Patent ID: 11961305
Assignee: THE BOEING COMPANY
Field: Transport (Mechanical engineering)
Classification: CPC B  G | IPC B  G

Claim 8:
9. A method for tracking a location of a motion platform carrying first and second scanners that respectively comprise first and second one-dimensional sensor arrays which have respective mutually parallel centerlines separated by a fixed distance, the method comprising:
(a) setting filter threshold values for depth and intensity which are associated with a specific type of feature;
(b) moving the first scanner across a surface of a target object from a starting location to an ending location along a path;
(c) operating the first scanner to acquire a first sequence of sets of sensor data at a known capture rate as the first scanner moves along the path;
(d) operating the second scanner to acquire a second sequence of sets of sensor data at the known capture rate as the first scanner moves along the path;
(e) converting the first sequence of sets of sensor data to a corresponding first sequence of scan strips of scan image data;
(f) converting the second sequence of sets of sensor data to a corresponding second sequence of scan strips of scan image data, wherein a number of scan strips in the second sequence of scan strips is the same as a number of scan strips in the first sequence of scan strips;
(g) constructing successive first scan images from the first sequence of scan strips;
(h) constructing successive second scan images from the second sequence of scan strips;
(i) filtering the first and second scan images using the filter threshold values to isolate the feature of the specific type, wherein the path along which the first scanner moves during step (b) is adjusted based on results of the filtering;
(j) finding feature points in the first and second scan images;
(k) determining which feature points found in step (j) are common feature points in the first and second scan images;
(l) computing a pixel position difference between the respective positions of a common feature point in the first and second scan images; and
(m) computing a scanner displacement by multiplying the pixel position difference computed in step (l) by a scaling factor representing a distance traveled by the first scanner per scan strip.