KR101752651B1 - Clutter elimination and multi target trace method of radar system - Google Patents

Abstract

(A) transmitting a radar signal to a periphery of a transmitting and receiving unit of a radar system and receiving a signal reflected from the target, (b) (C) removing the clutter information from the radar detection information; (d) comparing the target tracking prediction information using the radar detection information from which the clutter information is removed and the actual tracking information And (e) updating the tracking history by using all tracking information matched and unmatched as a result of the checking in the step (d), so that the multi-target detection information is used The same target is tracked, the target false alarm rate is reduced through non-detection target estimation, and the target detection rate and measurement information Accuracy can be improved to.

Description

[0001] CLUTTER ELIMINATION AND MULTI TARGET TRACE METHOD OF RADAR SYSTEM [0002]

The present invention relates to a radar system, and more particularly, to a radar system for removing clutter using multiple target detection information, tracking the same target, removing a clutter of a radar system estimating a non- Tracking method.

A radar sensor is a sensing means for measuring the distance, velocity, and angle information by transmitting a radio wave using a microwave and receiving a reflection signal reflected from the target.

The radar sensor may be a pulse radar, a frequency modulated continuous wave (FMCW), a stepped-frequency continuous wave (SFCW) And a frequency shift keying (FSK) radar. The radar waveform is used to measure target information.

The applicant of the present invention has disclosed a radar sensor technology to many of the following Patent Documents 1 and 2 and has been patented and registered.

Patent Document 1 discloses a radio communication system including a transmission / reception unit that transmits a radar signal to a periphery and a signal reflected from a target during traveling, a control unit that determines whether a collision with a target occurs based on radar detection information of a signal received through the transmission / reception unit, And a warning section for generating a collision risk warning before the occurrence of the collision, wherein the radar detection information includes a configuration including a distance from the target, a velocity of the target, and angle information, detects a target around the target using the radar detection information , A collision warning and an accident recording method of a radar terminal that warns a collision risk according to a distance from a detected target, a speed and angle information of a target, and the like.

In Patent Document 2, a radar signal is transmitted to the surroundings during traveling, a signal reflected from the target is received, radar detection information is generated by using the received detection signal, a near interference signal included in the detection signal is removed, By extracting the spectrum and generating the radar detection information including the distance from the target, the velocity of the target, and the angle information, the digital signal processing method resolves the shadow area of the near-field radar to detect the detection probability and target of the near- A method of removing a near-shaded area of a radar device is disclosed.

On the other hand, a target detected in a radar system for a vehicle is detected not only as an actual target vehicle but also as unwanted clutter information such as a guard rail or a telephone pole.

In addition, a target may not be detected due to destructive interference caused by a multipath reflection signal such as a change in the radar cross section (RCS) of a target such as a relative vehicle or a signal reflected from the road surface.

For example, Patent Documents 3 to 5 below disclose a technique for removing a clutter in a radar system for a vehicle according to the prior art.

Patent Document 3 discloses a configuration of a lateral boundary recognition method of a running road that recognizes a boundary using a road database. Patent Document 4 discloses a guardrail recognition method of judging a clutter in size and shape through collection, And Patent Document 5 discloses a configuration for preventing the detection of a target from being missed by adding an array component in the vertical direction of the antenna element.

Korean Patent Registration No. 10-1513878 (issued on April 22, 2015) Korean Patent Registration No. 10-1505044 (issued on March 24, 2015) Korean Patent Registration No. 10-1500168 (Announcement on Mar. 6, 2015) Korean Patent Registration No. 10-1394574 (issued on May 27, 2014) Korean Patent Publication No. 10-2013-0021996 (published on Mar. 6, 2013)

However, the clutter removal method applied to the vehicle radar system according to the related art detects and removes the guard rail or the road side by using the external data or the cluster characteristics of the measurement data, Not only accuracy is required but also it is difficult to apply to various complex environments that change in real time

Also, the clutter removing method applied to the conventional radar system has a problem that the gazing direction of the radar is limited to the forward direction.

In addition, in the conventional radar system for a vehicle, a method of solving a target non-detection problem by detecting a target by adding a receiving channel is applied, but the size of the hardware due to the antenna addition increases, There has been a problem of increasing.

