Amplitude 6) Shown in figure the sustained oscillations developed from an unknown system after setting: T = 0, T = 0 and increasing kp to a certain value (ker = 25). a. Use Ziegler-Nichols tuning tables to design a PID Controller for the system. b. Using MATLAB to obtain a unit-step response curve for BEFORE and AFTER using the PID controller (t-domain). Assume system forward loop is 5(5+2)(5+6) with unity feedback loop. 04- 02 18 Systemy Time (second) 16 A1 14- 14 System sys Time (seconds): 44 Ampie 191 Time(seconds)