US 12,087,003 B2
Auto calibration from epipolar line distance in projection pattern
Patrick Schindler, Ludwigshafen (DE); Friedrich Schick, Ludwigshafen (DE); Christian Lennartz, Ludwigshafen (DE); Peter Schillen, Ludwigshafen (DE); and Jakob Unger, Freiburg im Breisgau (DE)
Filed by TRINAMIX GMBH, Ludwigshafen am Rhein (DE)
Filed on Aug. 1, 2023, as Appl. No. 18/363,420.
Application 18/363,420 is a continuation of application No. PCT/EP2022/064655, filed on May 30, 2022.
Claims priority of application No. 21176939 (EP), filed on May 31, 2021.
Prior Publication US 2024/0020864 A1, Jan. 18, 2024
Int. Cl. G06T 7/521 (2017.01); G06T 7/80 (2017.01)
CPC G06T 7/521 (2017.01) [G06T 7/80 (2017.01)] 30 Claims
OG exemplary drawing
 
1. A detector for determining a position of at least one object, the detector comprising:
at least one projector for illuminating the object with at least one illumination pattern, wherein the illumination pattern comprises a plurality of illumination features;
at least one sensor element having a matrix of optical sensors, the optical sensors each having a light-sensitive area, wherein each optical sensor is designed to generate at least one sensor signal in response to an illumination of its respective light-sensitive area by a reflection light beam propagating from the object to the detector, wherein the sensor element is configured to determine at least one reflection image comprising a plurality of reflection features, wherein each of the reflection features comprises a beam profile; and
at least one evaluation device configured for determining initial distance information of the reflection features by analysis of their respective beam profiles, wherein the analysis of a beam profile comprises evaluating a combined signal Q from the at least one sensor signal, wherein the evaluation device is configured for performing a calibration method comprising:
a) matching the reflection features to reference features of a reference image using the initial distance information thereby determining pairs of matched reflection and reference features;
b) determining an epipolar line of the matched reference feature in the reference image for each of the pairs of matched reflection and reference features;
c) determining an epipolar line distance d of a center of the matched reflection feature to said epipolar line;
d) evaluating the epipolar line distances d as a function of an image position (x,y) in the reference image thereby determining a geometric pattern; and
e) determining at least one correction for rotation and/or translation of the reflection image depending on the geometric pattern.