KR101462156B1 - method for removing noise signal by second offset of radar signal processor - Google Patents

Abstract

In order to improve the signal processing speed and improve the image quality of the detector by removing the noise signal from the analog signal received from the radar, the present invention is characterized in that the transmission signal transmitted through the radar antenna is reflected by the detector, A first step of receiving an echo signal having an echo signal; A second step of delaying the echo signal by a predetermined time and storing the delayed signal; And calculating a point of intersection of the echo signal and the delayed signal, wherein the first condition that the signal strength of the calculated maximum value intersection point is equal to or less than a predetermined first offset value, And a third step of filtering the signal corresponding to the second condition in which the slope of the signal intensity change amount according to the second condition is greater than a predetermined slope to calculate and output a correction signal.

Description

[0001] The present invention relates to a method of removing a noise signal by using a second offset value of a radar signal processing apparatus,

The present invention relates to a radar signal processing apparatus, and more particularly, to a radar signal processing apparatus that efficiently removes a signal not including information on a detector from a signal received by a radar, thereby improving a signal processing speed, And a second offset value of the radar signal processing apparatus in which power consumption is reduced.

Generally, a radar is a sensing device that emits an electromagnetic wave and receives a reflected wave reflected by an object in the area to detect the presence and distance of the target. Such a radar uses a continuous wave RADAR A pulse Doppler RADAR and a pulse compression RADAR using a Doppler RADAR, a frequency modulation continuous wave (FMCW) radar, a pulse wave RADAR, have.

On the other hand, the echo signal that is transmitted back through the radar antenna is reflected by the detector and analyzed by the time-space characteristics such as the frequency characteristics of the signal frequency, the signal width, and the signal intensity, and the signal arrival direction and the signal arrival time .

At this time, the radar signal processing apparatus uses an algorithm for extracting the parameters such as the position and the motion state of the detection object as accurately as possible by using the characteristics of the echo signal, and a processing with a high-speed processor Board.

1 is a diagram illustrating an example of a method for removing a noise signal in a conventional radar signal processing apparatus.

As shown in FIG. 1, the echo signal 11 received through the radar antenna can be represented by the intensity of the received signal over time. Here, the echo signal 11 includes a signal 11 having information on the detection body. At this time, the signal period h changes according to the velocity of the detection object, and the signal intensity v changes according to the distance of the detection object.

In addition to the information 11 about the detection object, the echo signal 11 includes interference signals generated by other propagation sources, errors generated by amplification of radio waves in the radar device, clutter due to scattering occurring on the terrain, The echo signal 11 is converted into a video signal and an overload is generated in analyzing the characteristics of the detection object to lower the processing speed and the resolution of the converted video signal There is a problem that the image quality deteriorates.

Conventionally, an offset 1 is formed based on a predetermined signal intensity to remove the noise signals 12 and 13, and a signal having a signal intensity equal to or lower than the offset 1 is converted into a noise signal 13 It is judged and removed.

However, in the case of the noise signal 12 having a signal intensity equal to or higher than the offset (1), it still remains as a signal including information on the detection object, which not only degrades the signal processing speed but also degrades the resolution and image quality of the image signal .

Korean Patent Publication No. 10-2003-0079690

In order to solve the above-mentioned problems, the present invention provides a radar signal processing apparatus improved in image quality of a detector recovered through an echo signal by removing a noise signal from an echo signal received from a radar, And a noise signal cancellation method using the second offset value.

According to an aspect of the present invention, there is provided a method for detecting an echo signal, the method comprising: receiving echo signals having amplitude and period of a transmitted signal transmitted through a radar antenna reflected by a detector; A second step of delaying the echo signal by a predetermined time and storing the delayed signal; And calculating a point of intersection of the echo signal and the delayed signal, wherein the first condition that the signal strength of the calculated maximum value intersection point is equal to or less than a predetermined first offset value, And a third step of calculating a correction signal by filtering a signal corresponding to a second condition in which the slope of the signal intensity change amount according to the second condition is greater than a predetermined slope and outputting the corrected signal. .

Preferably, in the third step, the preceding reference point is set as a preceding intersection point of a line corresponding to a second offset value set lower than the first offset value and any one of the echo signal and the delay signal.

