KR101886366B1 - Apparatus of fmcw radar system for detecting moving target and method thereof - Google Patents

Abstract

The present invention relates to a signal processing apparatus, comprising: a signal generator for generating a transmission signal whose frequency varies during a predetermined period; a signal transmitter for radiating the transmission signal into a detection space; A bit frequency calculating unit for calculating a bit frequency corresponding to a difference frequency component between the transmission signal and the reflection signal, a first FFT value calculator for performing fast Fourier transform on the bit frequency, Calculates a correlation value between a pattern of the first FFT value and a pattern of the FFT value for each distance to determine a FFT value that is most similar to the pattern of the first FFT value among the set distance FFT values, A signal processing unit for determining a distance corresponding to the detected one FFT value as a distance of the moving target, And more particularly, to a moving target detection apparatus and method of an FMCW radar system including a pattern storage unit storing one information.

Description

FIELD OF THE INVENTION [0001] The present invention relates to an apparatus and method for detecting a moving target of an FMCW radar system,

The present invention relates to a moving target detection apparatus and method for detecting a distance to a moving target in an FMCW radar system.

A device for detecting a moving target such as an intruder or a vehicle is used in a security system or an active safety system of a vehicle. A frequency modulated continuous wave (FMCW) radar is used as a device for detecting a moving target. A typical FMCW radar receives a reflected wave reflected by an object by continuously emitting a frequency-modulated transmission wave, and performs FFT (Fast Fourier Transform) on a bit frequency, which is a difference frequency component between a transmission wave and a reflected wave, ) To detect the moving target and to detect the speed and distance of the object based on the Doppler frequency.

In the FMCW radar system, when the mobile target is detected, the FFT result is greatly increased against the situation where the intruder does not occur. At this time, the signal intensity of the FFT point corresponding to the distance between the radar and the moving target is largest.

However, such a conventional FMCW radar requires calculation and comparison of signal intensity for each FFT point.

On the other hand, in the conventional FMCW radar, there is a problem that the error is increased in the distance calculation of the moving target as the modulation bandwidth is small. For example, to implement an FMCW radar to have a 1 m resolution performance, a modulation bandwidth of at least 150 MHz is required by the following equation (1).

An FFT result for a beat frequency using a modulation band of 150 MHz, 150 MHz / 2, 150 MHz / 4, and 150 MHz / 8 is shown in FIG. 1 for a conventional FMCW radar system with respect to an object at a distance of 5 m . Here, the bit frequency is a difference frequency component between the transmission signal transmitted from the radar and the reflection signal received by the transmission signal reflected by the object.

1 (a) is a waveform of an FFT result (i.e., FFT spectrum) when 150 MHz is used, (b) is an FFT result waveform when 75 MHz is used, (D) is the FFT result waveform when 18.75 MHz is used.

Referring to FIG. 1, when a modulation band of 150 MHz is used, accurate information is shown that the object is at 5 m. However, when the modulation band of 75 MHz is used, a distance error of 1 m appears at 4 m and a modulation band of 37.5 MHz In case of using it, 3m appears and a distance error of 2m occurs. When using the modulation band of 17.75MHz, 1m appears and a distance error of 4m occurs.

For this reason, it is not possible to use broadband FMCW radar in short distance high resolution radar using narrow band, or to use narrow band to get result of using conventional wide band.

One embodiment of the present invention is to provide an apparatus and method for moving target detection of an FMCW radar system that achieves the same result as using a modulation band of a wide band using a narrow band modulation band.

One embodiment of the present invention is to provide an apparatus and method for moving target detection of an FMCW radar system that reduces the amount of computation for calculating intrusion detection and distance to an intruder.

Embodiments according to the present invention can be used to accomplish other tasks not specifically mentioned other than the above-described tasks.

A moving target detection apparatus of an FMCW radar system according to an embodiment of the present invention includes a signal generation unit for generating a transmission signal whose frequency is changed for a predetermined period, a signal transmission unit for radiating the transmission signal to a detection space, A bit frequency calculating unit for calculating a bit frequency corresponding to a difference frequency component between the transmission signal and the reflection signal; A first FFT value for a moving target is calculated by performing Fourier transform and removal of ambient noise, and a pattern of the first FFT value is correlated with a pattern of an FFT value for each distance, One FFT value, which is most similar to the pattern of one FFT value, is determined, and a distance corresponding to the obtained FFT value is obtained from the moving target Lee judgment signal processor, and which includes a storage information for the established distance value by FFT, and stores that pattern.

