Apparatus and Method of radar for life signal detection of human trapped in subsurface

Abstract

The present invention relates to a radar device and method for detecting a buried person's life signal. The radar device according to the present invention comprises: a continuous wave generator that generates a continuous wave signal within a predetermined frequency range; a distributor that distributes the continuous wave signal into a first path and a second path; a power amplifier and a transmitting antenna that amplify the signal of the first path and radiate it underground; a hybrid coupler that separates the signal of the second path into a 0° phase signal and a 180° phase signal; a phase converter that generates a direct transmission wave removal signal by adjusting the phase of the 180° phase signal; a receiving antenna that receives a direct transmission wave transmitted directly from the transmitting antenna and a reflected signal reflected from a person in distress underground; a low-noise amplifier that amplifies the receiving signal received by the receiving antenna; a synthesizer that synthesizes the receiving signal amplified by the low-noise amplifier and the direct transmission wave removal signal generated by the phase converter to output a person in distress life signal from which the direct transmission wave has been removed from the receiving signal; and a gain ratio between the person in distress life signal output from the synthesizer and the 0° phase signal. It includes a gain / phase detector that detects the phase difference.

Description

Technology Field

[0001] The present invention relates to a radar device and method for detecting life signals of buried persons, and more specifically, to a continuous wave radar device and method that improves the detection sensitivity of weak life signals by effectively removing direct transmission waves. Background Technology

[0002] High-sensitivity acoustic devices are utilized to detect vital signs of individuals buried underground, and if space allows, endoscopic cameras can be inserted to visualize and identify the buried person. Alternatively, Ground Penetrating Radar (GPR), which sends electromagnetic waves underground to detect buried objects, is being used. Furthermore, technology utilizing Doppler radar to detect heartbeats or the movement of victims is being employed.

[0003] At collapse sites, it is difficult to detect buried victims through auditory means due to the simultaneous operation of numerous rescue activities. Furthermore, when victims are buried in soil or debris, there is no space to deploy endoscopic cameras, making their application impossible. Although Ground Penetrating Radar (GPR) is utilized as an alternative, victims are often mixed with debris, resulting in complex radar waveforms that cannot be identified solely through waveform analysis. Additionally, while Doppler radar utilizes frequency bands above 10 GHz to detect heartbeats or movement, its low penetration depth makes it ineffective for detecting vital signs of victims buried underground. Although frequency bands ranging from tens of MHz to below 1 GHz must be utilized, the frequency shift at which the Doppler effect occurs is too low to enable detection. The problem to be solved

[0004] The technical problem that the present invention aims to solve is to provide a radar device and method capable of effectively removing direct transmission waves generated in a continuous wave radar to improve the detection sensitivity of weak vital signals and effectively detecting victims buried at various depths.

[0005] In addition, another objective of the present invention is to secure a wide detection range from shallow to deep areas through frequency band-optimized detection and to provide a user interface capable of real-time monitoring. means of solving the problem

[0006] A radar device for detecting a life signal of a buried victim according to the present invention for solving the above-mentioned technical problem comprises: a continuous wave generator that generates a continuous wave signal within a predetermined frequency range; a distributor that distributes the continuous wave signal into a first path and a second path; a power amplifier and a transmitting antenna that amplify the signal of the first path and radiate it underground; a hybrid coupler that separates the signal of the second path into a 0° phase signal and a 180° phase signal; a phase converter that generates a direct transmission wave removal signal by adjusting the phase of the 180° phase signal; a receiving antenna that receives a direct transmission wave directly transmitted from the transmitting antenna and a reflected signal reflected from the victim underground; a low-noise amplifier that amplifies the received signal received by the receiving antenna; a synthesizer that synthesizes the received signal amplified by the low-noise amplifier and the direct transmission wave removal signal generated by the phase converter to output a victim life signal from which the direct transmission wave has been removed from the received signal; and the victim output from the synthesizer It includes a gain / phase detector that detects the gain ratio and phase difference between the life signal and the 0° phase signal.

