Use of motion data in the processing of automotive radar image processing

• US 9,423,498 B1
• Filed: 09/25/2012
• Issued: 08/23/2016
• Est. Priority Date: 09/25/2012
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Brown, Adam
• Primary Examiner(s): BYTHROW, PETER M
• Application Number:
  US13/626,673
• Time in Patent Office: 1,428 Days
• Field of Search: 701/1, 701/2, 701/10, 701/23, 701/70, 701/117
• US Class Current: 1/1
• CPC Class Codes: G01S 13/60 wherein the transmitter and receiver are mounted on the moving object, e.g. for determining ground speed, drift angle, ground track G01S13/64 takes precedence
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• CPC Class Codes: G01S 13/865 Combination of radar systems with lidar systems
• CPC Class Codes: G01S 13/867 Combination of radar systems with cameras
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 2013/9318 Controlling the steering
• CPC Class Codes: G01S 2013/93185 Controlling the brakes
• CPC Class Codes: G01S 2013/9319 Controlling the accelerator
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9322 using additional data, e.g. driver condition, road state or weather data
• CPC Class Codes: G01S 2013/9323 Alternative operation using light waves
• CPC Class Codes: G01S 2013/93273 on the top of the vehicles
• CPC Class Codes: G01S 2013/93275 in the bumper area
• CPC Class Codes: G01S 2013/93277 in the lights
• CPC Class Codes: G01S 7/40 Means for monitoring or calibrating
• CPC Class Codes: G05D 1/0257 using a radar radar systems designed for anti-collision purposes between land vehicles or between land vehicle and fixed obstacles G01S13/931
• CPC Class Codes: G08G 1/00 Traffic control systems for road vehicles arrangement of road signs or traffic signals E01F9/00 ; automatic vehicle control B62D
• CPC Class Codes: G08G 1/16 Anti-collision systems road vehicle drive control systems for predicting or avoiding probable or impending collision otherwise than by control of a particular sub-unit B60W30/08
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes

Abstract

In an example method, a vehicle configured to operate in an autonomous mode could have a radar system used to aid in vehicle guidance. The method could include a plurality of antennas configured to transmit and receive electromagnetic signals. The method may also include a one or more sensors configured to measure a movement of the vehicle. A portion of the method may be performed by a processor configured to: i) determine adjustments based on the movement of the vehicle; ii) calculate distance and direction information for received electromagnetic signals; and iii) recover distance and direction information for received electromagnetic signals with the adjustments applied. The processor may be further configured to adjust the movement of the autonomous vehicle based on the distance and direction information with adjustments applied.

Claims

1. A system comprising:

an antenna configured to receive electromagnetic signals, wherein each electromagnetic signal provides distance and direction information for at least one object in an environment of an autonomous vehicle;

at least one sensor configured to provide an output based on a movement of the autonomous vehicle wherein the movement includes a front end of the vehicle pitching down towards the ground below the vehicle as a result of a decrease in speed of the vehicle; and

at least one processor configured to;

prior to the movement, identify a first object and a second object from first signals of the electromagnetic signals;

use the distance and direction information of the second signals the electromagnetic signals to identify and determine an object velocity for a first object indicating that the first object is moving relative to the vehicle;

determine a movement parameter based on the output of the at least one sensor, wherein the movement parameter is an adjustment value that compensates for the movement;

determine that the first object is stationary relative to the vehicle based on the movement parameter and the object velocity;

use the determination that the first object is stationary to control the vehicle;

determine that the second electromagnetic signals do not provide current distance and direction information for the second object;

determine that the movement parameter meets a threshold value; and

when the movement parameter is determined to meet the threshold value, temporarily ignoring, by the computing system, the determination that the second electromagnetic signals do not provide distance and direction information for the second object when controlling the vehicle.

2. The autonomous vehicle of claim 1, further comprising a plurality of antennas.

3. The autonomous vehicle of claim 2, wherein the plurality of antennas form an array.

10. The system of claim 1, further comprising the autonomous vehicle.

11. The system of claim 1, wherein the at least one processor is further configured to:

when the movement parameter is determined to meet the threshold value, estimate current distance and direction information for the second object; and

use the estimate to control the vehicle.

12. The system of claim 1, wherein the threshold value corresponds to a width of a radar beam used to collect the radar data.