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to eliminate clutter using multi-target detection information, to eliminate the clutter of a radar system capable of tracking the same target, Target tracking method.

It is another object of the present invention to provide a method and a method for tracking multiple targets in a radar system that can reduce the target false alarm rate due to clutter and undetected targets and improve the accuracy of measurement information.

In order to achieve the above object, a clutter removal method and a multi-target tracking method of a radar system according to the present invention are characterized in that (a) a radar system transmits a radar signal to a periphery of a transmission / reception unit of a radar system, (B) generating radar detection information using the radar signal received at the control unit, (c) removing clutter information from the radar detection information, (d) Checking whether the target tracking prediction information using the detection information matches the actual detection information, and (e) updating the tracking history by using all tracking information matched and unmatched as a result of the inspection in the step (d) .

As described above, according to the clutter removal and multi-target tracking method of the radar system according to the present invention, the clutter is removed using the multi-target detection information, the same target is tracked, and the target false alarm It is possible to reduce the rate and improve the accuracy of the target detection rate and the measurement information.

That is, according to the present invention, it is possible to reduce the false alarm rate by removing the clutter, to estimate the undetected target, and to improve the accuracy of the target information by performing the integration and classification of the matching target using the past tracking information Is obtained.

Further, according to the present invention, it is possible to apply not only to a radar system for a vehicle but also to all radar systems for tracking radar detection targets such as a fixed system, a naval system, and an aircraft radar system.

1 is a configuration diagram of a radar system for a vehicle,
FIG. 2 is a flowchart for explaining steps of removing a clutter and tracking a multi-target in a radar system for a vehicle according to a preferred embodiment of the present invention.
3 is a view showing a radar Iso-Range, a Doppler,
4 is a diagram for explaining a method for estimating information of an undetected target,
5 is a diagram for explaining a tracking history update method;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a vehicle radar system according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the present embodiment, a vehicle radar system having a vehicle collision prevention and an accident recording function will be described.

However, it should be noted that the present invention can be applied to a radar system for short range detection and detection, which is used for various purposes such as an ITS traffic measurement radar, a radar level meter, a near displacement measurement radar, do.

First, before describing a clutter removal and a multi-target tracking method of a radar system according to a preferred embodiment of the present invention, the configuration of a radar system for a vehicle will be described with reference to FIG.

1 is a configuration diagram of a radar system for a vehicle.

As shown in Fig. 1, a radar system for a vehicle includes a transmission / reception unit 10 that transmits a radar signal around a vehicle and receives signals reflected from a target, and a radar system 10 that is based on radar detection information of signals received through the transmission / reception unit 10 And a control unit 20 for determining whether a collision between the vehicle and the other vehicle occurs.

In addition, the vehicle radar system includes a warning unit 30 for generating a collision risk warning before a collision occurs, and a storage unit 40 for storing tracking information generated by accumulating radar detection information and radar detection information when a collision occurs .

The transmission and reception unit 10 is provided with a transmission antenna 11 for transmitting a radar signal in a predetermined direction and a reception antenna 12 for receiving a signal reflected from the target, A first signal converter 13 for converting a signal into a radio frequency (RF) signal, a power amplifier 14 for amplifying the power of the RF signal, a low noise amplifier 14 for amplifying the signal received at the receiving antenna 12 and attenuating the noise, And a second signal converter 16 for converting the RF signal output from the low noise amplifier 15 and the low noise amplifier 15 into the LF signal form and outputting a beat frequency signal.

The control unit 20 includes a signal generation unit 21 for generating a continuous wave type radar signal such as FMCW, SFCW, FSK, etc., a signal for processing the signal received by the transmission / reception unit 10 so as to generate radar detection information A controller 23 for generating radar detection information by using the output signals of the processing section 22 and the signal processing section 22 and an analog signal output from the second signal converter 16 of the transmission / And an A / D converter 24 for converting the A /

The controller 23 can generate radar detection information using the output signal of the signal processing unit 22 and accumulate the generated radar detection information to generate tracking information.

The tracking information includes position information (x, y) with the target, velocity information (x, y) of the target, acceleration information (x, y) x, y) and travel direction information.

