Wireless encoder

• US 6,876,105 B1
• Filed: 05/18/2001
• Issued: 04/05/2005
• Est. Priority Date: 02/26/1998
• Status: Expired due to Term

• Current Assignee: Rockwell Automation, Inc.
• Original Assignee: Anorad Corporation (Rockwell Automation, Inc.)
• Inventors: Faizullabhoy, Mustansir, Chitayat, Anwar
• Primary Examiner(s): Lam, Thanh
• Assistant Examiner(s): Jones, Judson H.
• Application Number:
  US09/861,216
• Time in Patent Office: 1,418 Days
• Field of Search: 310 12- 14, 310/68.B, 318/135, 318/687
• US Class Current: 310/12.19
• CPC Class Codes: H02K 11/22 Optical devices
• CPC Class Codes: H02K 41/03 Synchronous motors; Motors moving step by step; Reluctance motors H02K41/035 takes precedence
• CPC Class Codes: H02P 25/06 Linear motors
• CPC Class Codes: H02P 25/064 of the synchronous type

Abstract

A wireless encoder system facilitates operation and control of a motor, such as linear motor. The system includes an encoder sensor moveable with a first part of the motor. The encoder sensor is operative to sense movement of the first part relative the second part and provide an encoder signal having an electrical characteristic indicative of the sensed movement. A transmitter, which is associated with the encoder sensor, is operative to transmit a wireless transmitter signal based on the encoder signal. A remote receiver that receives the wireless transmitter signal thus may determine position and/or movement of the first part of the motor relative to a second part of the motor.

Claims

1. A wireless encoder system for a motor having a first part that is moveable relative a second part of the motor, the encoder system comprising:

an encoder sensor moveable with the first part of the motor and operative to sense movement of the first part relative the second part and to provide an encoder signal having an electrical characteristic indicative of the sensed movement;

a transmitter moveable with the first part of the motor associated with the encoder sensor, the transmitter being operative to transmit a wireless transmitter signal based on the encoder signal for receipt by a remote receiver, whereby at least one of position and movement of the first part relative the second part is determinable from the wireless transmitter signal;

a receiver that accepts a wireless command signal that includes program data; and

a processor coupled to and operative to control the transmitter, the processor controls operation of the transmitter based on the program data and the encoder signal.

2. The encoder system of claim 1, wherein the first part is moveable along at least one axis relative the second part.

3. The encoder system of claim 1, further comprising a counter having a count value that varies as a function of the encoder signal.

4. The encoder system of claim 3, further comprising a pulse generator connected between the encoder sensor and the counter, the pulse generator providing to the counter a pulse signal that varies as a function of the encoder signal, the counter adjusting the count value as a function of the pulse signal.

5. The encoder system of claim 3, wherein the transmitter is operative to transmit the transmitter signal based on the count value relative a predetermined value.

6. The encoder system of claim 5, the wireless command signal defines the predetermined value.

7. The encoder system of claim 6, further comprising memory that is programmable based on the command signal, the memory storing a command value as the predetermined value to control activation of the transmitter based on the command value and the count value.

8. The encoder system of claim 1, further comprising memory coupled to the processor, the memory storing program data based on which the processor is operative to control operation of at least one of the transmitter and the encoder sensor.

9. The encoder system of claim 1, further comprising memory coupled to the processor programmable based on the program data received by the receiver, the memory storing a command data based on which the processor controls operation of the transmitter.

10. The encoder system of claim 1, further comprising a pulse generator operatively coupled between the transmitter and the encoder sensor, the pulse generator providing a pulse signal to the transmitter based on the encoder signal, the transmitter transmitting the transmitter signal according to the pulse signal.

11. The encoder system of claim 1, further comprising a second receiver operative to receive a wireless command signal, the transmitter being operative to transmit the transmitter signal in response to the command signal.

12. The encoder system of claim 1 in combination with the motor, wherein the motor defines linear motor system, the second part defining a path that comprises a plurality of armature windings and the first part defines a stage moveable on the path, the motor further comprising a controller operative to control application of power to the armature windings based on the transmitter signal.

13. The combination of claim 12, wherein the path further comprises a plurality of modular path portions assembled to define the path.

14. The combination of claim 12, where the path describes a closed path.

15. The combination of claim 12, further comprising a plurality of the stages moveable along the path, a transmitter for each of the plurality of stages transmitting a wireless transmitter signal that includes information to uniquely identify each respective stage, such that the motor controller is operative to control application of power to the armature windings based on the transmitter signals and, in turn, effect desired movement of each of the plurality of stages.

