Robust filtering for systems with state-dependent uncertainties and application to a class of tunnel diode circuits

The paper is concerned with the problem of robust filtering for a class of systems with state-dependent uncertainties and energy-bounded disturbance. The state-dependent uncertainties can more precisely describe many practical dynamic systems with parameters varying with system states, such as spring stiffness, nonlinear resistor and friction coefficient. A non-quadratic Lyapunov function is adopted, upon which the sufficient condition for the filtering performance analysis is first derived. Then, the parameter-dependent full-order filter is designed such that the corresponding filtering error system is globally asymptotically stable and guarantees a noise attenuation performance index. A numerical example of a class of tunnel diode circuit systems is provided to show the effectiveness of the derived theoretical results.