Questions tagged [transfer-function]

Transfer function is a mathematical representation of relationship between input and output (signal) of a linear, time-invariant system.

Filter by
Sorted by
Tagged with
0
votes
1answer
18 views

What does it mean for a transfer function to have multiple sets of zeros in the numerator?

I was looking at the source code for Matlab's tf2ss function and I noticed that it parses the numerator assuming that it is a matrix, not a vector. So I looked at ...
4
votes
1answer
41 views

Phase Response of $N$-th order Digital All-Pass Filter

I am having trouble reconciling my derivation of the phase response of an N-th order all-pass filter with those I am finding in the literature, and I figured someone here could help me. Real Version: ...
1
vote
1answer
35 views

Amplitude-and phasefunctions for a system

I am studying a course in signalanalysis and have run into som trouble with a exercise. I am to dimension the circuit below in such a way that the DC-amplification is 1 and that the frequencies $\...
0
votes
0answers
44 views

Meaning of term in notch filter coefficient

I have a discrete implementation of a notch/bandstop filter that allows me to specify the stop band frequency, the width of the notch and the attenuation of the stop band frequency. I've been tasked ...
0
votes
1answer
29 views

how to calculate $H_{lp} = z(1- H_{hp}) $ , given coefficients for $H_{hp}$?

Given a high pass transfer fn of the form $H_{hp}=a_{1}*z^0 +a_{2}*z^{-1} + ... a_{n}*z^{-n}$ Is it possible to calculate a causal low pass filter using $H_{lp} = z*(1-H_{hp})$ ? attempting $H_{...
1
vote
2answers
111 views

Transfer functions for Scipy and Matlab's Butterworth filter don't seem to match theory

The squared transfer function for a Butterworth filter of order $n$ should be $$ |H(f)|^2 = \frac{1}{1+\left(\frac{f}{f_c}\right)^{2n}} $$ where $f_c$ is the cut-off frequency. (Here's one of many ...
4
votes
0answers
33 views

Who first coined “Direct Form I” and “Direct Form II”?

I see "Direct Form I" and "Direct Form II" commonly in literature to refer to FIR / IIR implementation from the filter transfer function, and reference it myself, but where did ...
0
votes
0answers
25 views

Filter a signal with a complex dB SPL filter

I've been tasked with filtering a sound with a filter that looks something like this. I don't have any real DSP training, so I'm not sure if my attempt at tackling this is correct. I can filter ...
0
votes
1answer
53 views

Definition of frequency response

I studied various signal processing materials for a long time, and I have a question. Considering an LTI filter, one can define its frequency response by evaluating its transfer function $H(z)$ on the ...
0
votes
1answer
46 views

Zeros and poles from transfer function

I have a transfer function $$ H(z) = \frac{Y(z)}{X(z)} = 1 - 0.5z^{-1} \text{.}$$ I'm interested in zeros and poles. I know I need to adjust the function to $$ H(z) = \frac{\prod_i(z-n_i)}{\prod_i(z-...
0
votes
2answers
85 views

Difference equation to FIR filter coefficients

I have a difference equation $$y[n] = y[n-1] + 0.5x[n] - 0.5x[n-2] \text{.}$$ According to this answer, the filter should have finite impulse response. I just can't figure out how to get the FIR ...
0
votes
1answer
24 views

Finding transfer function from bode plot

Given a bode diagram From the figure, I see that when $\omega = 100 \text{ rad/s}$ the magnitude response starting to go down and when $\omega = 1000 \text{ rad/s}$ the slope become higher. Then $$H(...
0
votes
2answers
73 views

A system having impulse response $ h(t)=u(t) $ stable or not?

I know that for a system to be BIBO stable its impulse response must be absolutely integrable and the impulse response $ h(t)= u(t)$ integrates to approach infinity (i guess) I proceeded as$$ \int_{-\...
0
votes
1answer
23 views

Trying to plot frequency response of a filter Transfer Function in MATLAB, it looks wrong

I have the transfer function below which is for a IIR filter and trying to plot its frequency response for omega<pi. r=0.99 and theta=pi/3: Here is my attempt at implementing it in MATLAB: ...
0
votes
1answer
35 views

I tried two approaches and gained the different conclusions of judging the stability of the transfer function of the system

We want to judge whether the system is stable or not. Given the below transfer function. $$ H\left( z \right) =\frac{\left( 1+2 z^{-1} \right) }{\left( 2+z^{-1} \right) } $$ $$ H\left( z \right) ...
0
votes
1answer
25 views

