COBEM99

S5 Controle Ativo de Vibrações e Estruturas Inteligentes

Title:

CONTROLE DE ESTRUTURAS FLEXÍVEIS ATIVADAS POR ESCOAMENTO DE FLUIDOS

Summary :

KEYWORDS: MODELING, MANIPULATOR, FLEXIBLE, CONTROL, ROBUSTNESS. ABSTRACT. THIS WORK CONTAINS A STUDY ABOUT THE ACTIVE CONTROL OF A FLEXIBLE STRUCTURE SUBJECT TO EXTERNAL DISTURBANCE, COMING FROM THE FLOW OF A FLUID IN CONTACT WITH THE STRUCTURE. PRACTICAL PROBLEMS OF THIS SORT MAY HAPPEN FOR EXAMPLE IN UNDERWATER ROBOTICS. AS GENERALLY THERE ARE TECHNICAL DIFFICULTIES TO IMPLEMENT IN A PHYSICAL PLANT MANY SENSORS, WE CONSIDERED THAT ONLY ONE STATE VARIABLE IS OBSERVED. THIS FACT IMPOSES EXTRA DIFFICULTIES TO THE CONTROLLERS PROJECT THAT IDEALLY SHOULD HAVE THE RETURN OF THE FULL STATE FOR THE CASE OF FLEXIBLE STRUCTURES. FIRST WE TRIED TO SOLVE THE PROBLEM WITH THE LQG/LTR TECHNIQUE BUT THE RESULTS OF THE PERFORMANCE FOR THIS APPLICATION WERE NOT SATISFACTORY ENOUGH. THEN WE DEVELOPED CONTROLLERS BASED ON THE POLES PLACEMENT TECHNIQUE BOTH FOR THE REGULATOR AND FILTER. WE TRIED TO IMPOSE ROBUSTNESS REQUERIMENTS TO STABILITY AT HIGH FREQUENCIES AND PERFORMANCE AT LOW FREQUENCIES OF THE DIRECT LOOP TRANSFER FUNCTION. SIMULATIONS WERE ACCOMPLISHED CONSIDERING BOTH FLOW DISTURBANCE AND PARAMETRIC VARIATION OF THE PLANT RELATED TO THE NOMINAL MODEL. THE RESULTS SHOWED THAT A SIMPLE TECHNIQUE PROJECTED WITH STRENGTH FEATURES WAS BE ABLE TO SOLVE THE PROBLEM SATISFACTORILY.

Author :

De Bortoli, Álvaro Luiz
Gomes, Sebastião Cícero Pinheiro
Machado, Celiane Costa

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