Wherein the signal processing unit includes: an FFT unit for FFT-transforming the bit frequency to calculate a current FFT value; an environmental noise removing unit for removing an old FFT value from the current FFT value to calculate an FFT value, The signal strength of each FFT point of the FFT value is summed and summed and the summed signal strength is compared with the set value to determine the presence or absence of a moving target and the FFT value removed from the environment noise is determined as the first FFT value A normalization unit for normalizing the signal intensity of each FFT point of the first FFT value, and a normalization unit for normalizing the signal intensity value of each FFT point of the first FFT value normalized by the normalization unit, And comparing the FFT value with a pattern of a signal strength value for each FFT point of a star FFT value to measure a correlation, Correlation to identify the FFT value measurement unit, and includes distance determination unit for determining the distance to the distance stored in the moving targets in response to the value of the FFT of a similar one.

The pattern is a signal intensity value for each FFT point or a curve shape expressed by a signal intensity value for each FFT point. The correlation measuring unit measures the correlation using the following equation (3).

A method for detecting a moving target in an FMCW radar system according to an embodiment of the present invention includes the steps of radiating a transmission signal whose frequency varies in a predetermined period to a detection space, Calculating a bit frequency corresponding to a difference frequency component between the transmission signal and the reflection signal, calculating a current FFT value by performing a fast Fourier transform on the bit frequency, calculating a previous FFT value from the current FFT value, Calculating an FFT value by removing an environmental noise, comparing the signal strength of the FFT value with the set value, determining that the mobile target is sensed when the measured signal intensity exceeds the set value, Determining a noise-removed FFT value as an FFT value of the moving target, normalizing the FFT value of the moving target, Measuring a correlation value between a pattern of signal intensity values of the FFT points of the FFT points of the mobile target and patterns of signal intensity values of the FFT points of the set FFT points, Determining one FFT value most similar to a pattern of the FFT value of the normalized moving target among the set distance FFT values and determining a distance stored corresponding to the most similar FFT value as a distance of the moving target .

According to the embodiment of the present invention, it is possible to obtain the same result as using the wide-band modulation band using the narrow-band modulation band, and to calculate the distance from the intruder to the intrusion detection It is possible to reduce the amount of computation required for the operation.

FIG. 1 is a diagram showing an FFT result waveform for each modulation band in a conventional FMCW radar system.
2 is a block diagram of a moving target detection apparatus of an FMCW radar system according to an embodiment of the present invention.
3 is a diagram illustrating a process for detecting a moving target according to an embodiment of the present invention.
FIG. 4 is a graph showing a 16-point FFT value before and after removal of ambient noise in a 37.5 MHz modulation band according to an embodiment of the present invention.
5 is a diagram illustrating an example of a signal intensity pattern for each distance according to an embodiment of the present invention.
FIG. 6 is a flowchart illustrating a process of setting an FFT value for each distance according to an embodiment of the present invention.
7 is a detailed circuit diagram of a moving target detection apparatus according to an embodiment of the present invention.
8 is a flowchart illustrating a method of detecting a moving target in an FMCW radar system according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same reference numerals are used for the same or similar components throughout the specification. In the case of publicly known technologies, a detailed description thereof will be omitted.

Whenever a component is referred to as "including" an element throughout the specification, it is to be understood that the element may include other elements, not the exclusion of any other element, unless the context clearly dictates otherwise. Also, the term "part" in the description means a unit for processing at least one function or operation, which may be implemented by hardware, software, or a combination of hardware and software.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus and method for detecting a moving target of an FMCW radar system according to an embodiment of the present invention will be described with reference to the accompanying drawings.

2 is a block diagram of a moving target detection apparatus of an FMCW radar system according to an embodiment of the present invention. 2, a mobile target detection apparatus according to an embodiment of the present invention includes a signal generation unit 110, a signal transmission unit 120, a signal reception unit 130, a bit frequency calculation unit 140, a signal processing unit 150, And a pattern storage unit 160.

