OPTIMAL CONTROL OF A 3D CRANE USING DIRECT TRANSCRIPTION

Marcos Rogério de Oliveira Tenório¹; Fabrizio Leonardi¹

¹ FEI

doi:10.20906/CPS/COB-2015-0554

Resumo

Cranes continue to be used in a variety of ways in the field of freight transport. Increasing the performance of the operation may result in a reduction of the operation time, improvements of the maneuvers and a reduction of the consumed energy. A strategy to ensure these improvements could be by means of an optimization problem representing the optimal control problem of its trajectory. It is a challenge for a 3D crane due to its nonlinear behavior. Optimal control problems can be converted into nonlinear discrete optimization problems that include the dynamic equations of the system as constraints of the problem. Other constraints are given by the limitations of the actuator, the initial and final conditions and the limit of the payload oscillation. The minimum-time optimal control problem of a 3D crane, whose model is available in the literature, has been studied in this work. The continuous optimal control problem was manually formulated and then automatically converted into the equivalent nonlinear discrete optimization problem through the PROPT compiler. The numerical results from simulations show non-trivial solutions that would not be easily obtained without a rigorous formulation of the problem. However, it has been noticed that the optimal control problem of the 3D crane is sensitive to the initial guess of the trajectory and the number of nodes chosen.

Palavras-chave: optimal control; optimal trajectory; crane