Next, referring to FIG. 2, a clutter removal and a multi-target tracking method of a vehicular radar system according to a preferred embodiment of the present invention will be described in detail.

FIG. 2 is a flowchart illustrating steps of removing a clutter and tracking a multi-target in a radar system for a vehicle according to a preferred embodiment of the present invention.

2, the transmission / reception unit 10 of the vehicle radar system transmits a radar signal to the vicinity of the vehicle and receives a signal reflected from the target. The control unit 20 processes the received signal to detect radar detection information do.

In step S12, the control unit 20 removes the clutter information from the detected radar detection information.

The clutter information is detected information that is unnecessary for determining whether or not the vehicle collides with the vehicle radar system such as a fixed target such as a guard rail and a vehicle opposite to the target.

3 shows a radar Iso-Range, Doppler.

As shown in FIG. 3, the radar Iso-Range is displayed in a circular shape connecting points having the same distance from the radar system, and the Iso-Doppler can be displayed in a cosine curve shape around the radar system.

Due to this radar Iso-Doppler characteristic, the velocity information of the detected target changes with the relative speed and angle of the radar and the target.

Therefore, in this embodiment, the control unit 20 can estimate the relative speed by compensating the detected speed information by the radar detection information using the detected angle information and the installation angle of the radar using the radar Iso-Doppler characteristic.

That is, in the case of a fixed target, since the relative speed of the fixed target is -Vt when the vehicle speed is Vt, the fixed clutter such as the guard rail can be removed.

Here, the detection speed Vm and the relative speed Vt of the target can be expressed by Equation (1).

In summary, the relative velocity (Vt) of the target can be summarized as shown in Equation (2).

In addition, the control unit 20 can remove the detection information classified as the clutter using the compensated relative speed information according to the operation mode such as the vehicle opposite the center lane, the vehicle having the large relative speed difference, and the like.

In step S14, the controller 20 checks whether the target tracking prediction information using the radar detection information matches the actual detection information.

Here, the controller 20 can determine whether the target is matched using the distance between the n-th detected information and the actual n-th detected information estimated using the (n-1) th tracking information and the speed information.

If the target tracking prediction information matches the actual detection information at step S14, the control unit 20 uses a tracking filter such as an? -Filter,? -? - filter, or Kalman filter at step S16 And updates the tracking information (S16).

Here, when a plurality of pieces of detection information are matched to one piece of track information as a plurality of reflection signals are received on the same target, the control unit 20 allocates them to a new ID and separates them, or information on the closest distance as target information It can be judged.

When a plurality of pieces of target tracking prediction information are matched with one piece of actual detection information, the control unit 20 can apply the actually detected information to all matching target tracking tracking information as inputs.

On the other hand, if it is determined in step S14 that the target tracking prediction information and the detection result are unmatching, the control unit 20 determines that the target is not detected, and uses the target tracking history to detect information of the target, The angle and velocity can be estimated.

Subsequently, the control unit 20 proceeds to step S22.

Fig. 4 is a diagram for explaining a method of estimating information of a non-detection target.

In step S18, as shown in FIG. 4, the control unit 20 calculates the position of the n-th target using the tracking history for the prediction information that is not matched with the n-th actual detection information among the prediction information using the n- , Velocity and acceleration information.

Here, the current position information of the estimated target is calculated by averaging the speed and acceleration using the tracking information within the distribution range of 1sigma, 2sigma, 3sigma, etc. among the M pieces of the past tracking information, Information can be estimated.

In step S20, the controller 20 allocates a new ID to the detection result that does not match the (n-1) th target tracking prediction information among the nth actual detection information, and stores detection information.

In step S22, the control unit 20 determines whether or not the same tracking target is used for all tracking information using the tracking history, and performs clustering if the target is the same as the determination result (S24).

As described above, the present invention minimizes the number of tracking information to be calculated by determining whether all the tracking information is the same target and clustering it.

On the other hand, if it is determined in step S22 that the target is not the same target, the control unit 20 separates the tracking information, which is not the same target, into a new target (S26).

In the tracking history, the tracking information of the detected target, which is judged to be the same target and given an ID, may be stored in a periodical time basis.

The tracking information includes not only the distance to the target, the speed and angle of the target but also the X-direction distance, Y-direction distance, X-direction speed, Y-direction speed, X-direction acceleration and Y- .

