A linear actuator is used in the system shown in Figure P8.10 to position a mass M. The actual position of the mass is measured by a slide wire resistor, and thus H(s) = 1.0. The amplifier gain is selected so that the steady-state error of the system is less than 1 % of the magnitude of the position reference R(s). The actuator has a field coil with a resistance Rf = 0.1 Ω.
