Systems and methods for measuring rotational speed and position of a rotating device

• US 8,334,687 B2
• Filed: 10/07/2009
• Issued: 12/18/2012
• Est. Priority Date: 06/09/2009
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Ma, Qi, Tulkki, Brian M.
• Primary Examiner(s): VALONE, THOMAS F
• Application Number:
  US12/574,935
• Publication Number:
  US 20100308799A1
• Time in Patent Office: 1,168 Days
• Field of Search: 324/166
• US Class Current: 324/166
• CPC Class Codes: G01D 5/202 by movable a non-ferromagnetic conductive element G01D5/2033 takes precedence
• CPC Class Codes: G01D 5/2451 Incremental encoders G01D5/2454 takes precedence
• CPC Class Codes: G01P 3/48 by measuring frequency of generated current or voltage in general G01R23/00
• CPC Class Codes: G01P 3/481 of pulse signals
• CPC Class Codes: G01P 3/488 delivered by variable reluctance detectors

Abstract

A system includes a transceiver module and a rotating device. The transceiver module generates an electromagnetic (EM) field using an antenna. The rotating device includes N transponders arranged such that each of the N transponders passes through the EM field during one revolution of the rotating device. Each of the N transponders damps the EM field when passing through the EM field. The transceiver module determines a rotational speed of the rotating device based on a number of times the EM field is damped during a period. N is an integer greater than or equal to 1.

Claims

1. A system comprising:

a transceiver module that generates an electromagnetic (EM) field using an antenna; and

a rotating device that includes N transponders arranged such that each of the N transponders passes through the EM field during one revolution of the rotating device,

wherein each of the N transponders damps the EM field when passing through the EM field, wherein the transceiver module determines a rotational speed of the rotating device based on a number of times the EM field is damped during a period, and wherein N is an integer greater than or equal to 1.

2. The system of claim 1 wherein the transceiver module determines a position of the rotating device based on data transmitted from one or more of the N transponders in the EM field.

3. The system of claim 2 wherein the transceiver module determines when the rotating device is stationary and determines the position of the rotating device when the rotating device is stationary.

4. The system of claim 3 wherein the transceiver module commands the one or more of the N transponders in the EM field to stop transmitting the data after the transceiver module receives the data, wherein the one or more of the N transponders does not transmit the data when passing through the EM field after receiving the command.

5. The system of claim 1 wherein the rotating device is included in a vehicle, and wherein the rotating device is connected to at least one of a crankshaft, a camshaft, an output shaft of a transmission, and a wheel.

6. The system of claim 1 wherein each of the N transponders includes an antenna and memory.

7. The system of claim 2 wherein the transceiver module determines the position of the rotating device based on a table that relates the data transmitted from the one or more of the N transponders to the position of the rotating device.

8. The system of claim 1 wherein the transponders are arranged to produce a pattern of damping when the rotating device is rotating, and wherein the transceiver module determines a position of the rotating device when the rotating device is rotating based on the pattern of damping.

9. The system of claim 2 wherein the transceiver module generates the EM field at a first strength when the rotating device is stationary, wherein the N transponders transmit data when the transponders are in the EM field having the first strength, wherein the transceiver module generates the EM field at a second strength when the rotating device is rotating, and wherein the N transponders do not transmit data when the transponders are in the EM field having the second strength.

10. A method comprising:

generating an electromagnetic (EM) field using an antenna; and

determining a rotational speed of a rotating device based on a number of times the EM field is damped during a period,

wherein the rotating device includes N transponders arranged such that each of the N transponders passes through the EM field during one revolution of the rotating device, wherein each of the N transponders damps the EM field when passing through the EM field, and wherein N is an integer greater than or equal to 1.

11. The method of claim 10 further comprising determining a position of the rotating device based on data transmitted from one or more of the N transponders in the EM field.

12. The method of claim 11 further comprising:

determining when the rotating device is stationary; and

determining the position of the rotating device when the rotating device is stationary.

13. The method of claim 12 further comprising commanding the one or more of the N transponders in the EM field to stop transmitting the data after receiving the data, wherein the one or more of the N transponders does not transmit the data when passing through the EM field after receiving the command.

14. The method of claim 10 wherein the rotating device is included in a vehicle, and wherein the rotating device is connected to at least one of a crankshaft, a camshaft, an output shaft of a transmission, and a wheel.

15. The method of claim 10 wherein each of the N transponders includes an antenna and memory.

16. The method of claim 11 further comprising determining the position of the rotating device based on a table that relates the data transmitted from the one or more of the N transponders to the position of the rotating device.

17. The method of claim 10 further comprising determining a position of the rotating device when the rotating device is rotating based on a pattern of damping, wherein the transponders are arranged to produce the pattern of damping when the rotating device is rotating.

18. The method of claim 11 further comprising:

generating the EM field at a first strength when the rotating device is stationary, wherein the N transponders transmit data when the transponders are in the EM field having the first strength; and

generating the EM field at a second strength when the rotating device is rotating, wherein the N transponders do not transmit data when the transponders are in the EM field having the second strength.