METHOD AND APPARATUS FOR DETERMINING DIRECTION OF THE BEGINNING OF VEHICLE MOVEMENT

• US 20170046953A1
• Filed: 10/26/2016
• Published: 02/16/2017
• Est. Priority Date: 06/16/2010
• Status: Active Grant

• Current Assignee: Topcon Positioning Systems Incorporated (Topcon Corporation)
• Original Assignee: Topcon Positioning Systems Incorporated (Topcon Corporation)
• Inventors: Zhdanov, Alexey V., Zintsov, Eugene I.
• Granted Patent: US 10,026,311 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 21/08 involving use of the magnetic field of the earth
• CPC Class Codes: G08G 1/056 with provision for distinguishing direction of travel

Abstract

A method of movement mode determination comprising measurement of vehicle'"'"'s position and orientation and calculation of movement parameters, a compass on the vehicle, is azimuthally oriented along the prevailing and is mostly used movement direction (“forward” direction), a movement vector measurement unit, is used for measuring the azimuth of movement vector. A calculation unit being used for measuring an angle between vehicle movement vector azimuth measured by the movement vector measurement unit and vehicle azimuth measured by the compass fixed on the vehicle; movement is regarded as “backward” if the calculated angle is greater than 90 degrees, and “forward” if the calculated angle is smaller than 90 degrees. Also, an apparatus for movement direction determination includes a compass and a computation unit and further comprises a movement vector measurement unit for determining vehicle movement azimuth and connected through a signal connection to the computation unit.

Claims

1. A method for determining whether a moving vehicle is moving in a forward movement mode or in a backward movement mode, the method comprising the steps of:

measuring a magnetic azimuthal angle of the moving vehicle using a magnetic sensor mounted on the moving vehicle;

measuring a vehicle movement vector associated with the moving vehicle using a GNSS receiver mounted on the moving vehicle;

computing, with a computation unit, a movement vector azimuthal angle of the moving vehicle using the vehicle movement vector; and

determining, with the computation unit, whether the moving vehicle is moving in the forward movement mode or in the backward movement mode based at least in part on the magnetic azimuthal angle and the movement vector azimuthal angle.

2. The method of claim 1, wherein the magnetic sensor is a compass.

3. The method of claim 2, wherein the determining step further comprises:

calculating a difference between the magnetic azimuthal angle and the movement vector azimuthal angle, wherein;

if the calculated difference is less than 90 degrees the moving vehicle is determined to be moving in the forward movement mode, and

if the calculated difference is greater than 90 degrees the moving vehicle is determined to be moving in the backward movement mode.

4. The method of claim 3, wherein the magnetic azimuthal angle is referenced to a North axis.

5. The method of claim 4, wherein the measuring of the vehicle movement vector further comprises:

measuring (i) at a first time, a first vehicle position, and (ii) at a second time, a second vehicle position; and

determining the vehicle movement vector as a function of at least the first vehicle position and the second vehicle position.

6. The method of claim 4, wherein the measuring of the vehicle movement vector further comprises:

measuring a plurality of velocities associated with the moving vehicle; and

determining the vehicle movement vector as a function of particular ones of the plurality of velocities.

7. The method of claim 4, wherein:

the compass is oriented such that, when the moving vehicle is moving along the North axis in the forward movement mode, the compass azimuthal angle is zero; and

the step of determining, with the computation unit, whether the moving vehicle is moving in the forward movement mode or in the backward movement mode comprises the steps of;

computing an angle based at least in part on a difference between the magnetic azimuthal angle and the movement vector azimuthal angle;

computing an absolute value of the angle;

comparing the absolute value to 90 degrees;

upon determining that the absolute value is greater than 90 degrees, determining that the moving vehicle is moving in the backward movement mode; and

upon determining that the absolute value is not greater than 90 degrees, determining that the moving vehicle is moving in the forward movement mode.

8. The method of claim 7, further comprising:

transmitting the magnetic azimuthal angle from the compass to the computation unit; and

transmitting the vehicle movement vector from the GNSS receiver to the computation unit.

9. The method of claim 7, wherein the vehicle movement vector utilizes coordinates defined by a local geodetic coordinate system.

10. The method of claim 9, further comprising:

initializing a direction mode of the moving vehicle in the local geodetic coordinate system based upon determining whether the absolute value is less than or greater than 90 degrees.

11. An apparatus for determining whether a moving vehicle is moving in a forward movement mode or in a backward movement mode, the apparatus comprising:

a magnetic sensor mountable on the moving vehicle and configured for measuring a magnetic sensor azimuthal angle of the moving vehicle;

a GNSS receiver mountable on the moving vehicle and configured for measuring a vehicle movement vector associated with the moving vehicle;

a computation unit configured to;

receive, from the magnetic sensor, the magnetic azimuthal angle;

receive, from the GNSS receiver, the vehicle movement vector;

compute a movement vector azimuthal angle of the moving vehicle using the vehicle movement vector; and

determine whether the moving vehicle is moving in the forward movement mode or in the backward movement mode based at least in part on the magnetic azimuthal angle and the movement vector azimuthal angle.