The signal generation unit 110 generates a transmission signal whose frequency varies for a predetermined period. For example, the signal generator 110 may generate a transmission signal in the form of a triangle wave whose frequency increases at a constant slope and decreases. In this case, the signal generator 110 may set the sampling frequency and the frequency rise of the sampling signal based on resolution for detecting the target. For example, if the signal generator 110 is designed to have a resolution of 1 m, the sampling frequency is set to 150 MHz and the frequency rise of the sampling signal is set to 6.6 kHz. The signal generator 110 modulates the transmission signal of the triangle wave into an analog signal having a specific phase value. For example, a modulated analog type signal is a cosine signal or a sine signal.

The signal transmitter 120 amplifies the transmission signal of the analog form generated by the signal generator 110 and radiates the amplified transmission signal into a detection space outside the FMCW radar. Since the moving target detection device does not detect a fixed target and is a device that detects a moving target that can appear anywhere in the space, it detects a moving target by radiating a transmission signal throughout the detection space.

The signal receiving unit 130 receives a reflected signal that is reflected by a target existing in the detection space and returned from the signal transmission unit 120. Here, the target means an object (an object, a wall surface, a person, etc.) detected by the radar in a space where the radar is installed. The reflected signal is received with a predetermined delay time for the transmitted signal. The delay time of the reflected signal increases as the distance from the target increases. As the delay time increases, the difference frequency component (hereinafter referred to as a 'beat frequency') between the transmission signal and the reflected signal increases.

The bit frequency calculator 140 calculates a bit frequency which is a difference frequency component between the transmission signal and the reflection signal.

For example, the bit frequency calculator 140 calculates a bit frequency through the following process. First, the bit frequency calculation unit 140 calculates the received transmission signal and the reflection signal according to the following equation (2).

In Equation 2, Φtx denotes the phase of the transmission signal, Φrx is the phase of the reflected signal, cos (Φ _tx) is a cosine (cos) signal generated by the signal generator 110.

Then, the bit frequency calculator 140 filters the sum signal of the phase of the transmission signal and the sum of the reflection signals by using a low pass filter, Leaving only the difference frequency component (i.e., the bit frequency) of the reflected signal.

The signal processing unit 150 uses the bit frequency calculated by the bit frequency calculating unit 140 to determine whether a new target is generated or not, that is, a moving target detection, and generates a signal intensity pattern corresponding to the moving target when the moving target is detected The signal strength pattern having a high degree of correlation is compared with the predetermined signal strength patterns, and the distance corresponding to the detected signal strength pattern is recognized as the intruder distance. Herein, the signal intensity pattern is a pattern for the signal intensity for each FFT point obtained by using the result of FFT of the bit frequency, and the predetermined signal intensity pattern is a signal intensity pattern obtained for each distance.

For this, the signal processing unit 150 includes an FFT unit 151, an environmental noise removing unit 152, a moving target grasping unit 153, a normalizing unit 154, a correlation degree measuring unit 155 and a distance determining unit 156 ).

The FFT unit 151 performs fast Fourier transform on the bit frequencies calculated by the bit frequency calculating unit 140 to calculate FFT spectra, that is, FFT values. That is, the FFT value is displayed in a form indicating a predetermined signal intensity for each FFT point, and the signal intensity for each FFT point includes noise (clutter etc.) (see FIG. 3).

The environmental noise removing unit 152 removes environmental noise from the environment of the currently measured detection space and leaves only new information. Here, the environmental noise includes information on noise and fixed target as radar measurement information on a state in which a new target does not enter. This environmental noise corresponds to the previous FFT value measured immediately before the present measured FFT value. Therefore, the environment noise removing unit 152 performs an operation of removing the previously measured FFT value from the currently measured FFT value, leaving only new information. If the new target is not intruded, the previous FFT value and the current FFT value become equal to each other, so that the signal intensity (power) of "0" is output without any new information. However, in actuality, the environmental noise removing unit 152 outputs a result in which the signal intensity appears at each FFT point (point) by the change of the external environment (noise, clutter, etc.). Of course, when the new target enters the intruding state, the environmental noise removing unit 152 outputs the FFT value corresponding to the new target.

An operation according to an example of the environmental noise removing unit 152 will be described with reference to FIG. 3 is a diagram illustrating a process for detecting a moving target according to an embodiment of the present invention.

