Finite Frequency $\mathrm{H}\infty$ Control for Electro-Hydraulic Servo System With Parameter Uncertainties

The frequency of the disturbance of electro-hydraulic servo system is often within a certain range, and the uncertainty of system parameters is common in physical systems. For the above issues, this paper focuses on solving the disturbances within a certain frequency range and the parameters uncertainties in the electro-hydraulic servo system by using finite frequency $H\infty$ control method. To accomplish this study, a nonlinear model of electro-hydraulic servo system was established and derived into an uncertain linearized mathematical model. This linear model also fully considered the uncertainties of system parameters and reserved a large space for them. For the stability of electro-hydraulic servo system with parameter uncertainties and disturbance within a certain range, the finite frequency $H\infty$ control method was used here. After performing operations on linear matrix inequalities, a feasible solution was obtained for satisfying asymptotic stability. The simulation shows that the proposed method has a better robust effect on the stability under the influence of parameters uncertainties and external disturbance within a certain frequency domain.