Electrohydraulic servoniechanisms are used in control systems requiring a rapid response for a large mass. An electrohydraulic servomechanism can provide an output of 100 kW or greater [17]. A photo of a servo valve and actuator is shown in Figure P9.8 (a). The output sensor yields a measurement of actuator position, which is compared with Vin. The error is amplified and controls the hydraulic valve position, thus controlling the hydraulic fluid flow to the actuator. The block diagram of a closed-loop electrohydraulic servomechanism using pressure feedback to obtain damping is shown in Figure P9.8 (b) [17, 18]. Typical values for
