WO2016089175A1

WO2016089175A1 - Radar system and target detection method for detecting target located together with clutter

Info

Publication number: WO2016089175A1
Application number: PCT/KR2015/013258
Authority: WO
Inventors: 남상욱; 김병준
Original assignee: 서울대학교산학협력단
Priority date: 2014-12-05
Filing date: 2015-12-04
Publication date: 2016-06-09

Abstract

Disclosed is a radar system antenna comprising: a chirp signal generator for generating a chirp signal; a transmission unit for transmitting the chirp signal toward a target or an obstacle; a reception unit for receiving a reflected signal of the chirp signal which is transmitted from the transmitting unit, reflected and returned from the target or the obstacle; a mixer for outputting a mixing signal corresponding to a frequency difference between the chirp signal generated in the chirp signal generator and the reflected signal; one or more filters, having band-pass characteristics or band-stop characteristics, for filtering the mixing signal; and a filter control unit for controlling the pass frequency band or the stop frequency band of the filter according to the position of the target or the obstacle. According to the present invention, it is possible to effectively attenuate a clutter signal and effectively detect a target, even if the position of the target or obstacle changes.

Description

Radar system and target detection method for detecting targets with clutter

The present invention relates to a radar system and a target detection method. More specifically, according to the position of the target or obstacle, the radar system for adjusting the pass frequency band or the stop frequency band of the filter, adjust the delay time of the chirp signal, or adjust the rise / fall time or period of the chirp signal; It relates to a target detection method.

Radar is a system that uses a reflected wave that sends a specific type of radio wave to detect an object and then returns to the target. Therefore, in order to detect a specific target, it is necessary to receive and restore the reflected wave by the target. In the case of an object hidden in the clutter or an object placed under a complicated environment, the receiver may be caused by the reflected wave caused by an object other than the target to be detected. Inoperable or poor reception sensitivity, unintended distortion of the received signal may occur. One radar structure to overcome this is the FMCW radar structure. Unlike the PULSE radar, the FMCW radar structure has a low peak power per hour even though the output power per frequency is the same, making the transmitter easy to configure, and the reflected wave is small in size, causing the receiver to saturate or malfunction due to unwanted reflected waves. The phenomenon is alleviated. However, these FMCW radars typically amplify the signal from the target at baseband and process it by digitizing it, in which case the signal caused by the obstruction increases, thus using an ADC that is not affected by the large signal caused by this obstruction. The signal caused by the obstacle must be processed by software or visually distinguished.

In addition, in the case of the existing technology, the FMCW radar structure is used to alleviate the saturation of the receiver due to the large reflected wave caused by obstacles, thereby reducing the constraints in obtaining a high resolution image or in hardware configuration. . However, the existing FMCW radar also has limitations in hardware configuration and can only be used in limited situations. If the reflected wave of the clutter is large and the distance between the clutter and the target is close, a higher order filter is required at the intermediate frequency or baseband to distinguish it well. This higher order filter not only increases the construction cost but also results in signal loss by the target. In addition, the existing structure may not be able to remove when the distance between the clutter and the radar changes. For example, FIG. 1 shows Through-Dielectric Radar Imaging System ”, IEEE Trans. Ant. Prop., Vol. 58, no. 8, Aug. As a diagram disclosed in 2010, a diagram illustrating an example of an FMCW radar structure may include the above-mentioned problems in the FMCW radar structure illustrated in FIG. 1.

Therefore, the present inventors can detect a target with the clutter even when the distance between the clutter and the radar changes, and the radar for detecting the target when the clutter has a large reflected wave and the distance between the clutter and the target is close. I would like to propose a system.

The object of the present invention is to solve all the above-mentioned problems.

Another object of the present invention is to effectively attenuate the clutter signal when the target and the position of the obstacle are close.

Another object of the present invention is another object to effectively detect the target when the target and the position of the obstacle is close.

Another object of the present invention is to effectively attenuate the clutter signal even if the position of the target or obstacle is changed.

Another object of the present invention is another object to effectively detect a target even if the position of the target or obstacle is changed.

Representative configuration of the present invention for achieving the above object is as follows.

