Nonlinear feedback control of Lorenz system

A robust nonlinear feedback controller is designed to make the first state of uncertain Lorenz system track arbitrary bounded smooth reference signal via combining backstepping design and variable structure control (VSC). Backstepping design transforms the design of the feedback controller into the designs of two simple controllers while VSC is used to repress uncertainties in each step of backstepping design. Theoretical analysis and numerical simulations show the effectiveness of this controller.