In this paper, we consider the global control problem for a class of high-order nonlinear systems in the nontriangular form. Compared with the existing results, the growth rate of the nonlinearities depends on the control input, which cannot be dominated by the traditional constant gain. Under the assumption that the nonlinear terms satisfy the homogeneous growth conditions, a dynamic state-feedback controller is elaborately designed to stabilize the system based on the adding a power integrator technique and the domination methodology. Moreover, by choosing the dynamic gain appropriately, the assumptions on the nonlinearities can be further relaxed to the polynomial case. Numerical simulations are provided to show the effectiveness of the proposed control laws.
KEYWORDSadding a power integrator, dynamic scaling gain, homogeneous domination approach, input dependent growth rate, nontriangular nonlinear systems where x = (x 1 , … , x n ) T ∈ R n and u ∈ R are the system state and control input, respectively. For i = 1, … , n − 1, p i ∈ R ≥1 odd = {q ∈ R: q ≥ 1, q is a ratio of odd integers}, and the unknown nonlinear functions f i (t, x, u)'s are continuous in system states and control input, i = 1, … , n. Int J Robust Nonlinear Control. 2019;29:1325-1338 wileyonlinelibrary.com/journal/rnc