Valesca Alves Corrêa

Trajectories generation for a robotic manipulator

The inverse kinematics determines the joint angles that result in the desired position of the manipulators end-effector with regard to the reference coordinated system. The inverse kinematics solution is difficult a time that the mapping between the Cartesian space and the joint space is nonlinear and involves equations that can have multiple solutions. This work presents the application of a neural network with radial basis function (RBF) for the inverse kinematics solution of a robotic manipulator with three degrees of freedom. For a good learning generalization in the training phase of RBF network, some initial and final points had been initially generated inside of the manipulators work volume. In order to prevent extreme angular oscillations, the angles for each one of the n generated points, they had been optimized by genetic algorithms. In accordance with the cartesian coordinate (x, y) supplied, the RBF neural network implemented in this work supplied angles that it had presented very next to the desired values.

Modeling the Mechanical Behaviour of a Subsea Guide Base Subject to Installation and Operations Loads

Historically, the guide cable system for installation of subsea oil production equipment has proven its efficiency. These cables extend from the rig to the wellhead, which are fixed to the guide base posts and will be subject to loads during the installation and operation of the production equipment. The majority of guide base designs have been calculated by analytical methods, although they allow obtaining exact answers in all infinite points of a structure, they are not applicable to all cases. This motivated the application of finite element analysis method (FEA) in this work, which from the development of approximate procedures can be applied regardless of the structure shape and loading conditions. This paper consists of a structural analysis of the guide base frame model, generated in Autodesk Inventor® software and analyzed in ANSYS® Workbench. The study brings a diagnostic research using a quantitative and exploratory approach. Different mathematical models were generated to obtain the results at the most critical points of the structure in order to determine its resistance to the loads applied during installation and operation, taking into account the criteria laid down in DNV 2.7-3, API 17D 1st Ed and von-Mises equivalent stress.