Non-contact speed encoder
An eddy current (EC) detection system comprises an EC probe including a plurality of sensors to provide corresponding EC response signals; and processing circuitry to evaluate speed of the EC probe based on a measurement of similarity of the EC response signals; determine whether the speed of the EC probe is too fast or two slow based on quality of the measurement; and generate a command to adjust speed of the EC probe during further EC inspection.
1. An eddy current (EC) inspection system comprising:
an EC probe including a first coil and a second coil to provide corresponding first and second EC response signals; and processing circuitry configured to:
set a time window for analyzing the first and second EC response signals;
determine a speed of the EC probe based on determining a time delay between the EC response signals based on a maximum of a cross-correlation of a noise frequency pattern of the first and second EC response signals in the time window; and
generate a command to adjust operations of the EC probe based on the speed of the EC probe.
2. The EC inspection system of claim 1 , wherein the plurality of first and second coils are wound around a round EC probe core.
3. The EC inspection system of claim 1 , wherein the EC probe is a surface probe.
4. The EC inspection system of claim 1 , wherein the command is to adjust the speed of the EC probe during an EC inspection.
5. The EC inspection system of claim 4 , further comprising:
control circuitry to control the speed of the EC probe responsive to receiving the command.
6. The EC inspection system of claim 1 , wherein determining the speed of the EC probe includes:
dividing a distance d between the first and second EC coils by the time delay.
7. The EC inspection system of claim 1 , wherein the processing circuitry is further configured to determine a position of the EC probe by performing an integration operation based on the speed.
8. The EC inspection system of claim 7 , further comprising a memory to store landmark information, and wherein the processing circuitry is further configured to verify the determined position based on the landmark information.
9. The EC inspection system of claim 1 , wherein the processing circuitry is further configured to evaluate acceleration of the EC probe.
10. The EC inspection system of claim 1 , wherein the processing circuitry is configured to evaluate acceleration based on information from an Inertial Measurement Unit.
11. The EC inspection system of claim 1 , further comprising a filter to filter at least one of the EC response signals, and wherein the processing circuitry is further configured to adjust a cutoff frequency of the filter based on the speed.
12. The EC inspection system of claim 1 , further comprising:
indicator circuitry configured to indicate the speed.
13. The EC inspection system of claim 1 , wherein the time delay is determined based on only real components of the cross-correlation.
14. A method for eddy current (EC) inspection, the method comprising:
acquiring a first and second EC response signals from respective first and second EC coils of an EC probe;
setting a time window for analyzing the first and second EC response signals:
determining a speed of the EC probe based on determining a time delay between the EC response signals based on a maximum of a cross-correlation of a noise frequency pattern of the first and second EC response signals in the time window; and
adjusting the speed of the EC probe during an EC inspection based on the determined speed.
15. The method of claim 14 , wherein determining the speed of the EC probe includes:
dividing a distance d between the first and second EC coils by the time delay.
16. The method of claim 14 , further comprising:
determining a position of the EC probe by performing an integration operation based on the speed.
17. The method of claim 16 , further comprising:
verifying the determined position based on landmark information.
18. The method of claim 14 , further comprising:
performing filtering of a signal generated during determining of the speed, wherein a cutoff frequency of the filtering is adjusted based on the speed.
19. The method of claim 14 , wherein the time delay is determined based on only real components of the cross-correlation.
20. A non-transitory computer readable medium including instructions that, when implemented on a processor, cause the processor to perform operations including:
acquiring a first and second EC response signals from respective first and second EC coils of an EC probe;
setting a time window for analyzing the first and second EC response signals;
determining a speed of the EC probe based on determining a time delay between the EC response signals based on a maximum of a cross-correlation of a noise frequency pattern of the first and second EC response signals in the time window; and
adjusting the speed of the EC probe during an EC inspection based on the determined speed.
21. The non-transitory computer readable medium of claim 20 , wherein the operations further include:
dividing a distance d between the EC coils by the time delay.
22. The non-transitory computer readable medium of claim 20 , further comprising:
determining a position of the EC probe by performing an integration operation based on the speed.
23. The non-transitory computer readable medium of claim 22 , further comprising:
verifying the determined position based on landmark information.
24. The non-transitory computer readable medium of claim 20 , further comprising:
performing filtering of a signal generated during determining of the speed, wherein a cutoff frequency of the filtering is adjusted based on the speed.
25. The non-transitory computer readable medium of claim 20 , wherein the time delay is determined based on only real components of the cross-correlation.