[0007] The radar device may further include a signal amplifier that amplifies a rescuer life signal output from the synthesizer, and a control computer that sets the frequency of the continuous wave generator, controls the phase of the phase converter, and adjusts the gain of the low-noise amplifier and the signal amplifier.

[0008] The low-noise amplifier can amplify and output the received signal under the control of the control computer so that the amplitude of the direct transmission wave component included in the received signal matches the amplitude of the direct transmission wave removal signal output from the phase converter.

[0009] The control computer can quantize the value of the output signal of the gain / phase detector.

[0010] The control computer can fix the phase of the phase converter by finding the phase value at which the RMS value of the gain output of the gain / phase detector is minimized while changing the phase of the phase converter from 0° to 360° to cancel the direct transmission wave between the transmitting antenna and the receiving antenna in calibration mode, and fix the gain of the low-noise amplifier by adjusting the gain of the low-noise amplifier while the phase value is set to find the gain value at which the RMS value of the gain output of the gain / phase detector is minimized.

[0011] The above continuous wave generator can generate a continuous wave in at least one frequency band among a low frequency band of 36 MHz to 54 MHz, a medium frequency band of 366 MHz to 466 MHz, and a high frequency band of 700 MHz to 1 GHz.

[0012] A method for detecting a life signal of a buried victim according to the present invention for solving the above-mentioned technical problem comprises: a step of radiating a continuous wave signal generated from a continuous wave generator into the ground through a transmitting antenna; a step of receiving a direct transmission wave directly transmitted from the transmitting antenna and a reflected signal reflected from the victim in the ground through a receiving antenna; a step of generating a direct transmission wave cancellation signal from the continuous wave signal that has the same magnitude as the direct transmission wave but opposite phase using a hybrid coupler and a phase converter; a step of synthesizing the received signal and the direct transmission wave cancellation signal in a synthesizer to cancel out the direct transmission wave and extract the life signal of the victim; and a step of determining whether the victim is alive by detecting the gain ratio and phase difference between the extracted life signal and a reference signal in a gain / phase detector.

[0013] The step of generating the direct transmission wave removal signal above includes a calibration process before performing the life signal detection above, and the calibration process may include: (a) a step of fixing the phase of the phase converter by finding a phase value at which the RMS value of the gain output of the gain / phase detector is minimized while changing the phase of the phase converter from 0° to 360°, and (b) a step of fixing the gain of the low-noise amplifier by adjusting the gain of the low-noise amplifier while the phase value is fixed to find a gain value at which the RMS value of the gain output of the gain / phase detector is minimized. Effects of the invention

[0014] According to the present invention, the detection sensitivity of weak vital signs can be significantly improved by effectively eliminating direct transmission waves, and buried persons can be effectively detected over a wide range from shallow to deep areas through detection optimized by frequency band. In addition, vital signs such as respiration and heart rate of buried persons can be accurately distinguished and detected by utilizing the Doppler effect of continuous wave radar, and rapid decision-making at the rescue site can be supported through a user interface capable of real-time monitoring. Brief explanation of the drawing

[0015] FIG. 1 is a representative diagram illustrating the process of detecting a life signal of a buried victim using a radar device according to the present invention. FIG. 2 is a block diagram provided to explain the configuration and operation of a radar device for detecting life signals according to one embodiment of the present invention. FIG. 3 is a diagram showing various signal waveforms obtained by operating a buried person life signal detection radar device according to the present invention. FIG. 4 is a flowchart illustrating a correction process for generating a direct transmission wave removal signal to efficiently remove a direct transmission wave according to the present invention. Figure 5 is a diagram illustrating the detection depth by frequency band for operating the buried person life signal radar according to the present invention. FIG. 6 is a flowchart illustrating a sensing process according to the present invention. FIG. 7 is a diagram illustrating an exemplary software screen operated on a tablet PC for operating a buried person life signal radar according to the present invention. Specific details for implementing the invention

[0016] Then, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention.

