On-demand multi-scan micro doppler for vehicle

• US 10,073,171 B2
• Filed: 08/30/2017
• Issued: 09/11/2018
• Est. Priority Date: 04/25/2016
• Status: Active Grant

• Current Assignee: Uhnder, Inc.
• Original Assignee: Uhnder, Inc.
• Inventors: Bordes, Jean P., Rao, Raghunath K., Maher, Monier
• Primary Examiner(s): Barker, Matthew M
• Application Number:
  US15/690,898
• Publication Number:
  US 20170363731A1
• Time in Patent Office: 377 Days
• CPC Class Codes: G01S 13/18 wherein range gates are used
• CPC Class Codes: G01S 13/325 using transmission of coded signals, e.g. P.S.K. signals
• CPC Class Codes: G01S 13/36 with phase comparison between the received signal and the contemporaneously transmitted signal
• CPC Class Codes: G01S 13/50 Systems of measurement based on relative movement of target
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles
• CPC Class Codes: G01S 2013/93272 in the back of the vehicles
• CPC Class Codes: G01S 2013/93274 on the side of the vehicles
• CPC Class Codes: G01S 2013/93276 in the windshield area
• CPC Class Codes: G01S 7/354 Extracting wanted echo-signals Doppler systems G01S13/50
• CPC Class Codes: G01S 7/356 involving particularities of FFT processing

Abstract

A radar sensing system for a vehicle includes a transmitter, a receiver, a memory, and a processor. The transmitter transmits a radio signal and the receiver receives a reflected radio signal. The processor samples reflected radio signals during a plurality of time slices. The processor produces samples by correlating reflected radio signals to time-delayed replicas of transmitted radio signals. The processor accumulates the time slices into a first radar data cube (RDC) and selectively processes a portion of the first RDC to produce a first partial Doppler output. The processor produces samples during a second scan and accumulates time slices into a second RDC, and then selectively processes a portion of the second RDC to produce a second partial Doppler output. The processor numerically accumulates the first and second partial Doppler outputs to create a full Doppler output and stores the full Doppler output in memory.

Claims

1. A radar sensing system for a vehicle, the radar sensing system comprising:

a transmit pipeline comprising a plurality of transmitters configured for installation and use on a vehicle, and configured to transmit radio signals;

a receive pipeline comprising a plurality of receivers configured for installation and use on the vehicle, and configured to receive radio signals, wherein the received radio signals include reflected radio signals that are the transmitted radio signals reflected from an object; and

a processor;

wherein the receive pipeline is configured to correlate received radio signals of the plurality of receivers with a plurality of time-delayed replicas of the transmitted radio signals to produce samples;

wherein each time-delayed replica of the plurality of time-delayed replicas of the transmitted radio signals corresponds with a particular range bin of a particular receiver of the plurality of receivers;

wherein samples are produced during a first plurality of time slices of a first scan;

wherein a time slice of the first plurality of time slices comprises a two-dimensional array of samples, the two-dimensional array defined by the plurality of receivers and a respective plurality of range bins for each receiver of the plurality of receivers;

wherein each range bin of each respective plurality of range bins contains a sample from the respective receiver of the plurality of receivers;

wherein the first plurality of time slices is accumulated into a first three-dimensional array during the first scan;

wherein the receive pipeline is further configured to produce samples during a second plurality of time slices of a second scan;

wherein the second plurality of time slices is accumulated into a second three-dimensional array during the second scan;

wherein the receive pipeline is further configured to output the first and second three-dimensional arrays to the processor;

wherein the processor is configured to (a) selectively process a portion of the first three-dimensional array, (b) produce a first partial Doppler output, (c) discard the first three-dimensional array, and (d) save the first partial Doppler output into memory;

wherein the portion of the first three-dimensional array comprises less than the entire first three-dimensional array;

wherein the portion of the first three-dimensional array comprises a first time series of samples for at least one range bin of each receiver of the plurality of receivers;

wherein the processor is further configured to selectively process a second time series of samples from a second three-dimensional array to produce a second partial Doppler output; and

wherein the processor stores the second partial Doppler output into the memory by numerically accumulating the second partial Doppler output with the first partial Doppler output.

