Two steps piecewise affine identification of nonlinear systems

Given a set of input-output measurements, the paper proposes a method for approximation of a nonlinear system by a piecewise affine model (PWA). First step of the two-stage procedure is identification from input-output data, in order to obtain an appropriate nonlinear function in analytic form. The analytic expression of the model can be represented either by a static nonlinear function or by a dynamic system and can be obtained using a basis function expansion modeling approach. Subsequently we employ nonlinear programming to derive optimal PWA approximation of the identified model such that the approximation error is minimized. Moreover, we show that approximation of multivariate systems can be transformed into a series of one-dimensional approximations, which can be solved efficiently using standard optimization techniques

Three-dimensional reconstruction of a static and unstructured environment using a teleoperated platform and it's virtual representation employing ros

El avance de las herramientas computacionales permite al área de robótica plantearse problemas cada vez mas complejos y que brinden apoyo en tareas en las que el ser humano lo requiere, tal es el caso de digitalizar espacios que: o bien pueden contener un ambiente de difícil acceso, o algunos de sus límites son complicados de alcanzar, o simplemente por error humano es un trabajo que prefiere encargar a un sensor con una precisión constante, El presente trabajo de grado pretende aportar una solución en la tarea de obtener reconstrucciones tridimensionales de ambientes no conocidos mediante una plataforma móvil tele-operada, que hace uso del sistema operativo ROS (Robot Operating System) para emplear SLAM (Simultaneus Localization And Mapping), odometría y una central inercial, en la determinación integrada de la ubicación del robot, y así añadir información a una nube de puntos a partir de la información 3D obtenida rotando el plano visualizado por un sensor LIDAR (Laser Imaging Detection And Ranging ); para luego representar dicha información en una herramienta computacional.This works consists in the design, programming and manufacture of a mobile robotic platform which need to be able to develop a trhree-dimensional scan of a real environment using a two-dimensional sensor (SICK TIM 351). The mobile platform is commanded by remote control that allows the user to control position and orientation in the scene in order to increase the information in those areas that could be more important to scan. The algorithms has been programmed throw the Robot Operating System (ROS) and the sensor information it’s acquire by a FITPC settle at the platform and send it to a central computer by a WIFI connection, where the spatial coordinates of the scan environment are calculated. Finally the point cloud created it’s represented in a Matlab Graphical User Interface(GUI).Pregrad