US 12,307,718 B2
Cascading expansion method of working space and working visual angle of stereo vision system
Cai Meng, Beijing (CN); and Xinliang Deng, Beijing (CN)
Assigned to BEIHANG UNIVERSITY, Beijing (CN)
Filed by BEIHANG UNIVERSITY, Beijing (CN)
Filed on Aug. 29, 2022, as Appl. No. 17/897,244.
Application 17/897,244 is a continuation of application No. PCT/CN2021/072834, filed on Jan. 20, 2021.
Claims priority of application No. 202010487757.3 (CN), filed on Jun. 2, 2020.
Prior Publication US 2022/0405971 A1, Dec. 22, 2022
Int. Cl. G06T 7/80 (2017.01); B25J 9/16 (2006.01)
CPC G06T 7/85 (2017.01) [B25J 9/1697 (2013.01); G06T 2207/10012 (2013.01)] 2 Claims
OG exemplary drawing
 
1. A cascading expansion method of working space and working visual angle of stereo vision system, comprising:
S1: selecting N stereo vision systems, with a No. 1 stereo vision system as a master stereo vision system and No. 2 to No. N stereo vision systems as slave stereo vision systems, and taking a visual coordinate system of the master stereo vision system as a global reference coordinate system {W}; wherein N is an integer greater than 1;
S2: pasting or printing a manual marker Markern on an outer surface of the No. n stereo vision system, and establishing a local coordinate system {Mn} by the manual marker Markern; wherein, n=2, 3, . . . , N, and different stereo vision systems correspond to different manual markers;
S3: describing, by a spatial mapping matrix T{Cn}→{Mn}, an inherent position and posture relationship between the local coordinate system {Mn} established by the manual marker Markern and a visual coordinate system {Cn} of the No. n stereo vision system; wherein, the spatial mapping matrix T{Cn}→{Mn} is determined by calibration method;
S4: fixedly connecting the No. 1 stereo vision system with a global vision system bracket, determining a working position and visual angle direction of the No. 1 stereo vision system, fixing the No. 1 stereo vision system and keeping the No. 1 stereo vision system unchanged throughout the working process;
S5: fixedly connecting the No. n stereo vision system with a No. n self-locking traction manipulator, and adjusting the working position and visual angle direction of the No. n stereo vision system at any time through force traction, so that the manual marker Markern is visible in an effective working space of the No. 1 stereo vision system, and a target P to be measured is visible in an effective working space of the No. n stereo vision system;
S6: measuring, by the No. 1 stereo vision system, a spatial position and posture of the local coordinate system {Mn} established by the manual marker Markern on the No. n stereo vision system, and recording the measured spatial position and posture as T{Mn}→{W}, measuring, by the No. n stereo vision system, a position and posture of the target P to be measured in the effective workspace of the No. n stereo vision system, and recording the measured position and posture of the target P to be measured as P{Cn}; and in combination with the spatial mapping matrix T{Cn}→{Mn} of the local coordinate system {Mn} established by the calibrated manual marker Markern and the visual coordinate system {Cn} of the No. n stereo vision system, realizing a transformation of the position and posture of the target P to be measured from the visual coordinate system {Cn} of the No. n stereo vision system to the visual coordinate system of the No. 1 stereo vision system, that is, the global reference coordinate system {W}:
P{W}=T{Mn}→{W}·T{Cn}→{Mn}P{Cn}
wherein, P{W} is coordinates of the target P to be measured in the global reference coordinate system {W}, P{Cn} is coordinates of the target P to be measured in the visual coordinate system {Cn} of the No. n stereo vision system, P=[x y z 1]T is homogeneous coordinates of P=[x y z]T, and (x, y, z) is coordinates of the target P to be measured in the three-dimensional space coordinate system.