“…However, in each application, the value of the robustness factor ξ in the UT-H∞ filter has to be artificially chosen by experience, and once selected, the value of ξ is a constant [19], [27], [31]. This will require significant time in determining the value of ξ before using the UT-H∞ filter, and the selected value of ξ is not guaranteed to be optimal in various situations [7], [30]. Moreover, there are always external disturbances in a real system, and the disturbances are time-varying and uncertain [17], [18].…”