1. TUTORIAL 1 SOLUTION MRS ANIS ATIKAH AHMAD

2. QUESTION 1 Figure Q1.1 shows two possible ways to design feedback control loop to obtain a desired rate of liquid flow, w sp. The control valve in System I is “air to open”, meaning that an increasing pressure signal from the controller will open the valve more, thus increasing the flow rate. On the other hand, System II is “air to close”. Identify which controller must be direct acting and reverse acting. What sign should the controller gain have for each case? System I System II

3. QUESTION 1 System I (ATO) : Flow rate too high → need to close valve → decrease controller output → reverse acting System I : K c is positive (+ve) System II (ATC): Flow rate too high → need to close valve → increase controller output → direct acting. System II : K c is negative (-ve)

4. QUESTION 2 Analog proportional-derivatives (PD) controllers sometimes are formulated with a transfer function of the form: (a)Show how to obtain this transfer function with a parallel arrangement of two much simpler functions in Figure Q2.1: (b)Find expressions for K 1, K 2, and τ 1 that can be used to obtain desired values of K c, τ D and α. (c) Verify the relations for K c = 3, τ D = 2, α = 0.1 Figure Q2.1:

5. QUESTION 2 (a)

6. QUESTION 2 (b) Comparing with PD transfer function; Thus; OR

7. QUESTION 2 (c) If K c = 3, τ D = 2, α = 0.1 Hence; Thus;