Questions tagged [control-systems]
The control-systems tag has no usage guidance.
240
questions
0
votes
0answers
36 views
Is it allowable to place a zero to cancel out a complex pole?
Consider the following transfer function :
$$
T(s)=\frac{4}{s^{2}+2s+4}
$$
I wish to design a lead-lag compensator satisfying a set of requirements. What matters for now is the process done to meet ...
2
votes
1answer
70 views
How to design a Controller that would adjust the steady-state error of a system?
I have a simple model (input-plant-output) with a transfer function :
$$
T(s)=\frac{4}{s^{2}+2s+4}
$$
The goal of this problem is to design a system such that it has the following specification for a ...
0
votes
0answers
21 views
How can we translate this statement into an input signal expression?
I want to make sure if I got this right, the following statement:
if the operator
enters a unity sloped linearly increasing input then the output must eventually track the
input and be at most 0.1 cm ...
0
votes
0answers
12 views
Poles and Zeros of a DiscreteTimeModelFunction with delay in Wolfram Mathematica
help me please, I have a problem with this TransferFunctionModel, When I want to obtain the poles from the Discrete Model Wolfram gives me an error, what am I doing wrong? Could it be the delay of the ...
1
vote
2answers
79 views
How can I use an irrational transfer function to convolve a signal?
I have the irrational transfer function
$$H(s)=\mathrm{e}^{-a\sqrt{s}}$$
With the inverse Laplace transform
$$
h(t) = \frac{a\,\mathrm{e^{-a^2/(4t)}}}{2\sqrt{\pi}~t^{3/2}}
$$
For $a > 0$
How can I ...
0
votes
0answers
11 views
Discretization of a controller
The desired control is $u_f=\frac{1+\eta s}{1+hs}a$, where $u_f$ is the feedforward control, $a$ is the feedforward observation and $\eta$ and $h$ are two constant parameters. However, I can only ...
2
votes
1answer
41 views
Designing a controller with hard output limits
I'm trying to put together a control algorithm to use a heater to drive a 2nd order thermal system to the target temperature as quickly as possible. I've done a nice state-space model with an extra ...
1
vote
1answer
39 views
Stability concerns for closed-loop systems
I came across the statement
Stability is a big problem in closed-loop systems, where a system may tend in some instances to overcorrect errors and cause oscillations.
I wish to know some examples in ...
0
votes
1answer
40 views
Realize the given system in cascade form of 2nd order section in signal flow graph representation(with complex exponents)?
I know how to solve cascade form for normal case, but I don't know how to solve cascade form if I get complex exponentials. How do I solve this? Can you provide me 1 solved example or some hint or ...
7
votes
1answer
101 views
Kalman Filter: How to Define Inputs and Outputs of a Model
I'm a software engineer with a CS degree working in machine learning. I'm trying to learn about Kalman Filters.
In this short YouTube video from Mathworks, there's a discussion on a Kalman Filter with ...
2
votes
0answers
37 views
Are there control loops that attempt to maximize a process variable?
I'm working on Remote-Procedure Call (RPC) server that processes incoming streams of data from clients, and looking for a way to set a limit on the number of simultaneous streams allowed.
There is ...
1
vote
2answers
76 views
Matlab Pade approximation influence on bode plot and step response
I would like to approximate a delay via the pade approximation. I set a normal delay via the exponential term and I set a delay via the pade approximation and I look the difference between the both ...
1
vote
1answer
34 views
Mixed - Discrete and Continuous system Laplace domain stability - Effect of Sampler and DAC
I have a system whose the plant transfer function is continuous and the compensation is discrete. I have an ADC which allows to measure the output of the system and a DAC which allows to control the ...
3
votes
0answers
60 views
real time - active noise control
I am trying to implement an adaptive filter for system identification and active noise control for realtime signal processing on an FPGA using Labview. For system identification, I implemented the ...
4
votes
2answers
169 views
How to set parameters of the PI controller inside the PLL?
I am going to implement in C++ software the synchronous frame phase locked loop (SFPLL) for estimation
of angle and frequency of the three phase grid 220V/50Hz.
For the internal PI controller setting ...
1
vote
1answer
254 views
Why is modern control theory in the time domain instead of the S-domain?
I am not sure if I am missing something, but from what I read I understand that modern control systems work in the time domain rather than the frequency frequency or S-domain.
Wikipedia article ...
2
votes
2answers
35 views
cancellation controller transfer function design
This chapter offers a free overview on cancellation controllers.
However, i did not get equation (6.4), how the transfer function of $G_R$ is determined?
1
vote
0answers
18 views
derivating input output relationship of a block diagram when there is noise added to the output
For the following system, I am not quite sure how the equation representing the input output relation is derived.
Here, r is an input reference signal, $d_e$ is external disturbance and $n$ is noise. ...
2
votes
1answer
78 views
Linear system stability criteria
Suppose we have a closed-loop system $H(s)=\frac{A(s)}{1+A(s)f(s)}=\frac{A(s)}{1+T(s)}$. I've seen the stability of the system stated a couple ways:
If $H(s)$ has any poles in the RHP, then it is ...
0
votes
2answers
45 views
map float to fixed point
I have designed a system in simulink and works well through simulation. In order to convert to fixed point, I tried fixed point advisor with little success. The reason being that the coefficients on ...
4
votes
1answer
151 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
2answers
53 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 ...
1
vote
1answer
129 views
3D (time, scale, amplitude) plot in Continuous Wavelet Transform
I will be extremely grateful if someone could please answer this basic question.
How can one plot a 3D (translation, scale, amplitude) plot from the Continuous wavelet transform (CWT) coefficients?
...