2. The radar sensing system of claim 1, wherein a radar unit comprising the plurality of transmitters and plurality of receivers is configured to be installed at at least one of a front portion of the vehicle, a side portion of the vehicle, a rear portion of the vehicle, and behind a windshield of the vehicle.

3. The radar sensing system of claim 1, wherein the transmitted radio signals and the received radio signals are respectively transmitted and received simultaneously.

4. The radar sensing system of claim 3, wherein the processor is further configured to post process the accumulated partial Doppler outputs to establish an angle of arrival for the object.

5. The radar sensing system of claim 1, wherein the processor comprises a CMOS-based processor, and wherein the processor, receivers, and transmitters are established within a radar system architecture that is established on a single semiconductor substrate.

6. The radar sensing system of claim 1, wherein a time-delayed replica of the transmitted radio signals that is highly correlating with a delay of the received signal produces a complex value with a larger amplitude as compared to an amplitude of non-correlating signals.

7. The radar sensing system of claim 1, wherein the Doppler processing is performed on a time series synthesized from the time series data from two or more range bins.

8. The radar sensing system of claim 1, wherein the radio signals comprise phase modulated continuous wave radio frequency (RF) signals.

9. The radar sensing system of claim 1, wherein the numerically accumulated first partial Doppler output and second partial Doppler output provides a higher Doppler resolution than the first time series of samples, and wherein the high Doppler resolution is achieved during the second scan, and wherein the second scan is substantially equal in time duration to the first scan.

10. The radar sensing system of claim 1, wherein the samples comprise complex-valued digitized samples.

11. A method for achieving high resolution Doppler measurements for a vehicle radar sensing system, the method comprising:

providing a radar sensing system comprising (i) a transmit pipeline configured for installation and use on a vehicle, wherein the transmit pipeline comprises a plurality of transmitters configured to transmit radio signals, (ii) a receive pipeline configured for installation and use on the vehicle, wherein the receive pipeline comprises a plurality of receivers configured to receive radio signals that include the transmitted radio signals reflected from objects in the environment, and (iii) a processor for processing the radio signals received by the plurality of receivers;

sampling the received radio signals during a first plurality of time slices of a first scan, wherein each time slice comprises a plurality of samples, a respective sample for each range bin of each plurality of range bins for each receiver of the plurality of receivers in each time slice, and wherein the samples are produced by correlating the received signals to time-delayed replicas of the transmitted signals;

accumulating the first plurality of time slices into a first radar data cube during the first scan;

sampling the received radio signals during a second plurality of time slices of a second scan;

accumulating the second plurality of time slices into a second radar data cube during the second scan;

outputting the first and second radar data cubes to the processor;

with the processor, selectively Doppler processing a portion of the first radar data cube, producing a first partial Doppler output, discarding the first radar data cube, and saving the first partial Doppler output into a memory;

wherein the portion of the first radar data cube comprises a first time series of samples for at least one range bin of each receiver of the plurality of receivers;

with the processor, selectively Doppler processing a second time series of samples from the second radar data cube to produce a second partial Doppler output; and

with the processor, storing the second partial Doppler output into the memory by numerically accumulating the second partial Doppler output with the first partial Doppler output.

12. The method of claim 11, wherein the portion of the first radar data cube comprises less than the entire first radar data cube.

13. The method of claim 11, wherein the transmitted radio signals and the received radio signals are respectively transmitted and received simultaneously.

14. The method of claim 11 further comprising post-processing the accumulated partial Doppler outputs to establish an angle of arrival for each object.

15. The method of claim 11, wherein the Doppler processing is performed on a time series synthesized from the time series data from two or more range bins.

16. The method of claim 11, wherein the numerically accumulated first partial Doppler output and second partial Doppler output provides a higher Doppler resolution than the first time series of samples, and wherein the high Doppler resolution is achieved during the second scan, and wherein the second scan is substantially equal in time duration to the first scan.

