Wide-range displacement monitoring method

Abstract

A wide-range displacement sensing method performs signal processing on four consecutive orthogonal channel signals measured by radar, including DC offset removal, linear combination, amplitude correction, nonlinear combination, and phase demodulation. It can achieve accurate phase demodulation through waveform shaping and Doppler feature enhancement, thus avoiding trajectory fitting being limited by the displacement of the moving target and achieving wide-range displacement sensing.

Claims

1. A wide-range displacement sensing method, comprising: a computing device receiving a first channel signal, a second channel signal, a third channel signal, and a fourth channel signal from a radar, wherein the phase of the second channel signal differs from the phase of the first channel signal by 90 degrees, the phase of the third channel signal differs from the phase of the second channel signal by 90 degrees, and the phase of the fourth channel signal differs from the phase of the third channel signal by 90 degrees; the computing device obtaining a first voltage signal, a second voltage signal, a third voltage signal, and a fourth voltage signal by removing DC offset from the first channel signal, the second channel signal, the third channel signal, and the fourth channel signal; the computing device linearly combining the first voltage signal, the second voltage signal, the third voltage signal, and the fourth voltage signal into a first combined signal, a second combined signal, a third combined signal, and a fourth combined signal; The computing device performs amplitude correction on the first combined signal, the second combined signal, the third combined signal, and the fourth combined signal to obtain a first amplitude correction signal, a second amplitude correction signal, a third amplitude correction signal, and a fourth amplitude correction signal; the computing device nonlinearly combines the first amplitude correction signal, the second amplitude correction signal, the third amplitude correction signal, and the fourth amplitude correction signal to obtain a co-phase channel signal and a positive traffic channel signal; and the computing device demodulates the co-phase channel signal and the positive traffic channel signal to obtain a Doppler phase shift.

2. The wide-range displacement sensing method of claim 1, wherein the first channel signal, the second channel signal, the third channel signal, and the fourth channel signal can be represented as: , where, The first channel signal, the second channel signal, the third channel signal, the fourth channel signal, the initial adjustment voltage of a self-injection-locked oscillator of the radar, the locking range of the self-injection-locked oscillator, the adjustment sensitivity of the self-injection-locked oscillator, and the Doppler phase shift are all represented by the following values: ______.

3. The wide-range displacement sensing method of claim 2, wherein the computing device removes the DC offset in the signal using the first channel signal, the second channel signal, the third channel signal, and the fourth channel signal, which can be expressed as: , and , wherein, 。 4. As in the wide-range displacement sensing method of claim 3, the linear combination of the first voltage signal, the second voltage signal, the third voltage signal, and the fourth voltage signal into a first combined signal, a second combined signal, a third combined signal, and a fourth combined signal by the computing device can be expressed as: , where, Let be the first combination signal, the second combination signal, the third combination signal, and the fourth combination signal. The first combination signal, the second combination signal, the third combination signal, and the fourth combination signal can be represented as: , where and are a first initial phase and a second initial phase, respectively.

5. The wide-range displacement sensing method as described in claim 4, wherein the first initial phase, the second initial phase, ...

6. The wide-range displacement sensing method of claim 4, wherein the amplitude correction of the first combined signal, the second combined signal, the third combined signal, and the fourth combined signal by the computing device can be expressed as: , where, Let be a first amplitude correction factor, be a second amplitude correction factor, and be a Doppler phase shift factor. The computing device divides the first and third combined signals by the first amplitude correction factor to obtain the first and third amplitude correction signals. The computing device also divides the second and fourth combined signals by the second amplitude correction factor to obtain the second and fourth amplitude correction signals, which can be expressed as: , where is the first amplitude correction signal, is the second amplitude correction signal, is the third amplitude correction signal, and is the fourth amplitude correction signal.

7. The wide-range displacement sensing method of claim 1, wherein the arithmetic device performs amplitude correction on the first combined signal, the second combined signal, the third combined signal, and the fourth combined signal, comprising: the arithmetic device calculating a first amplitude correction factor using the first and third combined signals; the arithmetic device calculating a second amplitude correction factor using the second and fourth combined signals; and the arithmetic device dividing the first and third combined signals by the first amplitude correction factor to obtain the first and third amplitude correction signals, and the arithmetic device dividing the second and fourth combined signals by the second amplitude correction factor to obtain the second and fourth amplitude correction signals.

8. As in the wide-range displacement sensing method of claim 6, the computing device nonlinearly combines the first amplitude correction signal, the second amplitude correction signal, the third amplitude correction signal and the fourth amplitude correction signal to obtain the in-phase channel signal and the positive traffic channel signal, which can be expressed as: , .

9. The wide-range displacement sensing method of claim 8, wherein before the computing device demodulates the in-phase channel signal and the positive traffic channel signal to obtain the Doppler phase shift, the computing device further optimizes the in-phase channel signal and the positive traffic channel signal using the Pythagorean trigonometric identity to solve for the Doppler phase shift factor, the optimization can be expressed as: , where, To optimize the in-phase channel signal, optimize the positive traffic channel signal.

10. The wide-range displacement sensing method of claim 9, wherein the computing device performs arctangent demodulation on the optimized in-phase channel signal and the optimized positive traffic channel signal to obtain the Doppler phase shift, and the arctangent demodulation on the optimized in-phase channel signal and the optimized positive traffic channel signal can be expressed as: .

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