Representation of 3D motion by projective angles

The paper describes a new laser device conceived for surface scanning and more specifically for mini robot calibrations. The system is based on a laser triangulation sensor which is moved by an extremely accurate device to collect a set of 3D points lying on surfaces. If the surfaces belong to the gripper of a robot that must be calibrated and a sufficient number of points of this gripper are collected, the pose of the robot can be measured. If the robot is moved to several different configurations and the gripper poses are measured for each of them, it is possible to reconstruct the kinematics of the robot and calibrate it. The paper presents the theory and describes the design, tests and calibration of the laser instrumentation with a focus on the first experimental results. These results are obtained in a working cell including a vision system, a 4-dof (xyz,) mini robot and a 2-dof rotating platform.