MIMO U-model based control: real-time tracking control and feedback analysis via small gain theorem

Abstract

In this paper, MIMO U-model based IMC is used for the tracking control of multivariable nonlinear systems. The algorithm is implemented in real-time on a 2DoF robot arm. The stability and convergence issues for the control-oriented U-model are also discussed. In order to guarantee stability and faster convergence speeds, bounds are suggested for the learning rate of adaptation algorithm that estimate the parameters of U-model. The adaptation algorithm is first associated with a feedback structure and then its stability is investigated using l2 stability and small gain theorem. The paper also discusses about the robustness of adaptation algorithm in the presence of noise and suggests optimal choices for faster convergence speeds.