FMCW radar blocking detection

• US 10,267,897 B2
• Filed: 05/16/2014
• Issued: 04/23/2019
• Est. Priority Date: 05/23/2013
• Status: Active Grant

• Current Assignee: Magna Electronics Sweden AB (SSW Partners LP)
• Original Assignee: Veoneer Sweden AB (SSW Partners LP)
• Inventors: Jenkins, Alan
• Primary Examiner(s): Barker, Matthew M
• Application Number:
  US14/892,638
• Publication Number:
  US 20160091599A1
• Time in Patent Office: 1,803 Days
• CPC Class Codes: G01S 13/288 phase modulated
• CPC Class Codes: G01S 13/34 using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
• CPC Class Codes: G01S 13/343 using sawtooth modulation
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 7/4004 of parts of a radar system
• CPC Class Codes: G01S 7/4039 of sensor or antenna obstruction, e.g. dirt- or ice-coating

Abstract

A method and apparatus for detection of blocking of a frequency-modulated continuous-wave, FMCW, radar device. A first signal being a first transmission signal including an object detection signal is transmitted. A second signal being a frequency offset signal relative the first signal is transmitted. A reception signal including at least a received version of the second signal is received. Blocking of the FMCW radar device is determined by identifying a blocking pattern in the received version of the second reception signal.

Claims

1. A method for detecting blocking of a frequency-modulated continuous-wave (FMCW), radar device, comprising the steps of:

generating a first signal;

generating a second signal from at least two frequency shifted versions of the first signal;

transmitting the first signal being a first transmission signal, the first signal comprising an object detection signal;

transmitting the second signal being a frequency offset signal relative the first signal;

receiving a reception signal, the reception signal comprising at least a received version of the second signal; and

determining blocking by identifying a blocking pattern in the received version of the second reception signal.

2. The method according to claim 1, further comprising:

subjecting the reception signal to a high pass filtering prior to the determining blocking step.

3. The method according to claim 1, wherein the determining blocking step further comprises:

frequency processing an offset frequency component in the reception signal, the offset frequency component being indicative of the blocking pattern and associated with a frequency shifted zero-frequency bin.

4. The method according to claim 3, wherein the determining blocking step further comprises:

determining the offset frequency component as a deterministic signal received in a single range gate.

5. The method according to claim 4, wherein the deterministic signal comprises frequency components spread in at least two adjacent frequency range bins or Doppler bins.

6. The method according to claim 1, wherein the FMCW radar device has a field of view, and wherein the determining blocking step provides an indication of transmission from the FMCW radar device being blocked by a physical object being placed so as to cover the field of view.

7. The method according to claim 1, wherein the first signal is an up chirp ramp signal or a down chirp ramp signal.

8. The method according to claim 1, wherein the reception signal is received from a device external reflection.

9. The method according to claim 1, further comprising the steps of:

transmitting a further first signal being a further first transmission signal, the further first signal comprising the object detection signal; and

wherein the step of transmitting the second signal being the frequency offset signal is performed at least one of;

during start-up of the FMCW radar device, once every I;

th transmission of the further first signal, where I≥

1, and once every J;

th millisecond during operation of the FMCW radar device, where J≥

1.

10. The method in accordance with claim 1, wherein the blocking is in the form of a physical barrier interfering with the transmission or reception of the frequency-modulated continuous wave.

11. A frequency-modulated continuous-wave (FMCW), radar device for detecting blocking of the FMCW radar device, comprising:

a signal generator configured to generate a first signal;

the signal generator configured to generate a second signal from at least two frequency shifted versions of the first signal;

a transmitter arranged to transmit the first signal being a first transmission signal, the first signal comprising an object detection signal;

the transmitter further being arranged to transmit the second signal being a frequency offset signal relative the first signal;

a receiver arranged to receive a reception signal, the reception signal comprising at least a received version of the second signal; and

a controller arranged to determine blocking by identifying a blocking pattern in the received version of the second reception signal.

12. The FMCW radar device of claim 11, wherein the FMCW radar device is mounted to an automobile.

13. The radar device in accordance with claim 11, wherein the blocking is in the form of a physical barrier interfering with the transmission or reception of the frequency-modulated continuous wave.

14. A non-transitory computer readable medium for detecting blocking of a frequency-modulated continuous-wave (FMCW), radar device, the non-transitory computer readable medium having instructions sorted thereon, which when executed by a radar device cause the radar device to:

generate a first signal;

generate a second signal from at least two frequency shifted versions of the first signal;

transmit the first signal being a first transmission signal, the first signal comprising an object detection signal;

transmit the second signal being a frequency offset signal relative the first signal;

receive a reception signal, the reception signal comprising at least a received version of the second signal;

determine blocking by identifying a blocking pattern in the received version of the second reception signal.