[0017] The terms used in this specification are for describing embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. The terms "comprises" and / or "comprising" used in this specification do not exclude the presence or addition of one or more other components in addition to the components mentioned. Throughout the specification, the same reference numerals refer to the same components, and "and / or" includes each of the mentioned components and all combinations of one or more. Although terms such as "first," "second," etc., are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, the first component mentioned below may be the second component within the technical scope of the invention.

[0018] FIG. 1 is a representative diagram illustrating the process of detecting a life signal of a buried victim using a radar device according to the present invention.

[0019] Referring to FIG. 1, the overall concept of detecting a person in need of rescue (20) surviving within an underground cavity (10) formed due to a collapse accident, etc. is shown. A radar device (100) is installed on the surface of the ground and emits electromagnetic waves toward the underground. The electromagnetic waves (S) emitted from the radar device (100) penetrate the underground medium and are reflected from the body surface of the person in need of rescue (20), and this reflected signal (R) returns to the radar device (100). Since the reflective surface changes over time due to the breathing, heart rate, and minute movements of the person in need of rescue (20), the reflected signal (R) contains such life signal information. The radar device (100) can detect these weak life signals to determine whether the person in need of rescue (20) is alive and where they are located.

[0020] FIG. 2 is a block diagram provided to explain the configuration and operation of a radar device for detecting life signals according to one embodiment of the present invention.

[0021] Referring to FIG. 2, the radar device according to the present invention may include a continuous wave generator (101), a distributor (102), a power amplifier (103), a transmitting antenna (104), a hybrid coupler (105), a phase converter (106), a receiving antenna (107), a low-noise amplifier (108), a synthesizer (109), a signal amplifier (110), a gain / phase detector (111), a control computer (112), and a tablet PC (113).

[0022] The continuous wave generator (101) can receive a frequency setting signal (S112a) from the control computer (112) and generate a continuous wave signal (S101) of a preset frequency. In this embodiment, the continuous wave generator (101) can generate a continuous wave in a range from several MHz to 1 GHz or less, and in particular, can generate a continuous wave of a frequency selected from a low frequency band (36 MHz to 54 MHz), a medium frequency band (366 MHz to 466 MHz), and a high frequency band (700 MHz to 1 GHz). The use of these various frequency bands enables optimized detection according to the burial depth.

[0023] The distributor (102) can distribute the continuous wave signal (S101) into two independent paths. The continuous wave signal (S102a) of the first path is transmitted to the power amplifier (103) as a transmission path, and the continuous wave signal (S102b) of the second path can be transmitted to the hybrid coupler (105) as a reference signal for direct wave rejection. Through this distribution, direct wave rejection and life signal detection can be performed using signals from the same source. Here, the continuous wave signal (S102a) of the first path and the continuous wave signal (S102b) of the second path have the same phase (0°).

[0024] The power amplifier (103) can amplify the distributed signal (S102a) to a sufficient output level to radiate it underground through the transmitting antenna (104). For example, the power amplifier (103) can provide an output of at least 30 dBm (1 W) to effectively penetrate the underground medium. The signal (S103) amplified by the power amplifier (103) is radiated underground in the form of electromagnetic waves through the transmitting antenna (104).

[0025] The hybrid coupler (105) can separate the input signal (S102b) into a signal with a 0° phase (S205b) and a signal with a 180° phase (S205a). The 0° phase signal (S205b) is used as a reference signal for the gain / phase detector (111), and the 180° phase signal (S205a) can be input to the phase converter (106). Through this phase separation, a basis is established to generate an inverse phase signal necessary for direct transmission wave removal.

[0026] The phase converter (106) can finely adjust the phase of the input signal according to the phase control signal (S112b) from the control computer (112). In this embodiment, the phase converter (106) has an adjustment range from 0° to 360°, and precise phase control is possible in increments of 0.1° or 1°. The direct transmission wave cancellation signal (S106) thus generated can be used to cancel out the direct transmission wave of the receiving path.

