Prescribed Performance Tracking Control of Lower-Triangular Systems with Unknown Fractional Powers

This paper is concerned with the tracking control problem for lower-triangular systems unknown fractional powers and nonparametric uncertainties. A prescribed performance approach put forward as a means of resolving this problem. The proposed law incorporates set barrier functions to guarantee error constraints. Unlike previous works, our works cases where powers, nonlinearities, their bounding or bounds are totally unknown; no restrictive conditions on such power order restriction, specific size limitation homogeneous condition, made. Moreover, neither system nonlinearities nor needed. It achieves reference preassigned accuracy convergence speed. In addition, controller simple, it does not necessitate parameter identification, function approximation, derivative calculation, adding integrator technique. At end, comparative simulation demonstrates effectiveness advantage approach.