System and Method for Vehicle Position Sensing with Helical Windings

• US 20100235090A1
• Filed: 03/13/2009
• Published: 09/16/2010
• Est. Priority Date: 03/13/2009
• Status: Active Grant

• Current Assignee: General Atomics, Inc.
• Original Assignee: General Atomics, Inc.
• Inventors: Borowy, Bogdan S.
• Granted Patent: US 8,532,918 B2
• Time in Patent Office: Days
• US Class Current: 701/207
• CPC Class Codes: B60L 13/06 Means to sense or control vehicle position or attitude with respect to railway
• CPC Class Codes: B60L 2200/26 Rail vehicles

Abstract

A system and method are provided for determining the position of a vehicle on a guideway. For operation, the vehicle carries a magnetic array having a wavelength “λ”. Further, the guideway includes a propulsion winding for carrying a propulsion current. Also, the guideway is provided with a position winding that has the same wavelength “λ” and includes two helical wires that are displaced from each other by “λ/4”. Importantly, a transmitter is located on the vehicle for emitting a position current that interacts with the position winding to generate a return signal from each helical wire. Also, the system includes a processor for receiving and evaluating the return signals to determine the position of the vehicle on the guideway. As a result, the determined position is used to maximize the interaction of the propulsion current with the magnetic array for propulsion of the vehicle.

Claims

1. A system for determining a position of a vehicle on a guideway which comprises:

a magnetic array mounted on the vehicle, wherein the array has a wavelength “

λ

”

;

a propulsion winding located on the guideway for carrying a propulsion current;

a position winding located on the guideway, wherein the position winding has the same wavelength “

λ

” and

the position winding includes a first helical wire and a second helical wire, wherein the first and second helical wires are spatially displaced from each other by “

λ

/4”

;

a transmitter located on the vehicle for emitting a position current, with said position current interacting with the position winding to generate a first return signal from the first helical wire and a second return signal from the second helical wire; and

a processor for receiving and evaluating the first and second return signals to determine the position of the vehicle on the guideway for use in maximizing an interaction of the propulsion current in the propulsion winding along the guideway with the magnetic array on the vehicle, for propulsion of the vehicle.

2. A system as recited in claim 1 wherein the position current is a narrow-band high-frequency current.

3. A system as recited in claim 2 wherein the position current has a frequency of about 100 KHz.

4. A system as recited in claim 1 wherein the propulsion winding includes at least one section having a wavelength “

λ

”

, and each section has three coils linearly aligned along the guideway, with a phase difference of “

λ

/3”

between adjacent coils in the section.

5. A system as recited in claim 1 wherein the first helical wire and the second helical wire are a first pair, and the position winding further comprises a second pair, wherein the respective wires of the first and second pairs are spatially displaced from each adjacent wire in the position winding by “

λ

/4”

.

6. A system as recited in claim 5 wherein the position winding further comprises a center round core, and the first and second pairs are wound on the center round core.

7. A system as recited in claim 1 wherein “

λ

”

is approximately 17 inches.

8. A system for determining a position of a vehicle on a guideway which comprises:

a magnetic array mounted on the vehicle, wherein the array has a wavelength “

λ

”

;

a propulsion winding located on the guideway for carrying a propulsion current;

a first helical wire and a second helical wire, with each helical wire being located on the guideway and having the same wavelength “

λ

”

, wherein the helical wires are spatially displaced from each other by “

λ

/4”

;

a means located on the vehicle for emitting a position current, with said position current interacting with the helical wires to generate a first return signal from the first helical wire and a second return signal from the second helical wire; and

a means for receiving and evaluating the first and second return signals to determine the position of the vehicle on the guideway for use in maximizing an interaction of the propulsion current in the propulsion winding along the guideway with the magnetic array on the vehicle, for propulsion of the vehicle.

9. A system as recited in claim 8 wherein the position current is a narrow-band high-frequency current.

10. A system as recited in claim 9 wherein the position current has a frequency of about 100 KHz.

11. A system as recited in claim 8 wherein the propulsion winding includes at least one section having a wavelength “

λ

”

, and each section has three coils linearly aligned along the guideway, with a phase difference of “

λ

/3”

between adjacent coils in the section.

12. A system as recited in claim 8 wherein the first helical wire and the second helical wire are a first pair, and the position winding further comprises a second pair of helical wires, wherein the respective wires of the first and second pairs are spatially displaced from each adjacent wire in the position winding by “

λ

/4”

.

13. A system as recited in claim 12 wherein the position winding further comprises a center round core, and the first and second pairs are wound on the center round core.

14. A system as recited in claim 8 wherein “

λ

”

is approximately 17 inches.

15. A method for determining a position of a vehicle on a guideway which comprises the steps of:

mounting a magnetic array on the vehicle, wherein the array has a wavelength “

λ

”

;

locating a propulsion winding on the guideway for carrying a propulsion current;

locating a position winding on the guideway, wherein the position winding has the same wavelength “

λ

”

wherein the position winding includes a first helical wire and a second helical wire, and wherein the first and second helical wires are spatially displaced from each other by “

λ

/4”

;

placing a transmitter on the vehicle;

emitting a position current from the transmitter, with said position current interacting with the position winding to generate a first return signal from the first helical wire and a second return signal from the second helical wire; and

receiving and evaluating the first and second return signals to determine the position of the vehicle on the guideway for use in maximizing an interaction of the propulsion current in the propulsion winding along the guideway with the magnetic array on the vehicle, for propulsion of the vehicle.

16. A method as recited in claim 15 wherein the position current has a frequency of about 100 KHz.

17. A method as recited in claim 15 wherein the propulsion winding includes at least one section having a wavelength “

λ

”

, and each section has three coils linearly aligned along the guideway, with a phase difference of “

λ

/3”

between adjacent coils in the section.

18. A method as recited in claim 15 wherein the first helical wire and the second helical wire are a first pair, and the position winding further comprises a second pair, wherein the respective wires of the first and second pairs are spatially displaced from each adjacent wire in the position winding by “

λ

/4”

.

19. A method as recited in claim 15 wherein the position winding further comprises a center round core, and the first and second pairs are wound on the center round core.

20. A method as recited in claim 15 wherein “

λ

”

is approximately 17 inches.