Robust control of uncertain fully actuated systems with nonlinear uncertainties and perturbed input matrices.

Robust control of uncertain fully actuated systems (FASs) with nonlinear uncertainties and perturbed input matrices is considered. Motivated by the recent work on this issue, two novel robust controllers are further developed for two cases under different assumptions. For both cases, the assumption on the perturbation input matrix in the previous work is relaxed to a significant extent, which allows many typical perturbation input matrices, such as constant ones, to be handled, while the previous method cannot. Moreover, for the first case, the assumption on the system uncertainty is further relaxed, and the states of the closed-loop system are globally bounded and converge into an arbitrarily small spherical domain centered at the origin. For the second case, with another requirement on the system nonlinearity imposed, the global exponential stability of the closed-loop system is achieved. The successful application in an electromechanical system verifies the effectiveness of the method. • The nonlinear uncertainty and the uncertainty in the input matrix are considered. • A controller makes the states converge globally into an arbitrarily small region. • Another controller achieves the global exponential stability. • The assumptions on the perturbed input matrix in the previous work are relaxed. • A successful application in the control of electromechanical systems. [ABSTRACT FROM AUTHOR]