Abstract of Thesis presented at COPPE/UFRJ as a partial fulfillment of the requirements for the degree of Doctor of Science (D.Sc.)

Multivariable Adaptive Control: Uncertain High Frequency Gain, Robustness and Guaranteed Transient Performance

Andrei Giordano Holanda Battistel

January/2015

Advisors:

Liu Hsu Eduardo Vieira Leão Nunes

Department:

Eletrical Engineering

      This work proposes new solutions to Multivariable Model Reference Adaptive Control (MIMO-MRAC) for plants with arbitrary relative degree without requiring stringent symmetry assumptions related with the plant uncertain high frequency gain (HFG). Robust controllers with guaranteed transient performance are obtained without the need of augmented control parametrization.
      Compared to conventional MRAC techniques, the proposed controllers are applicable to a wider class of plants. Instead of fragile symmetry conditions, the HFG is required to have diagonal Jordan form with real and positive eigenvalues, which is a robust and generic condition. Controllers based on parameter projection with high adaptation gain are proposed to obtain improved robustness in comparison to pure gradient adaptive laws. The Binary-MRAC(BMRAC) is generalized to arbitrary relative degree using exact differentiators, such that global exact output tracking is obtained with guaranteed transient properties. A further extension of the BMRAC is proposed, which inherits its high gain and adaptation laws with projection combined with input filtering and prediction loop. The result is the Extended BMRAC (eBMRAC), a robust global practical output tracking controller with guaranteed transient. Simulations are presented to illustrate theoretical developments and performance of the proposed techniques.