 905-3 does not pass, and the straight line 903-3 and the straight line 904-3 do not pass. The straight line 905-3 passes through this intersection point 901-3. In this way it can be determined which received signals match and what the actual target is. On the other hand, judging the actual target by considering only step S760 without considering step S750 may not distinguish a false target such as “502” in the example of FIG. 5.

It is also to be understood that the terms such as " comprises, "" comprising," or "having ", as used herein, mean that a component can be implanted unless specifically stated to the contrary. But should be construed as including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas falling within the scope of the same shall be construed as falling within the scope of the present invention.

Claims (10)

A transmitter for transmitting at least two transmission signals having different frequency changes over time;
A receiver configured to receive a plurality of received signals in which the transmission signal is reflected by a plurality of targets;
An amplitude measuring unit measuring amplitudes of the plurality of received signals;
An amplitude matching unit for determining a relative amplitude between a plurality of received signals for each transmission signal and searching for received signals for different transmission signals reflected from the same target based on the relative amplitudes; And
And an information extraction unit for calculating the distance and the relative velocity of the target based on the frequency difference between the respective transmission signals and the reception signals with respect to the same target. The method of claim 1,
The at least two transmission signals include an up chirp signal whose frequency increases with time, a down chirp signal whose frequency decreases with time, and a continuous wave modulation whose frequency is constant with time. Radar device, characterized in that selected from the signal. The method of claim 1,
And the amplitude matching unit determines a plurality of received signals having relative amplitudes within a predetermined amplitude region as received signals reflected from the same target. The method of claim 1,
And the information extracting unit calculates the distance and the relative speed of the target based on the intersections of the straight lines based on the frequency difference between the transmission signal and the reception signal in the distance and relative velocity planes. The method of claim 1,
The different transmission signal is three or more,
The information extracting unit calculates the distance and the relative velocity of the target based on the intersection of the straight lines when the straight lines based on the frequency difference between the transmission signal and the received signal in the distance and relative velocity planes intersect within a predetermined comparison area. Radar device, characterized in that. A transmission step of transmitting at least two transmission signals having different frequency changes over time;
A reception step of receiving a plurality of reception signals in which the transmission signal is reflected on a plurality of targets;
An amplitude measuring step of measuring amplitudes of the plurality of received signals;
An amplitude matching step of determining relative amplitudes between a plurality of received signals for each transmitted signal and searching for received signals for different transmitted signals reflected from the same target based on the relative amplitudes; And
And an information extraction step for calculating a distance and a relative velocity of the target based on the frequency difference between the respective transmission signals and the reception signals with respect to the same target. The method according to claim 6,
The at least two transmission signals include an up chirp signal whose frequency increases with time, a down chirp signal whose frequency decreases with time, and a continuous wave modulation whose frequency is constant with time. Target detection method of the radar device, characterized in that selected from the signal. The method according to claim 6,
The amplitude matching step includes determining a plurality of received signals whose relative amplitudes are within a predetermined amplitude region as received signals reflected from the same target. The method according to claim 6,
And the information extraction step calculates the distance and the relative speed of the target based on the intersection of the straight lines based on the frequency difference between the transmission signal and the reception signal in the distance and relative velocity planes. The method according to claim 6,
The different transmission signal is three or more,
In the information extraction step, when the straight lines based on the frequency difference between the transmission signal and the reception signal in the distance and relative velocity planes intersect within a predetermined comparison area, the distance and the relative velocity of the target are calculated based on the intersections of the straight lines. Target detection method of the radar device, characterized in that.

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