The first step may include filtering a signal whose signal strength is equal to or less than a predetermined third offset value in the received echo signal, calculating an inflection point of the echo signal, and calculating an inflection point of the echo signal, Calculating and storing a first inflection point, a second inflection point, and a third inflection point sequentially from a point where a slope of a change amount changes from a negative value to a positive value, and storing and storing the first inflection point, the second inflection point, Calculating a mean value of the first inflection point and the third inflection point and substituting an average value calculated at the second inflection point and correcting the average value if the variation amount of the signal intensity value between the second inflection point and the third inflection point is not more than a predetermined correction value And stores the third inflection point as the first inflection point when the calculated average value is substituted for the second inflection point, It is also the step of storing the succeeding inflection point which is calculated by the second inflection point and the third inflection point further comprises preferred.

The correction signal may be calculated by summing a first correction signal obtained by filtering a signal corresponding to the first condition and a second correction signal obtained by filtering a signal corresponding to the second condition.

A signal receiver for receiving an echo signal having an amplitude and a period which are returned from a transmission signal transmitted through a radar antenna and reflected by a detector; The echo signal is stored as a delayed signal by delaying the echo signal by a predetermined period of time and an intersection of the echo signal and the delayed signal is calculated and the signal intensity of the calculated maximum value intersection is set to a first condition And a second condition that the slope of the signal intensity variation amount according to the time variation amount from the predetermined preceding reference point to the calculated maximum value intersection point is equal to or greater than a predetermined slope A signal processing unit for filtering the corresponding signal to calculate and output a correction signal; A first buffer for storing the echo signal; A second buffer in which the delay signal is stored; And a temporary storage unit for storing the calculated correction signal by filtering all of the signals corresponding to the first and second conditions.

Through the above solution, the present invention provides the following effects.

First, an intersection point of the echo signal and the delayed signal delayed by a predetermined time is calculated. The first condition that the signal strength of the calculated maximum value intersection is equal to or less than a predetermined first offset value, Since the signal corresponding to the second condition in which the slope of the signal intensity variation amount according to the time variation amount to the calculated maximum value intersection point is equal to or greater than a predetermined slope is filtered, noise peaks with high signal intensity can be removed, So that the overload of the product can be prevented and the processing speed can be improved.

Second, by filtering the corresponding signal of the first condition and the second condition, it is possible to restore a long distance detection signal having a low signal intensity, so that the detection accuracy of the detection object is improved and the reliability of the product can be improved.

The echo signal is calculated by calculating an inflection point of the echo signal, and the signal intensity value change amount of the first inflection point and the second inflection point is equal to or less than a predetermined correction value, or the signal intensity value variation amount of the second inflection point and the third inflection point is equal to or less than a predetermined correction value The average value of the first inflection point and the third inflection point is calculated and the average value calculated at the second inflection point is substituted and corrected to simplify the echo signal so that the amount of computation in the subsequent noise signal cancellation step decreases, Can be removed in real time and the signal processing speed can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exemplary view showing a method of removing a noise signal in a conventional radar signal processing apparatus. FIG.
2 is a block diagram showing a radar signal processing apparatus according to an embodiment of the present invention;
3 is a flowchart illustrating a method of removing a noise signal using a second offset value of a radar signal processing apparatus according to an embodiment of the present invention.
FIG. 4 is a flowchart illustrating a method of correcting a detection signal of an echo signal in a noise signal removing method using a second offset value of a radar signal processing apparatus according to an embodiment of the present invention. FIG.
5 is a diagram illustrating a method of correcting a detection signal of an echo signal in a noise signal removing method using a second offset value of a radar signal processing apparatus according to an embodiment of the present invention.
6 is a diagram illustrating a first condition in a noise signal cancellation method utilizing a second offset value of a radar signal processing apparatus according to an embodiment of the present invention;
FIG. 7 is a diagram illustrating a method of setting a preceding reference point for a second condition in a noise signal removing method using a second offset value of a radar signal processing apparatus according to an embodiment of the present invention; FIG.
8 is a diagram illustrating a correction signal in a radar signal processing apparatus according to a noise signal removing method utilizing a second offset value of a radar signal processing apparatus according to an embodiment of the present invention.
9 is a diagram illustrating a method of setting a preceding reference point of a second condition in a noise signal removing method utilizing a second offset value of a radar signal processing apparatus according to another embodiment of the present invention.

