Nonlinear State Dependent Sliding Sector Control of Gimbal Systems

Sliding Sector Control (SSC) design method for nonlinear systems is proposed in such a way that the system trajectories are kept around a nonlinear sliding surface which is surrounded by a nonlinear sliding sector. The SSC for the nonlinear system is derived so that the system trajectories are enforced to stay inside the sliding sector for tracking requirements. State-Dependent Differential Riccati Equations (SDDRE) are solved to design the nonlinear sliding surface for the nonlinear dynamical system. Within this context, SSC having nonlinear(or state-dependent) sliding surfaces are used to have a viable solution for the problem formulation. The evolving solutions of the Differential Riccati Equations are used to create the sliding surface which is kept inside the designed sliding sector so that the stability of the nonlinear system is ensured. The proposed SSC method is experimentally tested by applying it to an inner axis of a two axes gimbal system.