10 files changed, 113 insertions, 0 deletions
diff --git a/842/CH11/EX11.05/Example11_05Nyquist.sce b/842/CH11/EX11.05/Example11_05Nyquist.sce
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index 000000000..e891c5609
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+++ b/842/CH11/EX11.05/Example11_05Nyquist.sce
@@ -0,0 +1,11 @@
+//clear//
+//Example 11.5:Nyquist criterion for Continuous Time Systems
+//Nyquist Plot
+s = %s;
+//Open Loop Transfer Function
+G = syslin('c',[1/(s+1)]);
+H = syslin('c',[1/(0.5*s+1)]);
+F = G*H;
+clf;
+nyquist(F)
+show_margins(F,'nyquist')
diff --git a/842/CH11/EX11.09/Figure11_09.sce b/842/CH11/EX11.09/Figure11_09.sce
new file mode 100755
index 000000000..3b98cc1a4
--- /dev/null
+++ b/842/CH11/EX11.09/Figure11_09.sce
@@ -0,0 +1,14 @@
+//clear//
+//Figure11.9:Root locus analysis of Linear feedback systems
+s = %s;
+beta_b1 = 1;
+beta_b2 = -1;
+G1 = syslin('c',[2*beta_b1/s]);
+G2 = syslin('c',[2*beta_b2/s]);
+H = syslin('c',[s/(s-2)]);
+F1 = G1*H;
+F2 = G2*H;
+clf;
+evans(F1,2)
+figure
+evans(F2,2)
diff --git a/842/CH11/EX11.1/Example11_1.sce b/842/CH11/EX11.1/Example11_1.sce
new file mode 100755
index 000000000..6e97a14ac
--- /dev/null
+++ b/842/CH11/EX11.1/Example11_1.sce
@@ -0,0 +1,10 @@
+//clear//
+//Example11.1:Root locus Analysis of Linear Feedback Systems
+//Continuous Time Systems
+//Refer figure 11.12(a) in Openhiem &Willksy page 840
+s = %s;
+H = syslin('c',[1/(s+1)]);
+G = syslin('c',[1/(s+2)]);
+F = G*H;
+clf;
+evans(F,3)
diff --git a/842/CH11/EX11.2/Example11_2.sce b/842/CH11/EX11.2/Example11_2.sce
new file mode 100755
index 000000000..29672c755
--- /dev/null
+++ b/842/CH11/EX11.2/Example11_2.sce
@@ -0,0 +1,8 @@
+//clear//
+//Example11.2:Root locus Analysis of Linear Feedback Systems
+//Continuous Time Systems
+//Refer figure 11.14(a) in Openhiem &Willksy page 844
+s = %s;
+G = syslin('c',[(s-1)/((s+1)*(s+2))]);
+clf;
+evans(G,2)
diff --git a/842/CH11/EX11.3/Example11_3.sce b/842/CH11/EX11.3/Example11_3.sce
new file mode 100755
index 000000000..2e4a5242a
--- /dev/null
+++ b/842/CH11/EX11.3/Example11_3.sce
@@ -0,0 +1,8 @@
+//clear//
+//Example11.3:Root locus Analysis of Linear Feedback Systems
+////Discrete time system
+//Refer figure 11.16(a) in Openhiem &Willksy page 846
+z = %z;
+G = syslin('d',[z/((z-0.5)*(z-0.25))]);
+clf;
+evans(G,2)
diff --git a/842/CH11/EX11.5/Example11_5Bode.sce b/842/CH11/EX11.5/Example11_5Bode.sce
new file mode 100755
index 000000000..40de8822c
--- /dev/null
+++ b/842/CH11/EX11.5/Example11_5Bode.sce
@@ -0,0 +1,11 @@
+//clear//
+//Example 11.5:Nyquist criterion for Continuous Time Systems
+//Bode Plot
+s = %s;
+//Open Loop Transfer Function
+G = syslin('c',[1/(s+1)]);
+H = syslin('c',[1/(0.5*s+1)]);
+F = G*H;
+clf;
+bode(F,0.01,100)
+show_margins(F)
diff --git a/842/CH11/EX11.6/Example11_6.sce b/842/CH11/EX11.6/Example11_6.sce
new file mode 100755
index 000000000..fce612cf4
--- /dev/null
+++ b/842/CH11/EX11.6/Example11_6.sce
@@ -0,0 +1,9 @@
+//clear//
+//Example 11.6:Nyquist criterion for Continuous Time Systems
+//Nyquist Plot
+s = %s;
+//Open Loop Transfer Function
+F = syslin('c',[(s+1)/((s-1)*(0.5*s+1))])
+clf;
+nyquist(F)
+show_margins(F,'nyquist')
diff --git a/842/CH11/EX11.7/Example11_7.sce b/842/CH11/EX11.7/Example11_7.sce
new file mode 100755
index 000000000..7cc4d3cac
--- /dev/null
+++ b/842/CH11/EX11.7/Example11_7.sce
@@ -0,0 +1,10 @@
+//clear//
+//Example 11.7
+//Nyquist Plot
+s = %s;
+T =1;
+//Open Loop Transfer Function
+G = syslin('c',[-%e^(-s*T)]);
+clf;
+nyquist(G)
+show_margins(G,'nyquist')
diff --git a/842/CH11/EX11.8/Example11_8.sce b/842/CH11/EX11.8/Example11_8.sce
new file mode 100755
index 000000000..ce044e133
--- /dev/null
+++ b/842/CH11/EX11.8/Example11_8.sce
@@ -0,0 +1,10 @@
+//clear//
+//Example 11.8:Nyquist criterion for Discrete Time Systems
+//Nyquist Plot
+//Discrete Time System
+z = %z;
+//Open Loop Transfer Function
+F = syslin('d',[1/(z*(z+0.5))])
+clf;
+nyquist(F)
+show_margins(F,'nyquist')
diff --git a/842/CH11/EX11.9/Example11_9.sce b/842/CH11/EX11.9/Example11_9.sce
new file mode 100755
index 000000000..af628cd35
--- /dev/null
+++ b/842/CH11/EX11.9/Example11_9.sce
@@ -0,0 +1,22 @@
+//clear//
+//Example 11.9:Gain and Phase Margins and their
+//associated cross over frequencies
+s =poly(0,'s'); // Define ss as polynomial variable
+//Create s transfer function in forward path
+F = syslin('c',[(4*(1+0.5*s))/(s*(1+2*s)*(1+0.05*s+(0.125*s)^2))])
+B = syslin('c',(1+0*s)/(1+0*s)) 
+OL = F*B;
+fmin = 0.01; // Min freq in Hz
+fmax = 10; // Max freq in Hz
+scf(1);
+//clf;
+// Plot frequency response of open loop transfer function 
+bode(OL,0.01,10); 
+// display gain and phase margin and cross over frequencies
+show_margins(OL);
+[gm,fr1] = g_margin(OL)
+[phm,fr2] = p_margin(OL)
+disp(gm,'gain margin in dB')
+disp(fr1,'gain cross over frequency in Hz')
+disp(phm,'phase margin in dB')
+disp(fr2,'phase cross over frequency in Hz')