ESO Compensation Based Backstepping Control for MIMO System

For a class of nonlinear MIMO system, a novel decoupling control method was proposed. Firstly, equivalent input of each subsystem was designed using backstepping method. Then, the total uncertainties including coupling effect, external disturbance and parameter time-varying of each subsystem was estimated via an ESO, and the estimated value was introduced into the backstepping controller to compensate. At last, decoupling and control were achieved. The convergence of the new method was proved via Lyapunov stability theory. Simulation result showed the method can achieved fast response, good decoupling effect and good robustness.