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KR-102965050-B1 - MIMO BASED FMCW RADAR APPARATUS AND OPEARTING METHOD OF THE SAME FOR DETECTING DIRECTION OF TARGET

KR102965050B1KR 102965050 B1KR102965050 B1KR 102965050B1KR-102965050-B1

Abstract

A radar device according to one embodiment of the present disclosure is a frequency-modulated continuous-wave (FMCW) radar device based on multiple-input multiple-output (MIMO) and includes a plurality of MIMO-based transmitting antennas that transmit electromagnetic waves, a plurality of MIMO-based receiving antennas that receive reflected electromagnetic waves, and a processor that detects the direction of a target based on the received electromagnetic waves. The processor determines a received signal based on a combination of the indices of the plurality of transmitting antennas and the indices of the plurality of receiving antennas, performs a Fast Fourier Transform (FFT) on the received signal to generate a first signal, inputs at least a portion of the first signal to a Long Short-Term Memory (LSTM)-based neural network to generate a second signal, and is configured to detect the direction of a target based on the first signal and the second signal.

Inventors

  • 김상동
  • 김봉석
  • 이종훈
  • 진영석

Assignees

  • 재단법인대구경북과학기술원

Dates

Publication Date
20260513
Application Date
20221220

Claims (12)

  1. A method for detecting the target direction of a MIMO (multiple-input multiple-output) based FMCW (frequency-modulated continuous-wave) radar device, A step of transmitting electromagnetic waves using a transmission module including a plurality of MIMO-based transmission antennas; A step of receiving reflected electromagnetic waves using a receiving module comprising a plurality of MIMO-based receiving antennas; A step of determining a received signal having a combination of the indices of a plurality of transmitting antennas and the indices of a plurality of receiving antennas as an index based on the received electromagnetic waves; A step of generating a first signal by performing a Fast Fourier Transform (FFT) on the received signal; A step of determining at least a portion of the first signal that is greater than or equal to a preset value as a target; A step of removing noise by inputting at least a portion of the first signal determined as the target into an LMS (Least mean square) filter; A step of generating a second signal for a target by inputting at least a portion of the first signal, from which noise has been removed by the LMS filter, into a neural network based on a Long Short-Term Memory (LSTM) that has been pre-trained to extract time-series features using a plurality of gates in a memory cell; and A step comprising detecting the direction of the target using the first signal and the second signal together, Method for detecting the target direction of a MIMO-based FMCW radar device.
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  3. In Article 1, The number of signals used to detect the direction of the above target exceeds the value obtained by multiplying the number of the transmitting antennas and the number of the receiving antennas. Method for detecting the target direction of a MIMO-based FMCW radar device.
  4. In Article 1, The above LSTM-based neural network is a neural network trained with received signals acquired from a radar device having a number of antennas greater than the sum of the number of transmitting antennas and the number of receiving antennas, Method for detecting the target direction of a MIMO-based FMCW radar device.
  5. In Paragraph 4, The above LSTM-based neural network is a neural network trained with received signals acquired from a radar device having receiving antennas having a spacing narrower than the spacing of a plurality of receiving antennas, Method for detecting the target direction of a MIMO-based FMCW radar device.
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  7. As a MIMO (multiple-input multiple-output) based FMCW (frequency-modulated continuous-wave) radar device, Multiple MIMO-based transmitting antennas that transmit electromagnetic waves; Multiple MIMO-based receiving antennas for receiving reflected electromagnetic waves; It includes a processor that detects the direction of a target based on the received electromagnetic waves, and The above processor is, A receiving signal is determined based on a combination of the indices of a plurality of transmitting antennas and the indices of a plurality of receiving antennas, a Fast Fourier Transform (FFT) is performed on the receiving signal to generate a first signal, at least a portion of the first signal that is greater than or equal to a preset value is determined as a target, at least a portion of the first signal determined as a target is input to a Least Mean Square (LMS) filter to remove noise, at least a portion of the first signal from which noise has been removed by the LMS filter is input to a Long Short-Term Memory (LSTM)-based neural network pre-trained to extract time-series features using a plurality of gates in a memory cell to generate a second signal for the target, and the direction of the target is detected by using the first signal and the second signal together. MIMO-based FMCW radar device.
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  9. In Article 7, The number of signals used to detect the direction of the above target exceeds the value obtained by multiplying the number of the transmitting antennas and the number of the receiving antennas. MIMO-based FMCW radar device.
  10. In Article 7, The above LSTM-based neural network is a neural network trained with received signals acquired from a radar device having a number of antennas greater than the sum of the number of transmitting antennas and the number of receiving antennas, MIMO-based FMCW radar device.
  11. In Article 10, The above LSTM-based neural network is a neural network trained with received signals acquired from a radar device having receiving antennas having a spacing narrower than the spacing of a plurality of receiving antennas, MIMO-based FMCW radar device.
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Description