1
vote
1answer
54 views
What is the relation between eigenvalues and state-space response in control systems?
I understand the mathematics behind it but I want to know what happens physically in a real-life system. How do the eigenvalues come into the picture from a non-mathematical (physical) point of view? ...
4
votes
2answers
360 views
Which step response matches the system transfer function
A system has the following open loop bode plot: -
Which one of the plots below describe the closed loop step response for the entire system?
My attempt
My initial thought was to look at the static ...
4
votes
1answer
286 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
0answers
43 views
what is the difference between LMS and MPC?
I do understand that MPC is a control method and requires known model in the feedback path.
LMS, on the other hand, is more like an adaptive filtering, which estimates the tap coefficients yielding ...
0
votes
0answers
9 views
What are some reliable sources which I can use to validate my code for simulating MPC?
What I have done
I have written a code in Mathematica from scratch for simulating quadratic cost standard MPC problems for constant reference tracking.
My attempts
YALMIP's website has a solved ...
0
votes
0answers
10 views
Construct controller with given crossover frequency
I have this problem:
I can solve question a) by looking for the phase gain of the bode plot at $\omega_{\pi}$, find the phase gain = 0.2, and divide $\frac{1}{|G(w)|} = \frac{1}{0.2} = 5$, so K can be ...
0
votes
0answers
33 views
Feedback command for MIMO systems in matlab
I have a state space model with 12 outputs and 4 inputs. I want to close the loop of 8th output with 3 input. then in outer loop i want to close outer loop for 1 output and 3 input again (Quadrotor ...
2
votes
0answers
37 views
State space representation using a given nilppotent matrix
I want to build a question on state space using a given, nilpotent matrix, $A$.
$$q[n+1]=Aq[n]+Bx[n]$$
$$y[n]=Cq[n]+Dx[n]$$
Usually, I am using the canonical form so there is no problem extracting $A,...
0
votes
1answer
89 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
113 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
23 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 ...
3
votes
2answers
520 views
State space physical meaning
Let $T(s)$ be a transfer function that describes a mechanical system, where the input is force and the output is position.
And let $[A,B,C,D]$ be the equivalent state-space representation of $T(s)$, ...
2
votes
1answer
168 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 ...
0
votes
1answer
82 views
What is the frequency of the Gaussian white noise model in control systems?
The design of control systems, particularly for SISO systems, is made convenient by tools such as Bode plots and the corresponding Nyquist stability criterion. These concepts allow engineers to design ...
2
votes
1answer
52 views
Why can't this system be adequately represented using a z-domain transfer function?
According to this question and answer the following system cannot be adequately captured by a z-transform transfer function.
$$y[n] = y[n-1] + F_{\psi}(y[n-1)) + F_{\phi}(x[n-1])$$
where $F_{\alpha}(z)...
2
votes
1answer
85 views
Controller in the feedback path?
What happens if the controller of a closed-loop system is placed in the feedback path before the summation point, instead of between the summation point and the plant to control? Are we allowed to do ...
0
votes
1answer
76 views
How does the intuitive notion of causality fit in with control systems?
Edit: By causality, in this question, I do not mean the traditional mathematical definition in the theory o signals and systems; I mean causality as in an intuitive 'what's moving/pushing what notion'....
1
vote
0answers
52 views
Are there any State Space Control C libraries?
I'm searching for a C library which implements methods needed for state space control (e.g. state feedback controller and state observer equations).
Googling various terms only brought up a non-C (C# ?...
0
votes
0answers
16 views
music sampler control
I'm a reasonably competent web programmer and I would like to know how I should go about learning to program a software that would control a music sampler.
The hardware setup I was given is a sampler
(...
2
votes
1answer
72 views
Region of root locus not inside the feasible region for a given performance specification
I wanted to plot the root locus for a system, whose plant transfer function is
$$
P(s)= \frac{k}{Ts+1}e^{-ts}.
$$
A PI controller was suggested for this system, and the task is to find $K_p$ and $K_i$...
1
vote
4answers
160 views
What is the principle behind my voice echoing perpetually when 2 separate devices are used for playback and recording on video calls?
I had to use 2 separate devices for a video call, desktop for video/audio output and smartphone for recording, since the desktop microphone was not working properly. Unfortunately for me, when I ...
1
vote
0answers
40 views
Kalman Filter: Difference between sensor input and control input
I recently saw a matlab sensor fusion example which combined IMU and GPS data for drone localization.
What was surprising about it was that the IMU was used to predict future behavior of the system as ...
3
votes
1answer
102 views
Effects of delay in a discrete-time controller for a continuous-time plant
I'm trying to understand the effects of sample-to-update delay in digital control of power electronics. I am aware of the issue but not 100% sure how to quantify it. There is an interesting paper by ...
0
votes
1answer
49 views
How to approximate the transfer function of compensator using root locus?
I have the root locus of a system with and without compensator. The system is consist of a PD-controller and the process, the output is fed back to the controller via $G_s(s) = 1$.
The upper graph is ...
2
votes
0answers
27 views
Signifance of statistical information in a signal
I am learning control engineering for some time and I work with a lot of transfer functions and frequency domain design. Reading from textbook, to me everything seems deterministic. Whenever I come ...
1
vote
1answer
56 views
Transfer function estimation using system identification
I am posting a control system problem here because of this post reference.
Question:
I have input and output datasets. These are graphically shown below.
The blue line is output and the pink line is ...
1
vote
0answers
173 views
Time-Invariant (non)autonomous Systems
Regarding potential distinctions between autonomous, non-autonomous, time-invariant and time-varying systems, I have found out opinions supporting that:
autonomous systems are time-invariant and non-...
