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| Author(s): |
José Augusto Ignácio da Silva
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Ilha Solteira. 2019-08-13. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Engenharia. Ilha Solteira |
| Defense date: | 2019-06-13 |
| Advisor: | Gustavo Luiz Chagas Manhães de Abreu; Douglas Domingues Bueno |
| Abstract | |
The present work proposes a new strategy for robust active suppression of Ground Resonance (GR) phenomenon in Helicopters. The classical model to analysis of this phenomenon is developed for an isotropic rotor and stability analysis is done in Coleman domain, to nd the boundaries of instability. It is also proposed a new strategy for dealing with these boundaries of instability and suppressing GR using controllers with polytopic convex hulls formulation. Controllers are designed via Linear Matrix Inequalities (LMIs), formulated according to the Lyapunov Stability Theory. Additionally, parametric uncertainties in the lead-lag frequency of the blades and actuators faults are considered and thus new robust controllers are designed to expand the aircraft operating envelope. Also, di erent types of structural nonlinearities in the landing gear sti ness and damping of the helicopter are considered, and the characterization of the nonlinear stability of the system exhibits Limit Cycle Oscillation (LCO), which are determined from the construction of Bifurcation Diagrams. Fuzzy-TS modeling is used for each case study and, based on the nonlinear stability boundaries of the GR, de ned from the Bifurcation Diagrams, the controllers to suppress the LCO are designed. The results of numerical simulations, discussions and conclusions are presented and show that the control strategy proposed is an attractive solution to suppress the linear and nonlinear GR problem, being able to expand the operational envelope of the aircraft. (AU) | |
| FAPESP's process: | 16/05988-2 - Active vibration control of ground resonance phenomenon in helicopters using piezoelectric materials incorporated on the blades |
| Grantee: | José Augusto Ignácio da Silva |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |