For Problems 1 3 Given A Transfer Function G S Sketch The Magnitude And Phase Characteristics In The Logarithmic Scale 1 (119.42 KiB) Viewed 38 times
For Problems 1 3 Given A Transfer Function G S Sketch The Magnitude And Phase Characteristics In The Logarithmic Scale 2 (6.37 KiB) Viewed 38 times
For problems 1-3, given a transfer function G(s) sketch the magnitude and phase characteristics in the logarithmic scale (i.e. Bode-plots) of the system using the following rules-of-thumb: i. "Normalize" the G(s) by extracting poles/zeros, substituting s-jw and writing the TF using DC-gain KO and time-constants ii. Arrange break-points (poles, zeros or wn for complex-conjugate poles) in ascending order Based on the term Ko (jw) Fk, determine: iii. a. initial slope of the magnitude-response asymptote for low frequencies as F k 20 dB/dec (e.g. flat for k=0, -20 dB/Dec for one pole at s=0 etc.) b. "anchor" point through which the magnitude-response asymptote passes for w=1 (i.e. 20 log10 Ko) c. initial value of the phase-response asymptote for low frequencies as F k 90⁰ Start going from w=0 towards ∞ iv. V. For each break-point that corresponds to a real pole/zero you encounter, adjust: magnitude-response asymptote slope by - m 20 dB/Dec for a pole and + m20 dB/Dec for a zero (m= multiplicity/order of pole/zero at the breakpoint) a. b. phase-response asymptote by - m90° for a single pole and + m 900 for a single zero (m= multiplicity/order of pole/zero at the breakpoint) vi. For each break-point wn that corresponds to a complex-conjugate set of poles/zeros, adjust: a. magnitude-response asymptote slope by -m40 dB/Dec for a set of cc poles and +m40 dB/Dec for a set of cc zeros (m= multiplicity/order of cc poles/zeros at the breakpoint) b. phase-response asymptote by - m1800 for a set of cc poles and + m1800 for a set of cc zeros (m= multiplicity/order of cc poles/zeros at the breakpoint) vii. 2} For <√2/2 (or 0.7) be aware of a resonant "bump" or a "dip" of approximately Mr = ( i.e. Mr = 20 log10 dB). Draw the approximate magnitude and phase responses by fitting a curve along the asymptotes
Problem 2 G(s) = 400 (s² +4s+2 ) s(s+10)2 (s+100)
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