TransferFunctionPoles
gives a matrix of roots of the denominators in the TransferFunctionModel tfm.
TransferFunctionPoles[tfm,reg]
only gives the roots inside the region reg on the complex plane.
Examples
open allclose allBasic Examples (3)
Scope (5)
The poles of a fourth-order Butterworth filter:
The poles of a tenth-order Bessel filter:
The poles of a discrete-time second-order system:
The system is stable because the poles lie within the unit circle:
The poles of a time-delay system in a square around the origin:
Applications (2)
Use TransferFunctionPoles to determine if a system is asymptotically stable:
Asymptotic stability of various systems:
Find the poles of the time-delay system near the origin:
Create a delay-free approximation using the poles:
Compare step responses of the time-delay system and the delay-free approximation:
Properties & Relations (4)
For a SISO system, the poles of the transfer function are the eigenvalues of its state matrix:
The poles determine the natural response of a system:
The exponentials in the response are the real parts of the poles:
The root locus plot gives the closed-loop poles as any parameter is varied:
The root locus plot as k is varied:
A stable third-order system with one symbolic pole:
It can be better approximated by a second-order system if the third pole is further to the left:
Possible Issues (1)
TransferFunctionPoles may not find solutions for time-delay systems:
Text
Wolfram Research (2010), TransferFunctionPoles, Wolfram Language function, https://reference.wolfram.com/language/ref/TransferFunctionPoles.html (updated 2012).
CMS
Wolfram Language. 2010. "TransferFunctionPoles." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2012. https://reference.wolfram.com/language/ref/TransferFunctionPoles.html.
APA
Wolfram Language. (2010). TransferFunctionPoles. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/TransferFunctionPoles.html