A robust real-time laser measurement method based on noncoding
parallel multi-line
Chenbo Zhang, Haihua Cui, Wei Yin and Liu Yang,
College of Mechanical Engineering, Nanjing University of Aeronautics
and Astronautics, Nanjing, 210016, China
Jiangsu Key Lab of Digital Medical Equipment
Email: zcb5216@outlook.com, cuihh@nuaa.edu.cn
ABSTRACT
Single line scanning is the main method in traditional 3D hand-held laser scanning, however its reconstruction speed is
very slow and cumulative error is very large. Therefore, we propose a method to reconstruct the 3D profile by parallel
multi-line 3D hand-held laser scanning. Firstly, we process the two images that contain multi-line laser stripes shot by
the binocular cameras, and then the laser stripe centers will be extracted accurately. Then we use the approach of stereo
vision principle, polar constraint and laser plane constraint to match the laser stripes of the left image and the right image
correctly and reconstruct them quickly. Our experimental results prove the feasibility of this method, which improves the
scanning speed and increases the scanning area greatly.
Keywords: Parallel multi-line; stereo vision principle; polar constraint; laser stripe centers
1. INTRODUCTION
3D laser scanning technology is also called "live replication technology" which is a new and high technology began to
appear in the mid-nineties. It records the 3D coordinates of numerous dense points in the object surface measured to
reconstruct the object rapidly by using the laser triangulation ranging principle[1]. It overcomes the limitations of
traditional measuring instrument with its many advantages, such as non-contact, high scanning speed, large amount of
information acquired, high precision, strong real-time performance, full automatic, complex environment measurement
and etc. It’s also an important means of obtaining high precision 3D data and achieving 3D visualization[2].
It’s an important breakthrough for hand-held laser scanner to traditional fixed laser scanner. The position of the
scanner and the object can be exchanged, which greatly expands the scanning range and improves the scanning
feasibility on different occasions.
At present, 3D laser scanning device can be divided into two kinds, fixed scanner and handheld scanner. The 3D
scanning of 3D fixed laser scanning device can be achieved by a standard 2D scanner and a mechanical actuator[3].
Hand-held single-line laser scanner[4] is convenient to carry without geographical restrictions, and can scan medium and
small objects, but its scanning accuracy which is low and its cumulative error is large, which is difficult to scan large
objects.
We propose a method of hand-held 3D laser scanning based on noncoding parallel multi-line aiming at the
phenomenon above. This method uses the interrelation of binocular cameras and laser line planes to match feature points,
so as to obtain the precise 3D information of objects quickly and steadily. Firstly, the authors introduce the basic
principle of the method and implementation steps in detail. Secondly, the authors prove the feasibility of this method
through the physical experiment.