According to an aspect of the present invention, a chirp signal generator for generating a chirp signal; A transmitter for transmitting the chirp signal to a target or obstacle; A receiver which receives a reflected signal from which the chirp signal transmitted from the transmitter is reflected by the target or obstacle; A mixer for outputting a mixing signal corresponding to a frequency difference between the chirp signal generated by the chirp signal generator and the reflected signal; At least one filter having a bandpass characteristic or a bandstop characteristic and filtering the mixed signal; And a filter controller for adjusting a pass frequency band or a stop frequency band of the filter according to the position of the target or obstacle.

According to another aspect of the present invention, a chirp signal generator for generating a chirp signal; A mixing delay unit delaying the chirp signal and outputting the delayed signal; A transmission delay unit delaying the chirp signal and outputting it; A transmitter for transmitting an output signal of the transmission delay unit toward a target or an obstacle; A receiver which receives a reflected signal from which the signal transmitted from the transmitter is reflected by the target or obstacle; A mixer configured to output a mixing signal corresponding to a frequency difference between the output signal of the mixing delay unit and the reflection signal; And at least one filter having a bandpass characteristic or a bandstop characteristic and filtering the mixed signal.

According to another aspect of the invention, a chirp signal generator for generating a chirp signal; A transmitter for transmitting the chirp signal to a target or obstacle; A receiver which receives a reflected signal from which the chirp signal transmitted from the transmitter is reflected by the target or obstacle; A mixer for outputting a mixing signal corresponding to a frequency difference between the chirp signal generated by the chirp signal generator and the reflected signal; At least one filter having a bandpass characteristic or a bandstop characteristic and filtering the mixed signal; And a chirp signal controller that adjusts a rise time, a fall time, or a period of the chirp signal according to the position of the target or obstacle.

According to the present invention, even if the position of the target or obstacle is changed, the clutter signal can be effectively attenuated and the target can be effectively detected.

In addition, even when the distance between the clutter and the target is close, when the present invention is applied, the clutter signal can be effectively attenuated only by the low stage filter and the target can be effectively detected.

1 is a diagram illustrating an example of an FMCW radar structure.

2 is a view showing a radar system according to a first embodiment of the present invention.

3A is a diagram showing waveforms of a chirp signal, a reflection signal for a target, and a reflection signal for an obstacle.

3B is a diagram illustrating a mixing signal for a target and a mixing signal for an obstacle.

4 is a view for explaining the operation of the filter of FIG.

5A and 5B are exemplary circuit diagrams of the filter of FIG. 2.

6 is a view showing a radar system according to a second embodiment of the present invention.

FIG. 7 is a diagram for describing an operation of the radar system of FIG. 6.

8 is a view showing a radar system according to a third embodiment of the present invention.

9 is a view for explaining the operation of the radar system of FIG.

DETAILED DESCRIPTION The following detailed description of the invention refers to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different but need not be mutually exclusive. For example, certain shapes, structures, and characteristics described herein may be embodied in other embodiments without departing from the spirit and scope of the invention with respect to one embodiment. In addition, it is to be understood that the location or arrangement of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention, if properly described, is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled. Like reference numerals in the drawings refer to the same or similar functions throughout the several aspects.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention.

2, the radar system 200 according to the first embodiment of the present invention includes a chirp signal generator 210, a transmitter 230, a receiver 240, a mixer 250, a filter 270, and a filter. The control unit 280 is provided.

The chirp signal generator 210 generates a chirp signal. The transmitter 230 transmits a concubine signal toward a target or obstacle. The receiver 240 receives the reflected signal from which the chirp signal transmitted from the transmitter is reflected by the target or obstacle. The mixer 250 receives a chirp signal generated by the chirp signal generator 210 and a reflected signal received by the receiver 240, and outputs a mixing signal corresponding to a frequency difference between the chirp signal and the reflected signal. The filter 270 filters the mixed signal and may have a bandpass characteristic or a bandstop characteristic. The filter 270 may be one or more. The filter controller 280 adjusts the pass frequency band or the stop frequency band of the filter 270 according to the position of the target or obstacle.

In FIG. 3A, A is a chirp signal, B is a reflection signal for a target, and C1 and C2 each represent a reflection signal for an obstacle. In the present specification including FIG. 3A, the chirp signal is illustrated as having a triangular shape, but this is merely an example, and the shape of the chirp signal may be variously modified.

