US 11,994,631 B2
Calibration of LiDAR sensors
Dongyi Liao, Mountain View, CA (US); Zukai Wang, San Jose, CA (US); Mark A. McCord, Los Gatos, CA (US); and Chao Gu, Ottawa (CA)
Assigned to Cepton Technologies, Inc., San Jose, CA (US)
Filed by Cepton Technologies, Inc., San Jose, CA (US)
Filed on Oct. 13, 2020, as Appl. No. 17/069,727.
Claims priority of provisional application 62/915,563, filed on Oct. 15, 2019.
Prior Publication US 2021/0109204 A1, Apr. 15, 2021
Int. Cl. G01S 7/497 (2006.01); G01B 11/06 (2006.01); G01S 7/48 (2006.01); G01S 7/481 (2006.01); G01S 17/86 (2020.01); G01S 17/89 (2020.01); G01S 17/894 (2020.01); G01S 17/931 (2020.01); G06T 7/70 (2017.01); G06T 7/80 (2017.01); G06T 19/20 (2011.01); G05D 1/00 (2006.01)
CPC G01S 7/4972 (2013.01) [G01B 11/0608 (2013.01); G01S 7/4808 (2013.01); G01S 7/481 (2013.01); G01S 7/4811 (2013.01); G01S 17/86 (2020.01); G01S 17/89 (2013.01); G01S 17/894 (2020.01); G01S 17/931 (2020.01); G06T 7/80 (2017.01); G06T 19/20 (2013.01); G05D 1/0231 (2013.01); G06T 2207/10028 (2013.01); G06T 2207/30252 (2013.01); G06T 2219/20 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method of calibrating a LiDAR sensor mounted on a vehicle, the method comprising:
positioning the vehicle at a distance from a target, wherein:
the target comprises a planar mirror and features surrounding the planar mirror, an optical axis of the planar mirror being substantially horizontal;
the vehicle is positioned and oriented relative to the planar mirror so that an optical axis of the LiDAR sensor is nominally parallel to the optical axis of the planar mirror, and the target is nominally centered at a field of view of the LiDAR sensor;
acquiring, using the LiDAR sensor, a three-dimensional image of the target, wherein the three-dimensional image of the target includes images of the features of the target and a mirror image of the vehicle formed by the planar mirror; and
determining a deviation from an expected alignment of the LiDAR sensor with respect to the vehicle by analyzing the images of the features and the mirror image of the vehicle in the three-dimensional image of the target;
determining a position and an orientation of the LiDAR sensor relative to the target based on the images of the features;
determining a position and an orientation of the LiDAR sensor relative to the mirror image of the vehicle based on the mirror image of the vehicle; and
determining a transformation from a LiDAR coordinate system into a vehicle coordinate system based on: (i) the position and the orientation of the LiDAR sensor relative to the target, and (ii) the position and the orientation of the LiDAR sensor relative to the mirror image of the vehicle.