On-demand multi-scan micro doppler for vehicle

• US 9,599,702 B1
• Filed: 07/07/2016
• Issued: 03/21/2017
• 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:
  US15/204,002
• Time in Patent Office: 257 Days
• US Class Current: 1/1
• 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 and stores the first radar data cube in a memory. The processor combines a portion of the first radar data cube with a portion of a previously stored radar data cube. Based at least in part on the combined portions of the radar data cubes, the processor processes a time series that is a time series of the first radar data cube concatenated with a time series from the previously stored radar data cube.

Claims

1. A radar sensing system for a vehicle, the radar sensing system 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 are transmitted radio signals that are 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 comprising complex-valued digitized 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 selectively store a portion of the first three-dimensional array in a memory, wherein the portion of the first three-dimensional array comprises less than the entire first three-dimensional array, and wherein the portion of the first three-dimensional array comprises a first time series of samples from at least one range bin of each receiver of the plurality of receivers;

wherein the processor is further configured to selectively store a portion of the second three-dimensional array into the memory, wherein the portion of the second three-dimensional array comprises less than the entire second three-dimensional array, and wherein the portion of the second three-dimensional array comprises a second time series of samples for the at least one range bin of each receiver of the plurality of receivers;

wherein the processor is further configured to combine the portion of the second three-dimensional array with the portion of the first three-dimensional array and store the combined three-dimensional array in the memory, and wherein the portion of the second three-dimensional array that is less than the entire second three-dimensional array is combined with the portion of the first three-dimensional array that is less than the entire first three-dimensional array by concatenating the second time series of samples for the at least one range bin of each receiver of the plurality of receivers to the first time series of samples for the at least one range bin of each receiver of the plurality of receivers; and

wherein the processor is further configured to Doppler process the concatenated first and second time series of samples for the at least one range bin of each receiver of the plurality of receivers by performing Fourier analysis on each of the concatenated first and second time series of samples.

2. The vehicle radar sensing system of claim 1, wherein the radio signals comprise phase modulated continuous wave radio signals.

3. The vehicle 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.

4. The vehicle radar sensing system of claim 1, wherein the first and second three-dimensional arrays are defined in an x-axis by time, in a y-axis by range bins, and in a z-axis by receivers.

5. The vehicle radar sensing system of claim 1, wherein the plurality of receivers and transmitters comprise at least one of (i) eight receivers and four transmitters, (ii) eight receivers and eight transmitters, and (iii) sixteen receivers and twelve transmitters.

6. The vehicle radar sensing system of claim 1, wherein the concatenated first and second time series of samples provides a higher Doppler resolution than the first time series, and wherein the higher Doppler resolution is achieved during the second scan, and wherein the second scan is substantially equal in time duration to the first scan.

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

8. The vehicle 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 common semiconductor substrate.

9. The vehicle radar sensing system of claim 1, further comprising a plurality of virtual receivers defined by a quantity of physical receivers and a quantity of transmitters.

10. The vehicle radar sensing system of claim 9, wherein the receiver pipeline comprises a correlator block configured to perform the correlations.

11. The vehicle radar sensing system of claim 10, wherein the correlator block comprises a bank of correlators, with the bank of correlators comprising a correlator for every range bin and every virtual receiver combination.

12. The vehicle radar sensing system of claim 11, wherein the bank of correlators comprises a correlator for every range bin and every physical receiver combination, and wherein a first correlator is configured to correlate for each virtual receiver related to the first physical receiver.

13. The vehicle radar sensing system of claim 1, wherein the receive pipeline comprises an antenna and wherein the receive pipeline other than the antenna is integrated on a single integrated chip.

14. The vehicle radar sensing system of claim 1, wherein samples are accumulated into a three-dimensional array one time slice at a time, and wherein the samples are extracted for processing one range slice at a time, wherein a range slice is a horizontal slice of the three-dimensional array comprising a time series of samples for each receiver at a particular range bin.

15. The vehicle 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.