15. The system of claim 1, wherein the at least one processor is further configured to temporarily ignore the determination that the second electromagnetic signals do not provide distance and direction information for the second object when controlling the vehicle while the pitch of the front end of the vehicle exceeds a threshold associated with a width of a radar beam.

16. They system of claim 1, wherein the threshold value corresponds to a width of a radar beam used to collect the radar data in a direction corresponding to a direction of the pitching of the front end of the vehicle.

4. A method comprising:

receiving radar data representative of electromagnetic signals, wherein each electromagnetic signal provides distance and direction information for at least one object in an environment of an autonomous vehicle;

prior to the movement, identify a first object and a second object from first signals of the electromagnetic signals;

using the distance and direction information of second electromagnetic signals to determine an object velocity for the first object indicating that the first object is moving relative to the vehicle relative to the vehicle;

receiving movement data representative a movement of the autonomous vehicle wherein the movement includes a front end of the vehicle pitching down towards the ground below the vehicle as a result of a decrease in speed of the vehicle;

determining, by a computer system having at least one processor, a movement parameter including an adjustment value to compensate for the movement based on the movement data; and

determining, by the computer system, that the first object is stationary relative to the vehicle based on the movement parameter and the velocity;

determine that the second electromagnetic signals do not provide current distance and direction information for the second object;

determine that the movement parameter meets a threshold value;

using the determination that the at least one object is stationary to control the vehicle; and

when the movement parameter is determined to meet the threshold value, temporarily ignoring, by the computing system, the determination that the second electromagnetic signals do not provide distance and direction information for the second object when controlling the vehicle.

5. The method of claim 4, wherein receiving radar data representative of an electromagnetic signal further comprising receiving radar data representative of a plurality of electromagnetic signals, wherein each electromagnetic signal is received by a respective antenna in a plurality of antennas.

6. The method of claim 5, wherein the plurality of antennas form an array.

8. The method of claim 4, further comprising

when the movement parameter is determined to meet the threshold value, estimating, by the computing system, current distance and direction information for the second object;

and

using the estimate to control the vehicle.

17. The method of claim 4, wherein the method further comprises, temporarily ignoring the determination that the second electromagnetic signals do not provide distance and direction information for the second object when controlling the vehicle while the pitch of the front end of the vehicle exceeds a threshold associated with a width of a radar beam.

18. They method of claim 4, wherein the threshold value corresponds to a width of a radar beam used to collect the radar data in a direction corresponding to a direction of the pitching of the front end of the vehicle.

7. An article of manufacture including a tangible non-transitory computer-readable medium having computer-readable instructions encoded thereon, the instructions comprising:

instructions for, prior to the movement, identify a first object and a second object from first signals of the electromagnetic signals;

instructions for using the distance and direction information of second electromagnetic signals to determine an object velocity for the first object indicating that the first object is moving relative to the vehicle relative to the vehicle;

instructions for receiving movement data representative of a movement of the autonomous vehicle wherein the movement includes a front end of the vehicle pitching down towards the ground below the vehicle as a result of a decrease in speed of the vehicle;

instructions for determining a movement parameter including an adjustment value to compensate for the movement based on the movement data; and

instructions for determining that the second electromagnetic signals do not provide current distance and direction information for the second object;

instructions for determining that the movement parameter meets a threshold value;

instructions for determining that the first object is stationary relative to the vehicle based on the movement parameter and the velocity; and

instructions for when the movement parameter is determined to meet the threshold value, temporarily ignoring, by the computing system, the determination that the second electromagnetic signals do not provide distance and direction information for the second object when controlling the vehicle.

9. The method of claim 7, wherein the threshold value corresponds to a width of a radar beam used to collect the radar data.

13. The article of manufacture of claim 7, wherein the instructions further comprise:

instructions for, when the movement parameter is determined to meet the threshold value, estimating, by the computing system, current distance and direction information for the second object, and

instructions for using the estimate to control the vehicle.

14. The article of manufacture of claim 7, wherein the threshold value corresponds to a width of a radar beam used to collect the radar data.

19. The article of manufacture claim 7, wherein the instructions further comprise instructions for temporarily ignoring the determination that the second electromagnetic signals do not provide distance and direction information for the second object when controlling the vehicle while the pitch of the front end of the vehicle exceeds a threshold associated with a width of a radar beam.

20. They article of manufacture claim 7, wherein the threshold value corresponds to a width of a radar beam used to collect the radar data in a direction corresponding to a direction of the pitching of the front end of the vehicle.