2 and 3A, the chirp signal A generated by the chirp signal generator 210 is transmitted toward a target or obstacle through the transmitter 230, and is reflected by the target or obstacle and returns through the receiver 240. Received signals B, C1, C2. In this process, the reflected signals B, C1, and C2 have constant time delays TB, TC1, and TC2 than the chirp signal A, respectively. In more detail, after the transmitter 230 transmits a specific type of chirp signal, when the receiver 240 receives a signal in which the chirp signal is reflected from the target or obstacle, the radar system 200 starts from the target or obstacle. The reflected signal is delayed by a time proportional to the distance. Since the traveling speed of the electromagnetic waves in the air is constant, a time delay appears in proportion to the distance from the radar system 200 to the target or obstacle. In FIG. 3A, the delay time TB of the reflected signal B to the target is longer than the delay time TC1 of the reflected signal C1 to the obstacle and shorter than the delay time TC2 of the reflected signal C2 to the obstacle. Therefore, the target is located between the obstacles.

In FIG. 3B, the mixing signal for the target is a signal obtained by mixing a reflection signal for the target with a chirp signal, and the mixing signal for an obstacle is a signal obtained by mixing a reflection signal for an obstacle with a chirp signal.

2 and 3B, when the mixer 250 mixes the reflected signal received from the receiver 240 with the chirp signal, a baseband (low frequency band or intermediate frequency band) signal is obtained. The mixing signal output from the mixer 250 corresponds to the frequency difference between the chirp signal and the reflected signal. In FIG. 3B the frequency difference FB between the reflected signal B and the chirp signal A for the target is greater than the frequency difference FC1 between the reflected signal C1 and the chirp signal for the obstacle and the reflected signal for the obstacle. It is smaller than the frequency difference FC2 between (C2) and the chirp signal. That is, the frequency FB of the mixing signal MB for the target is between the frequencies FC1, FC2 of the mixing signals MC1, MC2 for the obstacle.

4 is a view for explaining the operation of the filter of FIG.

Figure 4a shows before the frequency band of the filter is adjusted, Figure 4b shows after the frequency band of the filter is adjusted.

When the mixing signal MB for the target as shown in FIG. 3B and the mixing signals MC1 and MC2 for the obstacle are obtained, if the filter 270 has a pass frequency band as shown in FIG. 4A, the mixing signal MB for the target is shown. ) And the mixed signals MC1 and MC2 for the obstacles pass through the filter 270, so that the target and the obstacle cannot be distinguished. However, in the radar system 200 according to the first embodiment of the present invention, the filter control unit 280 reduces the pass frequency band of the filter 270 so that only the mixing signal MB for the target is passed and the mixing signal for the obstacle. (MC1, MC2) are removed.

Meanwhile, in FIG. 3B, the pass frequency band of the filter 270 is reduced, but this is merely an example, and the pass frequency band of the filter 270 may be variously adjusted according to the frequency of the mixed signal for the target and the obstacle. .

In addition, filter 270 may be a band pass filter or a band stop filter, and one or more band pass filters or one or more band stop filters may be used together. For example, if you want to observe only the area between 2M and 8M, you only need to pass the signal between the frequency f1 corresponding to 2M and the frequency f2 corresponding to 8M. In this case, the pass band of the band pass filter may be set to f1 to f2. In addition, when there is a large obstacle in 4M and wants to remove and observe the obstacle, if the frequency corresponding to 4M is f3, the frequency corresponding to f3 can be removed by setting the band stop frequency to f3.

When using a combination of filters, for example, if you want to detect 2M to 8M objects, but there is an obstacle at a distance of 4M, using a band pass filter, the signal from a distance of 0M or more, 8M or more The signal caused by the obstacle at 4M can be removed and observed using a band stop filter.