[0027] Meanwhile, the continuous wave signal radiated from the transmitting antenna (104) can reach the receiving antenna (107) through two paths. The first is a direct transmission wave (S-1) that is directly received from the transmitting antenna (104), and the second is a rescuer life signal (R) that returns after the continuous wave signal (S-2) radiated from the transmitting antenna (104) passes through an underground medium and is reflected from the body surface of the rescuer (20). Since these two signals travel through different paths, they have different characteristics.

[0028] The direct transmission wave (S-1) travels along a short, fixed path between the transmitting and receiving antennas, so it has the characteristic that the phase and amplitude of the signal hardly change over time. On the other hand, the life signal of the rescuer (R) is characterized by containing very small phase fluctuations and amplitude modulation because the reflection surface changes over time due to the rescuer's breathing, heart rate, and minute body movements. The two signals can be distinguished by utilizing these differences in characteristics.

[0029] The receiving antenna (107) can receive these two signals (S-1, R) simultaneously, and the signal (S107) containing both signals (S-1, R) can be input to a low-noise amplifier (108).

[0030] The low-noise amplifier (108) can amplify the signal (S107) received from the receiving antenna (107) and output it to the synthesizer (109). At this time, the gain of the low-noise amplifier (108) is adjusted by a gain control signal (S112d) from the control computer (112), and this is done to accurately match the amplitudes of the direct transmission wave (S-1) and the direct transmission wave removal signal (S106) during the calibration process. For example, the low-noise amplifier (108) can amplify and output the received signal (S107) so that the amplitude (Ac) of the direct transmission wave component included in the received signal (S107) matches the amplitude (Ar) of the direct transmission wave removal signal output from the phase converter (106).

[0031] The synthesizer (109) synthesizes the amplified received signal (S108) and the direct transmission wave removal signal (S106) output from the phase converter (106). The principle of direct transmission wave removal is to cancel out the signal by synthesizing a signal that has the same amplitude (Ac = Ar) as the direct transmission wave component of the received signal and has a phase difference of exactly 180° (Φc = Φr + 180°). When ideal cancellation is achieved, only the life signal component of the buried person remains in the synthesized signal (S305).

[0032] The signal amplifier (110) can amplify the life signal (S109) output after the direct transmission wave signal component is removed from the synthesizer (109) to secure a sufficient signal-to-noise ratio (SNR). The gain of the signal amplifier (110) is adjusted by the gain control signal (S112c) of the control computer (112), and can amplify the remaining life signal after cancellation to a detectable level. Through appropriate gain adjustment, even weak life signals can be clearly detected.

[0033] The gain / phase detector (111) can compare the life signal (S116) amplified by the signal amplifier (110) with the reference signal (S105b) from the hybrid coupler (105) and output a gain signal (S111a) representing the gain ratio (Gain) of the input signal relative to the reference signal and a phase signal (S111b) representing the phase difference in the form of voltage. These outputs can be used to analyze the characteristics of the life signal.

[0034] The control computer (212) is a central processing unit that controls the operation of the entire system, and can set the frequency of the continuous wave generator (201), control the phase of the phase converter (206) of the direct wave removal signal, and adjust the gain values ​​of the low-noise amplifier (208) and the signal amplifier (210).

[0035] Additionally, the control computer (212) can quantize the value of the output signal of the gain / phase detector (211). It can perform functions such as digital conversion (quantization) of the output of the gain / phase detector (111), signal processing, execution of a correction algorithm, and detection and analysis of life signals. The analog gain signal (S307a) and phase signal (S307b) output from the gain / phase detector (211) are quantized into digital data through an analog-to-digital converter within the control computer (212), thereby enabling subsequent digital signal processing and analysis.

