Rotary Encoder with Built-in-Self-Test

• US 20100001177A1
• Filed: 04/21/2006
• Published: 01/07/2010
• Est. Priority Date: 04/21/2006
• Status: Active Grant

• Current Assignee: Flowserve Pte Ltd. (Flowserve Corporation)
• Original Assignee: Flowserve Management Company (Flowserve Corporation)
• Inventors: Dolenti, William T., Hooss, William C., Morris, Daniel J., Fleury, Byron A.
• Granted Patent: US 8,471,194 B2
• Time in Patent Office: Days
• US Class Current: 250/231.15
• CPC Class Codes: F16K 37/0083 by measuring valve parameters
• CPC Class Codes: G01D 5/24461 by redundancy or plausibility
• CPC Class Codes: G01D 5/347 using displacement encoding scales
• CPC Class Codes: G01D 5/3473 Circular or rotary encoders

Abstract

A rotary encoder using built-in self test ability with redundant and fault tolerant position sensing. Wherein the rotary encoder is used with a variety of rotary equipment including a valve actuator including the generation of speed data (1). The use for diagnosing valve actuator problem and other rotary equipment includes the frequency analysis performed upon speed or position or torque or thrust or vibration data including the speed or position data of the valve provided by the rotary encoder.

Claims

1. A rotary encoder for use with a rotary device, the rotary encoder comprising:

one or more encoding wheels, each of the one or more encoding wheels comprising at least one coding section operable to encode a position of the rotary device; and

at least one double set of sensors operable to monitor the at least one coding section.

2. The rotary encoder of claim 1, further comprising a timing mechanism.

3. The rotary encoder of claim 2, wherein the timing mechanism is integrated into one of the one or more encoding wheels.

4. The rotary encoder of claim 2, wherein the timing mechanism comprises a separate timing wheel operably connected to the one or more encoding wheels.

5. The rotary encoder of claim 1, wherein the one or more encoding wheels is configured to allow decoding using Viterbi logic

6. The rotary encoder of claim 1, wherein the at least one double set of sensors are able to self-test via direct transmission.

7. The rotary encoder of claim 1, wherein each set of the at least one double set of sensors opposes another set of sensors.

8. The rotary encoder of claim 1, wherein each set of the at least one double set of sensors is parallel to another set of sensors.

9. The rotary encoder of claim 1, wherein the rotary encoder is an absolute encoder or an incremental encoder.

10. The rotary encoder of claim 1, wherein one of the one or more encoding wheels is operable for incremental encoding and wherein at least one of the one or more encoding wheels is operable for absolute encoding.

11. The rotary encoder of claim 1, wherein the at least one coding section is operable to encode multiple positions of the rotary device.

12. The rotary encoder of claim 1, wherein the at least one coding section comprises multiple coding sections and further comprising at least one double set of sensors for each of the multiple coding sections.

13. The rotary encoder of claim 1, wherein the at least one double set of sensors is operable to monitor multiple coding sections.

14. The rotary encoder of claim 1, wherein the at least one coding section comprises multiple coding sections asymmetrically orientated in relation to each other.

15. An absolute encoder comprising:

an input wheel configured to receive rotary input;

a timing wheel capable of generating speed data and driven by the input wheel;

a plurality of encoding wheels operably coupled to the timing wheel; and

a plurality of sensors configured to sense the positions of the plurality of encoding wheels and the timing wheel, wherein each of the plurality of sensors includes a redundant sensor.

16. The absolute encoder of claim 15, further comprising a processor operable to transform the speed data generated by the timing wheel into frequency data.

17. The absolute encoder of claim 15, wherein the plurality of sensors is selected from the group consisting of optical sensors, Hall effect sensors, magnetic sensors, or electrical contacts.

18. The absolute encoder of claim 15, wherein the plurality of sensors and the redundant sensors are able to test each other when either the plurality of sensors or the redundant sensors are activated.

19. A valve actuator comprising:

an absolute encoder comprising;

at least one encoder disk;

a plurality of sensors operable to read the at least one encoder disk;

a speed sensor operable to generate speed data; and

at least one duplicate sensor for each of the plurality of sensors and the speed sensor; and

a drive train adapted to drive the absolute encoder.

20. The valve actuator of claim 19, further comprising a processor adapted to generate alarms upon failure of a component of the absolute encoder.

21. The valve actuator of claim 20, wherein the processor is adapted for evaluating the impact of the component failure on the position indicated by the absolute encoder.

22. The valve actuator of claim 21, wherein the processor is adapted to shutdown the valve actuator.

23. The valve actuator of claim 21, wherein the processor is adapted to generate an alarm.

24. The valve actuator of claim 20, wherein component failure comprises one of the plurality of sensors, the speed sensor, or one of the corresponding duplicate sensor failing to operate or operating at a wrong time.

25. The valve actuator of claim 20, wherein the processor is further adapted to generate alarms if a discontinuity is indicated in a record of valve positions.

26. The valve actuator of claim 19, further comprising a processor adapted to receive speed data from the speed sensor and perform frequency domain analysis on the speed data.

27. The valve actuator of claim 26, wherein the processor is a part of the absolute encoder.

28. The valve actuator of claim 19, wherein a drive sleeve of the drive-train is adapted to drive the absolute encoder.