Another use example is to fix a signal after a certain distance with a fixed low-frequency bandpass filter if you want to observe an object within a certain distance, the position of the obstacle changes, and you do not want to observe the area before the position of the obstacle. Using a high-frequency bandpass filter that can remove all and adjust the frequency band, you can remove and observe the signal from the obstacle's previous distance, including the signal from the obstacle. For example, if you have a wall in front of 2M and you want to observe a target behind the wall, but want to see objects within 10M of that space, use a high-frequency bandpass filter to remove the signal before 2M and then apply a low-frequency bandpass filter. Remove the signal after 10M. If the radar installation position or the wall position is changed to 1M forward, the frequency passband of the high passband filter can be adjusted to remove the signal before 1M.

If there is no change in the position of the obstacle, since the frequency is detected on the radar according to the position of the obstacle, the filter 270 may be set and used accordingly. For example, if the obstacle is located 1M ahead of the radar position, the target is at 2M, and the maximum distance to be observed is 10M, the high pass filter will set the cut-off frequency to 1M. Above the frequency generated if present, the low pass filter may set the cut-off frequency below the frequency generated when the target is at 10M.

Watch for changes in the position of obstacles. If the obstacle and the target are recognized in advance, the frequency band of the filter 270 is set to attenuate the frequency corresponding to the obstacle. Then, if the position of the obstacle is changed, the filter 270 may be operated in the same manner as described above. Adjust the frequency band to attenuate clutter signals. If the obstacle and the target is not distinguished, all signals are measured and recorded without passing through the filter 270, and then the filter 270 is set to filter the largest signal and the overall signal is measured. For example, if there is an obstacle with a large reflection at a distance of 1M and a target at a distance of 3M, the signal is measured once, and then the larger of the two signals is removed through the filter setting, and the signal is measured again. If the target signal is large, the target can be detected and reconstructed sufficiently in the first measurement result. On the contrary, if the obstacle signal is large, the target can be detected and reconstructed sufficiently in the second measurement result.

When there is a change in the position of the target, the frequency is detected according to the movement of the target, and when the frequency is about to go out of the pass band of the filter 270 initially set, the filter setting is changed to change the pass band. Zoom in to keep track of the target.

As such, the radar system 200 according to the first exemplary embodiment of the present invention adjusts the pass frequency band or the stop frequency band of the filter 270 according to the position of the target or obstacle, thereby passing only the mixing signal for the target and preventing the obstacle. The mixing signal for may be eliminated.

5A and 5B are exemplary circuit diagrams of the filter of FIG. 2.

5A is an exemplary circuit diagram of a high pass filter. By changing the Gm value in FIG. 5A, the band pass frequency may be changed. 5B is an exemplary circuit diagram of a band reject filter. 5b is configured in FIR form.

Referring to FIG. 6, the radar system 600 according to the second embodiment of the present invention includes a chirp signal generator 610, a transmitter 630, a receiver 640, a mixer 650, a filter 670, and a transmission delay. A unit 690, a reception delay unit 692, and a mixing delay unit 695 are provided.

The chirp signal generator 610 generates a chirp signal. The transmission delay unit 690 delays the chirp signal and outputs it. The transmitter 630 transmits the output signal of the transmission delay unit 690 toward the target or obstacle. The receiver 640 receives the reflected signal from which the signal transmitted from the transmitter 630 is reflected by the target or obstacle. The reception delay unit 692 delays and outputs the reflected signal. The mixing delay unit 694 delays and outputs the chirp signal. The mixer 650 receives the output signal of the mixing delay unit 694 and the output signal of the reception delay unit 692, and outputs a mixing signal corresponding to the frequency difference between the two signals. The filter 670 filters the mixed signal and may have a bandpass characteristic or a bandstop characteristic. The filter 670 may be one or more.

FIG. 7 is a diagram for describing an operation of the radar system of FIG. 6.

7A shows before adjusting the delay time, and FIG. 7B shows after adjusting the delay time.

When the mixed signal for the target and the obstacle as shown in FIG. 3B is obtained, the mixed signals MB, MC1, and MC2 for the target and the obstacle pass through the filter 670, as shown in FIG. 7A, to distinguish the target from the obstacle. It becomes impossible.