[0036] Meanwhile, the control computer (112) can be implemented to accurately detect the biological signal of a buried person by performing frequency analysis by performing a Fast Fourier Transform (FFT) on the output signal of the gain / phase detector (111), and by filtering and distinguishing the respiration frequency component in the range of 0.1 Hz to 0.5 Hz and the heart rate frequency component in the range of 0.8 Hz to 2.5 Hz.

[0037] The tablet PC (113) can be connected to the control computer (112) wirelessly or via a wired connection to control the system from the outside or to display quantized gain / phase detector values. In particular, the tablet PC (213) can display quantized gain and phase signals in the form of real-time graphs, allowing the user to visually monitor changes in vital signals. The gain graph shows changes in signal strength over time, and the phase graph can display phase changes according to the minute movements of the person being rescued. Through this graphic interface, the rescue worker can intuitively understand the survival status of the buried person.

[0038] FIG. 3 is a diagram showing various signal waveforms obtained by operating a buried person life signal detection radar device according to the present invention.

[0039] Referring to FIG. 3, the waveform characteristics of various signals are shown in the time domain. Reference numeral 401 is the waveform of a direct transmission wave (S-1) in which a continuous wave generated by a continuous wave generator (101) is radiated from a transmitting antenna (104) and transmitted directly to a receiving antenna (107). This signal exhibits a sinusoidal form that maintains a constant amplitude and phase, and it can be confirmed that there is almost no change over time. Since such a direct transmission wave has a very large amplitude, it becomes a major cause of interference with the detection of weak life signals.

[0040] Reference numeral 402 is the waveform of a life signal (R) of a person in distress that is radiated from a transmitting antenna (104), reflected from the person in distress, and transmitted to a receiving antenna (107). This signal exhibits a characteristic in which its amplitude changes over time due to the person in distress's breathing or heartbeat. In particular, a low-frequency modulation component due to breathing is clearly visible, which can serve as an important indicator for determining whether the buried person is alive.

[0041] Reference numeral 403 is the waveform of a received signal (S108) in which the direct transmission wave (S-1) and the rescuer life signal (R) are combined.

[0042] Reference numeral 404 is the waveform of a direct transmission wave cancellation signal (S106) generated through a hybrid coupler (105) and a phase converter (106). This signal has the same magnitude as the direct transmission wave but has a phase difference of 180°. Through precise amplitude and phase adjustment, a signal capable of effectively canceling out the direct transmission wave is generated.

[0043] Reference numeral 405 is the waveform of the life signal extracted after the direct transmission wave is canceled out through the synthesis of the received signal (S108) and the direct transmission wave removal signal (S106).

[0044] Reference numeral 406 is the waveform of a signal (S111a) output from the gain port (Gain) of a gain / phase detector (111) after receiving a life signal. This signal represents the amplitude ratio of the life signal relative to the reference signal in the form of a voltage, and periodic changes caused by breathing can be clearly observed. By analyzing this signal, the breathing frequency and the depth of breathing can be determined.

[0045] Reference numeral 407 is the waveform of a signal (S111b) output from the phase port (Phase) of a gain / phase detector (111). This signal represents the phase difference between the reference signal and the life signal in the form of a voltage, and shows the phase change according to the minute movement of the person in need of rescue. This phase information can be usefully used to detect the movement or position change of the person in need of rescue.

[0046] FIG. 4 is a flowchart illustrating a correction process for generating a direct transmission wave removal signal to efficiently remove a direct transmission wave according to the present invention.

[0047] Referring to FIG. 4, the calibration process can be composed of four steps. First, the initial gain value can be fixed by adjusting the low-noise amplifier control signal (S112d) (501). In this step, a basic gain value is set to ensure an appropriate signal level. The initial gain value is set so that the received signal has a sufficient signal level without saturating.

