Flashcards
Ch 10: Frequency Response Techniques
Cards in this deck (13)
- 1Bode plots are the log-magnitude and phase _____as functions of _____.frequency response curves;
- 2The magnitude frequency response is the product of _____.the magnitude frequency response of each term of a given transfer function
- 3Bode plots are ______ displayed as separate magnitude andasymptotic approximations to the frequency response
- 4Each pole of a system contributes how much of a slope to the Bode magnitude plot?Negative 6 dB/octave, or equivalently 20 dB/decade.
- 5A system with four poles and no zeros would exhibit what value of slope at high frequencies in a Bode magnitude plot?Negative 24 dB/octave or 80 dB/decade
- 6A system with four poles and two zeros would exhibit what value of slope at high frequencies in a Bode magnitude plot?Negative 12 dB/octave or 40 dB/decade
- 7Describe the asymptotic phase response of a system with a single pole at -2?Zero degrees until 0.2; a negative slope of 45 deg/decade from a frequency of 0.2 until 20; a constant -90 deg phase from a frequency of 20 until ∞.
- 8What is the major difference between Bode magnitude plots for first-order systems and for second-order systems?Second-order systems require a correction near the natural frequency due to the peaking of the curve for different values of damping ratio. Without the correction the accuracy is in question.
- 9For a system with three poles at -4, what is the maximum difference between the asymptotic approximation and the actual magnitude response?Each pole yields a maximum difference of 3.01 dB at the break frequency. Thus for a pole of multiplicity three, the difference would be 3*3.01 or 9.03 dB at the break frequency, - 4.
- 10The peak amplitudes of the frequency response occur at the _____.modal frequencies
- 11For each _____, the system has a a ‘unique shape’ called the mode shape.natural frequency
- 12As the ______, resonant peaks gets wider and smaller, and eventually this fundamentally 2 nd -order behavior vanishes into a pair of 1st-order responses.damping increases
- 13A mode shape is the_____ associated with a mode. The mode shape itself is defined by n-1 values.relative displacement of the various degrees of freedom
Information
- Description
- Undergraduate Controls Flashcards on Ch 10: Frequency Response Techniques, created by David Smith on 28/06/2016.
- Created by
- David Smith
- Views
- 0
- Rating