MODELING AND MODEL PREDICTIVE CONTROL (MPC) OF AN UNDERWATER DOUBLE INVERTED PENDULUM (UDIP) (Atena Editora)

Abstract

The Inverted Double Pendulum (IDP) is a classical nonlinear and unstable mechanical system used as a benchmark model for the application of innumerous control techniques. However, such a model was never treated in an off-the-self environment, which represents a gap in its applications range since the demand for underwater robotics is increasing together with the ocean engineering activities. Thus, to fill this gap and build a new benchmark model for the control development of underwater robotics, this paper presents the modeling and control of an Underwater Double Inverted Pendulum (UDIP). The dynamic model is formulated using the formalism of Analytical Mechanics and considering the pertinent hydrodynamic and hydrostatic effects. To keep straight with the control techniques trends, a Model Predictive Control (MPC) is designed for the UDIP. This controller is tested through numerical simulations in MATLAB/Simulink© environment considering two scenarios: 1) in the absence of disturbances, and 2) in the presence of a time-varying water current. The obtained results for the disturbances case reveal an increase in the control effort in comparison with the case without disturbances. In such a way, this reflect the difficulty associated to the control of underwater robots in unstructured environments.