[0048] Next, the phase control signal (S112b) can be adjusted to scan the phase value of the phase converter (106) from 0° to 360°, and the gain signal (S111a) of the gain / phase detector (111) can be monitored (502). The control computer (112) can calculate the Root Mean Square (RMS) value at each phase while changing the phase at intervals (Δθ) of 0.1° or 1°. The phase value (Φmin) at which the RMS value is minimized can be found and fixed to the phase converter (106). This is a process of matching the phase (Φc) of the direct transmission wave and the phase (Φr) of the direct transmission wave removal signal so that they differ by exactly 180°. Optimal cancellation conditions can be found through precise phase scanning.

[0049] With the phase fixed, the gain of the low-noise amplifier (108) can be changed by adjusting the low-noise amplifier control signal (S112d), and the gain value (Gmin) at which the gain output RMS value of the gain / phase detector (111) becomes minimum can be found and fixed (503). This is a process of accurately matching the amplitudes of the direct transmission wave and the removal signal. When both the phase and amplitude are accurately adjusted, perfect cancellation of the direct transmission wave is achieved.

[0050] Finally, by adjusting the signal amplifier control signal (S112c) to set the gain of the signal amplifier (110), the sensitivity of the remaining life signal after cancellation can be secured (504). In this step, the weak life signal is amplified to a detectable level to secure a sufficient signal-to-noise ratio. Through appropriate amplification, subsequent signal processing can be performed effectively.

[0051] Figure 5 is a diagram illustrating the detection depth by frequency band for operating the buried person life signal radar according to the present invention.

[0052] Referring to Fig. 5, three frequency bands are selected and used according to the detection depth. Since electromagnetic waves have the characteristic that the penetration depth increases and attenuation decreases as the frequency decreases, each frequency band is optimized for different detection depths. By utilizing these physical characteristics, victims buried at various depths can be effectively detected.

[0053] The low-frequency band (36 MHz to 54 MHz) is designed to detect movement or large motions of a victim buried at a depth of 10 to 20 meters. While this frequency band has the greatest penetration depth, its resolution is relatively low. Therefore, it is suitable for determining the presence and approximate location of a victim buried at deep depths. In the low-frequency band, large movements or motions of the victim can primarily be detected, but it is difficult to detect subtle vital signs such as respiration or heart rate.

[0054] The mid-frequency band (366 MHz to 466 MHz) is a band used to detect the movement of a victim when the victim is buried at a depth of 1 m to 10 m. This frequency band provides moderate penetration depth and resolution. Because it has higher resolution than the low-frequency band, it can detect the victim's movement more precisely, and in some cases, even detect breathing signals. It is the most effective band for detecting victims buried at medium depths.

[0055] The high-frequency band (700 MHz to 1 GHz) is used to detect vital signs such as respiration and heart rate when a victim is buried at a shallow depth of less than 1 meter. Although this frequency band has a shallow penetration depth, it can detect minute vital signs with high resolution. In particular, it can detect even minute chest movements caused by respiration or vibrations caused by the heartbeat, making it useful for accurately determining the victim's survival status. It enables the most precise detection of vital signs in shallow burial situations.

[0056] The relationship between the frequency band and detection depth presented in this invention may vary depending on the soil environment, such as the dielectric constant and moisture content of the medium. In particular, in soil or rocky areas with high moisture content, the attenuation of electromagnetic waves increases, which may reduce the detection depth. Therefore, during actual operation, appropriate frequency band selection and adjustment can be made according to the field conditions.

[0057] FIG. 6 is a flowchart illustrating the life signal detection process according to the present invention.

[0058] Referring to FIG. 6, the life signal detection process is performed as follows. First, a buried person life detection radar device (100) can be fixed at a location where a person in need of rescue (20) is expected to be buried (701).

[0059] After performing the calibration process described in FIG. 4 in the low frequency band, a life signal detection process can be performed for a certain period of time (702). In the low frequency band, the presence and approximate location of the person buried deep are mainly identified. If a life signal is detected at this stage, the approximate location of the person can be confirmed.

[0060] Next, after performing a correction process in the mid-frequency band, a life signal detection process can be performed for a certain period of time (703). In the mid-frequency band, more precise motion detection is possible, and the condition of the person in need of rescue can be assessed in more detail.

