To obtain the transfer function RC using the signal flow graph method, we will apply Mason's Gain Formula:
T=RC=Δ1∑k=1NPkΔk
where Pk is the gain of the k-th forward path, Δ is the system determinant, and Δk is the determinant of the graph when all loops touching the k-th forward path are removed.
Step 1: Convert the block diagram into a signal flow graph.
We define the following nodes:
R: Input
N1: Output of the first summing junction (SJ1)
N2: Output of G1
N3: Output of the second summing junction (SJ2)
N4: Output of G2
N5: Output of G3
C: Output of the third summing junction (SJ3)
The branches and their gains are:
R1N1
N1G1N2
N21N3
N3G2N4
N4G3N5
N51C
N4H1N1 (positive feedback)
N4−1N3 (negative feedback)
N5−H2N3 (negative feedback)
RG4C (parallel path)
Step 2: Identify all forward paths (Pk) and their gains.
P1: R→N1→N2→N3→N4→N5→C
Gain P1=1⋅G1⋅1⋅G2⋅G3⋅1=G1G2G3
P2: R→C (via G4)
Gain P2=G4
Step 3: Identify all individual loops (Li) and their gains.
L1: N3→N4→N3 (via G2 and −1)
Gain L1=G2⋅(−1)=−G2
L2: N3→N4→N5→N3 (via G2,G3 and −H2)
Gain L2=G2⋅G3⋅(−H2)=−G2G3H2
L3: N1→N2→N3→N4→N1 (via G1,1,G2 and H1)
Gain L3=G1⋅1⋅G2⋅H1=G1G2H1
Step 4: Identify all non-touching loops.
L1 involves nodes N3,N4.
L2 involves nodes N3,N4,N5.
L3 involves nodes N1,N2,N3,N4.
All three loops share common nodes (N3 and N4). Therefore, there are no non-touching loops.
Thus, ∑LiLj=0, ∑LiLjLk=0, etc.
Step 5: Calculate the system determinant Δ.
Δ=1−∑Li=1−(L1+L2+L3)Δ=1−(−G2−G2G3H2+G1G2H1)Δ=1+G2+G2G3H2−G1G2H1
Step 6: Calculate Δk for each forward path.
For P1=G1G2G3:
P1 passes through nodes N1,N2,N3,N4,N5.
L1 (nodes N3,N4) touches P1.
L2 (nodes N3,N4,N5) touches P1.
L3 (nodes N1,N2,N3,N4) touches P1.
Since all loops touch P1, Δ1=1.
For P2=G4:
P2 is the path R→C. It does not pass through any of the intermediate nodes N1,N2,N3,N4,N5.
L1 (nodes N3,N4) does not touch P2.
L2 (nodes N3,N4,N5) does not touch P2.
L3 (nodes N1,N2,N3,N4) does not touch P2.
Since no loops touch P2, Δ2=Δ=1+G2+G2G3H2−G1G2H1.
Step 7: Apply Mason's Gain Formula.
RC=ΔP1Δ1+P2Δ2RC=1+G2+G2G3H2−G1G2H1(G1G2G3)(1)+G4(1+G2+G2G3H2−G1G2H1)RC=1+G2+G2G3H2−G1G2H1G1G2G3+G4+G2G4+G2G3G4H2−G1G2G4H1
The final transfer function is:
\frac{C{R} = \frac{G_1 G_2 G_3 + G_4 + G_2 G_4 + G_2 G_3 G_4 H_2 - G_1 G_2 G_4 H_1}{1 + G_2 + G_2 G_3 H_2 - G_1 G_2 H_1}}
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To obtain the transfer function (C)/(R) using the signal flow graph method, we will apply Mason's Gain Formula: T = (C)/(R) = (1)/() _k=1^N P_k _k where P_k is the gain of the k-th forward path, is the system determinant, and _k is the determinant of…
Obtain the transfer function of the control system represented by block below, by the signal flow graph method
This computer science problem involves algorithmic thinking and programming concepts. The solution below explains the approach, logic, and implementation step by step.
