Machine diagnostic encoder

• US 9,927,265 B2
• Filed: 10/22/2014
• Issued: 03/27/2018
• Est. Priority Date: 10/22/2013
• Status: Active Grant

• Current Assignee: Nidec Motor Corporation (Nidec Corporation)
• Original Assignee: Nidec Avtron Automation Corp. (Nidec Corporation)
• Inventors: Niro, William P., Winter, Brian
• Primary Examiner(s): Breene, John
• Assistant Examiner(s): Islam, Mohammad
• Application Number:
  US14/520,933
• Publication Number:
  US 20150112640A1
• Time in Patent Office: 1,252 Days
• CPC Class Codes: G01D 15/00 Component parts of recorders for measuring arrangements not specially adapted for a specific variable
• CPC Class Codes: G01D 5/00 Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable G01D3/00 takes precedence; specially adapted for apparatus giving results other than momentary value of variable G01D1/00
• CPC Class Codes: G01M 99/005 Testing of complete machines, e.g. washing-machines or mobile phones testing of machine parts G01M13/00; testing of electric apparatus or components G01R31/50
• CPC Class Codes: G05B 2219/31211 Communicate diagnostic data from intelligent field device controller to central
• CPC Class Codes: G05B 23/0205 by means of a monitoring system capable of detecting and responding to faults
• CPC Class Codes: G05B 23/0221 Preprocessing measurements, e.g. data collection rate adjustment; Standardization of measurements; Time series or signal analysis, e.g. frequency analysis or wavelets; Trustworthiness of measurements; Indexes therefor; Measurements using easily measured parameters to estimate parameters difficult to measure; Virtual sensor creation; De-noising; Sensor fusion; Unconventional preprocessing inherently present in specific fault detection methods like PCA-based methods
• CPC Class Codes: G05B 23/0235 based on a comparison with predetermined threshold or range, e.g. "classical methods", carried out during normal operation; threshold adaptation or choice; when or how to compare with the threshold
• CPC Class Codes: G05B 23/027 Alarm generation, e.g. communication protocol; Forms of alarm

Abstract

A system includes an encoder to monitor a machine and generate an encoder output signal indicative of at least one of the motion or position of the machine. A combiner can be configured to receive the encoder output signal from the encoder and to receive machine diagnostic data from at least one other sensor. The combiner can combine the machine diagnostic data with the encoder output signal to provide a combined signal that includes the machine diagnostic data synchronized with the at least one of the motion or position of the machine. An output stage can provide the combined signal to a remote system.

Claims

1. A system comprising:

an encoder that monitors a machine and generates an encoder output signal indicative of at least one of motion or position of the machine;

a combiner that receives the encoder output signal from the encoder and receives machine diagnostic data based on sensor data from at least one sensor, the combiner modulating the machine diagnostic data onto the encoder output signal to provide a combined signal that includes the machine diagnostic data synchronized with the at least one of the motion or position of the machine; and

a communications stage that transmits the combined signal to a remote system over an existing communications path between the encoder and the remote system.

2. The system of claim 1, further comprising a preprocessor to analyze the sensor data and generate processed diagnostic data based on the analysis of the sensor data from the at least one sensor, the processed diagnostic data being synchronized with the at least one of the motion or position of the machine in the combined signal.

3. The system of claim 2, wherein the preprocessor is to analyze the machine diagnostic data with respect to at least one diagnostic threshold and generate a message if the at least one diagnostic threshold is exceeded.

4. The system of claim 3, wherein the message is provided as one of a local alarm at or near the encoder or a remote alarm that is combined with the encoder output signal in the combined signal and transmitted to a remote system.

5. The system of claim 2, wherein the preprocessor is configured to perform a Fast Fourier Transform (FFT) to convert time domain sensor data, corresponding to the sensor data from the at least one sensor, to frequency domain data that is combined by the combiner with the encoder output signal and provided to a remote system synchronized with the encoder output signal.

6. The system of claim 5, wherein the preprocessor is configured to analyze the frequency domain data with respect to a threshold and to provide the processed diagnostic data in the combined signal based on the analysis.

7. The system of claim 5, wherein the preprocessor further comprises a dynamic adjuster that adjusts a sampling rate for the at least one sensor based on the frequency domain data determined by the FFT.

8. The system of claim 2, wherein the preprocessor further comprises a dynamic adjuster that modifies an operating parameter for the at least one sensor based on analysis of the sensor data from at least one machine sensor.

9. The system of claim 2, wherein the preprocessor further comprises a dynamic adjuster that modifies an operating parameter for the at least one sensor based on the position or speed of the machine.

10. The system of claim 2, wherein the preprocessor further comprises a dynamic adjuster that adjusts a machine diagnostic threshold that is applied to the processed to detect a predetermined machine event.

11. The system of claim 10, wherein the dynamic adjuster is that modifies the machine diagnostic threshold utilized by the preprocessor to analyze the sensor data for the at least one sensor based on at least one of analysis of sensor data from at least one other machine sensor or the position or speed of the machine indicated by the encoder output signal.

12. The system of claim 1, wherein the existing communications path includes a primary communications path for communicating the encoder output signal to the remote station,

wherein machine diagnostic data includes diagnostic information about the primary path, the combined signal being transmitted to the remote station through another communications path if the diagnostic information about the primary path indicates that the quality for the primary communications path is below a quality threshold.

13. A method comprising:

generating an encoder output signal for a machine indicative of at least one of the motion or position of the machine;

monitoring the machine via one or more sensor signals and generating machine diagnostic data representing a characteristic of the machine;

modulating the machine diagnostic data onto the encoder output signal to provide a combined signal in which the machine diagnostic data is synchronized with at least one of the motion or the position of the machine; and

transmitting the combined signal to a remote system over an existing communications path between an encoder that generates the encoder output signal and the remote system.

14. The method of claim 13, further comprising processing the machine to generate processed diagnostic data, the processed diagnostic data being combined with the encoder output signal in the combined signal.

15. The method of claim 14, further comprising synchronizing capture of the machine diagnostic data relative to a frequency of at least one pulse on the encoder output signal to generate the processed diagnostic data that is synchronized with the motion of the machine.

16. The method of claim 13, wherein processing the machine diagnostic data further comprises:

analyzing the processed diagnostic data with respect to at least one diagnostic threshold; and

generating a message if the at least one diagnostic threshold is exceeded.

17. The method of claim 14, wherein the preprocessing further comprises:

executing a Fast Fourier Transform (FFT) to convert time domain data, corresponding to a given signal of the one or more sensor signals, to frequency domain sensor data;

analyzing the frequency domain sensor data with respect to the at least one diagnostic threshold to provide the processed diagnostic data characterizing health of the machine.

18. The method of claim 13, further comprising:

analyzing a quality of the communications path; and

controlling the transmission of the combined signal based on the analyzing.

19. An encoder apparatus comprising:

an encoder to generate an encoder output signal indicative of at least one of motion or position of a rotary machine;

a preprocessor to analyze at least one sensor signal indicative of a condition of the rotary machine and to provide motor diagnostic data based on the analysis;

a combiner to modulate the motor diagnostic data onto the encoder output signal the encoder output signal motor to provide a combined signal in which the motor diagnostic data is synchronized with the at least one of the motion or position of the rotary motor indicated by the encoder output signal; and

a communications stage to provide the combined signal to a remote system.