In step S28, the control unit 20 updates the n-th tracking information in the tracking history.

5 is a diagram for explaining a tracking history update method.

That is, the control unit 20 may update the additional history by adding the n-th tracking information to the first column of the tracking history at the i-th time n, and may provide the updated information at step S18.

Subsequently, in step S30, the controller 20 predicts the position of the target using the tracking result, and repeats step S14.

Through the process as described above, the present invention can eliminate the clutter using the multi-target detection information, track the same target, reduce the target false alarm rate through the non-target detection, detect the target detection rate and the accuracy Can be improved.

Although the invention made by the present inventors has been described concretely with the above embodiments, the present invention is not limited to the above embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

Although the present invention has been described using the vehicle radar system having the vehicle collision prevention and accident recording function in the above embodiment, the present invention is not limited to this, but the present invention can be applied to an ITS traffic measurement radar, a radar level meter, It should be noted that the present invention can be applied to a radar system for short range detection and detection, which is used for various purposes such as control radar, naval and aircraft radar systems.

The present invention is applied to a radar system technology that removes clutter using multiple target detection information, tracks the same target, reduces target false alarm rate through non-target detection, and improves target detection rate and accuracy of measurement information do.

10: transmitting / receiving unit 11: transmitting antenna
12: receiving antenna 13: first signal converter
14: power amplifier 15: low noise amplifier
16: second signal converter 20:
21: Signal generator 22: Signal processor
23: controller 24: AD converter
25: storage unit 26: filter unit
27: comparison unit 28: alarm generating unit
30: warning section 40: storage section

Claims (8)

CLAIMS 1. A method of tracking and tracking multiple targets in a radar system for transmitting radar signals around and tracking targets by receiving signals reflected from the target,
(a) transmitting a radar signal to the surroundings at a transmitting and receiving portion of the radar system and receiving a signal reflected from the target,
(b) generating radar detection information using the radar signal received by the control unit,
(c) removing clutter information from the radar detection information,
(d) checking whether the target tracking prediction information using the radar detection information from which the clutter information is removed matches the actual detection information; and
(e) updating the tracking history using all tracking information matched and unmatched as a result of the checking in the step (d)
In the step (b), the control unit estimates the relative speed by compensating the speed information detected by the radar detection information with the angle information of the target and the installation angle of the radar using the radar Iso-Doppler characteristic, To remove the clutter information,
In step (d), if the target tracking prediction information matches the actual detection information, the controller updates actual detection information to tracking information using a tracking filter. If the target tracking prediction information and the detection result are unmatching, And estimating information of a target including the distance from the target, the angle of the target, and the velocity using the target tracking history. delete delete delete 2. The method of claim 1, wherein step (d)
(d1) estimating the position, velocity and acceleration information of the n-th target using the tracking history for the n-th actual detection information and the unmatching prediction information among the prediction information using the (n-1)
(d2) allocating a new ID to a detection result unmapped with the (n-1) th target tracking prediction information among nth actual detection information, and storing detection information. Multiple target tracking method. 6. The method of claim 5,
The current position information of the target estimated in the step (d1) is calculated by averaging the velocity and the acceleration using the tracking information within the distribution range among the M pieces of the past tracking information, and then the velocity information calculated from the (n-1) Wherein the clutter removal and multi-target tracking method of the radar system is estimated using the method. 2. The method of claim 1, wherein step (e)
(e1) judging whether or not the same tracking target is used for all tracking information by using a tracking history, and performing clustering if the same target is determined,
(e2) separating each tracking information into tracking information for a new target, when the target is different from the determination result in the step (e1)
(e3) updating new tracking information in the tracking history and
(e4) estimating the location of the target using the updated tracking history. < Desc / Clms Page number 19 > 8. The method according to any one of claims 1 and 5 to 7,
In the tracking history, the tracking information of the detected target, which is determined to be the same target and given an ID, is stored periodically.
The tracking information includes all of the distance to the target, the velocity and angle of the target, the X-direction distance, the Y-direction distance, the X-direction speed, the Y-direction speed, the X-direction acceleration and the Y- A clutter removal and multiple target tracking method in a radar system.

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