3D-2D Laser Range Finder calibration using a conic based geometry shape Miguel Almeida 1 , Paulo Dias 1 , Miguel Oliveira 2 , Vítor Santos 2 1 Dept. of Electronics, Telecom. and Informatics, IEETA, University of Aveiro, Portugal {m.almeida,paulo.dias}@ua.pt 2 Dept of Mechanical Engineering, University of Aveiro, Portugal {mriem,vitor}@ua.pt Abstract. The AtlasCar is a prototype that is being developed at the University of Aveiro to research advanced driver assistance systems. The car is equipped with several sensors: 3D and 2D laser scanners, a stereo camera, inertial sensors and GPS. The combination of all these sensor data in useful representations is essential. Therefore, calibration is one of the first problems to tackle. This paper focuses on 3D/2D laser calibration. The proposed method uses a 3D Laser Range Finder (LRF) to produce a reference 3D point cloud containing a known calibration object. Manual input from the user and knowledge of the object ge- ometry are used to register the 3D point cloud with the 2D Lasers. Experimental results with simulated and real data demonstrate the effectiveness of the pro- posed calibration method. Keywords: laser range finder; laser to laser calibration; sensor fusion 1 INTRODUCTION Mobile platforms typically combine several data acquisition systems such as lasers, cameras and inertial systems. However the geometrical combination of the different sensors requires their calibration, at least, through the definition of the extrinsic pa- rameters, i.e., the transformation matrices that register all sensors in the same coordi- nate system. Geometric calibration is an active field of study due to its importance in sensor fusion. Several methods use cameras combined with laser range finders (LRF) and a chessboard pattern for calibration [1, 2]. Other approaches require the user to select key points in laser data in order to perform the calibration [3]. A more similar solution to the one proposed in this paper can be found in Lisca, Pangyu and Nedevshi [4], where the calibration between a multi-line LRF and a stereo camera is obtained from the information of a known calibration object in the scene. This paper focuses on 3D/2D laser calibration for the AtlasCar project, which is a prototype for research on Advanced Driver Assistance Systems [5]. The modified car includes several sensors as illustrated on Fig. 1.The 3D laser scanner is based on a modified 2D laser scanner originally proposed in Dias, Matos and Santos [6] and further modified to its actual configuration [7]. Besides the 3D laser, two 2D SICK