Systems and methods for determining shape and/or position

Patent metadata

Field	Value
Publication number	US-2016370177-A1
Application number	US-201615186051-A
Country	US
Kind code	A1
Filing date	Jun 17, 2016
Priority date	Jun 17, 2015
Publication date	Dec 22, 2016
Grant date	—

Abstract

Systems and methods for determining the shape and/or position of an object are described. A fiber optic shape sensor (FOSS) may be used in combination with one or more inertial measurement units (IMUs) to mutually cross-correct for errors in the sensors' measurements of position and/or orientation. The IMU(s) may be attached to the FOSS's optical fiber, such that each IMU measures the orientation of a corresponding portion of the optical fiber. The position and shape of the optical fiber can then be determined based on the measurements obtained from the IMU(s) and the measurements obtained from the FOSS. For example, the FOSS measurements and the IMU measurements can be provided to a state estimation unit (e.g., a Kalman filter), which can estimate the position and/or shape of the optical fiber based on those measurements. In some embodiments, the estimates of position are used for navigation of tethered mobile devices.

First claim

What is claimed is:

1 . A navigation system, comprising:
a first sensing device comprising a distributed spatial sensor, wherein the first sensing device is operable to produce distributed measurements of one or more spatial characteristics of the distributed spatial sensor selected from the group consisting of shape, spatial position, and angular position; a second sensing device comprising one or more localized position sensors corresponding to one or more respective portions of the distributed spatial sensor, wherein the second sensing device is operable to produce, for each of the localized position sensors, localized measurements of one or more positional characteristics of the corresponding portion of the distributed spatial sensor selected from the group consisting of spatial position and angular position; and an estimating unit operable to estimate one or more states of the navigation system based, at least in part, on the distributed measurements and the localized measurements.

2 . The system of claim 1 , wherein the distributed spatial sensor comprises a distributed fiber optic shape sensor comprising an optical fiber.

3 . The system of claim 2 , wherein the optical fiber comprises one or more optical fiber cores.

4 . The system of claim 2 , wherein the distributed spatial sensor is operable to produce measurements of distributed strain along the optical fiber, and wherein the first sensing device is operable to produce the distributed measurements of the one or more spatial characteristics of the distributed spatial sensor based, at least in part, on the measurements of the distributed strain along the optical fiber.

5 . The system of claim 1 , wherein the one or more localized position sensors comprise at least one sensor device operable to produce measurements of an angular position of a corresponding portion of the distributed spatial sensor.

6 . The system of claim 5 , wherein the sensor device comprises an inertial measurement unit comprising at least one sensor selected from the group consisting of a gyroscope and an accelerometer.

7 . The system of claim 5 , wherein the sensor device comprises a magnetometer.

8 . The system of claim 1 , wherein the one or more localized position sensors comprise at least one sensor device operable to produce measurements of a spatial position of a corresponding portion of the distributed spatial sensor.

9 . The system of claim 8 , wherein the sensor device is selected from the group consisting of a pressure sensor and a positioning system receiver.

10 . The system of claim 8 , wherein the sensor device comprises an imaging device.

11 . The system of claim 1 , wherein the second sensing device is further operable to produce, for each of the localized position sensors, localized measurements of a gravity vector at the corresponding portion of the distributed spatial sensor.

12 . The system of claim 1 , wherein the one or more localized position sensors comprise a first position sensor, the one or more portions of the distributed spatial sensor comprise a first portion of the distributed spatial sensor, the first position sensor corresponds to the first portion of the distributed spatial sensor, and the first position sensor is connected to the first portion of the distributed spatial sensor.

13 . The system of claim 12 , wherein the first portion of the distributed spatial sensor comprises an end portion of the distributed spatial sensor.

14 . The system of claim 1 , wherein the first sensing device is further operable to determine one or more positions of the one or more portions of the distributed spatial sensor corresponding to the one or more respective localized position sensors.

15 . The system of claim 1 , wherein the one or more estimated states of the system comprise at least one navigational parameter selected from the group consisting of a location of at least a portion of the distributed spatial sensor, an orientation of at least a portion of the distributed spatial sensor, a shape of at least a portion of the distributed spatial sensor, and a velocity of at least a portion of the distributed spatial sensor.

16 . The system of claim 15 , wherein the estimating unit is further operable to estimate an uncertainty in the at least one navigational parameter based, at least in part, on the distributed measurements and the localized measurements.

17 . The system of claim 1 , wherein the estimating unit is operable to estimate the one or more states using at least one filter selected from the group consisting of a Kalman filter, an enhanced Kalman filter, and a particle filter.

18 . The system of claim 1 , wherein the estimating unit is operable to estimate the one or more states using at least one numerical state estimation technique selected from the group consisting of weighted averaging, generalized state space estimation, and optimal state estimation.

19 . The system of claim 1 , wherein the estimating unit is operable to estimate the one or more states based, at least in part, on calibration data indicating one or more positions of the one or more portions of the distributed spatial sensor corresponding to the one or more respective localized position sensors.

20 . The system of claim 1 , wherein the first sensing device is operable to produce a first measurement of a position of an end portion of the distributed spatial sensor, the second sensing device is operable to produce a second measurement of the position of the end portion of the distributed spatial sensor, the one or more estimated states comprise an estimate of the position of the end portion of the distributed spatial sensor, and the estimate of the position of the end portion of the distributed spatial sensor is more accurate than the first and second measurements of the position of the end portion of the distributed spatial sensor.

21 . The system of claim 1 , wherein the estimating unit is further operable to estimate a value of a compensation parameter of the first sensing device based, at least in part, on the localized measurements.

22 . The system of claim 21 , wherein the distributed measurements produced by the first sensing device comprise corrected distributed measurements, the distributed spatial sensor is operable to produce raw distributed measurements of one or more spatial characteristics of the distributed spatial sensor, and the first sensing device is operable to produce the corrected distributed measurements based, at least in part, on the raw distributed measurements and the estimated value of the compensation parameter.

23 . The system of claim 22 , wherein the first sensing device is further operable to use the compensation parameter to compensate for an error in a measurement of an angular position of a portion of the distributed spatial sensor.

24 . The system of claim 22 , wherein the estimated value of the compensation parameter is indicative of an error in a measurement of an angular position of a portion of the distributed spatial sensor.

25 . The system of claim 21 , wherein the first sensing device is further operable to calibrate the distributed spatial sensor based, at least in part, on the estimated value of the compensation parameter.

26 . The system of claim 1 , wherein the one or more position sensors comprise a first position sensor corresponding to a first portion of the distributed spatial sensor, and

Assignees

• Charles Stark Draper Laboratory Inc
• Luna Innovations Inc

Inventors

• Laine Juha-Pekka J
• Dow Bruce
• Mcconley Marc
• Blasche Gregory
• Bohn Paul
• Bottkol Matthew S
• Ricard Michael
• Lally Evan M
• Klute Sandra M
• Reaves Matthew T
• Templeton Emily H
• Donna James

Classifications

• G01B11/16 Primary

  for measuring the deformation in a solid, e.g. optical strain gauge · CPC title

• G01C19/00

  Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects · CPC title

• G01D5/268 Primary

  using optical fibres (G01D5/28 - G01D5/38 take precedence) · CPC title