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Questions tagged [transfer-function]

A transfer function is a mathematical description of a system or part of a system. It relates the output of the system to the input. The system described by a transfer function is always linear and time invariant.

A transfer function is a mathematical description of a system or part of a system. It relates the output of the system to the input. The system described by a transfer function is always linear and time invariant.

Transfer functions are appropriate for single input single output systems; while several can be used to model a multiple input multiple output system it is usually more appropriate to use a state space representation in that case.

Common uses of transfer functions are;

  • Single-input single-output filters
  • Modelling systems for control theory
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How does the linear transfer function in perceptrons (artificial neural network) work?

I know how the step transfer function works but how does the linear transfer function work? What equation do you use? Relate answer to AND gate with two inputs and a bias
Jack
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Matlab Plotting roots (zeros and poles) of Z-Transform

I need to plot the roots onto a transfer function H(z) overlaying a unit circle, giving enough room to see all points. I'm able to get the roots from H(z) when it is given in the form zeros = [z0 z1 z2...], poles = [p0 p1 p2]. Using Matlab's roots…
MikaelCMiller
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Series digital filtering: how to combine the transfer function coefficients of each filter?

I'm performing two filtering steps in series, in Matlab. First a Butterworth filter, then a ChebyschevII filter. The functions butter() and cheby2() return the transfer function coefficients b (numerator coefficients), and a (denominator…
tehgankerer
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Why is MatLab giving such a weirdly scaled Nyquist plot?

I wrote this code: s = tf('s'); P = (s+35)/(s*(s+3.5)*(s+3500)); nyquist(P) which resulted in this very weirdly scaled plot: which, if I zoom WAY in, looks like this: There's clearly something weird going on with the scaling, as it made the…
Mikayla Eckel Cifrese
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Laplace Transform in Python

I have some input data, and output data and i want to evaluate the Transfer Function, and "Impulse Response". I want the Transfer Function for a Sine Wave, and the Impulse Response for a Dirac Delta impulse, both have their input,and output data. I…
Beans9991
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Understanding the ss() and tf2ss() functions and their differences

Following this question, I am trying to comprehend the functionality of MATLAB's ss() and tf2ss() functions and their differences. Consider the code below: Kf = 0.2; J = 0.02; h2 = tf(1, [J Kf]); dcm1 = ss(h2); dcm2 = tf2ss(h2.Numerator{1},…
Foad S. Farimani
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MATLAB: How to find plant given PID values, closed loop transfer function, and step response graph?

I was given a step response graph, and from it, obtained a transfer function. The loop includes a plant and a PID controller, and I know the PID values that produced the output graph. I verified that the transfer function I found was correct by…
unnecessarilylongusername1
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Labeled, horizontal arrows pointing into a vertical line

I'm trying to plot some annotations to go along with my step function graphs. I currently have these graphs, and I've been trying to figure out how to draw horizontal arrows that point towards vertical lines. I will also need labeled, vertical lines…
Cory
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Why when calculating impulse response of a filter (system) I get a "tail" at the end

I have measured time signals of input (pink noise) and output of a system. I need to calculate TF of a system and it's impulse response. In order to calculate TF I can do in Matlab directly TF = tfestimate(in, out) or compute fft of both then do TF…
acstc
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Simulating a sub-system in a Python (non real-time) simulation environment through a transfer function

I am coding a dynamic system simulation (fixed step, non real-time; it runs on my desktop) and I want to model some of the system's components (e.g. filters...) through the tools made available by scipy.signal (e.g. dlsim). For those components, I…
ga27
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Differing results in Scipy vs Matlab transfer functions

I can't understand why the scipy.signal.ss2tf() and scipy.signal.StateSpace().to_tf() give (the same) unexpected result. Example: A=[[0, 1, 0], [0, 0, 1], [-3, -4, -2]] B=[[0], [0], [1]] C=[[5, 1, 0]] D=[[0]] The result for scipy is num =…
sdn-96
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How to simulate the time response of a system transfer function with python-control (IVP problem)?

I'm trying to demonstrate how to "solve" (simulate the solution) of differential equation initial value problems (IVP) using both the definition of the system transfer function and the python-control module. The fact is I'm really a newbie…
iperetta
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Python Statespace Calculation from Transfer Function

I have a simple transfer function in Matlab, i.e.: num = [1,2,3] den = [300,5000,80000] sys_tf = tf(num,den) then, I transform sys_tf into statespace form as; sys_ss = ss(sys_tf) The resulting system consists of; >> sys_ss.A = [-16.67,…
xfile
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How can I "pretty print" a transfer function in Matlab?

how can I pretty print a transfer function in matlab? H(s)=4.25/((0.3s+1)(22.5+1)(40s+1)) And this is how I've implemented it in matlab: Hf=tf(K,conv(conv([T1 1],[T2 1]),[T3 1])); But the result is : Hf = 4.25/(270 s^3 + 918.8 s^2 + 62.8 s +…
user1234SI.
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Complex-value denominator in Simulink

I want to plot the step response of a transfer function. The equation is 1/as^2 + bs + c (sorry, I don't know how to write fractions here). I was given two sets of values, and corresponding equations for the transfer function parameters: a1 = [-2,…
itsMike
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