Vehicle odometry and motion direction determination

Patent metadata

Field	Value
Publication number	US-11536825-B2
Application number	US-201916715719-A
Country	US
Kind code	B2
Filing date	Dec 16, 2019
Priority date	Dec 14, 2018
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

The vehicle odometry and motion direction system and method is described. The vehicle odometry and motion direction system and method determines if the first ground speed data is acceptable. Ground speed data is calculated for all targets within a radar's field of view and targets ground speed data is processed to determine second ground speed data. The vehicle odometry and motion direction system and method determines trusted ground speed data using first ground speed data and second ground speed data and adjusts the trusted ground speed data due to errors in radar Doppler speed data.

First claim

What is claimed is:

1. A method of vehicle odometry and/or motion detection, comprising:
determining a vehicle motion direction based on radar Doppler speed data relative to one or more targets;
converting the radar Doppler speed data to first ground speed data;
determining the first ground speed data is acceptable based on speed histogram distributions and a spatial distribution of the one or more targets;
calculating second ground speed data for at least two stationary retroreflectors within a radar's field of view, wherein the separation distance between the two retroreflectors is known;
determining trusted ground speed data using the first ground speed data, the second ground speed data, range data including the range to the at least two retroreflectors and calculated range rate to the at least two retroreflectors; and
adjusting the trusted ground speed data due to errors in the radar Doppler speed data; and
checking the trusted ground speed data against diverse sensor data from a diverse sensor, wherein the diverse sensor failure modes are non-overlapping to radar failure modes.

2. The method of claim 1 , wherein the vehicle motion direction is determined from the first ground speed data and the second ground speed data from a first radar mounted at one end of the vehicle.

3. The method of claim 2 , wherein the vehicle motion direction is determined from the first ground speed data and the second ground speed data from a second radar mounted at another end of the vehicle.

4. The method of claim 1 , wherein the spatial distribution of the one or more targets is within a region-of-interest.

5. The method of claim 1 , wherein the diverse sensor is a body mounted IMU with 3-D accelerometer, 3-D gyroscope, a wheel/axle mounted accelerometer array, an optical tachometer, a Hall effect speed sensor, a LiDAR or a Visible/IR spectrum camera.

6. The method of claim 1 , wherein the diverse sensor provides vehicle motion direction, ground speed or dead reckoning distance travelled.

7. The method of claim 1 , further comprising a second diverse sensor having second diverse sensor failure modes and where the second diverse sensor failure modes are non-overlapping the diverse sensor failure modes and the radar failure modes.

8. A system for vehicle odometry and/or motion detection comprises:
a radar mounted at one end of a vehicle, wherein the radar has radar failure modes;
a diverse sensor mounted on the vehicle, wherein the diverse sensor has diverse sensor failure modes and the diverse sensor failure modes are non-overlapping to the radar failure modes;
a computer connected to the radar and the diverse sensor;

wherein the radar is configured to collect Doppler speed data, range data and radar-cross-section data based on one or more targets, the computer is configured to convert the radar Doppler speed data into first ground speed data and first motion direction data;
the computer is configured to determine if the first ground speed data and the first motion direction data is acceptable based on a speed histogram distribution and a spatial distribution of the one or more targets, the computer is configured to calculate second ground speed data and second motion direction data for at least two stationary retroreflectors within the radar's field of view, wherein the separation distance between the at least two retroreflectors is known; the computer is configured to determine trusted ground speed data using the first ground speed data, the second ground speed data, range data including the range to the at least two retroreflectors and calculated range rate to the at least two retroreflectors, the computer is configured to adjust the trusted ground speed data due to errors in the radar Doppler speed data; and the computer is configured to check the trusted ground speed data against diverse sensor data from a diverse sensor, wherein the diverse sensor has non-overlapping failure modes to the radar failure modes.

9. The system of claim 8 , further comprising a second radar mounted at another end of the vehicle that collects Doppler speed, range and radar-cross-section data to determine a second set of the first ground speed and the second ground speed.

10. The system of claim 8 , wherein the computer uses measured distances to the two reflective landmarks to determine length of the vehicle.

11. The system of claim 10 , wherein the computer uses Doppler speed data from the radar and Doppler speed data from the second radar based on the distances to the two reflective landmarks to determine the trusted ground speed data.

12. The system of claim 8 , wherein the computer groups the one or more targets to determine second ground speed data.

13. The system of claim 8 , wherein the spatial distribution of the one or more targets is within a region-of-interest.

14. The system of claim 8 , wherein the diverse sensor is a body mounted IMU with 3-D accelerometer, 3-D gyroscope, a wheel/axle mounted accelerometer array, an optical tachometer, a Hall effect speed sensor, a LiDAR or a Visible/IR spectrum camera.

15. The system of claim 8 , wherein the diverse sensor provides vehicle motion direction, ground speed or dead reckoning distance travelled.

16. The system of claim 8 , further comprising a second diverse sensor having second diverse sensor failure modes and where the second diverse sensor failure modes are non-overlapping the diverse sensor failure modes and the radar failure modes.

17. A method of vehicle odometry and/or motion detection, comprising:
determining, using a radar, first ground speed data based on one or more targets, wherein the radar has radar failure modes;
calculating second ground speed data for at least two stationary retroreflectors within a radar field of view, wherein the separation distance between the two retroreflectors is known;
determining trusted ground speed data using the first ground speed data, the second ground speed data, range data including the range to the at least two retroreflectors and calculated range rate to the at least two retroreflectors; and
checking the trusted ground speed data against diverse sensor data from a diverse sensor, wherein the diverse sensor has diverse sensor failure modes and the diverse sensor failure modes are non-overlapping to the radar failure modes.

18. The method of claim 17 , wherein the diverse sensor is a body mounted IMU with 3-D accelerometer, 3-D gyroscope, a wheel/axle mounted accelerometer array, an optical tachometer, a Hall effect speed sensor, a LiDAR or a Visible/IR spectrum camera.

19. The method of claim 17 , wherein the diverse sensor data includes vehicle motion direction, ground speed or dead reckoning distance travelled.

20. The method of claim 17 , further comprising a second diverse sensor having second diverse sensor failure modes and where the second diverse sensor failure modes are non-overlapping the diverse sensor failure modes and the radar failure modes.

Assignees

• Thales Canada Inc

Inventors

• Green Alon
• De Thomasis Marco

Classifications

• B61L23/041

  Obstacle detection · CPC title

• B61L25/021

  Measuring and recording of train speed · CPC title

• B61L25/026 Primary

  Relative localisation, e.g. using odometer · 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

• G01S13/62

  Sense-of-movement determination {(G01S13/589 takes precedence)} · CPC title