Self-contained holonomic tracking method and apparatus for non-destructive inspection

Patent metadata

Field	Value
Publication number	US-9470658-B2
Application number	US-201313796584-A
Country	US
Kind code	B2
Filing date	Mar 12, 2013
Priority date	Mar 12, 2013
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

A self-contained, holonomic motion tracking solution for supplementing the acquisition of inspection information on the surface of a structure, thereby enabling the real-time production of two-dimensional images from hand-held and automated scanning by holonomic-motion of non-destructive inspection (NDI) sensor units (e.g., NDI probes). The systems and methods disclosed enable precise tracking of the position and orientation of a holonomic-motion NDI sensor unit (hand-held or automated) and conversion of the acquired tracking data into encoder pulse signals for processing by a NDI scanning system.

First claim

The invention claimed is:

1. An inspection system comprising a scanning device, a display device and a computer system, said scanning device and said display device being coupled to communicate with said computer system,
wherein said scanning device comprises: a frame; a plurality of omni wheels rotatably coupled to said frame and arranged in a four-omni wheel, perpendicular, double-differential configuration; a plurality of rotational encoders respectively coupled to said plurality of omni wheels for converting rotation of each omni wheel into respective encoder data; and an inspection unit connected to said frame, and
wherein said computer system is programmed to execute the following operations:
(a) computing an absolute angle θ representing an orientation of the scanning device relative to a coordinate system based in part on said encoder data;
(b) computing relative changes in X and Y positions ΔP x and ΔP y of a point on the scanning device relative to said coordinate system based in part on said encoder data;
(c) computing an absolute position of the point on the scanning device relative to said coordinate system based in part on said computed absolute angle and said computed changes in X and Y positions;
(d) controlling said inspection unit to acquire inspection data;
(e) controlling said display device to display an image in which the inspection data is arranged based on the respective absolute angle and absolute position of the point on said scanning device when each inspection datum was acquired.

2. The inspection system as recited in claim 1 , wherein said computer system is further programmed to execute the following operations:
converting the computed absolute angles and absolute positions into simulated encoder pulses; and
correlating the inspection data with the simulated encoder pulses,
wherein said displaying operation arranges the inspection data in accordance with the results of said correlating operation.

3. The inspection system as recited in claim 2 , wherein said simulated encoder pulses are quadrature pulses suitable for processing by inspection scan software.

4. The inspection system as recited in claim 3 , wherein said computer system is further programmed to convert the simulated encoder pulses into X-Y coordinate positions, wherein said correlating operation comprises correlating the inspection data with the X-Y coordinate positions.

5. The inspection system as recited in claim 1 , wherein the absolute position of the point on the inspection unit is computed using the following rotation matrix formulation:

[

P
x

P
y

]

=

[

P
x_last

P
y_last

]

+

[

cos
⁢

⁢
θ

-
sin

⁢

⁢
θ

sin
⁢

⁢
θ

cos
⁢

⁢
θ

]

⁡

[

Δ
⁢

⁢

P
x

Δ
⁢

⁢

P
y

]

wherein P x _ last and P y _ last represent a last absolute position of the point on the inspection unit.

6. The inspection system as recited in claim 5 , wherein the absolute angle θ is computed using the following relationship:

θ
=

2
⁢

⁢
π
⁢

⁢

R
⁡

(

e
0

-

e
1

-

Assignees

• Boeing Co

Inventors

• Troy James J
• Lea Scott W
• Georgeson Gary E
• Nelson Karl E
• Wright Daniel James

Classifications

• G01N2291/106

  one or more transducer arrays · CPC title

• G01C22/02 Primary

  by conversion into electric waveforms and subsequent integration, e.g. using tachometer generator {(G01C22/002, G01C22/004, G01C22/006 take precedence)} · CPC title

• G01N27/9013

  Arrangements for scanning · CPC title

• G01N29/225

  Supports, positioning or alignment in moving situation · CPC title

• G01N29/265

  by moving the sensor relative to a stationary material · CPC title