[0061] Next, after performing a calibration process in the high-frequency band, a life signal detection process can be performed for a certain period of time (704). In the high-frequency band, respiration and heart rate can be detected separately, and the biological condition of the rescuer can be precisely monitored. At this stage, the exact survival status and health status of the rescuer can be evaluated.

[0062] FIG. 7 is a diagram illustrating an exemplary software screen operated on a tablet PC for operating a buried person life signal radar according to the present invention.

[0063] Referring to FIG. 7, the software screen of the tablet PC (113) may include various components for real-time monitoring and control. At the top of the screen, a life signal graph may be located under the title "Life Reaction Signal". This graph displays the time change of life signals detected in real time, and distinguishes between low-frequency components caused by respiration and high-frequency components caused by heartbeats. In the graph, a respiration signal with a cycle of approximately 0.2 Hz can be clearly observed. Through this visual display, the rescue worker can immediately determine whether the person in need of rescue is alive.

[0064] A "Phase" graph may be located at the bottom left of the screen. This graph displays real-time changes in the phase signal (S111b) output from the gain / phase detector (111). During the calibration process, it shows rapid changes when phase scanning, and when normal detection occurs, it shows phase changes according to the minute movements of the person in need of rescue. The phase information is useful for estimating the direction of movement or position changes of the person in need of rescue.

[0065] A "Gain" graph may be located at the bottom right of the screen. This graph displays real-time changes in the gain signal (S111a) output from the gain / phase detector (111). When the direct transmission wave is effectively removed, it maintains a low level and shows minute fluctuations according to the life signal. Since the gain information indicates the intensity of the life signal, it can be used to estimate the condition of the person being rescued or the depth of burial.

[0066] A control panel is located on the left side of the screen. On the control panel, the user can select a frequency band (e.g., 36 MHz, 400 MHz, 1 GHz, etc.) and perform the previously described calibration process automatically or manually. In other words, the user can quickly apply the optimal settings suitable for the field conditions through the control panel.

[0067] Meanwhile, the current screen can be captured and saved via the "Screenshot" button at the bottom of the screen, which can be used to record detection results and generate reports.

[0068] Through this user interface, operators at the rescue site can monitor vital signs in real time and control the system as needed to ensure optimal detection performance. The intuitive interface design allows even operators without specialized knowledge to easily operate the equipment and supports rapid decision-making in emergency rescue situations.

[0069] Although the embodiments have been described above with reference to the limited drawings, those skilled in the art can apply various technical modifications and variations based on the above. For example, suitable results may be achieved even if the described techniques are performed in a different order than described, and / or if the components of the described system, structure, device, circuit, etc. are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents.