ScanSolve AI Answer
To obtain the transfer function (C)/(R) using the signal flow graph method, we will apply Mason's Gain Formula: T = (C)/(R) = (1)/() _k=1^N P_k _k where P_k is the gain of the k-th forward path, is the system determinant, and _k is the determinant of the graph when all loops touching the k-th forward path are removed. Step 1: Convert the block diagram into a signal flow graph. We define the following nodes: R: Input N_1: Output of the first summing junction (SJ1) N_2: Output of G_1 N_3: Output of the second summing junction (SJ2) N_4: Output of G_2 N_5: Output of G_3 C: Output of the third summing junction (SJ3) The branches and their gains are: R 1 N_1 N_1 G_1 N_2 N_2 1 N_3 N_3 G_2 N_4 N_4 G_3 N_5 N_5 1 C N_4 H_1 N_1 (positive feedback) N_4 -1 N_3 (negative feedback) N_5 -H_2 N_3 (negative feedback) R G_4 C (parallel path) Step 2: Identify all forward paths (P_k) and their gains. P_1: R N_1 N_2 N_3 N_4 N_5 C Gain P_1 = 1 · G_1 · 1 · G_2 · G_3 · 1 = G_1 G_2 G_3 P_2: R C (via G_4) Gain P_2 = G_4 Step 3: Identify all individual loops (L_i) and their gains. L_1: N_3 N_4 N_3 (via G_2 and -1) Gain L_1 = G_2 · (-1) = -G_2 L_2: N_3 N_4 N_5 N_3 (via G_2, G_3 and -H_2) Gain L_2 = G_2 · G_3 · (-H_2) = -G_2 G_3 H_2 L_3: N_1 N_2 N_3 N_4 N_1 (via G_1, 1, G_2 and H_1) Gain L_3 = G_1 · 1 · G_2 · H_1 = G_1 G_2 H_1 Step 4: Identify all non-touching loops. L_1 involves nodes N_3, N_4. L_2 involves nodes N_3, N_4, N_5. L_3 involves nodes N_1, N_2, N_3, N_4. All three loops share common nodes (N_3 and N_4). Therefore, there are no non-touching loops. Thus, L_i L_j = 0, L_i L_j L_k = 0, etc. Step 5: Calculate the system determinant . = 1 - L_i = 1 - (L_1 + L_2 + L_3) = 1 - (-G_2 - G_2 G_3 H_2 + G_1 G_2 H_1) = 1 + G_2 + G_2 G_3 H_2 - G_1 G_2 H_1 Step 6: Calculate _k for each forward path. For P_1 = G_1 G_2 G_3: P_1 passes through nodes N_1, N_2, N_3, N_4, N_5. L_1 (nodes N_3, N_4) touches P_1. L_2 (nodes N_3, N_4, N_5) touches P_1. L_3 (nodes N_1, N_2, N_3, N_4) touches P_1. Since all loops touch P_1, _1 = 1. For P_2 = G_4: P_2 is the path R C. It does not pass through any of the intermediate nodes N_1, N_2, N_3, N_4, N_5. L_1 (nodes N_3, N_4) does not touch P_2. L_2 (nodes N_3, N_4, N_5) does not touch P_2. L_3 (nodes N_1, N_2, N_3, N_4) does not touch P_2. Since no loops touch P_2, _2 = = 1 + G_2 + G_2 G_3 H_2 - G_1 G_2 H_1. Step 7: Apply Mason's Gain Formula. (C)/(R) = (P_1 _1 + P_2 _2)/() (C)/(R) = ((G_1 G_2 G_3)(1) + G_4 (1 + G_2 + G_2 G_3 H_2 - G_1 G_2 H_1))/(1 + G_2 + G_2 G_3 H_2 - G_1 G_2 H_1) (C)/(R) = (G_1 G_2 G_3 + G_4 + G_2 G_4 + G_2 G_3 G_4 H_2 - G_1 G_2 G_4 H_1)/(1 + G_2 + G_2 G_3 H_2 - G_1 G_2 H_1) The final transfer function is: (C)/(R) = (G_1 G_2 G_3 + G_4 + G_2 G_4 + G_2 G_3 G_4 H_2 - G_1 G_2 G_4 H_1)/(1 + G_2 + G_2 G_3 H_2 - G_1 G_2 H_1) Drop the next question.