Methods and apparatus for measuring navigational parameters of a locomotive

• US 7,557,748 B1
• Filed: 06/01/2000
• Issued: 07/07/2009
• Est. Priority Date: 09/10/1999
• Status: Expired due to Fees

• Current Assignee: Ge-Harris Raliway Electronics LLC
• Original Assignee: General Electric Company
• Inventors: Zahm, Charles L., Clyne, Kevin M., Matheson, William L.
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): Amin; Bhavesh V
• Application Number:
  US09/585,192
• Time in Patent Office: 3,323 Days
• Field of Search: 701/19, 701/215, 701/208, 701/209, 701/20, 701/117, 701/205, 701/207, 701/213, 701/214, 701/224, 342/357.11
• US Class Current: 342/357.33
• CPC Class Codes: B61L 2205/04 Satellite based navigation systems, e.g. global positioning system [GPS]
• CPC Class Codes: B61L 25/026 Relative localisation, e.g. using odometer
• CPC Class Codes: G01S 19/50 whereby the position solution is constrained to lie upon a particular curve or surface, e.g. for locomotives on railway tracks

Abstract

The present invention, in one aspect, is a method for determining motion and/or location parameters of a locomotive. One method embodiment includes steps of phase locking a pair of receivers having antennas at different locations on a locomotive to reference signals received from a set of satellites, determining a set of phase differences between the reference signals received at the antennas, and determining at least one of an accurate heading, heading rate, attitude, and attitude rate of the locomotive using the set of phase differences between the reference signals.

Claims

1. A method for determining at least one of motion and location parameters of a railroad locomotive, with the locomotive oriented with either end thereof in the lead in the direction of travel of the locomotive, said method comprising the steps of:

providing at least two satellite signal receivers on the locomotive at spaced locations along the length of the locomotive;

determining a vector distance {right arrow over (d)} between the two satellite signal receivers using an integer ambiguity, wherein an initial integer ambiguity is resolved by consulting a database that provides an initial heading and track grade as a function of latitude and longitude;

determining a set of phase differences between satellite reference signals received by satellite receivers; and

determining an accurate heading, accurate heading rate, attitude, and attitude rate of the locomotive during normal locomotive transit operation using only the set of phase differences between the satellite reference signals and the vector distance {right arrow over (d)} the method further comprising the step of determining {right arrow over (d)} as {right arrow over (d)}=(H^TH)<sup>−

1</sup>H^T{right arrow over (y)}, where;

2. A method according to claim 1 wherein said step of determining an attitude and an attitude rate of a locomotive using {right arrow over (d)} further comprises determining the heading using

3. A method according to claim 1 further comprising the step of determining a track curvature, C.

4. A method according to claim 3 wherein determining a track curvature comprises the step of detecting an angular rotation rate ω

and a velocity ν

of the locomotive, wherein C=ω

/ν

.

5. A method according to claim 4 wherein detecting an angular rotation rate ω

and a velocity ν

of the locomotive comprises the step of detecting an angular rotation rate ω

using a gyroscope and a velocity ν

of the locomotive using a tachometer.

6. A method according to claim 4 wherein detecting an angular rotation rate ω

and a velocity ν

of the locomotive comprises the step of detecting an angular rotation rate ω

using received satellite signals and velocity ν

of the locomotive using a tachometer.

7. A method according to claim 3 wherein determining a track curvature comprises the step of determining a lateral acceleration α

and a velocity ν

of the locomotive, wherein C=α

/ν

².

8. A method according to claim 3 further comprising the step of controlling dispensing of a track lubricant in accordance with the determined curvature value C.

9. A method according to claim 8 wherein said step of controlling dispensing of a track lubricant further comprises the step of dispensing the lubricant when C exceeds a predetermined magnitude.

10. A method according to claim 1 further comprising the steps of:

determining a position of the locomotive; and

accessing a database of track heading and grade to determine a present track heading and grade at the determined position of the locomotive.

11. A method according to claim 1 further comprising the steps of:

sampling latitude and longitude from the satellite receivers; and

determining a distance traveled by the locomotive.

12. A method according to claim 11 wherein said step of sampling latitude and longitude from the satellite receivers further comprises the steps of:

sampling where the distance between the samples is determined as

Δ

d=R[Δ

lat²+cos²(lat)Δ

long²]^1/2

where Δ

lat is a difference between latitudes of consecutive measurements;

Δ

long is a difference between longitudes of consecutive measurements; and

R is the radius of the earth (about 3,440 nmi); and

said step of determining a distance traveled by the locomotive further comprises the step of summing Δ

d over successive measurements.

13. An apparatus for determining at least one of motion and location parameters of a railroad locomotive to detect curves and reduce track wear, with the locomotive oriented with either end of the locomotive in the lead in the direction of travel of the locomotive, said apparatus comprising:

at least two phase-locking satellite receivers configured to reference signals received from a set of satellites; and

a processor configured to;

determine a set of phase differences between the reference signals received by said satellite receivers;

determine a vector distance {right arrow over (d)} between the two satellite receivers using an integer ambiguity, wherein an initial integer ambiguity is resolved by consulting a database that provides an initial heading and track grade as a function of latitude and longitude; and

determine an accurate heading, accurate heading rate, attitude, and attitude rate of the locomotive during normal locomotive transit operation using only the set of phase differences between the reference signals and the vector distance {right arrow over (d)} wherein said processor is further configured to determine {right arrow over (d)} as {right arrow over (d)}=(H^TH)<sup>−

1</sup>H^T{right arrow over (y)}, where;

14. An apparatus according to claim 13 wherein said processor configured to determine the heading using

15. An apparatus according to claim 13 wherein said processor further configured to determine a track curvature, C.

16. An apparatus according to claim 15 wherein to determine a track curvature, said processor configured to detect an angular rotation rate ω

and velocity ν

of the locomotive.

17. An apparatus according to claim 16 wherein to detect an angular rotation rate ω

and velocity ν

of the locomotive, said processor configured to detect an angular rotation rate ω

using received satellite signals and velocity ν

of the locomotive using a tachometer.

18. An apparatus according to claim 16 wherein to detect an angular rotation rate ω

and velocity ν

of the locomotive, said processor configured to detect an angular rotation rate ω

using a gyroscope and velocity ν

of the locomotive using a tachometer.

19. An apparatus according to claim 15 wherein to determine a track curvature, said processor further configured to:

determine a lateral acceleration α and

a velocity ν

of the locomotive; and

determine track curvature C as;

C=α

/ν

².

20. An apparatus according to claim 15 further comprising a device for dispensing a lubricant to a track.

21. An apparatus according to claim 20 wherein said processor further configured to control said device dispensing the lubricant in accordance with the determined curvature value C.

22. An apparatus according to claim 21 wherein said processor further configured to dispense the lubricant when C exceeds a predetermine magnitude.

23. An apparatus according to claim 20 wherein said processor further configured to:

determine a position of the locomotive;

access a database of track heading and grade to determine a present track heading and grade at the determined position of the locomotive; and

control said device dispensing lubricant in accordance with a curvature value C contained within the track database.

24. An apparatus according to claim 13 wherein said processor further configured to:

sample latitude and longitude from the GPS receivers; and

determine a distance traveled by the locomotive.

25. An apparatus according to claim 24 wherein said processor configured to determine a distance between samples as:

Δ

d=R[Δ

lat²=cos²(lat)Δ

long²]^1/2.