SYSTEM AND METHOD FOR ERROR ANALYSIS OF FIBER OPTIC INSTRUMENT DATA
An instrument system that includes an elongate body, a first optical fiber, a second optical fiber, and a controller is provided. The first optical fiber is operatively coupled to the elongate body and has a first strain sensor provided on the first optical fiber. The second optical fiber is operatively coupled to the elongate body and has a second strain sensor provided on the second optical fiber. The controller is operatively coupled to the first optical fiber and the second optical fiber and is adapted to receive a first signal from the first strain sensor and a second signal from the second strain sensor and to compare the first signal with the second signal.
1 . An instrument system, comprising:
an elongate body;
a first optical fiber operatively coupled to the elongate body and having a first strain sensor provided on the first optical fiber;
a second optical fiber operatively coupled to the elongate body and having a second strain sensor provided on the second optical fiber; and
a controller operatively coupled to the first optical fiber and the second optical fiber and adapted to:
receive a first signal from the first strain sensor and a second signal from the second strain sensor; and
compare the first signal with the second signal.
2 . The instrument system of claim 1 , wherein the controller is further adapted to compare the first signal with the second signal by determining a difference between the first signal and the second signal and is adapted to determine a position of the elongate body based on the difference.
3 . The instrument system of claim 2 , wherein the first optical fiber is located on a first side of the elongate body and the second optical fiber is located on a second side of the elongate body, wherein the first side is opposite the second side.
4 . The instrument system of claim 3 , wherein the first strain sensor or the second strain sensor comprises axially-spaced Bragg gratings.
5 . The instrument system of claim 4 , wherein the axially-spaced Bragg gratings are substantially continuous along the first optical fiber or the second optical fiber.
6 . The instrument system of claim 1 , wherein the controller is adapted to compare the first signal with the second signal by determining an average of the first signal and the second signal.
7 . The instrument system of claim 6 , wherein the controller is adapted to compare the first signal with the second signal based on a known distance between the first optical fiber and the second optical fiber.
8 . A method for processing signals in an instrument system, comprising:
receiving a first signal from a first strain sensor provided on a first optical fiber operatively coupled to an elongate body;
receiving a second signal from a second strain sensor provided on a second optical fiber operatively coupled to the elongate body; and
comparing the first signal with the second signal.
9 . The method of claim 8 , wherein the comparing the first signal with the second signal comprises determining a difference between the first signal and the second signal, the method further comprising determining a position of the elongate body based on the difference.
10 . The method of claim 9 , wherein the receiving the first signal and the second signal comprises receiving signals from two optical fibers that are on opposite sides of the elongate body.
11 . The method of claim 10 , wherein the receiving the first signal and the second signal comprises receiving a signal from a strain sensor that comprises axially-spaced Bragg gratings.
12 . The method of claim 11 , wherein the axially-spaced Bragg gratings are substantially continuous along the first optical fiber or the second optical fiber.
13 . The method of claim 8 , wherein the comparing the first signal with the second signal comprises determining an average of the first signal and the second signal.
14 . The method of claim 13 , wherein the comparing the first signal with the second signal is based on a known distance between the first optical fiber and the second optical fiber.