Nonlinear Suboptimal Robust Control for Twin Rotor MIMO System

The article deals with a problem of suboptimal stabilization for a nonlinear plant under disturbances presence with application to a laboratory setup “Twin Rotor MIMO System” (TRMS). First, a complete nonlinear model of TRMS is considered and linearized using feedback linearization technique. Then, a Linear Quadratic Regulator is applied to obtain a stable closed-loop system with prespecified cost function minimization for the case when no disturbances affect the system. At the last step of algorithm synthesis, unknown bounded disturbances are taken into account, and a specialized dynamical system called “auxiliary loop” is defined to compensate disturbances and ensure convergence of the closed-loop system solutions to the optimal case.