Robotics 2
Frequency Response Modeling
Quiz          Question 4:  When we test the frequency response of a second-order system, what is the relationship between the input frequency and the output frequency?
Question 1:  A Bode plot includes two plots, but both have the same variable on the X axis.  What is this variable?
Question 2:  The top plot in a Bode plot has what variable on the Y axis?
Question 7: In the Bode plot of a second-order system, what happens with the phase plot at the natural frequency?
The phase has a constant value of 1.
The phase suddenly rises to 90.
The phase suddenly drops to -180.
The phase begins to decrease steadily.
Time
Amplitude
Frequency
Phase
Amplitude of the input
Amplitude of the output
Amplitude of the input divided by the amplitude of the output
Amplitude of the output divided by the amplitude of the input
Phase
Frequency
Question 3:  The bottom plot in a Bode plot has what variable on the Y axis?
Amplitude
Time delay
It depends on the frequency - sometimes the input frequency is greater, and sometimes the output frequency is greater
The output frequency is always less than the input frequency
The input frequency and the output frequency are the same
The output frequency is always greater than the input frequency
The damping ratio is found from the height of the peak at the natural frequency
The damping ratio is found from the amplitudes at frequencies lower than the natural frequency
The damping ratio is found from the amplitudes at frequencies higher than the natural frequency
The damping ratio is found from the phase plot, by looking at where the phase goes to -180 degrees
Question 5:  When we test the frequency response of a second-order system, how can we figure out the value of zeta, the damping ratio?
The natural frequency is the frequency at which the amplitude is a minimum
The natural frequency is found by looking at what frequency the amplitude peak occurs
Question 6:  When we test the frequency response of a second-order system, how can we figure out the value of wn, the natural frequency?
The natural frequency is found by looking at what frequency has an amplitude ratio of 1
The natural frequency can be found from the phase plot, by looking at where the phase is 90 degrees
There is no natural frequency.
The natural frequency is high.
Question 8: If you are performing a frequency response test on a second-order system and you cannot find a peak in the amplitude part of the Bode plot, what does that mean?
The damping ratio is high.
The damping ratio is low.
The amplitude has a constant value of 1.