MIMO-based FMCW radar apparatus and operating method of the same for detecting the direction of the radar apparatus The present disclosure relates to a MIMO (multiple-input multiple-output) based FMCW (frequency-modulated continuous-wave) radar device and a method of operating the same, and more specifically, to a radar device and a method of operating the same that improves the resolution of a received signal input to determine the direction of a target. Recently, radar has been widely utilized as a sensor to detect and track the distance, speed, and angle information of objects of interest in many application fields, such as autonomous driving and national defense. Unlike other sensors such as cameras or lidar, radar is based on electromagnetic waves, offering the advantage of stable operation in all-weather environments; however, it still has limitations in precise recognition due to its low parameter resolution. In particular, due to low angular resolution, it is difficult to recognize human faces or precise movements compared to other sensors. As an alternative, MIMO-based radar can be utilized. However, since MIMO-based radar is still affected by the number of transmitting and receiving antennas, there are limitations in obtaining radar results with high angular resolution. FIG. 1 is a block diagram showing the configuration of a radar device in one embodiment of the present disclosure. FIG. 2 is a drawing illustrating a MIMO-based antenna of a radar device according to one embodiment of the present disclosure. FIG. 3 is a diagram illustrating the flow of a MIMO-based transmission signal of a radar device according to one embodiment of the present disclosure. FIG. 4 is a diagram illustrating an LSTM-based neural network that generates a second signal of a radar device according to one embodiment of the present disclosure. FIG. 5 is a drawing illustrating an LSM filter that filters a first signal of a radar device according to one embodiment of the present disclosure. FIG. 6 is a flowchart illustrating a method of operation of a radar device according to one embodiment of the present disclosure. FIGS. 7 and 8 are drawings showing experimental results according to one embodiment of the present disclosure. Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Identical or similar components regardless of drawing symbols will be assigned the same reference number, and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably solely for the ease of drafting the specification and do not inherently possess distinct meanings or roles. Furthermore, in describing embodiments disclosed in this specification, if it is determined that a detailed description of related prior art could obscure the essence of the embodiments disclosed in this specification, such detailed description will be omitted. Additionally, the attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification; the technical concept disclosed in this specification is not limited by the attached drawings, and it should be understood that they include all modifications, equivalents, and substitutions that fall within the spirit and technical scope of the present invention. Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. With reference to FIG. 1, the configuration of a radar device according to one embodiment of the present disclosure will be described. The radar device (100) according to an embodiment of the present disclosure is a MIMO (multiple-input multiple-output) based FMCW (frequency-modulated continuous-wave) radar device. Referring to FIG. 1, a radar device (100) according to one embodiment may include a plurality of transmitting antennas (111) that transmit electromagnetic waves forward or toward a specific direction with a constant beam width, a plurality of receiving antennas (151) that receive electromagnetic waves reflected from the direction of the transmitted electromagnetic waves, and a processor (120) that extracts information about an object that reflected the electromagnetic waves based on the received electromagnetic waves. For example, the processor (120) may be configured to ca