Seemingly no division operation is done of the diagram of the transfer function

Given the below system. $$ y\left[n \right] =2 x\left[n \right] -x\left[n -1\right] +0.5 y\left[n -2 \right] $$ We'll find out the transfer function of it. So, easiely using z-transform, $$ Y(z) ...
1
vote
3answers
265 views

Filter odd or even harmonics with notch or inverse notch filter

Hi i had the following question. I have a signal containing a 200Hz sine wave and it's odd and even harmonics (no other frequencys or disturbing signals are contained). What i'm looking for is a kind ...
1
vote
1answer
81 views

Real Data Complex Transfer Function using H0, H1, H2 Estimators

BACKGROUND: This question is attempting to consolidate material discussed in two previous topics. These are: Understanding the H1 and H2 estimators @Pontus S Frequency-domain deconvolution: "...
1
vote
2answers
36 views

Coupled system instability

Suppose there are two linear devices (containing some multi-physics but the details don't matter here), and these devices are given to us as two black boxes that can be studied experimentally. Black ...
0
votes
1answer
48 views

Stabilizing an unstable system and removing oscillations from step response

I have a system with the transfer function given in this MATLAB code ...
0
votes
0answers
22 views

Confusion regarding terminology?

While studying the topic of filter design,i came across following terms: 1)Factored form 2)SOS(second order sections)form 3)Rational form 4)Transfer function form What is the difference between all ...
4
votes
1answer
74 views

Developing Lead Compensator to Decrease Settle Time

This is a follow up to this question. I've approximated the transfer function for a system to be H = zpk([0.012 -1.05 18],[-0.22 -0.22 -45 -1000],10000);. My goal ...
0
votes
1answer
42 views

Get the transfer function when using the “designfilt” command in MATLAB

To put things into perspective, I initially had these four graphs in MATLAB, whose data were sampled with a rate of 10 samples/sec :- I wanted to remove some of the spikes on the blue graphs, so I ...
2
votes
1answer
43 views

Tuning a PID Controller

I have the following transfer function $$10000 \cdot\frac{(s-0.012)(s+1.05)(s-18)}{(s+0.22)^2(s+45)(s+1000)}$$ For which I am trying to tune a PID controller for. I'm using the pidTuner in MATLAB to ...
1
vote
2answers
55 views

Adding noise to frequency response

I have the dynamics of a 2nd order system, mass-spring-damper for example, in the transfer-function format. For the analysis that I am doing, I am calculating the frequency response of the system by ...
2
votes
1answer
78 views

Creating Bode Plot from Experimental Data

I have a blackbox system in which I can input a function and obtain the output signal (in MATLAB). I'm attempting to reconstruct a Bode diagram and have had success with the Magnitude plot, however, I'...
0
votes
2answers
51 views

how to take a second order transfer function without any zeros and represent it using two first order transfer functions

does anybody know how to take a second order transfer function with no zeros (no s terms in the numerator): $$ g(s) = K\frac{\omega_n^2}{s^2 + 2\zeta \omega_n s + \omega_n^2} $$ and represent it using ...
0
votes
0answers
39 views

How to find H(z) from just zeros and poles

I have a system with a DC gain of 8, poles at z = +- j/2 and zeroes at e^+-j5, I need to find the H(z). I have tried this but not sure if it is right. $$ H(z) = G_o * z^{-1} \frac{(z-z_0)(z-z_1)}{(z-...
0
votes
2answers
162 views

Transfer function estimation from frequency response

Let's assume that we know that we are dealing with a SISO second order system for which we have the frequency response (magnitude and phase for a known frequency range ω). What methods would people ...
0
votes
2answers
75 views

Amplitude spectrum (transfer function) of signal?

I have one question related to finding amplitude spectrum (transfer function) of signal knowing that output signal is time derivative of input signal. I have the answer graph but I don't understand ...
4
votes
1answer
145 views

How do I get a faster system response?

I have this model in simulink (the graph is my output): The step input has amplitude 0.5 m/s, and it steps up after 0.1 seconds. The gain $K_p=5$. The saturation block is to keep the voltage between -...
0
votes
1answer
39 views

Digtial FIR Impulse response & transfer function

I am currently working the figure through below. as it is an FIR Filter i have worked out using convolution that the output is 4,2,4,6,0,0. i am trying to obtain the 'z' domain transfer function of ...
4
votes
1answer
65 views

Transfer function with blackbox modelling is too slow compared to real expectation

I collected this data from a robot that drives with its wheels up. The blue curve is the voltage and that is my input. The orange curve is the wheel velocity and that is my output. I want to create a ...
0
votes
0answers
24 views

