Method to measure the rotation angles in vibrating systems

In the measurement systems of three-dimensional (3-D) positions using active vision (e.g., laser and camera), it is necessary to know the precise rotation angles of the camera and the laser with respect to the object on which the 3-D coordinate measures are desired. A small variation of these angles can result in substantial errors of measurement. In this work, we present a novel solution to measure the rotation-angle variations of the elements that form the measurement system under vibration. In our case, the objective is to determine these angles for a 3-D-coordinate measurement system of the wires that feed the electric trains (contact wires). The measurement system must go onboard a measurement car. The 3-D-coordinate measurements are done by triangulation, from a digital camera and a laser that emits a plane of structured light incident on contact wires. In order to measure the angle variations, which result from the vibrations that take place in the measurement system, two line scan cameras and two artificial marks are used. In this paper, the procedure that allows the measurement of the rotation angles of the camera and the laser, the proposed models, and the results obtained in the simulations are shown.