Hereinafter, a radar signal processing apparatus and a noise signal removing method according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing a radar signal processing apparatus according to an embodiment of the present invention.

2, the radar signal processing apparatus includes a signal receiving unit 10, a signal processing unit 20, a first buffer 40, a second buffer 50, and a temporary storage unit 30. Here, the radar signal processing extracts the characteristics such as the presence, the position, and the motion state of the detector in an echo signal having an amplitude and a period which are reflected by the detector by emitting a wave medium such as an electromagnetic wave or a sound wave from the radar antenna The procedure.

The signal receiver 10 receives the echo signal and stores the received echo signal in the first buffer 40. At this time, since the echo signal may be weakened in various environmental conditions such as the intensity of the transmitted signal and the distance of the detector or jamming propagation, it is preferable that an amplifying device for amplifying the signal intensity of the echo signal is provided.

The received echo signal may be rearranged into a digital input signal having a predetermined form, for example, a repetition period of the input signal with respect to the input signal or a frequency value according to time. At this time, the intensity, frequency, direction, signal width, signal arrival time, etc. of the input pulse signal of the received input signal exceeding the reception sensitivity can be measured and stored in the form of a preset digital bitmap.

On the other hand, the signal processing unit 20 can detect the existence of the detection object using energy scattering in the received echo signal, classify and classify the object using polarization or polarization, distance identification with the object, detection using the Doppler effect And the like. Here, it is preferable that the signal processing unit 20 includes an algorithm for accurately and quickly extracting information to be grasped in the echo signal, and a high-speed processor capable of rapidly processing the information in real time.

The signal processing unit 20 filters the noise signal to improve the operation speed by removing unnecessary information for analyzing the information of the detector included in the echo signal and to improve the accuracy of the analyzed information.

At this time, the echo signal is delayed by a predetermined time period and stored as a delayed signal. Preferably, the delay signal is stored in the second buffer 50 and is fetched in response to a data request from the signal processing unit 20.

The signal processing unit 20 calculates an intersection point of the echo signal and the delay signal, and calculates a difference between a first condition that the signal intensity of the calculated maximum value intersection is equal to or less than a predetermined first offset value, A signal corresponding to all of the second conditions in which the angle from the reference point is equal to or greater than a predetermined angle is filtered to calculate and output a correction signal.

At this time, it is preferable that intermediate information such as a signal to be filtered in the first condition and a signal to be filtered in the second condition, which are generated according to the operation of the signal processing unit 20, is stored in the temporary storage unit 30.

FIG. 3 is a flowchart illustrating a method of removing a noise signal using a second offset value of a radar signal processing apparatus according to an embodiment of the present invention. FIG. FIG. 5 is a flow chart illustrating a method of correcting a detection signal of an echo signal in a noise signal canceling method using an offset value according to an embodiment of the present invention. 6 is a diagram illustrating a first condition in a noise signal cancellation method using a second offset value of a radar signal processing apparatus according to an embodiment of the present invention. 7 is a flowchart illustrating a method of removing a noise signal using a second offset value of a radar signal processing apparatus according to an embodiment of the present invention. 8 is a diagram illustrating an example of a correction signal in a radar signal processing apparatus according to a noise signal removing method utilizing a second offset value of a radar signal processing apparatus according to an embodiment of the present invention.

3 to 8, the radar signal processing apparatus 100 receives an echo signal 21 having an amplitude and a period that are returned from a transmission signal transmitted through a radar antenna, ), And performs a series of processing steps for analyzing the information on the detection body included in the echo signal 21. [

Here, the echo signal 21 includes a bottom noise 25 appearing as a random period while forming a low signal intensity value, a noise peak 23 appearing as a narrow period while forming a high signal intensity value, and characteristics of a detection object And are formed as detection peaks 22 and 24 appearing in relatively wide intervals while forming a high signal intensity value. In this case, the period refers to a time period during which the signal intensity increases and then attenuates and disappears, and the amplitude is preferably a difference between the highest value and the lowest value in one period.

The individual signals 22, 23, and 24 of the echo signal 21 are classified into a point where the differential value of the wave function derived from the temporal change amount of the echo signal 21 and the signal intensity change amount changes from negative to positive .