SPL dB to voltage conversion misunderstanding

base on these links: https://electronics.stackexchange.com/questions/96205/how-to-convert-volts-to-db-spl https://electronics.stackexchange.com/questions/302833/convert-digital-and-analog-values-to-...
5
votes
1answer
73 views

how to find frequency response of microphone

hello I want to find the frequency response of a microphone. I give the input signal to my speaker and it produces a specific SPL with specific frequency. on the other side, I read the microphone ...
0
votes
1answer
54 views

Additive disturbance in block diagram representation

Drawing the open loop block diagram between valve and pump is straightforward (please see illustration). But why should $v$ be an additional disturbance in this system (please see solution)? $v$ is ...
0
votes
2answers
234 views

From transfer function to differential equation

I have the below detailed solution (boxed in blue) that I don't understand completely: I can reconstitute the differential equation from: $$ (1+Ts) X(s) = K_v U(s) $$ $$ x(t) + T\dot x(t) = K_v u(t) $...
4
votes
3answers
985 views

Is this system causal or not?

My efforts of solving this question are below. I came to a conclusion that this system is causal, since: $$ \begin{cases} w[k]+5w[k-1]+6w[k-2]=x[k] \\ y[k]=w[k]+2w[k-1]+3w[k-2]+4w[k-3] \end{cases} $$...
0
votes
0answers
19 views

Gradient of transfer function (z-transform) with respect to coefficients/parameters?

my problem is perhaps very simple but I just can not find the answer, even though this is used (though not explained) in several books: What is $\frac{\partial G (z, \theta)}{\partial \theta}$ when $G$...
0
votes
0answers
44 views

Why the transfer function is equal to the output in this case

In this description of transfer functions on the z-plane (image linked), I'm confused by equation 1.49, which says that $H(f)=v_{out}(f)$ when $v_{in}(f)= 1 * e^{j 2 \pi (f/f_s)}$. (For another matter ...
0
votes
1answer
51 views

Part 2: Root Locus, Transfer Functions and Unit Step Response?

I'm continuing my question referenced here: Part 1 Question / Problem Description Say I have a new Root Locus shown below Consider the generic feedback loop, and the transfer function $G(s)$ shown by ...
1
vote
1answer
69 views

Root Locus, Transfer Functions and Unit Step Response?

Consider the generic feedback loop, and the transfer function $G(s)$ shown by the following root locus plot. Where $\mathbf{x}$ denotes the open-loop poles and $\square$ denotes the closed loop poles....
0
votes
0answers
22 views

How to handle cross products in feedback loop?

I'm trying to simplify the following block diagram from to the following block diagram However, h(t), H(s) in time domain, has a cross product in it (gyroscopic torque). How can I represent the ...
2
votes
1answer
139 views

Ending points of the root locus

Let $$D(s) + KN(s) = 0 \tag{1}$$where $D(s)$ and $N(s)$ are polynomials of $s \in \mathbb{C}$ such that $\text{Deg}(D) = n, \ \text{Deg}(N) = m$ and $n\ge m$. The root locus method tells us how the ...
1
vote
2answers
208 views

Can we choose a sampling frequency to remove unwanted noise at a specific frequency?

I am studying for my exam in signal processing. In one of the old exam papers I am told to find a sampling frequency, which will remove 80 Hz noise. The filter the exam question is based around has an ...
0
votes
0answers
27 views

Interpreting Nyquist Plot for Phase and Gain Margins

I have an open-loop system transfer function given by $G(s) = \frac{K(ABs^2+As+1)(Cs+1)}{s^2A(s(C+D)+1)}$ so I'd expect two poles at the origin and one at $s=\frac{-1}{C+D}$. After using Matlab to ...
0
votes
2answers
78 views

Converting Audacity Filter Curve EQ into transfer function and applying it to a signal via python

First of I am very new to Signal Processing and to python in general. I am trying to write a script where I would feed a voice recording into it, internally apply an eq and have the modified signal ...
0
votes
0answers
34 views

Creating a prediction from data in MATLAB

How can I create a closed loop system that can guess the input value that is going to return 0 from unknown transfer function. The output of this transfer function is either a positive constant, a ...
0
votes
1answer
51 views

What is the relation between input and output PSDs given system transfer function $H(s)$

If I have the system transfer function $H(s)$ in the complex frequency domain, how would I relate the input/output power spectral densities? I have come across the relation $P_{out}(f) = |H(f)|^2P_{in}...
0
votes
1answer
44 views

Is this an error in Oppenheim and Schafer's Discrete-Time Signal Processing (3rd edt)?

Q: According to Fig 71, y[n]=something+e[n] and hence the transfer function from e[n] to y[n] denoted as He(z) should be 1. Am I wrong?

1
2 3 4 5
8