University of Tabriz Tabriz Journal of Electrical Engineering 2008-7799 50 4 2021 02 19 Roust Controller Design for a Class of Nonlinear Time-Varying Systems with Optimality Approach Roust Controller Design for a Class of Nonlinear Time-Varying Systems with Optimality Approach 1521 1531 12248 FA F. Pishkari Faculty of Electrical and Electronic Engineering, Shiraz University of Technology, Shiraz, Iran, T. , Binazadeh Faculty of Electrical and Electronic Engineering, Shiraz University of Technology, Shiraz, Iran, Journal Article 2018 12 09 <strong>:</strong>In this paper, a novel controller is presented with an optimal approach for asymptotic stabilizing of a class of nonlinear time-varying systems in presence of model uncertainties and external disturbances. The proposed controller has two nominal and robust parts and there are new ideas in designing of both of them. In the first part, a new ccontrol Lyapunov function is presented for the nominal controller design. The suggested structure of the proposed control Lyapunov function is different from the common versions. This function is designed in a way that a sliding surface equation is appeared in it directly and therefore, provides the possibility of combining the robust part (which is designed based on sliding mode control technique) with nominal one. This combination leads to a different sub-optimal control law where its discontinuous part switches based on the moment value of the sliding surface and the continuous terms will be designed based on the optimality approach. At the end of the paper, this controller is applied to a nonlinear time-varying inertia pendulum and the simulation results are given to confirm the performance and efficiency of proposed approach and verifying the theoretical achievements. <strong>:</strong>In this paper, a novel controller is presented with an optimal approach for asymptotic stabilizing of a class of nonlinear time-varying systems in presence of model uncertainties and external disturbances. The proposed controller has two nominal and robust parts and there are new ideas in designing of both of them. In the first part, a new ccontrol Lyapunov function is presented for the nominal controller design. The suggested structure of the proposed control Lyapunov function is different from the common versions. This function is designed in a way that a sliding surface equation is appeared in it directly and therefore, provides the possibility of combining the robust part (which is designed based on sliding mode control technique) with nominal one. This combination leads to a different sub-optimal control law where its discontinuous part switches based on the moment value of the sliding surface and the continuous terms will be designed based on the optimality approach. At the end of the paper, this controller is applied to a nonlinear time-varying inertia pendulum and the simulation results are given to confirm the performance and efficiency of proposed approach and verifying the theoretical achievements. https://tjee.tabrizu.ac.ir/article_12248_90373bde4cda71153488e722ffb47698.pdf