17. The method of claim 11, wherein the samples comprise complex-valued digitized samples.

18. The method of claim 11, wherein the transmitted radio signals comprise phase modulated continuous wave radio signals.

19. The method of claim 11, wherein a time-delayed replica of the transmitted radio signals that is highly correlating with a delay of the received signal produces a complex value with a larger amplitude as compared to an amplitude of non-correlating signals.

20. The method of claim 11, wherein the processor comprises a CMOS-based processor, and wherein the processor, receivers, and transmitters are established within a radar system architecture that is established on a single semiconductor substrate.

21. A radar sensing system for a vehicle, the radar sensing system comprising:

a transmit pipeline configured for installation and use on a vehicle, wherein the transmit pipeline comprises a plurality of transmitters configured to transmit radio signals;

a receive pipeline configured for installation and use on the vehicle, wherein the receive pipeline comprises a plurality of receivers configured to receive radio signals that include the transmitted radio signals reflected from objects in the environment; and

a processor;

wherein the receive pipeline is configured to correlate received radio signals of the plurality of receivers with a plurality of time-delayed replicas of the transmitted radio signals to produce samples;

wherein each time-delayed replica of the plurality of time-delayed replicas of the transmitted radio signals corresponds with a particular range bin of a particular receiver of the plurality of receivers;

wherein samples are produced during at least two or more scans, each scan comprising a respective plurality of time slices;

wherein each time slice of the respective plurality of time slices comprises a two-dimensional array of samples, the two-dimensional array defined by the plurality of receivers and a respective plurality of range bins for each receiver of the plurality of receivers;

wherein each range bin of each respective plurality of range bins contains a sample from the respective receiver of the plurality of receivers;

wherein each plurality of time slices is accumulated into a corresponding radar data cube of the two or more radar data cubes during a respective scan of the at least two or more scans;

wherein the receive pipeline is configured to output each of the two or more radar data cubes to the processor;

wherein the processor is configured to (i) selectively process a portion of each of the two or more radar data cubes to produce a respective partial Doppler output for each of the two or more radar data cubes, and (ii) discard the two or more radar data cubes;

wherein a portion of a radar data cube comprises a time series of samples for at least one range bin of each receiver of the plurality of receivers; and

wherein the processor is configured to store in memory a full Doppler output by successively numerically accumulating together each of the partial Doppler outputs to form the full Doppler output.

22. The radar sensing system of claim 21, wherein a radar unit comprising the plurality of transmitters and plurality of receivers is configured to be installed at at least one of a front portion of the vehicle, a side portion of the vehicle, a rear portion of the vehicle, and behind a windshield of the vehicle.

23. The radar sensing system of claim 21, wherein the transmitted radio signals and the received radio signals are respectively transmitted and received simultaneously.

24. The radar sensing system of claim 21, wherein the processor is further configured to post process the accumulated partial Doppler outputs to establish an angle of arrival for each object.

25. The radar sensing system of claim 21, wherein the processor comprises a CMOS-based processor, and wherein the processor, receivers, and transmitters are established within a radar system architecture that is established on a single semiconductor substrate.

26. The radar sensing system of claim 21, wherein a time-delayed replica of the transmitted radio signals that is highly correlating with a delay of the received signal produces a complex value with a larger amplitude as compared to an amplitude of non-correlating signals.

27. The radar sensing system of claim 21, wherein the Doppler processing is performed on a time series synthesized from the time series data from two or more range bins.

28. The radar sensing system of claim 21, wherein the radio signals comprise phase modulated continuous wave radio frequency (RF) signals.

29. The radar sensing system of claim 21, wherein a numerically accumulated first partial Doppler output of a first scan and a second partial Doppler output of a second scan provides a higher Doppler resolution than a first time series of samples, and wherein a high Doppler resolution is achieved during the second scan, wherein the second scan is substantially equal in time duration to the first scan, and wherein the first partial Doppler output and the second partial Doppler output are numerically accumulated during the second scan.

30. The radar sensing system of claim 21, wherein the samples comprise complex-valued digitized samples.