Optical Butting of Plane Array Sensors for PA-LiDAR

Abstract

In order to expand the field of view and improve the resolution, a method of optical butting was proposed for two plane array sensors using beam splitter prism in this paper. The principle of optical butting, the optical design, calibration and focusing technology, and alignment method were presented and analyzed. In addition, the gray image stitch and point cloud data registration were also realized. To prove the concept of the optical butting method, we built a prototype system for experiment. The splicing of two <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$320\times240$ </tex-math></inline-formula> sensors of plane array laser imaging detection and ranging (PA-LiDAR) was implemented. After optical butting, the total effective pixel number was <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$320\times480$ </tex-math></inline-formula> , the total effective area was <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6.4\times4.8$ </tex-math></inline-formula> mm, and the field of view was <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$22\,\,^{\circ }\times 15\,\,^{\circ }$ </tex-math></inline-formula> . Compared with the conventional laser radar system, the optical butting system can improve the field of view and resolution by a factor about <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 1$ </tex-math></inline-formula> . This method had the advantages of simple constitution, easy accomplishment, small space and high assembly precision which guaranteed the operating requirement of the PA-LIDAR sensor.