Calibration method for multiple 2D LIDARs system

Many robotic and mobile mapping systems have been developed using multiple 2D LIDARs (briefly multi-LIDAR system) to sense environment. In such systems, extrinsic calibration of all LIDARs is essential for making collaborative use of the data from different sensors. This research aims at developing a calibration method for multi-LIDAR systems at the general scene, such as an outdoor place or an underground parking-lot, without modification to environment by putting calibration targets. In this paper, the calibration method is proposed by aligning the 3D data of different LIDARs. They are concerned at two-levels: 1) reference calibration, i.e. finding the transformation from a reference LIDAR to the platform frame; 2) multi-LIDAR calibration, i.e. finding the LIDARs´ relative geometries by referring to the reference one. The method is examined in calibrating the multiple 2D LIDARs on an intelligent vehicle platform POSS-V, where the data collected through a driving in an underground parking-lot are registered to find sensors´ geometry. Calibration accuracy is examined by comparing with a CAD model of the scene, which was measured by using a total station.