In detail, the detection pixels 22 and 24 of the echo signal 21 and the noise pixels 23 may be separated into individual signals having respective periods. In addition, the signal processing unit (20 in FIG. 2) can derive a wave function having the signal intensity change amount and the time change amount of the echo signal 21 as a variable. At this time, the calculated wave function is differentiated so that the time value of the zero value point at which the differential value changes from negative to positive is determined as the start time of the individual signal, and after passing through the value point of 0 changing from positive to negative, It is preferable that the time value of the value point of 0 which changes in the positive direction is determined as the end time of the individual signal.

Accordingly, the continuous waveform of the echo signal 21 is divided into a plurality of divided signals, and a series of procedures are performed to determine whether the individual signal is a signal including the information of the detector or a signal due to a clutter or jammer can do.

On the other hand, the echo signal 21 received in the actual radar device may appear as a zigzag shape in which the signal intensity repeats increase and decrease in one period, rather than a complete curve shape in which the signal intensity increases and decreases in one period .

4 to 5, in order to determine the period of the echo signal 21, an average value of signal intensities is calculated in a zigzag curve in which signal intensity is repeatedly increased or decreased in one period, The step of correcting may be further included.

First, when the echo signal 21 is received (s10), a signal having a signal intensity lower than a predetermined third offset value 7 in the received echo signal 21 is filtered (s11). Here, the predetermined third offset value 7 is a value obtained by measuring the maximum signal intensity value of the bottom noise 25 appearing in the actual radar through experiments and setting the value of the signal intensity value of the detection noise 22 It is preferable to set it. As a result, the signal processing amount in the subsequent signal processing step can be reduced and the basic signal processing speed can be improved.

The inflection point of the echo signal 21 is calculated, and the inflection point of the echo signal 21 is sequentially calculated from the point where the gradient of the signal intensity change amount according to the time variation amount changes from negative to positive at the first inflection point, the second inflection point and the third inflection point And stores it (s12).

At this time, the inflection point of the echo signal 21 can be calculated through the differential value of the wave function derived by using the signal strength change amount and the time variation amount of the echo signal 21 in the signal processing section 20 have.

Then, a value point of 0 where the differential value changes from negative to positive is calculated as a first inflection point, a value point of 0 that changes from positive to negative is calculated as a second inflection point, Value point to the third inflection point.

Of course, the inflection point can also be calculated from a database in which the echo signal 21 is digitized and stored. At this time, it is preferable that the database includes a time formed at a predetermined time interval and a signal strength value received at that time.

For example, when the preset time interval is set to 1 second, the tables stored in the database may be 1 second 90 seconds, 2 seconds 91 seconds, 3 seconds 90 seconds, and 4 seconds 89. At this time, when the time changes from 1 second to 2 seconds, the signal intensity increases from 90 to 91, and when the time changes from 2 seconds to 3 seconds, the signal intensity decreases from 91 to 90. Accordingly, the inflection point is calculated can do.

When the first inflection point, the second inflection point, and the third inflection point are calculated (s12), the signal intensity value change amount between the first inflection point and the second inflection point is equal to or less than a predetermined correction value (s13) (S131), the mean value of the first inflection point and the third inflection point is calculated, and the average value calculated at the second inflection point is substituted to correct the signal strength value variation amount of the third inflection point (s14).

In particular, looking at the remote sensing descriptor 22, the remote sensing descriptor 22 includes information about one sensor but a plurality of inflection points are displayed. At this time, according to the observation result derived by driving the radar device, the inflection point is generated not by the characteristic of the detection body but by the influence of the signal reception sensitivity or the jamming wave, and is filtered for the characteristic analysis of the accurate detection body desirable.

The first inflection point 22c of the remote sensing signal 22 is a point at which the remote sensing signal 22 starts and is calculated as a first inflection point at a point where the slope variation is changed from negative to positive. The next inflection point 22a is a point at which the slope change amount changes from positive to negative and is generated as a second inflection point as a point to be filtered since it is generated not by the characteristics of the detection object but by the signal reception sensitivity or by the influence of jamming waves. Further, the next inflection point 22b is calculated as a third inflection point to the point where the slope variation is again changed from negative to positive.

At this time, the second inflection point 22b shown in the long distance detection signal 22 has a signal strength value different from that of the first inflection point 22c, but a difference in signal strength value from the third inflection point 22b .