On the other hand, in the radar system 600 according to the second embodiment of the present invention, a time delay by the mixing delay unit 694 occurs, and a time delay by the transmission delay unit 690 and the reception delay unit 692. This happens. When the time delay of the mixing delay unit 694 is greater than the time delays of the transmission delay unit 690 and the reception delay unit 692, the output signal of the mixing delay unit 694 and the output signal of the reception delay unit 692 are determined. The frequency difference becomes small, and thus the mixing signal output from the mixer 650 has a low frequency. By lowering and then filtering the frequency of the mixing signal as described above, as shown in FIG. 7B, only the mixing signal NMB for the target may be passed and the mixing signal NMC1 for the obstacle may be removed. On the other hand, when the time delay of the mixing delay unit 694 is smaller than the time delay of the reception delay unit 692, the frequency difference between the output signal of the mixing delay unit 694 and the output signal of the reception delay unit 692 becomes large. Accordingly, the mixed signal output from the mixer 650 has a high frequency. In this way, by increasing the frequency of the mixed signal and then filtering, only the mixed signal for the target may be passed and the mixed signal for the obstacle may be removed.

On the other hand, by adjusting the delay time it is possible to reduce the burden on the filter when filtering by changing the frequency of the mixed signal to a lower frequency. For example, if the signal caused by the obstacle is 2 MHz and the signal caused by the target is 3 MHz, the delay time is all lowered by 1.9 MHz, so that the signal caused by the obstacle is 100 kHz and the signal caused by the target is 1.1 MHz. By increasing the frequency ratio of the two signals, the low stage filter can be used without using a higher order filter. That is, in the above case, by adjusting the delay time, the frequency of the mixed signal caused by the obstacle and the frequency of the mixed signal caused by the target are both lowered by 1.9 MHz (2 MHz-100 kHz, 3 MHz-1.1 MHz), thereby reducing the mixing signal caused by the obstacle. Since the frequency ratio of the mixed signal by the target can be made large from 1: 1.5 (2 MHz: 3 MHz) to 1: 11 (100 kHz: 1.1 MHz), even when the distance between the obstacle and the target is close, the low stage filter without the higher-order filter can be used. It can be distinguished well, thus effectively attenuating clutter signals and effectively detecting targets. In addition, by using the low stage filter in this way, not only the filter construction cost but also the signal loss can be reduced.

The radar system 600 according to the second embodiment of the present invention, according to the position of the target or obstacle, the delay time of the mixing delay unit 694, the delay time of the transmission delay unit 690 or the reception delay unit 692 You can adjust the delay time. If the location of the target or obstacle moves away from the radar system 600, the frequency of the mixed signal is increased. To counteract this, the delay time of the mixing delay unit 694 may be increased, or the delay time of the transmission delay unit 690 or the delay time of the reception delay unit 692 may be reduced. In this case, the frequency of the mixing signal can be lowered, and the rise of the frequency of the mixing signal can be canceled as the position of the target or obstacle becomes farther away. Therefore, even if the frequency pass band of the filter 670 is fixed, the signal caused by the obstacle can be eliminated. On the other hand, when the position of the obstacle changes and approaches, the delay time of the mixing delay unit 694 is reduced, or the delay time of the transmission delay unit 690 or the delay time of the reception delay unit 692 is increased, thereby increasing the target or the like. The fall of the frequency of the mixing signal may be canceled as the position of the obstacle approaches.

The transmitter 630 may include a transmitter 632 and a transmission antenna 634. The transmission delay unit 690 may include a first transmission delayer 690_1 and a second transmission delayer 690_2. The first transmission delayer 690_1 delays and outputs the chirp signal, the transmitter 632 is connected to the output terminal of the first transmission delayer 690_1, and the second transmission delayer 690_2 is the transmitter 632. The transmit antenna 634 may be connected to the output terminal of the second transmission delay unit 690_2. The receiver 640 may include a receiver 642 and a reception antenna 644. The reception delay unit 692 may include a first reception delay unit 692_1 and a second reception delay unit 692_2. The receiving antenna 644 receives the reflected signal by the target or obstacle, the first reception delay unit 692_1 is connected to the output terminal of the reception antenna 644, and the receiver 642 is the first reception delay unit 692_1. ), And the second reception delay unit 692_2 may be connected to the output terminal of the receiver 642.