16. A linear motor system, comprising:

a plurality of armature windings arranged to form a path; and

a stage moveable along the path, the stage comprising motor magnets;

an encoder sensor connected for movement with the stage and operative to sense relative movement between the stage and the path, the encoder sensor being operative to provide an encoder signal having an electrical characteristic indicative of relative movement between the stage and the path;

a transmitter connected for movement with the stage and operative to transmit a wireless transmitter signal based on the encoder signal;

a controller operative to control energization of the armature windings based on the transmitter signal, thereby effecting movement of the stage along the path;

a component that receives a wireless command signal; and

a second receiver moveable with the stage and operative to receive a wireless command signal, the transmitter being operative to transmit the transmitter signal in response to the command signal.

17. The linear motor system of claim 16, further comprising a counter coupled between the encoder sensor and the transmitter, the counter having a count value that varies as a function of the encoder signal.

18. The linear motor system of claim 17, further comprising a pulse generator moveable with the stage and connected between the encoder sensor and the counter, the pulse generator providing a pulse signal to the counter that varies as a function of the encoder signal, the counter adjusting the count value as a function of the pulse signal.

19. The linear motor system of claim 18, wherein the transmitter is operative to transmit the transmitter signal based on the count value relative a predetermined value.

20. The linear motor system of claim 19, further comprising a receiver moveable with the stage operative to receive a wireless command signal from a command transmitter that defines the predetermined value, the command transmitter being associated with the controller.

21. The linear motor system of claim 20, further comprising memory moveable with the stage that is programmable based on the command signal, the memory storing the predetermined value as a command value to control activation of the transmitter based on the command value and the count value.

22. The linear motor system of claim 16, further comprising a processor moveable with the stage, the processor operatively coupled to the transmitter and operative to control at least one of the transmitter and the encoder sensor.

23. The linear motor system of claim 22, further comprising memory coupled to the processor, the memory storing program data based on which the processor controls operation of the transmitter.

24. The linear motor system of claim 22, further comprising a receiver moveable with the stage and operative to receive a wireless command signal having program data from a command transmitter associated with the controller, the processor being operative to control operation of the transmitter based on the program data and the encoder signal.

25. The linear motor system of claim 24, further comprising memory coupled to the processor that is programmable based on the program data received by the receiver, the memory storing the program data.

26. The linear motor system of claim 16, further comprising a pulse generator operatively coupled between the transmitter and the encoder sensor, the pulse generator providing a pulse signal to the transmitter based on the encoder signal, the transmitter transmitting the transmitter signal according to the pulse signal.

27. The combination of claim 16, wherein the path further comprises a plurality of modular path portions assembled to define the path.

29. The combination of claim 16, further comprising a plurality of the stages moveable along the path, a transmitter for each of the plurality of stages transmitting a wireless transmitter signal that includes information to uniquely identify each respective stage, such that the controller is operative to control application of power to the armature windings based on each transmitter signal and, in turn, effect desired movement of each of the plurality of stages.

30. A wireless encoder system for a motor having a first part that is moveable relative a second part, the encoder system comprising:

sensor means moveable with the first part of the motor for sensing movement of the first part relative the second part and for providing an encoder signal indicative of the sensed movement;

means associated with the encoder sensor and moveable with the first part transmitting a wireless transmitter signal based on the decoder signal for receipt by a remote receiver, whereby at least one of position and movement of the first part relative the second part is determinable from the transmitter signal; and

second means moveable with the first part for controlling the means for transmitting in response to wireless command information received from the first means for controlling.

28. The combination of claim 30, where the path describes a closed path.

31. The encoder system of claim 30 in combination with the motor, wherein the motor is linear motor system, the second part defining a path that comprises a plurality of armature windings and the first part defines a stage moveable on the path, the combination further comprising first means for controlling application of power to the armature windings based on the wireless transmitter signal.

32. A method for wirelessly providing motor position information in a motor, comprising:

sensing relative movement between a first part of the motor and a second part of a motor, the sensing occurring at the first part which is moveable relative the second part;

providing an encoder signal based on the sensed movement;

transmitting a wireless signal from the first part based on the encoder signal; and

receiving a wireless command signal at the first part and storing program data at the first part to control the transmission of the wireless signal.

33. The method of claim 32, further comprising receiving the signal and selectively controlling armature windings based on the transmitted wireless signal.