• Contents
• 1 Example 8-5 OGATA 4ed(Bode plot)
  

  Let's plot Bode plot by Scilab (Bode, syslin,xtitle)

  
  
• 2 Example 8-6 OGATA 4ed(Bode plot)
  

  Let's plot Bode plot by Scilab (Bode, logspace,xtitle,tf2ss,repfreq ,dbphi,subplot,xgrid,plot2d,mtlb_axis)

  
  
• 3 Example 8-10 OGATA 4ed(Nyquist plot)
  

  Let's plot Nyquist plot by Scilab (nyquist, syslin, xgrid, xtitle, mtlb_axis)

  
  
• 4 Example 8-11 OGATA 4ed(Nyquist plot)
  

  Let's plot Nyquist plot by Scilab (nyquist, syslin, xgrid, xtitle, mtlb_axis)

  
  
• 5 Example 8-21 OGATA 4ed(Phase and gain margins)
  

  Let's calculate the phase and gain margins when K=10 and K=100. Calculations and checks by Scilab (g_margin, p_margin)

  
  
• 6 Example 8-22 OGATA 4ed(Phase and gain margins, Bode plot)
  

  Let's calculate the phase and gain margins. Checks and Bode plot by Scilab (g_margin, p_margin, bode, show_margins)

  
  
• 7 Example 8-24 OGATA 4ed(Bode plot, resonant peak magnitude, resonant peak frequency, bandwidth)
  

  Let's calculate Bode plot, resonant peak magnitude, resonant peak frequency, bandwidth by Scilab (tf2ss, repfreq, dbphi, max)

  
  
• 8 Problem A8.4 OGATA 4ed (Bode plot)
  

  Let's plot Bode plot of the feedback close-loop system for the gain values K=1,10,20 by Scilab (bode)

  
  
• 9 Problem A8.5 OGATA 4ed(Polar plot)
  

  Let's show that the polar plot is a semicircle

  
  
• 10 Problem A8.11 OGATA 4ed(Nyquist plot)
  

  Let's plot Nyquist plot by Scilab (nyquist, syslin, mtlb_axis).

  
  
• 11 Problem A8.13 OGATA 4ed(Nyquist plot)
  

  Let's draw on polar plot the points of frequency w=0.2,0.3,0.5,1,2,6,10,20 and calculate the phase and gain of these points by Scilab.(repfreq, nyquist real, imag, string, dbphi)

  
  
• 12 Problem A8.14 OGATA 4ed(Nyquist plot)
  

  Let's draw the polar plot of positive and negative feedback transfer functions by Scilab (Nyquist, syslin, xstring, mtlb_axis)

  
  
• 13 Problem A8.17 OGATA 4ed(Nyquist plot)
  

  Let's draw Nyquist plot for the values of K=1,7.5,20 by Scilab (nyquist, syslin, mtlb_axis)

  
  
• 14 Problem A8.18 OGATA 4ed(Nichols chart)
  

  Let's draw the Bode plot and the G(jw) locus on Nichols chart by Scilab (bode, chart, black, mtlb_axis).

  
  
• 15 Example 9.1 OGATA 4ed(Lead compensator, Bode and Nyquist plot)
  

  Let's draw the Bode plot, polar plot and output by Scilab (bode, legend, nyquist, m_circle, xgrid, mtlb_axis, csim, step, plot, xtitle).

  
  
• 16 Example 9.2 OGATA 4ed(lag compensator, Bode and Nyquist plot)
  

  Let's calculate the lag compensator. Checks and calculations by Scilab (bode, nyquist, g_margin, p_margin, tf2ss, logspace, dbphi, plot2d, subplot, clf, horner, mtlb_axis, legend).

  
  
• 17 Problem A9.3 OGATA 4ed(Lead compensator, Bode plot)
  

  We want the phase margin equal to 60. Let's calculate K. (tf2ss, repfreq, dbphi, subplot, plot2d, legends, xgrid, p_margin, show_margins, horner, polarplot)

  
  
• 18 Problem A9.5 OGATA 4ed(Lead compensator, Nichols chart)
  

  Let's insert a compensator for the open-loop system is tangent to circle M=3dB in w=3rad/seg. (clf, chart, black, mtlb_axis)

  
  
• 19 Problem A9.7 OGATA 4ed(Lead compensator, Nyquist plot)
  

  Let's draw the Nyquist plot of G(jw),G1(jw) and Gc(jw) *G1(jw) by Scilab (horner, polarplot, real, imag, mtlb_axis, legends)

  
  
• 20 Problem A9.8 OGATA 4ed(Lead compensator, Bode plot)
  

  Let us calculate a compensator that satisfies the following requirements of static velocity error constant Kv=20, phase margin 50 and gain margin >10dB (g_margin, p_margin, bode, csim, plot, step, clf, xgrid, xtitle, legends)

  
  
• 21 Problem A9.9 OGATA 4ed(Lag-lead Compensator)
  

  Let us calculate a lag-lead compensator that satisfies the following requirements static velocity constant error Kv=10, phase margin 50 and gain margin > 10dB (logspace, tf2ss, repfreq, dbphi, clf, subplot, plot2d, xgrid, bode, g_margin, p_margin, bode, csim, plot, step, clf, xgrid, xtitle, legends)

  
  
• 22 Problem A9.10 OGATA 4ed(PID compensator)
  

  Let's do the programming by Scilab of compensator that the system verifies the following values: static velocity constant error Kv=4, phase margin 50 and gain margin > 10dB.(bode, clf, csim, step, subplot, plot, xgrid, xtitle, legends)

  
  
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