Question 3 The figure below shows the open loop response of a system when subjected to a step input change of 4%. Response _ B C Time A PID controller is to be used with a control loop rate of 1 s. The values of time (normalised to the control loop rate) at points A, B and C are 56 s, 292 s and 1002 s respectively whilst the measured signal change is 7.3%. For the Ziegler-Nichols process reaction method: K(1.2 P)/(RL) T = 2L Td = 0.5 L 0 A a) What value would the Ziegler-Nichols method imply for the proportional gain term of the controller? Give your answer to 3 decimal places. Round your answer to 3 decimal places. b) What value would the Ziegler-Nichols method imply for the integral gain term of the controller? Give your answer to 3 decimal places. Round your answer to 3 decimal places. C) What value would the Ziegler-Nichols method imply for the derivative gain term of the controller? Give your answer to 3 decimal places. Round your answer to 3 decimal places. Advice The correct answers are: a: 2.771 [2 marks, 3 decimal places otherwise 1.6 marks] b: 0.025 [2 marks, 3 decimal places otherwise 1.6 marks] c: 77.589 [2 marks, 3 decimal places otherwise 1.6 marks] You get a mark of 0 for each incorrect answer. Maximum mark is 6 for this question. See Bolton sections 22.3 to 22.8 for more details on this topic. Score: 0/2 Unanswered Score: 0/2 Unanswered Score: 0/2 Unanswered