In FIG. 3, (a) is the previous FFT value, (b) is the current FFT value, and is the result in the same detection space. If the FFT points are four, the signal strength (including noise) appears for each FFT point in the previous FFT value and the current FFT value. If the previous FFT value is removed from the current FFT value by the environmental noise removing unit 152 As shown in (c) of FIG. 3, only the signal strength of each FFT point corresponding to the changed information in the previous environment is left. At this time, the changed information is information about the moving target as new information for the previous environment.

Here, if the previous FFT value at the same FFT point is larger, the signal intensity has a negative value. In this case, the signal strength of the FFT point corresponding to the FFT removed with environmental noise is set to " 0 " .

The operation of the environmental noise removing unit 152 can be used in a technique of extracting only the changed FFT value in the detection space using the previous FFT value and the current FFT value, in addition to the above example.

4 is a graph showing a 16-point FFT value before and after removal of ambient noise in a 37.5 MHz modulation band according to an embodiment of the present invention. Also, the signal strength before the environmental noise cancellation is 10 ⁴ times larger than the signal strength after the environmental noise cancellation. In FIG. 4, (a) is the FFT value before the environmental noise removal for the target at 5 m distance, and (b) is the FFT value after the environmental noise removal for the target at 5 m distance. (C) is the FFT value before the environmental noise removal for the target at the distance of 6 m, and (d) is the FFT value after removing the environmental noise for the target at the distance of 6 m.

Referring to FIGS. 4A and 4B, it can be seen that the pattern of the signal strength of each point of the FFT value before the removal of the environmental noise for the target of 5 m distance is changed after the environmental noise is removed, It can be seen that the pattern is a pattern of a moving target located at a distance of 5 m. Similarly, referring to FIGS. 4C and 4D, the pattern of the signal intensity of each point of the FFT value before the removal of the environmental noise for the target of 6 m distance shows that the pattern changes after the environmental noise is removed And it is a pattern of a moving target located at a distance of 5 m.

On the other hand, the FFT value of the environmental noise removing unit 152 in a state in which a new target does not intrude and the FFT value of the environmental noise removing unit 152 in a state in which a new target is intruded have different signal intensity values. This is because the FFT value measured by the external environment, that is, the change in the size of the noise, is small and the FFT value measured by the new target is large. Therefore, the signal processor 150 of the present invention detects the intrusion of the mobile target by using the difference in magnitude of the FFT value. At this time, the mobile target grasping unit 153 is used for intrusion detection of the mobile target.

The mobile target grasping unit 153 compares the signal intensity of each FFT point from the FFT value output from the environmental noise removing unit 152 and compares the signal intensity with the set value to determine whether or not the mobile target exists do. It is ideal to set the set value to the maximum value of the FFT value generated by the change of the external environment in the state where the new target does not enter. According to this, the set value is about 3 dB. Of course, the setting value can be set smaller or larger than 3dB depending on the installation environment.

Therefore, the mobile target grasping unit 153 determines that the mobile target is not detected if the signal strength is less than the set value, and determines that the mobile target is detected when the signal strength exceeds the set value. 4 (b) and 4 (d)), the mobile target grasping unit 153 determines that the mobile target has been detected. The FFT value received from the environment noise removing unit 152 is normalized Section 154 of FIG.

The normalization unit 154 normalizes the FFT value for the moving target, that is, the signal intensity for each FFT point. At this time, the normalization sets the maximum value or the minimum value of the signal intensity as a set value, and adjusts the signal strength of the different FFT points by the adjusted ratio of the maximum value or the minimum value to the set value. Here, the real value and the image value of the FFT value are normalized by the normalization unit 154.

The correlation measurement unit 155 measures the FFT value of the moving target normalized by the normalization unit 154 and the FFT value of each distance stored in the pattern storage unit 160. At this time, the degree of similarity is the degree of similarity of the FFT point-specific signal strength pattern (see FIG. 5) in the FFT value of one distance to be compared with the FFT point-to-FFT point-to-FFT value. Here, the pattern is a signal intensity value per FFT point or a signal intensity value per FFT point.

Accordingly, the correlation measuring unit 155 may measure the pattern correlation between the FFT value of the normalized moving target and the FFT value by distance based on the signal intensity of each FFT point, or may calculate the correlation value between the FFT value of the moving target and the distance Measure the pattern correlation between star FFT values. In a case where the signal strength is used as a reference for each FFT point, the correlation measuring unit 155 measures the degree of correlation using the following equation (3).