Claims

Claim 1 A radar device for detecting life signals of a buried victim, comprising: a continuous wave generator that generates a continuous wave signal within a predetermined frequency range; A splitter that distributes the continuous wave signal into a first path and a second path; a power amplifier and a transmitting antenna that amplify the signal of the first path and radiate it underground; a hybrid coupler that separates the signal of the second path into a 0° phase signal and a 180° phase signal; a phase converter that generates a direct transmission wave removal signal by adjusting the phase of the 180° phase signal; a receiving antenna that receives a direct transmission wave transmitted directly from the transmitting antenna and a reflected signal reflected from a rescuer underground; a low-noise amplifier that amplifies the received signal received by the receiving antenna; a synthesizer that synthesizes the received signal amplified by the low-noise amplifier and the direct transmission wave removal signal generated by the phase converter to output a rescuer life signal in which the direct transmission wave is removed from the received signal; a signal amplifier that amplifies the rescuer life signal output from the synthesizer; and a device that detects the gain ratio and phase difference between the rescuer life signal amplified by the signal amplifier and the 0° phase signal. Gain / Phase Detector;and includes a control computer that sets the frequency of the continuous wave generator, controls the phase of the phase converter, and adjusts the gains of the low-noise amplifier and the signal amplifier, wherein the mode of the continuous wave generator is adjusted to generate a continuous wave in at least one frequency band among a low-frequency band of 36 MHz to 54 MHz for detecting movement of a rescuer at a depth of 10 to 20 meters, a medium-frequency band of 366 MHz to 466 MHz for detecting movement of a rescuer at a depth of 1 to 10 meters, and a high-frequency band of 700 MHz to 1 GHz for detecting respiration and heart rate of a rescuer within a depth of 1 meter, depending on the burial depth and the detection target; and the control computer, in order to correct leakage electromagnetic waves that vary whenever the exploration position of the radar device is fixed or the mode of the frequency band is changed, changes the phase of the phase converter from 0° to 360°, finds and fixes the phase value at which the RMS value of the gain output of the gain / phase detector is minimized, and subsequently the low-noise amplifier A radar device characterized by performing a calibration process each time to find and fix a gain value at which the RMS value of the gain output of the gain / phase detector is minimized by adjusting the gain, and after the calibration process is completed, monitoring the amount of change in the phase value of the continuous wave radar output from the gain / phase detector to detect the movement and biosignals of the person in need of rescue. Claim 2 delete Claim 3 A radar device according to claim 1, wherein the low-noise amplifier amplifies and outputs the received signal under the control of the control computer such that the amplitude of the direct transmission wave component included in the received signal matches the amplitude of the direct transmission wave removal signal output from the phase converter. Claim 4 A radar device according to claim 1, wherein the control computer quantizes the value of the output signal of the gain / phase detector. Claim 5 delete Claim 6 delete Claim 7 A method for detecting vital signs of a buried victim using a radar device comprises: a step of generating a continuous wave signal in at least one frequency band selected from a low frequency band of 36 MHz to 54 MHz for detecting victim movement at a depth of 10 to 20 meters, a medium frequency band of 366 MHz to 466 MHz for detecting victim movement at a depth of 1 to 10 meters, and a high frequency band of 700 MHz to 1 GHz for detecting victim respiration and heart rate within a depth of 1 meter, depending on the burial depth and the detection target, using a continuous wave generator; a step of distributing the continuous wave signal into a first path and a second path using a splitter; a step of amplifying the signal of the first path using a power amplifier and radiating it underground through a transmitting antenna; a step of separating the signal of the second path into a 0° phase signal and a 180° phase signal using a hybrid coupler, and adjusting the phase of the 180° phase signal using a phase converter to directly transmit from the transmitting antenna to a receiving antenna A step of generating a direct transmission wave removal signal having the same magnitude as the transmitted direct transmission wave but opposite phase; a step of receiving the direct transmission wave directly transmitted from the transmitting antenna and the reflected signal reflected from the underground rescuee through the receiving antenna, and amplifying the received signal in a low-noise amplifier; a step of synthesizing the received signal amplified by the low-noise amplifier and the direct transmission wave removal signal generated by the phase converter in a synthesizer to output a rescuee life signal in which the direct transmission wave is removed from the received signal; a step of amplifying the rescuee life signal output from the synthesizer in a signal amplifier; a step of detecting the gain ratio and phase difference between the rescuee life signal amplified by the signal amplifier and the 0° phase signal in a gain / phase detector;A method for detecting life signals, characterized by comprising: a step of performing a correction process each time in a control computer to correct leakage electromagnetic waves that vary whenever the detection position of the radar device is fixed or the mode of the frequency band is changed, wherein the phase of the phase converter is changed from 0° to 360° to find and fix a phase value at which the RMS value of the gain output of the gain / phase detector is minimized, and then the gain of the low-noise amplifier is adjusted to find and fix a gain value at which the RMS value of the gain output of the gain / phase detector is minimized; and a step of detecting the movement and biosignals of a person in need of rescue by monitoring the amount of change in the phase value of the continuous wave radar output from the gain / phase detector after the correction process is completed. Claim 8 delete

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