Influence of Control Valve Delay and Dead Zone on the Stability of a Simple Hydraulic Positioning System

Figure 3

Scheme of the control. Instants signed with green circles represent the sampling; red circles show the moments of velocity actuations. For $h_n$, see equation (2.2); $t_c$ stands for computational time, $t_{\text{id}}$ represents the internal dynamics of the hydraulic system (see text for details), $t_d=t_c+t_{\text{id}}$ is the overall delay, and $t_s$ denotes sampling time.