In Equation (3), R denotes an index value for designating a specific distance among the distance-dependent FFT values stored in the pattern storage unit, a value ranging from a minimum sensing distance to a maximum sensing distance of the radar, LUTRE [R] [i] is a real value of the signal intensity of the i-th point in the normalized FFT value, and LUTRE [R] [i] , NormIM [i] is the image value of the signal intensity at the i-th point in the normalized FFT value, and LUTIM [R] [i] is the real value of the signal strength of the i-th point in the FFT value, E [R] is the image value of the signal intensity of the i-th point in the FFT value for R, Euclidean Distance (Euclidean Distance) corresponding to the correlation between the FFT value for the distance R stored in the pattern storage unit and the normalized FFT value )to be.

According to Equation (3), the correlation measuring unit 155 compares the FFT values of the normalized moving target with the FFT values of the predetermined distance to compare the signal intensity values of the same FFT points and compares the two signal intensity values . Ideally, the FFT value of the FFT value of the normalized moving target is made to coincide with the set FFT value for each FFT point, but a slight error occurs due to the external environment such as noise.

Therefore, the correlation measuring unit 155 measures the Euclidean distance between the FFT value of the normalized moving target and the FFT value for each distance set, and determines the Euclidean distance as a set FFT having the smallest e [R] Value is regarded as the highest correlation value.

The distance determining unit 156 determines a distance corresponding to the set FFT value with respect to one set FFT value having the highest degree of correlation obtained by the correlation measuring unit 155 and sets the distance to the moving target .

The pattern storage unit 160 stores an FFT value for each distance, and the stored FFT value (the set FFT value) may be a value measured and stored in the moving target detection apparatus of the FMCW radar system, or a value measured and stored from an external apparatus. FIG. 5 shows an example of a pattern value for each distance stored in the pattern storage unit 160. As shown in FIG. 5 is a diagram illustrating an example of a signal intensity pattern for each distance according to an embodiment of the present invention. As shown in FIG. 5, it can be seen that the pattern of signal intensity by distance (i.e., FFT value by distance) has the same maximum signal intensity value of " 1 " have.

Hereinafter, a process of calculating the FFT value according to the set distance stored in the pattern storage unit 160 will be described with reference to FIG. FIG. 6 is a flowchart illustrating a process of setting an FFT value for each distance according to an embodiment of the present invention. In the following description with reference to FIG. 6, a case where the minimum distance is 1 m, the maximum distance is 10 m, and the measurement distance is 1 m will be described as an example.

Referring to FIG. 6, the object is positioned at a distance of 1 m, which is the shortest distance among the distances to be measured in the detection space. In this state, the moving target detection apparatus of the FMCW racer system generates a transmission signal whose frequency varies for a predetermined period and transmits the generated transmission signal to the detection space (S601).

The moving target detection apparatus receives a reflected signal reflected by an object including a target whose transmission signal exists in a detection space (S602), calculates the received reflection signal and transmission signal according to Equation (1) And a reflection signal to calculate a bit frequency (S603).

The moving target detection apparatus FFTs the bit frequency to calculate an FFT value (S604), and normalizes the calculated FFT value as shown in FIG. 5 (S605). Then, the moving target detection apparatus matches the normalized FFT value with the 1-m distance information and stores it in the pattern storage unit 160 as a look-up table (S606).

Then, the moving target detection apparatus determines whether the currently measured distance is a set maximum distance, that is, 10 m (S607). If the distance is 10 m, the setting FFT value storage is completed. Otherwise, the object is located only at 2 m (S607), and repeats the process from S601 to S606.

In the pattern storage unit 160, the FFT values for each distance are matched with the corresponding distance information and stored as a lookup table.

Hereinafter, a circuit configuration of a moving target detection apparatus according to an embodiment of the present invention will be described with reference to FIG. The block diagram of the moving target detection apparatus of FIG. 2 may be constructed using the circuit shown in FIG. 7 is a detailed circuit diagram of a moving target detection apparatus according to an embodiment of the present invention.

