Composite Controller

Q. A plant with a transfer function $\frac{2}{s(s+3)}$ is controlled by a PI controller with $K_p=1$ and $k_i\ge 0$ in a unity feedback configuaration.The lowest value of $K_i$ that ensures zero steady state error for a step change in the referance input is

1. 0
2. 1/3
3. 1/2
4. 1

Q. A conttrol system with a PD controller is shown in the figure. If the velocity error constant $K_v=1000$ and the damping ratio $\zeta =0.5$, then the values of $K_P$ and $K_D$ are

1. $K_P=100,K_D=0.09$
2. $K_P=100,K_D=0.9$
3. $K_P=10,K_D=0.09$
4. $K_P=10,K_D=0.9$

Q. A stable closed loop control system with PI controller is shown below,

The suitable values of controller parameters are

1. $K_p>0and{K}_I>\frac{K_p}{3}-3$
2. $K_I>0and{K}_p>(\frac{K_I}{3}-2)$
3. $K_I>\frac{K_p}{3}-2\left(or\right)K_p>0$
4. 
   $K_I>0,K_p>0$

Q. The block diagram of a control system is shown below,

The control specification are such that the damping ratio of the closed loop system is 0.6 and damped frequency, ${\omega }_d$ is 10 rad/sec. The parameters of PD controller $K_P$ and $K_D$ are

1. 156.25, 14
2. 277.78, 19
3. 2, 4
4. 11, 100

Q. A PD controller is tuned to get desired phase margin for second order control system. Phase crossover frequency for compensated system is

1. 2.52 rad/sec
2. 3.94 rad/sec
3. 1.45 rad/sec
4. does not exist