The difference between the signal intensity values of the first and second inflection points 23a and 23a of the noise peak is high and the difference between the second inflection point 23a and the third inflection point 23c is high, The difference in the signal strength value between the two is also high.

As described above, since the difference between the inflection points of the noise peak 23 is high, it is not corrected because it does not meet the condition below the predetermined correction value, and the second inflection point of the far- Since the echo signal 21 is simplified, the amount of computation can be reduced in the subsequent noise signal removing step.

Then, the calculated average value is substituted into the second inflection point (s14), the third inflection point is stored as the first inflection point, and the subsequently calculated inflection point is calculated as the second inflection point and the third inflection point (S15). This is a step for sequentially correcting the vehicle inflection point, and it is possible to correct for the next inflection point in real time after the second inflection point is corrected.

As described above, if the echo signal is corrected to a complete curve shape, an operation of calculating an intersection point and filtering the noise signal in the subsequent operation step can be further simplified, and the processing speed of the operation can be improved.

Meanwhile, the echo signal 21 is delayed by a preset time period and stored as a delay signal 26 (s20). In this case, the echo signal 21 may be in a form in which the bottom noise 25 is removed through the step of correcting the waveform, and the inflection point disappears in the signals 22 and 24 of the individual periods.

The predetermined time for generating the delay signal 26 by delaying the period may be 0.5 to 2 seconds so as to acquire the information of the detector in real time without interfering with the information analysis through the echo signal 21. [ Second, and so on.

That is, when the echo signal 21 is delayed by the predetermined time, the delay signal 26 has the same waveform as that of the echo signal 21, and the start time and the end time of each individual signal are preset The phase is changed by a delay time.

Referring to FIG. 6, when the delay signal 26 is generated from the echo signal 21, an intersection between the echo signal 21 and the delay signal 26 is calculated (s30). In detail, the signals 22, 23 and 24 of the individual periods in the echo signal 21 have intersections 3, 4 and 5 due to the phase difference with the delay signal 26. Since the near distance detection subject 24 is formed in a relatively wide cycle, the calculated maximum intersection point 5 appears above the predetermined first offset value 6, but the noise pick 23 appears for a short period of time The calculated maximum intersection point 4 appears below the predetermined first offset value 6, as shown in FIG.

At this time, the noise peak 23 satisfies the first condition that the signal intensity of the calculated maximum value intersection point 4 is equal to or less than the predetermined first offset value 6 (s40). By filtering the noise signal through the calculated intersection with the delayed signal 26, the noise peak 23 having a high signal intensity can be included in the filtering object, and the overall signal processing operation amount is reduced, It is possible to analyze information on a more accurate detector in real time.

On the other hand, the detection signal 22 of the echo signal reflected from the remotely located detector appears over a wide period with low signal intensity. Here, since the detection subject 22 satisfies the first condition, if the noise is removed only by the first condition, the information about the remote object is removed and the accurate information about the object can not be analyzed.

Therefore, if the calculated signal intensity of the calculated maximum intersection point satisfies the first condition that is equal to or less than the predetermined first offset value (s40) (s40), the signal intensity according to the time variation from the predetermined preceding reference point to the calculated maximum value intersection It is determined whether the slope of the change amount corresponds to a second condition that is equal to or greater than a predetermined slope (s50), and a signal satisfying both conditions is filtered by the noise signal through an AND operation between the first condition and the second condition (s60).

Here, since the preset reference point is used as a reference for calculating the slope to the calculated maximum value intersection point, when the preceding reference point changes, the slope to the calculated maximum value intersection point is changed. Therefore, it is preferable that the preset value is changed according to the method of setting the preceding reference point, as the predetermined slope as a reference for filtering the noise signal.

Referring to FIG. 7, the preceding reference point in the second condition is set to a preceding intersection of the line corresponding to the second offset value 8 set lower than the first offset value and the echo signal 21 .

The second offset value 8 is a maximum offset value of the detection signal 27 of the detection signal 27 of the delay signal 26 and the detection signal 22 of the echo signal 21 reflected from the far- 3) or less.

In detail, when the hypothetical line extending in parallel with the time line is drawn in the second offset value 8, two intersections are formed with the detection subject 22 of the echo signal 21, It can be set as a reference point.

At this time, it is determined whether or not the slope of the signal intensity variation amount according to the time variation from the preceding reference point (3a) to the calculated maximum value intersection (3) corresponds to a second condition of a predetermined slope or more, Filter with noise signal through condition and AND operation.

