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CN-115327649-B - Doppler microwave detection method with detection boundary determination

CN115327649BCN 115327649 BCN115327649 BCN 115327649BCN-115327649-B

Abstract

The invention provides a Doppler microwave detection method with a detection boundary determination, which is based on piecewise linear frequency modulation of an excitation signal, transmits a microwave beam in a linear frequency modulation mode, receives an echo signal corresponding to a reflection echo formed by reflecting the microwave beam by at least one object, and generates a Doppler intermediate frequency signal corresponding to the frequency and phase difference between the excitation signal and the echo signal in a mixing detection mode, wherein different frequency components of the Doppler intermediate frequency signal in a frequency domain correspond to different distances between the object in a coverage space of the microwave beam and a corresponding microwave detection module, and when the motion of the object exists in the space, the frequency and the initial phase of the Doppler intermediate frequency signal have fluctuation in a time domain, so that the object activity in an effective detection space with the detection boundary determination can be detected based on multiple limit value setting of the Doppler intermediate frequency signal in the frequency and the initial phase.

Inventors

  • ZOU GAODI
  • ZOU MINGZHI

Assignees

  • 深圳迈睿智能科技有限公司

Dates

Publication Date
20260505
Application Date
20220902
Priority Date
20210903

Claims (19)

  1. 1. A doppler microwave detection method with a defined detection boundary, comprising the steps of: (A) Piecewise chirping an excitation signal to emit a microwave beam in a chirped form, wherein a coverage space of the microwave beam is taken as an actual detection space; (B) Receiving at least one reflected echo formed by the reflection of the microwave beam by at least one object in the actual detection space to generate an echo signal corresponding to the reflected echo; (C) Generating a Doppler intermediate frequency signal corresponding to the frequency and phase difference between the excitation signal and the echo signals in a time domain signal form in a mixing detection mode, wherein the frequency of the Doppler intermediate frequency signal is a discrete state of the frequency difference between the excitation signal and each echo signal and has at least one frequency component, and the initial phase of the Doppler intermediate frequency signal is a discrete state of the phase difference between the excitation signal and the corresponding echo signal at a time point corresponding to the starting point of the Doppler intermediate frequency signal of each frequency component; (D) Defining an outer boundary of an effective detection space in the actual detection space by using an upper limit frequency limit value based on the limit value setting of the Doppler intermediate frequency signal in frequency; (E) And judging the object activity in the effective detection space according to the limit value setting of the Doppler intermediate frequency signal in frequency and/or initial phase and the lower limit frequency difference limit value and/or the lower limit phase difference limit value, wherein the Doppler intermediate frequency signal corresponding to the frequency component smaller than or equal to the upper limit frequency limit value has frequency value fluctuation larger than or equal to the lower limit frequency difference limit value or has initial phase fluctuation larger than or equal to the lower limit phase difference limit value, and judging the object activity in the effective detection space.
  2. 2. A doppler microwave detection method with defined detection boundaries according to claim 1, wherein in said step (D) said doppler intermediate frequency signal with frequency components less than or equal to said upper frequency limit is selected in a frequency selective filtering manner to generate a range-doppler intermediate frequency signal, said range-doppler intermediate frequency signal characterizing only said effective detection space to define said effective detection space based on setting of said upper frequency limit by setting of corresponding filtering parameters.
  3. 3. A doppler microwave detection method with defined detection boundaries in accordance with claim 2, wherein in said step (E), comprising the steps of: (E10) Converting the range-Doppler intermediate frequency signal into a frequency fluctuation signal according to the change of the frequency of the range-Doppler intermediate frequency signal along with the time, wherein the amplitude fluctuation of the frequency fluctuation signal corresponds to the frequency value fluctuation of the range-Doppler intermediate frequency signal (E11) And judging that the object activity exists in the effective detection space based on amplitude fluctuation of the frequency fluctuation signal which is more than or equal to the lower frequency difference limit value.
  4. 4. A doppler microwave detection method with determined detection boundaries in accordance with claim 3, wherein in said step (E11), comprising the steps of: (E111) Frequency-selective filtering the frequency fluctuation signal to obtain the frequency fluctuation signal with an amplitude fluctuation frequency of 10Hz or less, and (E112) And judging that human body activity exists in the effective detection space based on amplitude fluctuation of the frequency fluctuation signal subjected to frequency selection filtering processing, wherein the amplitude fluctuation is larger than or equal to the lower limit frequency difference limit value.
