Howtosignalprocessing
- Can we draw Bode plot for unstable system?
- What makes a Bode plot unstable?
- What is the importance of Bode plot in determining system stability?
- What are the limitations of Bode plot?
Can we draw Bode plot for unstable system?
It can be obtained experimentally by providing inputs to the system and measuring the output frequencies (if the system is stable) and it can also be obtained by hand (even if the system is not stable) [1]. The tricky thing about Bode plots is that they will not always tell you if your system is unstable or not.
What makes a Bode plot unstable?
If both the gain margin GM and the phase margin PM are equal to zero, then the control system is marginally stable. If the gain margin GM and / or the phase margin PM are/is negative, then the control system is unstable.
What is the importance of Bode plot in determining system stability?
The Bode plot provides the relative stability of the system in terms of the gain margin and phase margin. It can be drawn both for the closed loop system and open-loop system. It also provides us a method to improve the stability of the system.
What are the limitations of Bode plot?
The disadvantage is that the Bode plot is not very sensitive to changes in the measured system as long as the fundamental behavior of the system isn't changing.
