4) Consider the position control of an inertial load with a proportional controller of gain Kp. A tachometer is built- in the electric motor and provides a feedback proportional to the angular velocity of the load. (25P) a) Determine the values of the control parameters Kp and Kt such that the undamped natural frequency of the system is at least 2 rad/s, and the system is critically damped. b) Calculate the values of the control parameters Kp and Kt such that the steady state error due to a unit ramp input is less than 5% when the damping ratio is 0.5 and the disturbance is zero. 6,(s Disturbance Controller + K Motor + Load (15s-3) Tachometer 18.(s)