  5. 5. A doppler microwave detection method with defined detection boundaries in accordance with claim 2, wherein in said step (E), comprising the steps of: (E20) Fourier transforming the range-doppler intermediate frequency signal to obtain information of the distribution of the frequency values of the range-doppler intermediate frequency signal of each frequency component in the time dimension, and (E21) And judging that the object activity exists in the effective detection space based on the distribution information of the frequency value of the range-Doppler intermediate frequency signal of at least one frequency component in the time dimension, wherein the frequency value fluctuation is larger than or equal to the lower frequency difference limit value.
  6. 6. The doppler microwave detection method with the detection boundary determined according to claim 5, wherein in the step (E21), the distribution information of the frequency value of the range-doppler intermediate frequency signal based on at least one frequency component in the time dimension has a frequency value fluctuation of the lower frequency difference limit value or more, and the frequency range in which the frequency value of the range-doppler intermediate frequency signal of the frequency component in the time dimension has a fluctuation frequency of 10Hz or less is determined that there is human body activity in the effective detection space.
  7. 7. A doppler microwave detection method with defined detection boundaries in accordance with claim 2, wherein in said step (E), comprising the steps of: (E30) Fourier transforming the range-doppler intermediate frequency signal to obtain information of the distribution of the initial phase of the range-doppler intermediate frequency signal of each frequency component in the time dimension, and (E31) Determining that there is object activity in the effective detection space based on the distribution information of the initial phase of the range-doppler intermediate frequency signal of at least one frequency component in the time dimension having a fluctuation greater than or equal to the lower-limit phase difference limit value.
  8. 8. A doppler microwave detection method with defined detection boundaries in accordance with claim 2, wherein in said step (E), comprising the steps of: (E40) Fourier transforming the range-doppler intermediate frequency signal to obtain information of the distribution of the frequency values of the range-doppler intermediate frequency signal in the time dimension of each frequency component and obtain information of the distribution of the initial phase of the range-doppler intermediate frequency signal in the time dimension of each frequency component, and (E41) Determining that there is object activity in the effective detection space based on at least one of a condition that distribution information of frequency values of the range-doppler intermediate frequency signal of at least one frequency component in a time dimension has frequency value fluctuation greater than or equal to the lower frequency difference limit value, and a condition that distribution information of initial phases of the range-doppler intermediate frequency signal of at least one frequency component in a time dimension has fluctuation greater than or equal to the lower frequency difference limit value.
  9. 9. The doppler microwave detection method with the detection boundary determined according to claim 8, wherein in the step (E41), it is determined that there is an object activity in the effective detection space based on distribution information of frequency values of the range-doppler intermediate frequency signal of at least one frequency component in a time dimension not having frequency value fluctuations equal to or larger than the lower frequency difference limit value, and distribution information of initial phases of the range-doppler intermediate frequency signal of the frequency component in a time dimension having fluctuations equal to or larger than the lower frequency difference limit value.
  10. 10. The doppler microwave detection method with the detection boundary determined according to claim 8, wherein in the step (E41), it is determined that there is human activity in the effective detection space based on the frequency value fluctuation of the range doppler intermediate frequency signal of at least one frequency component in the time dimension not having the frequency value fluctuation equal to or greater than the lower frequency difference limit value, and the distribution information of the initial phase of the range doppler intermediate frequency signal of the frequency component in the time dimension having the fluctuation equal to or greater than the lower frequency difference limit value, and the frequency range in which the fluctuation frequency of the initial phase of the range doppler intermediate frequency signal of the frequency component in the time dimension is equal to or less than 10 Hz.
  11. 11. A doppler microwave detection method with defined detection boundaries in accordance with claim 1, wherein in said step (E), comprising the steps of: (E50) Fourier transforming the Doppler IF signal to obtain distribution information of frequency values of the Doppler IF signal of each frequency component in a time dimension, and (E51) And judging that the object activity exists in the effective detection space based on the distribution information of the frequency value of the Doppler intermediate frequency signal of at least one frequency component which is smaller than or equal to the upper frequency limit value in the time dimension and has the frequency value fluctuation which is larger than or equal to the lower frequency limit value.