For example, since the noise peak 23 of a narrow period has a large change in signal intensity with time, the slope of the signal intensity variation amount according to the time variation amount from the preceding reference point 4a to the maximum value intersection 4 the signal intensity variation amount corresponding to the time variation amount from the leading reference point 3a to the maximum value intersection point 3 because the variation of the signal intensity is small in the wide- The slope? 1 is small.

Here, a method of comparing the slopes can use a trigonometric function. That is, the slopes (? 1,? 2,? 3) of the signal intensity variation amounts from the preceding reference points (3a, 4a, 5a) to the calculated maximum value intersections (3,4,5) 4a, and 5a) is calculated by dividing the amount of change in signal intensity from the calculated maximum intensity point (3,4,5) by the amount of time variation by an arc tangent function, and an angle corresponding to the gradient is calculated and assigned to the cosine function Can be compared based on one value.

That is, since the value assigned to the cosine function has a value of 1 at 0 degrees and has a value of 0 at 90 degrees, assuming that a preset slope is set to 45 degrees, if the value assigned to the cosine function is 0.5 or less It can be filtered by the noise pick 23.

Referring to FIG. 8, the signal corresponding to the first condition and the second condition is filtered (s60), and the correction signal 21a is calculated and output (s70).

Here, the term filtering means that the corresponding signal is removed from the echo signal 21 and the removed part is corrected by replacing the state in which the individual signal is not received, that is, . For example, it is preferable that the signal intensity is corrected to zero or a constant constant value in the time period of the removed part.

In more detail, the long distance detection subject 22 and the near distance detection subject 24, which satisfy only one of the first condition and the second condition, are calculated as the correction signal 21a without being filtered by the noise signal.

At this time, since the general noise signal is formed in a very short period, the time for calculating the intersection with the delay signal 26 by delaying the echo signal 21 is very short. The signal strength of the intersection is compared with the first offset value 8 to determine whether the first condition is satisfied and whether the second condition is satisfied by calculating the slope from the minimum intersection to the maximum intersection Can be made substantially in real time, so that the noise signal can be quickly filtered.

Of course, the correction signal 21a may be calculated by summing a first correction signal obtained by filtering the signal corresponding to the first condition and a second correction signal obtained by filtering the signal corresponding to the second condition.

Here, the first correction signal obtained by filtering the signal corresponding to the first condition is first calculated in the echo signal 21, and the second correction signal obtained by filtering the signal corresponding to the second condition in the echo signal 21 is calculated. Signal. At this time, the first correction signal and the second correction signal do not include the noise signal 23, and the first correction signal does not include the remote sensing signal 22.

Therefore, when the second correction signal is calculated by adding the second correction signal to the first correction signal by the 0R calculation, the noise peak 23 is removed from the echo signal 21, and the near detection signal 24 and the remote detection signal 22 ) Can be calculated.

9 is a diagram illustrating a method of setting a preceding reference point of a second condition in a noise signal removing method that utilizes a second offset value of a radar signal processing apparatus according to another embodiment of the present invention. In this embodiment, the basic configuration except for the method of setting the preceding reference point is the same as that of the above-described embodiment, so that the description of the same parts will be omitted.

9, the preceding reference point in the second condition according to another embodiment of the present invention may be a line corresponding to a second offset value 8 set lower than the first offset value, It may be set as the preceding intersection 3b.

In detail, by drawing a virtual line extending parallel to the time line at the second offset value 8, it is possible to calculate the preceding intersection 3b in the detection signal 22 of the delay signal 21, ) Can be set as the preceding reference point.

At this time, it is determined whether or not the slope of the signal intensity change amount according to the time variation from the preceding reference point (3b) to the calculated maximum value intersection (3) corresponds to a second condition of a predetermined slope or more, The noise signal 23 is filtered through the AND operation with the condition.

Since the set value of the predetermined slope for extracting the noise signal is set to correspond to the method of selecting the preceding reference point even if the criterion for selecting the preceding reference point is changed, It is possible to extract a result such as a virtual line extending in parallel with the time line and a case where the preceding intersection 3a with the detection subject 22 of the echo signal 21 is set as the preceding reference point.

