DP12.1 A position control system for a large turntable is shown in Figure DP12.1(a), and the block diagram of the system is shown in Figure DP12.1

(b) [11, 14].

This system uses a large torque motor with Km = 15.

The objective is to reduce the steady-state effect of a step change in the load disturbance to 5% of the magnitude of the step disturbance while maintaining a fast response to a step input command R s( ), with P O. . ≤ 5%. Select K1 and the compensator when

(a) G s c( ) = K and

(b) G s c P ( ) = + K KDs.

Plot the step response for the disturbance and the input for both compensators. Determine whether a prefilter is required to meet the percent overshoot requirement.

FIGURE DP12.1 Turntable control. Input Controller Position signal Turntable (a) T(s) Tm(s) + I w(s) R(s) Ge Km s+2 K Thi Torque motor Velocity sensor Position sensor 80 51- Y