  12. 12. The doppler microwave detection method with the detection boundary determined according to claim 11, wherein in the step (E51), the distribution information in the time dimension of the frequency value of the doppler intermediate frequency signal based on at least one frequency component of the upper limit frequency limit value or less has a frequency value fluctuation of the lower limit frequency difference limit value or more, and a frequency range in which a frequency of fluctuation of the frequency value of the doppler intermediate frequency signal in the time dimension of the frequency component is 10Hz or less determines that there is human body activity in the effective detection space.
  13. 13. A doppler microwave detection method with defined detection boundaries in accordance with claim 1, wherein in said step (E), comprising the steps of: (E60) Fourier transforming the Doppler IF signal to obtain distribution information of initial phases of the Doppler IF signal of each frequency component in a time dimension, and (E61) Determining that object activity exists in the effective detection space based on the distribution information of the initial phase of the Doppler intermediate frequency signal of at least one frequency component which is smaller than or equal to the upper limit frequency limit value in the time dimension with fluctuation which is larger than or equal to the lower limit phase difference limit value.
  14. 14. A doppler microwave detection method with defined detection boundaries in accordance with claim 1, wherein in said step (E), comprising the steps of: (E70) Fourier transforming the Doppler IF signal to obtain information of distribution of frequency values of the Doppler IF signal in a time dimension of each frequency component and information of distribution of initial phases of the Doppler IF signal in a time dimension of each frequency component, and (E71) Determining that there is object activity in the effective detection space based on at least one of a condition that distribution information of frequency values of the doppler intermediate frequency signal of at least one frequency component which is equal to or less than the upper frequency limit value in a time dimension has frequency value fluctuation which is equal to or greater than the lower frequency difference limit value, and a condition that distribution information of initial phases of the doppler intermediate frequency signal of at least one frequency component which is equal to or less than the upper frequency limit value in a time dimension has fluctuation which is equal to or greater than the lower frequency difference limit value.
  15. 15. The doppler microwave detection method with the detection boundary determined according to claim 14, wherein in the step (E71), it is determined that there is object activity in the effective detection space based on distribution information of frequency values of the doppler intermediate frequency signal of at least one frequency component that is equal to or less than the upper limit frequency limit value in a time dimension not having frequency value fluctuations equal to or greater than the lower limit frequency difference limit value, and distribution information of initial phases of the doppler intermediate frequency signal of the frequency component in the time dimension having phase fluctuations equal to or greater than the lower limit frequency difference limit value.
  16. 16. The doppler microwave detection method with the detection boundary determined according to claim 15, wherein in the step (E71), it is determined that there is human activity in the effective detection space based on a frequency range in which a frequency value of the doppler intermediate frequency signal of at least one frequency component that is equal to or less than the upper limit frequency limit value does not have a frequency value fluctuation in a time dimension that is equal to or greater than the lower limit frequency difference limit value, and a frequency range in which an initial phase of the doppler intermediate frequency signal of the frequency component has a fluctuation in a time dimension that is equal to or greater than the lower limit frequency difference limit value.
  17. 17. The doppler microwave detection method with the detection boundary determined according to any one of claims 1 to 16, wherein in the step (D), when a frequency value of the doppler intermediate frequency signal of at least one frequency component has a frequency value fluctuation equal to or greater than the lower limit frequency difference limit value, and/or an initial phase of the doppler intermediate frequency signal of at least one frequency component has an initial phase fluctuation equal to or greater than the lower limit phase difference limit value, the upper limit frequency limit value is set at one of a minimum frequency and a maximum frequency of the frequency components based on an instruction to set the upper limit frequency limit value.
  18. 18. The doppler microwave detection method with the detection boundary determined according to claim 17, wherein in the step (D), when a frequency value of the doppler intermediate frequency signal of at least one frequency component has a frequency value fluctuation equal to or greater than the lower frequency difference limit value, and/or an initial phase of the doppler intermediate frequency signal of at least one frequency component has an initial phase fluctuation equal to or greater than the lower frequency difference limit value, the upper frequency limit value is set with a minimum frequency of the frequency components as the upper frequency limit value based on an instruction to set the upper frequency limit value.
  19. 19. The method for detecting Doppler microwaves with a determined detection boundary according to claim 17, further comprising the step of controlling the state of at least one electrical device based on the detection result of the presence of the object in the effective detection space.

