Development of a force actuator for hybrid model tests in a wave tank.

• Ano de defesa: 2021
• Autor(a) principal: Huang, Alex Saratani
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Controle de força; Controle por modos deslizantes super-twisting; Embarcações; Ensaio com modelo híbrido; Force control; Hybrid model testing; Sistemas dinâmicos; Super-twisting sliding mode control; Tanques
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/3/3152/tde-16072021-110003/

One solution to overcome the limitations of small scale model testing, such as scaling conflicts or infrastructure constrains, while retaining the physical phenomena\' complexity, is hybrid model testing. In hybrid model testing, the physical substructure (tested experimentally) and the numerical substructure (simulated in a computer) interact with each other through a network of sensors and actuators. Hence, to apply the desired effects in the physical substructure, precise control of the actuators is necessary. In this work, we will develop a force actuator for hybrid model testing of a vessel in a wave tank. It will be employed a robust control technique (super-twisting sliding mode) to develop the controller of the force actuator consisting in a servomotor that applies a desired force through a line attached to the vessel model. We describe the force actuator dynamics and develop the sliding mode controller considering the system uncertainties (external disturbances, unknown plant parameters or unmodeled dynamics). Then, the force actuator is validated experimentally. We analyzed a step and a sinusoid input (0.1 to 2.0 Hz), with a disturbance motion of frequencies up to 1.5 Hz. The actuator developed showed good results (mean absolute error inferior to 0.1 N in all tests), where the high frequency error spikes (up to 0.33 N) should not have a significant effect on the hybrid model tests slow dynamics. We conclude that the force actuator will be a valuable tool for hybrid model testing.