For example, when the virtual line extending parallel to the time line at the second offset value 8 and the preceding intersection points 3b, 4b, 5b of the delay signal 26 are set as the preceding reference points, , 6 and 7 are smaller than the inclination angles? 1,? 2 and? 3 in the case where the echo signal 21 and the preceding intersection 3a, 4a and 5a are set as the preceding reference points.

Therefore, in the case of setting the preceding intersection 3b, 4b, 5b of the delay line 26 and the imaginary line extending parallel to the time line at the second offset value 8 as the preceding reference point, A preset slope of a set value lower than that in the case of setting the preceding intersection 3a, 4a, 5a of the echo signal 21 as a preceding reference point is used for noise signal filtering .

For example, the predetermined slope extracted by the noise signal can be set to 40 degrees when setting 3b to the preceding reference point, and to 45 degrees when setting 3b to the preceding reference point.

Of course, the inclination extracted by the noise signal is 40 degrees and 50 degrees. However, in order to extract a precise noise signal, it is necessary to calculate a set value of a predetermined slope corresponding to a general noise filtering theory value and an experimental result using actual radar equipment desirable. Accordingly, the result of filtering the noise signal 23 may be represented by a correction signal 21a as shown in FIG.

As described above, the present invention is not limited to the above-described embodiments, and variations and modifications may be made by those skilled in the art without departing from the scope of the present invention. And such modifications are within the scope of the present invention.

11, 22, 24: Detection subjects 12, 23: Noise pick
25: bottom noise 21: echo signal
26: delay signal 10: signal receiving section
20: signal processing unit 30: temporary storage unit
40: first buffer 50: second buffer

Claims (5)

A first step of receiving an echo signal having an amplitude and a period returned from a transmission signal transmitted through a radar antenna and reflected by a detector;
A second step of delaying the echo signal by a predetermined time and storing the delayed signal; And
Calculating a point of intersection between the echo signal and the delayed signal and calculating a point where a signal intensity of the calculated maximum point of intersection is equal to or less than a predetermined first offset value and a first condition And a third step of filtering a signal corresponding to a second condition in which a slope of a signal intensity change amount is equal to or greater than a predetermined slope to calculate and output a correction signal, and outputting the corrected signal. The method according to claim 1,
Wherein in the third step, the preceding reference point is set as a preceding intersection point of a line corresponding to a second offset value set lower than the first offset value and any one of the echo signal and the delay signal. A method for removing a noise signal utilizing a second offset value of a device. The method according to claim 1,
Wherein the first step includes filtering a signal whose signal strength is lower than a predetermined third offset value in the received echo signal,
Calculating an inflection point of the echo signal and calculating and storing the first inflection point, the second inflection point, and the third inflection point sequentially from a point where the slope of the signal intensity variation amount changes from negative to positive at the calculated inflection point, Wow,
When the amount of change in the signal intensity value of the first inflection point and the second inflection point is equal to or less than a predetermined correction value, or when the variation amount of the signal intensity value of the second inflection point and the third inflection point is equal to or less than a predetermined correction value, Calculating an average value and substituting an average value calculated at the second inflection point to correct the average value;
Storing the third inflection point as the first inflection point and storing the sequentially calculated inflection points as the second inflection point and the third inflection point when the calculated average value is substituted for the second inflection point And a second offset value of the radar signal processing apparatus. The method according to claim 1,
Wherein the correction signal is calculated by summing a first correction signal obtained by filtering a signal corresponding to the first condition and a second correction signal obtained by filtering a signal corresponding to the second condition. A noise signal cancellation method using an offset value. A signal receiving unit for receiving an echo signal having an amplitude and a period returned from a transmission signal transmitted through a radar antenna reflected by a detector;
The echo signal is stored as a delayed signal by delaying the echo signal by a predetermined period of time and an intersection of the echo signal and the delayed signal is calculated and the signal intensity of the calculated maximum value intersection is set to a first condition And a second condition that the slope of the signal intensity variation amount according to the time variation amount from the predetermined preceding reference point to the calculated maximum value intersection point is equal to or greater than a preset slope A signal processing unit for filtering the corresponding signal to calculate and output a correction signal;
A first buffer for storing the echo signal;
A second buffer in which the delay signal is stored; And
And a temporary storage unit for storing the calculated correction signal by filtering all signals corresponding to the first and second conditions.

Images