Velocity measurement with asymmetric doppler spectrum

Patent metadata

Field	Value
Publication number	US-10585182-B2
Application number	US-201715468192-A
Country	US
Kind code	B2
Filing date	Mar 24, 2017
Priority date	Mar 24, 2017
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

A method and system to obtain a velocity measurement of a target detected by a radar system using an asymmetric Doppler spectrum includes a receive portion of the radar system to receive a reflected signal from the target. A mixer mixes the reflected signal with a shifted signal to obtain a mixed signal. The shifted signal is a shifted version of a transmitted signal that results in the reflected signal and the Doppler spectrum is defined by a frequency shift value of the shifted signal. A processor processes the mixed signal to obtain the velocity measurement.

First claim

What is claimed is:

1. A system to obtain a velocity measurement of a target detected by a radar system using an asymmetric Doppler spectrum, the system comprising:
a receive portion of the radar system configured to receive a reflected signal from the target;
a mixer configured to mix the reflected signal with a shifted signal to obtain a mixed signal, wherein the shifted signal is a shifted version of a transmitted signal that results in the reflected signal and the Doppler spectrum that determines a range of detectable values of the velocity measurement is defined by and is asymmetrical around zero based on a frequency shift value of the shifted signal that is mixed with the reflected signal by the mixer; and
a processor configured to process the mixed signal to obtain the velocity measurement.

2. The system according to claim 1 , wherein the transmitted signal is at a carrier frequency f c and the shifted signal is at a frequency of f c +f Δ and f Δ is the frequency shift value.

3. The system according to claim 2 , wherein the Doppler spectrum is from −f D +f Δ to f D +f Δ and f D is a pulse repetition frequency of the transmitted signal.

4. The system according to claim 1 , wherein the processor controls the Doppler spectrum to set different maximum detectable values of the velocity measurement for the target based on whether the target is approaching or receding from the radar system in accordance with the Doppler spectrum.

5. The system according to claim 4 , wherein the different maximum detectable values of the velocity measurement are set based on the frequency shift value.

6. The system according to claim 1 , wherein the system is housed in a vehicle.

7. A method to obtain a velocity measurement of a target detected by a radar system using an asymmetric Doppler spectrum, the method comprising:
receiving, using a receive portion of the radar system, a reflected signal from the target;
generating a shifted signal as a shifted version of a transmitted signal that results in the reflected signal;
defining the Doppler spectrum, which determines a range of detectable values of the velocity measurement and is asymmetrical around zero, based on a frequency shift value of the shifted signal;
mixing, using a mixer, the reflected signal with the shifted signal to obtain a mixed signal; and
processing the mixed signal to obtain the velocity measurement, wherein a maximum detectable velocity is in accordance with the Doppler spectrum.

8. The method according to claim 7 , further comprising transmitting the transmitted signal at a carrier frequency f c , wherein the generating the shifted signal is at a frequency of f c +f Δ and f Δ is the frequency shift value.

9. The method according to claim 8 , wherein the defining the Doppler spectrum is from −f D +f Δ to f D +f Δ and f D is a pulse repetition frequency of the transmitted signal.

10. The method according to claim 7 , further comprising controlling the Doppler Spectrum to set the maximum detectable velocity as different maximum detectable values of the velocity measurement for the target based on whether the target is approaching or receding from the radar system in accordance with the Doppler spectrum.

11. The method according to claim 10 , wherein the determining the different maximum detectable values of the velocity measurement for approaching versus receding targets is based on the frequency shift value.

12. An automobile, comprising:
a receive portion of a radar system configured to receive a reflected signal from a target;
a mixer configured to mix the reflected signal with a shifted signal to obtain a mixed signal, wherein the shifted signal is a shifted version of a transmitted signal that results in the reflected signal and the Doppler spectrum that determines a range of detectable values of the velocity measurement is defined by and is asymmetrical around zero based on a frequency shift value of the shifted signal that is mixed with the reflected signal by the mixer; and
a processor configured to process the mixed signal to obtain the velocity measurement, wherein the processor provides the velocity measurement to another system of the automobile, the another system including a braking system or autonomous driving system.

13. The automobile according to claim 12 , wherein the transmitted signal is at a carrier frequency f c and the shifted signal is at a frequency of f c +f Δ and f Δ is the frequency shift value.

14. The automobile according to claim 13 , wherein the Doppler spectrum is from −f D +f Δ to f D +f Δ and f D is a pulse repetition frequency of the transmitted signal.

15. The automobile according to claim 12 , wherein the processor controls the Doppler spectrum to set different maximum detectable values of the velocity measurement for the target based on whether the target is approaching or receding from the radar system in accordance with the Doppler spectrum.

16. The automobile according to claim 15 , wherein the different maximum detectable values of the velocity measurement are set based on the frequency shift value.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Bilik Igal
• Pokrass Alexander
• Villeval Shahar

Classifications

• G01S2013/93185

  Controlling the brakes · CPC title

• G01S13/581 Primary

  using transmission of interrupted pulse modulated waves and based upon the Doppler effect resulting from movement of targets · CPC title

• G01S2013/9318

  Controlling the steering · CPC title

• G01S13/931

  of land vehicles · CPC title

• G01S13/583 Primary

  using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting from movement of targets · CPC title