7, in the case of generating a transmission signal, the signal generation unit 110 includes a summation unit 111, a cosine signal generation unit 112, and a digital-to-analog converter 113. The signal generating unit 110 adjusts the frequency band by adding f _bias to the transmission signal f _M (i) whose frequency changes every sample. The bit frequency calculator 140 can easily obtain a signal including the phase difference information of the transmission signal and the reflection signal by removing the signal that has been _shifted to the high frequency band by the f _bias with the low pass filter (LPF).

The signal generating unit 110 calculates the phase of the transmission signal by summing the sample frequencies of the transmission signals using the summing unit 111. [ The cosine signal generating unit 112 generates a cosine signal using the calculated phase. Also, the signal generating unit 110 converts a cosine signal into an analog signal using a digital-to-analog converter (DAC) 113.

The signal transmitting unit 120 can shift the frequency band of the transmission signal by multiplying the transmission signal converted by the mixer 121 by the carrier wave cosf _c and emits the signal with the frequency band shifted to the detection space .

The signal receiving unit 130 receives the reflected signal, multiplies the received signal using the mixer 131, and downsamples the signal to move the frequency band of the reflected signal to the baseband.

The bit signal calculator 140 multiplies the reflected signal of the baseband by a cosine signal by the mixer 141 as shown in Equation 1 and outputs a signal of the product of the reflected signal and the transmitted signal to an analog- ) 142 as a digital signal. The bit signal calculation unit 140 then removes the high frequency component of the converted signal using a low pass filter (LPF) 143 and outputs the difference frequency component of the transmitted signal and the reflected signal to the signal processing unit (DSP) Bit frequency.

Hereinafter, a moving target detection method of the FMCW radar system according to an embodiment of the present invention will be described with reference to FIG. 8 is a flowchart illustrating a method of detecting a moving target in an FMCW radar system according to an embodiment of the present invention.

Referring to FIG. 8, the moving target detection apparatus generates a transmission signal whose frequency varies for a predetermined period (S801), and emits the transmission signal to the detection space (S802).

The moving target detection apparatus receives a reflection signal reflected by an object including a target whose transmission signal exists in a detection space (S803), calculates the received reflection signal and transmission signal as shown in Equation (1) The signal for the product of the signal and the reflected signal is filtered to calculate the bit frequency (S804).

The moving target detection apparatus FFTs the bit frequency to calculate an FFT value (S805), and performs an environmental noise removal on the calculated FFT value (S806). Then, the moving target detection apparatus sums the signal strengths of the FFT points of the FFT values of which the environmental noise is removed, and determines whether the summed signal strength exceeds 3 dB (S807).

If the sum of the signal intensities is less than 3 dB, the moving target detection apparatus determines that the moving target has not appeared and performs the detection operation continuously. If the sum of the signal intensities exceeds 3 dB, the moving target detection apparatus determines that the moving target is detected, The FFT value for the moving target is determined and the FFT value from which the environmental noise is removed is normalized (S808).

The moving target detection apparatus compares the pattern of the normalized FFT values with the patterns of the FFT values according to the set distance stored in the pattern storage unit 160, respectively, and measures correlations corresponding to the patterns of FFT values by distance (S809) The measured correlation values are compared to determine one FFT value having the greatest similarity (S810).

The moving target detection apparatus determines that one FFT value having the greatest similarity is an FFT value corresponding to the FFT value of the moving target, determines a distance corresponding to the FFT value from the lookup table and determines the distance as a distance from the moving target (S811).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

110: Signal generator 120: Signal transmitter
130: Signal receiving unit 140: Bit frequency calculating unit
150: signal processing unit 151: FFT unit
152: Environmental noise removing unit 153: Moving target grasping unit
154: normalization unit 155: correlation measurement unit
156: Distance judging unit 160:

Claims (7)

