Patent ID: 11919663
Assignee: ARCA DYNAMICS SOCIETA' A RESPONSABILITA' LIMITATA SEMPLIFICATA
Field: Transport (Mechanical engineering)
Classification: CPC B  G | IPC B  G

Claim 0:
1. Method for estimating an angular velocity of a space platform equipped with at least one optical sensor, comprising:
a) acquiring, using an optical sensor, a first image and a second image, wherein the first image is related to a first time instant and the second image is related to a second time instant subsequent to the first time instant;
b) identifying, based on intensities of pixels in the first image acquired, a first plurality of clusters of pixels related, each, to a respective star;
c) determining, for each of the first plurality of clusters of pixels, a respective first centroid;
d) identifying, based on intensities of pixels in the second image acquired, a second plurality of clusters of pixels related, each, to a respective star;
e) determining, for each of the second plurality of clusters of pixels, a respective second centroid;
f) detecting pairs of clusters of pixels, wherein each pair of clusters of pixels includes a respective first cluster of pixels in the first image and a respective second cluster of pixels in the second image, and the first cluster of pixels and the second cluster of pixels are both related to one and the same star;
g) for each pair of clusters of pixels detected, detecting whether said pair of clusters of pixels is of a first predefined type or of a second predefined type;
h) for each pair of clusters of pixels of the first predefined type, computing
a respective first star versor based on the respective first centroid of the respective first cluster of pixels, and
a respective second star versor based on the respective second centroid of the respective second cluster of pixels;
i) for each pair of clusters of pixels of the second predefined type,
performing a polynomial interpolation of the first cluster of pixels of the pair and the second cluster of pixels of the pair thereby obtaining a respective interpolation polynomial, which interpolates the respective first cluster of pixels and the respective second cluster of pixels,
sampling said respective interpolation polynomial in a plurality of sampling points and,
computing a plurality of third star versors, wherein each of the plurality of third star versors is associated with one of the plurality of sampling points;
j) estimating an angular velocity of the space platform based on the first versor, the second versor and the plurality of third star versors if computed, thereby obtaining an angular velocity estimate related to the first time instant.