Research on non-concentric spatial scanning measurement system

For the requirement of 3D coordinate measurement of structures, a novel non-concentric measurement system is proposed. This measurement system consists of a laser rangefinder and a two-dimensional rotating table, in which the rotation center of rotating table does not coincide with the light-emitting point of the laser rangefinder. Additionally, a mathematical model for distance correction is established in order to control systematic errors and meet high accuracy demands. Then, two calibration parameters of this system is defined and corresponding calibration method is introduced. Finally, a non-concentric scanning system is constructed and a comparison experiment with laser scanners is conducted. Experimental results demonstrate that this new system can obtain the same high precision point clouds and monitoring deformation within the measurement distance of 44 m. That means the system can meet the high-precision measurement requirements of structures. Compared with traditional laser scanners, this system is easy to set up and has fewer parameters. As a result, the cost price can be controlled and the calibration process is more convenient so as to be employed in monitoring structure deformation under complex conditions.