The frequency of the mixed signal is increased by increasing the sum of the delay times of the first transmission delay unit 690_1, the second transmission delay unit 690_2, the first reception delay unit 692_1, and the second reception delay unit 692_2. And reduce the sum of delay times of the first transmission delay unit 690_1, the second transmission delay unit 690_2, the first reception delay unit 692_1, and the second reception delay unit 692_2. You can lower the frequency.

Meanwhile, the radar system 600 according to the second embodiment of the present invention includes a first transmission delayer 690_1, a second transmission delayer 690_2, a first reception delayer 692_1, and a second reception delay. It may not have a portion of the group 692_2. Only one of the delayers 690_1, 690_2, 692_1, and 692_2 may be used, or two may be used if it is difficult to implement a sufficient time delay. Also, if a larger time delay is required, three or four can be used to create a sufficient time delay. If there is no space constraint or implementation constraint, the delay time may be generated and controlled only in the first transmission delay unit 690_1 in view of power efficiency of the system.

Referring to FIG. 8, the radar system 800 according to the third embodiment of the present invention includes a chirp signal generator 810, a chirp signal controller 815, a transmitter 830, a receiver 840, a mixer 850, And a filter 870.

The chirp signal generator 810 generates a chirp signal. The chirp signal controller 815 adjusts the rise time, fall time, or period of the chirp signal according to the position of the target or obstacle. The transmitter 830 transmits a concubine signal toward a target or obstacle. The receiver 840 receives a reflection signal in which a chirp signal transmitted from a transmitter is reflected by a target or obstacle. The mixer 850 receives the chirp signal generated by the chirp signal generator 810 and the reflected signal received by the receiver 840, and outputs a mixing signal corresponding to a frequency difference between the chirp signal and the reflected signal. The filter 870 filters the mixed signal and may have a bandpass characteristic or a bandstop characteristic. The filter 870 may be one or more.

9 is a view for explaining the operation of the radar system of FIG.

FIG. 9A shows before adjusting the rise / fall time or period of the chirp signal, and FIG. 9B shows after adjusting the rise / fall time or period of the chirp signal.

When the mixed signal for the target and the obstacle as shown in FIG. 3B is obtained, the mixed signals MB, MC1, and MC2 for the target and the obstacle pass through the filter 870 as shown in FIG. 9A, so that the target and the obstacle can be distinguished. It becomes impossible.

On the other hand, the radar system 800 according to the third embodiment of the present invention can lengthen the rise time or fall time of the chirp signal (slowly rise or fall the chirp signal) or lengthen the period. As a result, the frequency of the mixing signal can be lowered as shown in FIG. 9B, so that the mixing signal NMB for the target can be passed and the mixing signal NMC1 for the obstacle can be eliminated. In FIG. 9B, the frequency of the mixed signal is illustrated as being lowered. This is merely an example, and it is also possible to increase the frequency of the mixed signal by shortening the rise time or the fall time of the chirp signal. That is, the mixing signal caused by the obstacle may be removed by increasing or decreasing the frequency of the mixing signal according to which section of the frequency band of the filter 970 is filtered.

The radar system 800 according to the third embodiment of the present invention may adjust the rise time, fall time, or period of the chirp signal according to the position of the target or obstacle. If the location of the target or obstacle is far from the radar system 800, the frequency of the mixed signal is increased. In order to offset this, the rise time or fall time of the chirp signal may be lengthened or the period may be lengthened. In this case, the frequency of the mixing signal can be lowered, and the rise of the frequency of the mixing signal can be canceled as the position of the target or obstacle becomes farther away. Therefore, even if the frequency pass band of the filter 870 is fixed, the signal caused by the obstacle can be eliminated. On the other hand, in the case where the position of the obstacle is changed and approaches, it is possible to cancel the fall of the frequency of the mixed signal as the position of the target or obstacle is closer by reducing the rise time or the fall time of the chirp signal or by shortening the period. For example, if the target is between 3 and 5 m, the frequency is between 3 and 5 MHz, and the target moves between 6 and 10 m, double the rise / fall time of the spy signal or double the period. By increasing, the target can be detected. If the target or obstacle moves a lot from the existing position and exceeds the detectable frequency range, if the obstacle and the frequency corresponding to the target are both increased, the rise / fall time or period of the chirp signal is reduced. On the contrary, if both the obstacle and the frequency corresponding to the target are reduced, the rise / fall time or period of the chirp signal is increased. If the observation is good afterwards, the observation can be continued, and if necessary, the rising / falling time or period of the chirp signal can be adjusted again.