A signal generator for generating a transmission signal whose frequency varies during a predetermined period,
A signal transmitter for radiating the transmission signal into a detection space,
A signal receiving unit for receiving a reflected signal of the transmission signal reflected by the target existing in the detection space,
A bit frequency calculator for calculating a bit frequency corresponding to a difference frequency component between the transmission signal and the reflection signal,
Calculating a first FFT value for a moving target by performing a fast Fourier transform on the bit frequency and removing an ambient noise, calculating a pattern of the first FFT value normalized by normalizing the first FFT value, And a signal processor for determining a distance corresponding to one FFT value as a distance of the moving target by measuring one correlation value and determining one FFT value most similar to the pattern of the first FFT value among the FFT values for each distance, , And
And a pattern storage unit for storing information on the set distance FFT value,
The first FFT value and the FFT value for the distance are FFT values at the set M FFT points,
The pattern is a signal intensity value per FFT point,
Wherein the normalization is performed by setting a maximum value or a minimum value of the signal intensity as a set value and adjusting the signal strength of each FFT point by a ratio of the maximum value or the minimum value adjusted to the set value. The method of claim 1,
The signal processing unit,
An FFT unit for fast Fourier transforming the bit frequency to calculate a current FFT value,
An environmental noise removing unit for removing the previous FFT value from the current FFT value to calculate an FFT value that is removed from the environment noise,
The signal strength of each FFT point of the FFT value removed from the environment noise is summed and summed, and the signal intensity is compared with a set value to determine whether or not a moving target exists. 1 < / RTI > FFT value,
A normalizer for normalizing the signal strength of each FFT point of the first FFT value,
A pattern of a signal intensity value of each FFT point of the first FFT value normalized by the normalizing unit is compared with a pattern of signal intensity value of each FFT point of the set distance FFT value to measure a correlation, A correlation measurement unit for determining one FFT value most similar to the normalized pattern of the first FFT value among the FFT values, and
A distance determining unit that determines a distance stored corresponding to the most similar FFT value as a distance of the moving target,
Wherein the moving target detection device of the FMCW radar system comprises: delete 3. The method of claim 2,
Wherein the correlation measuring unit measures the correlation using the following formula: < EMI ID =

Wherein R is an index value for designating a specific distance among the FFT values by distance stored in the pattern storage unit, M is a total number of points of the FFT, i is an FFT LUTRE [R] [i] is a real value of the signal intensity of the i-th point in the normalized FFT value, and FTR value of the distance R stored in the pattern storage unit Normim [i] is an image value of the signal intensity of the i-th point in the normalized FFT value, LUTIM [R] [i] is an FFT value of the distance R stored in the pattern storage, And e [R] is an Euclidean distance corresponding to the degree of correlation between the FFT value for the distance R stored in the pattern storage unit and the normalized FFT value. Emitting a transmission signal whose frequency changes during a predetermined period to a detection space,
Receiving a reflected signal reflected by a target existing in the detection space,
Calculating a bit frequency corresponding to a difference frequency component between the transmission signal and the reflection signal,
Performing a fast Fourier transform on the bit frequency to calculate a current FFT value,
Removing the previous FFT value from the current FFT value to calculate an FFT value with the environment noise removed,
Comparing the signal strength of the FFT value with the set value, and when the signal strength of the FFT removed from the environment noise exceeds the set value, it is determined that the mobile target is detected, and the FFT value, Determining an FFT value,
Normalizing an FFT value of the moving target,
Comparing the pattern of the FFT value of the FFT value of the normalized mobile target with the pattern of the signal intensity value of each FFT point of the set distance FFT value to measure the correlation,
Determining one FFT value most similar to the pattern of the FFT value of the normalized mobile target among the set FFT values based on the measured correlation, and
Determining a distance stored corresponding to the most similar FFT value as a distance of the moving target,
The FFT value of the normalized moving target and the FFT value of the set distance are FFT values at the set M FFT points,
The pattern is a signal intensity value per FFT point,
Wherein the normalization is performed by setting a maximum value or a minimum value of a signal intensity as a set value and adjusting a signal strength of each FFT point by a ratio of a maximum value or a minimum value adjusted to a set value. delete The method of claim 5,
The correlation measurement step may be a moving target detection method of an FMCW radar system for measuring a correlation using the following equation

R is an index value for designating a specific distance among the FFT values for each distance stored, and is a value ranging from the minimum sensing distance to the maximum sensing distance of the radar, M is the total number of points of the FFT, LUTRE [R] [i] is the real value of the signal intensity at the i-th point in the FFT value for the R, and NormIM [i] is the real value of the signal intensity at the i- [i] is an image value of the signal intensity of the i-th point in the normalized FFT value, LUTIM [R] [i] is the image value of the signal intensity of the i-th point in the FFT value for R, The Euclidean distance corresponds to the degree of correlation between the FFT value for R and the normalized FFT value.

Images