12. The apparatus of claim 11, wherein the magnetic sensor is a compass.

13. The apparatus of claim 12, wherein the computation unit is further configured to:

calculate a difference between the magnetic azimuthal angle and the movement vector azimuthal angle, wherein;

if the calculated difference is less than 90 degrees the moving vehicle is determined to be moving in the forward movement mode, and

if the calculated difference is greater than 90 degrees the moving vehicle is determined to be moving in the backward movement mode.

14. The apparatus of claim 13, wherein the magnetic azimuthal angle is referenced to a North axis.

15. The apparatus of claim 14, wherein the measuring of the vehicle movement vector further comprises:

measuring (i) at a first time, a first vehicle position, and (ii) at a second time, a second vehicle position; and

determining the vehicle movement vector as a function of at least the first vehicle position and the second vehicle position.

16. The apparatus of claim 14, wherein the measuring of the vehicle movement vector further comprises:

measuring a plurality of velocities associated with the moving vehicle; and

determining the vehicle movement vector as a function of particular ones of the plurality of velocities.

17. The apparatus of claim 14, wherein:

the compass is oriented such that, when the moving vehicle is moving along the North axis in the forward movement mode, the compass azimuthal angle is zero; and

the step of determining, with the computation unit, whether the moving vehicle is moving in the forward movement mode or in the backward movement mode comprises the steps of;

computing an angle based at least in part on a difference between the magnetic azimuthal angle and the movement vector azimuthal angle;

computing an absolute value of the angle;

comparing the absolute value to 90 degrees;

upon determining that the absolute value is greater than 90 degrees, determining that the moving vehicle is moving in the backward movement mode; and

upon determining that the absolute value is not greater than 90 degrees, determining that the moving vehicle is moving in the forward movement mode.

18. The apparatus of claim 17, wherein the compass is configured for transmitting the magnetic azimuthal angle from the compass to the computation unit, and the GNSS receiver is configured for transmitting the vehicle movement vector from the GNSS receiver to the computation unit.

19. The apparatus of claim 17, wherein the vehicle movement vector utilizes coordinates defined by a local geodetic coordinate system.

20. The apparatus of claim 19, wherein the computation unit is further configured to:

initialize a direction mode of the moving vehicle in the local geodetic coordinate system based upon determining whether the absolute value is less than or greater than 90 degrees.

21. A vehicle capable of moving in a forward movement mode or in a backward movement mode, the vehicle comprising:

a magnetic sensor mounted on the moving vehicle and configured for measuring a magnetic sensor azimuthal angle of the moving vehicle;

a GNSS receiver mounted on the moving vehicle and configured for measuring a vehicle movement vector associated with the moving vehicle;

a computation unit configured to;

receive, from the magnetic sensor, the magnetic azimuthal angle;

receive, from the GNSS receiver, the vehicle movement vector;

compute a movement vector azimuthal angle of the moving vehicle using the vehicle movement vector; and

determine whether the moving vehicle is moving in the forward movement mode or in the backward movement mode based at least in part on the magnetic azimuthal angle and the movement vector azimuthal angle.

22. The vehicle of claim 21, wherein the magnetic sensor is a compass.

23. The vehicle of claim 22, wherein the computation unit is further configured to:

calculate a difference between the magnetic azimuthal angle and the movement vector azimuthal angle, wherein;

if the calculated difference is less than 90 degrees the moving vehicle is determined to be moving in the forward movement mode, and

if the calculated difference is greater than 90 degrees the moving vehicle is determined to be moving in the backward movement mode.

24. The vehicle of claim 23, wherein the magnetic azimuthal angle is referenced to a North axis.

25. The vehicle of claim 24, wherein the measuring of the vehicle movement vector further comprises:

measuring (i) at a first time, a first vehicle position, and (ii) at a second time, a second vehicle position; and

determining the vehicle movement vector as a function of at least the first vehicle position and the second vehicle position.

26. The vehicle of claim 24, wherein the measuring of the vehicle movement vector further comprises:

measuring a plurality of velocities associated with the moving vehicle; and

determining the vehicle movement vector as a function of particular ones of the plurality of velocities.

27. The vehicle of claim 24, wherein:

the compass is oriented such that, when the moving vehicle is moving along the North axis in the forward movement mode, the compass azimuthal angle is zero; and

the step of determining, with the computation unit, whether the moving vehicle is moving in the forward movement mode or in the backward movement mode comprises the steps of;

computing an angle based at least in part on a difference between the magnetic azimuthal angle and the movement vector azimuthal angle;

computing an absolute value of the angle;

comparing the absolute value to 90 degrees;

upon determining that the absolute value is greater than 90 degrees, determining that the moving vehicle is moving in the backward movement mode; and

upon determining that the absolute value is not greater than 90 degrees, determining that the moving vehicle is moving in the forward movement mode.