The radar system according to another embodiment of the present invention may include the components of the

radar systems

200, 600, and 800 according to the first to third embodiments of the present invention described above. For example, the radar system according to another embodiment of the present invention is based on the radar system 200 according to the first embodiment of the present invention, and the radar system 600 according to the second embodiment of the present invention.

Additional delay units

690, 692, and 694 may be provided, or a chirp signal controller 815 of the radar system 800 according to the third embodiment of the present invention may be further provided. In addition, the radar system according to another embodiment of the present invention, based on the radar system 200 according to the first embodiment of the present invention, the delay of the radar system 600 according to the second embodiment of the present invention It may be provided with both the

parts

690, 692, 694 and the chirp signal controller 815 of the radar system 800 according to the third embodiment of the present invention. In addition, the radar system according to another embodiment of the present invention, based on the radar system 600 according to the second embodiment of the present invention, the chief of the radar system 800 according to the third embodiment of the present invention A signal controller 815 may be further provided.

The target detection method according to an embodiment of the present invention, the step of generating a concub signal, transmitting the concub signal to a target or obstacle, receiving the reflection signal reflected back to the target or obstacle Step, outputting a mixing signal corresponding to the frequency difference between the chirp signal and the reflected signal, detecting the position of the target or obstacle, and if the position of the target or obstacle is changed, passing frequency band or blocking Adjusting the frequency band to filter the mixed signal.

Target detection method according to another embodiment of the present invention, the step of generating a concubine signal, detecting the position of the target or obstacle, when the position of the target or obstacle is changed, according to the position change width of the target or obstacle Delaying and outputting the chirp signal, transmitting the chirp signal toward the target or obstacle, receiving a reflected signal from which the transmitted signal is reflected by the target or obstacle, and delaying the chirp signal Outputting a mixed signal corresponding to a frequency difference between the signal and the reflected signal, and filtering the mixed signal.

Target detection method according to another embodiment of the present invention, detecting the position of the target or obstacle, the step of generating, by adjusting the rise time, fall time, or period of the chirp signal according to the position of the target or obstacle, Transmitting the chirp signal toward a target or obstacle, receiving a reflection signal from which the chirp signal transmitted from the transmitter is reflected by the target or obstacle, between the chirp signal generated by the chirp signal generator and the reflected signal Outputting a mixed signal corresponding to the frequency difference of?, And filtering the mixed signal.

Although the present invention has been described by specific embodiments such as specific components and the like, but the embodiments and the drawings are provided to assist in a more general understanding of the present invention, the present invention is not limited to the above embodiments. For those skilled in the art, various modifications and variations can be made from these descriptions.

Accordingly, the spirit of the present invention should not be limited to the above-described embodiments, and all of the equivalents or equivalents of the claims, as well as the appended claims, fall within the scope of the spirit of the present invention. I will say.

Claims

A chirp signal generator for generating a chirp signal;

A transmitter for transmitting the chirp signal to a target or obstacle;

A receiver which receives a reflected signal from which the chirp signal transmitted from the transmitter is reflected by the target or obstacle;

A mixer for outputting a mixing signal corresponding to a frequency difference between the chirp signal and the reflected signal;

At least one filter having a bandpass characteristic or a bandstop characteristic and filtering the mixed signal; And

And a filter controller for adjusting a pass frequency band or a stop frequency band of the filter according to the position of the target or obstacle.
The method of claim 1,

And a chirp signal controller for adjusting a rise time, a fall time, or a period of the chirp signal according to the position of the target or obstacle.
The method of claim 1,

A mixing delay unit delaying the chirp signal and outputting the delayed signal; And

A transmission delay unit for delaying and outputting the chirp signal;

The transmitting unit,

Transmits an output signal of the transmission delay unit toward the target or obstacle,

The receiving unit,

A signal transmitted from the transmitter receives a reflected signal returned from the target or obstacle,