Description

Doppler microwave detection method with detection boundary determination Technical Field The invention relates to the field of Doppler microwave detection, in particular to a Doppler microwave detection method with a detection boundary determination function. Background With the development of the internet of things technology, the requirements of artificial intelligence, intelligent home and intelligent security technology on environment detection, especially on detection accuracy of motion characteristics of existence, movement and inching of people, are higher and higher, and accurate judgment basis can be provided for intelligent terminal equipment only by acquiring enough stable detection results. The radio technology, including the existing microwave detection technology based on the Doppler effect principle, has unique advantages in the technology of behavior detection and existence detection, and can transmit a microwave beam at a fixed frequency and receive a reflected echo formed by the reflection of the microwave beam by the corresponding object, and generate a Doppler intermediate frequency signal corresponding to the frequency difference between the microwave beam and the reflected echo in a subsequent mode through frequency mixing detection, then the amplitude fluctuation of the Doppler intermediate frequency signal corresponds to the Doppler effect generated by the motion of the corresponding object, thus representing the motion of the corresponding object based on the effective amplitude of the Doppler intermediate frequency signal meeting the corresponding threshold setting, and realizing the wide application prospect due to the intelligent interconnection between the human and the object when applied to the detection of human activities, on the one hand, the boundary of the corresponding microwave beam is a gradient boundary with a certain degree of radiation energy, on the other hand, the electromagnetic radiation is not deterministic, on the other hand, namely, the shaping means of the corresponding microwave beam boundary is used for shaping the electromagnetic radiation, the main gradient boundary is used for the electromagnetic interference, the detection is difficult to realize the electromagnetic interference of the corresponding microwave beam, the electromagnetic interference is not really matched with the actual condition of the corresponding object, and the real condition is not really realized, the space is not matched with the real condition of the real condition, and the space is not available, and the space is not matched with the real condition of the real condition exists, and the space is not available, the space is actually controlled, the space is not occupied by the detection conditions, the problems of poor precision and/or poor anti-interference performance of the existing microwave detection technology based on the Doppler effect principle are caused, namely, the boundary of the microwave beam is a gradient boundary where radiation energy is attenuated to a certain degree, and meanwhile, a shaping means for the gradient boundary of the microwave beam is lacked, so that the actual detection space of the existing microwave detection module is difficult to match with the corresponding target detection space in actual application, and the defect that the adaptability of the existing microwave detection module in different application scenes in actual application is limited and the detection stability is poor is caused. In order to solve the above-mentioned drawbacks of the existing microwave detection module, an effective detection space is currently defined in an actual detection space of the microwave detection module mainly by adjusting the sensitivity of the microwave detection module, and specifically, the corresponding sensitivity adjustment of the microwave detection module is implemented by setting a corresponding threshold value of the doppler intermediate frequency signal in amplitude, so that the effective detection space can be matched with the target detection space based on the definition of the effective detection space in a scene that the actual detection space of the microwave detection module is larger than the corresponding target detection space, thereby excluding the environmental interference of the actual detection space outside the target detection space. However, since the amplitude of the doppler intermediate frequency signal is related to the energy level of the reflected echo formed by the reflection of the moving object and is also related to the reflecting surface level and the moving speed of the moving object and the distance from the microwave detection module, the definition of the effective detection space based on the sensitivity adjustment of the microwave detection module is not stable and accurate, for example, different moving objects with the same distance as the microwave detection module have different amplitude feedback in the