The mixer,

And a mixed signal corresponding to a frequency difference between the output signal of the mixing delay unit and the reflected signal.
The method of claim 3,

And a chirp signal controller for adjusting a rise time, a fall time, or a period of the chirp signal according to the position of the target or obstacle.
A chirp signal generator for generating a chirp signal;

A transmission delay unit delaying the chirp signal and outputting the delayed signal;

A transmitter for transmitting an output signal of the transmission delay unit toward a target or an obstacle;

A receiver which receives a reflected signal from which the signal transmitted from the transmitter is reflected by the target or obstacle;

A mixing delay unit delaying the chirp signal and outputting the delayed signal;

A mixer configured to output a mixing signal corresponding to a frequency difference between the output signal of the mixing delay unit and the reflection signal; And

And at least one filter having a bandpass characteristic or a bandstop characteristic and filtering the mixed signal.
The method of claim 5,

The transmission delay unit,

A first transmission delayer for delaying and outputting the chirp signal;

The transmitting unit,

A transmitter coupled to an output end of the first transmission delay unit; And

And a transmit antenna coupled to the output end of the transmitter.
The method of claim 6,

The transmission delay unit,

And a second transmission delayer coupled between the output end of the transmitter and the antenna.
The method of claim 5,

Further comprising a reception delay unit for delaying and outputting the reflected signal,

The mixer,

And a mixing signal corresponding to a frequency difference between an output signal of the mixing delay unit and an output signal of the reception delay unit.
The method of claim 8,

The receiving unit,

A receiving antenna for receiving the reflected signal; And

With a receiver,

The reception delay unit,

A first reception delay unit coupled between the reception antenna and an input terminal of the receiver; And

And a second receive delay connected between the output of the receiver and the mixer.
The method of claim 8,

And a delay time of the mixing delay unit, a delay time of the transmission delay unit, or a delay time of the reception delay unit according to the position of the target or obstacle.
A chirp signal generator for generating a chirp signal;

A transmitter for transmitting the chirp signal to a target or obstacle;

A receiver configured to receive a reflected signal from which the chirp signal is reflected by the target or obstacle;

A mixer for outputting a mixing signal corresponding to a frequency difference between the chirp signal and the reflected signal;

At least one filter having a bandpass characteristic or a bandstop characteristic and filtering the mixed signal; And

And a chirp signal controller for adjusting a rise time, a fall time, or a period of the chirp signal according to the position of the target or obstacle.
The method of claim 11,

A mixing delay unit delaying the chirp signal and outputting the delayed signal; And

A transmission delay unit for delaying and outputting the chirp signal;

The transmitting unit,

Transmits an output signal of the transmission delay unit toward a target or obstacle,

The receiving unit,

A signal transmitted from the transmitter receives a reflected signal returned from the target or obstacle,

The mixer,

And a mixed signal corresponding to a frequency difference between the output signal of the mixing delay unit and the reflected signal.
A chirp step of generating a chirp signal;

Transmitting the concubine signal towards a target or obstacle;

Receiving a reflected signal in which the chirp signal is reflected back to the target or obstacle;

Outputting a mixing signal corresponding to a frequency difference between the chirp signal and the reflected signal;

Detecting the location of the target or obstacle; And

And filtering the mixed signal by adjusting a pass frequency band or a stop frequency band when the position of the target or obstacle is changed.
A chirp step of generating a chirp signal;

Detecting the location of the target or obstacle;

If the position of the target or obstacle is changed, delaying and outputting the concubine signal according to the change in position of the target or obstacle;

Transmitting the concubine signal towards the target or obstacle;

Receiving a reflected signal in which the transmitted signal is reflected back to the target or obstacle;

Outputting a mixed signal corresponding to a frequency difference between the delayed signal and the reflected signal; And

And filtering the mixed signal.
Detecting the location of the target or obstacle;

Generating by adjusting the rise time, fall time, or period of the chirp signal according to the position of the target or obstacle;

Transmitting the concubine signal towards a target or obstacle;

Receiving a reflection signal in which a chirp signal transmitted from the transmitter is reflected by the target or obstacle;

Outputting a mixing signal corresponding to a frequency difference between the chirp signal generated by the chirp signal generator and the reflected signal; And

And filtering the mixed signal.