Questions tagged [control-systems]
The control-systems tag has no usage guidance.
222
questions
2
votes
0answers
17 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
0answers
20 views
why do cascaded pole plant models create an internal/apparent time delay
My question is why do plants made up of many poles in cascade cause apparent time delays in a system?
0
votes
2answers
37 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
1answer
32 views
How to calculate velocity error of a control system in Matlab?
I am trying to calculate de position, velocity and acceleration error in Matlab. My transfer function is $\frac{1}{s^2+6s+8}$, and the system has a unit feedback. I am calculating the input-output ...
1
vote
1answer
30 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
33 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
142 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
104 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
40 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
9 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
24 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
36 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
39 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
43 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
21 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
468 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
112 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
41 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
49 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
64 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
45 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
29 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
44 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
140 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
33 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
49 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
41 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
26 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
37 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
141 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-...
0
votes
1answer
36 views
Extracting the DC component of a signal, that proportional to the displacement about the y-axis
I’m not sure that I clearly enough reflected the essence of a small problem in the title of the topic, but I’ll try to reveal its essence in the question itself.
https://www.wolframalpha.com/input/......
0
votes
0answers
25 views
Control of a nonlinear static MIMO System
I am currently writing my master thesis and trying to design a controller for my system. However, the system is somewhat unconventional.
It has a large number of inputs and outputs, is static, non-...
0
votes
0answers
27 views
Trajectory Planning and Optimal Control
When finding control inputs for ODE systems, gradient based solutions are often used. With the increase computational power will these solutions still be important over things like Monte-Carlo ...
0
votes
2answers
78 views
Why is the close looped model under control called plant?
I am not sure if the question even belongs here. Please correct me if it is out of context.
Consider a closed feedback loop.
Usually, we say that $K^L(s)$ is a controller over the plat $G(s)$. Is ...
2
votes
1answer
32 views
Feedforward disturbance signal compensation
The reference Feedforward control concepts through Interactive Tools says, to minimise the effect of the disturbance $d$ on the process output $y$, a compensator $G_{\text{ff}}=P_3/P_1$ shall be used. ...
1
vote
1answer
37 views
How to find the perfect regularization number?
I have an issue!
Assume that we are going to solve $Ax=b$ but $x$ contains noise.To minimize that noise we can use regularization:
$$x = (A^TA + \lambda I)^{-1}A^Tb$$
Where $\lambda$ is a small ...
1
vote
0answers
22 views
How can I correct the settling time when implementing a pre-filter (reference filtering)?
I have designed a controller for the speed of a motor, I calculated that for a settling time $0.1 \; s$, it works when I test it without pre-filtering. However, I need $0$ overshoot, so I implemented ...
7
votes
1answer
183 views
Fundamental questions about state-space and Kalman filters
I am a dsp guy, I only did a minimum of control theory back in university. While trying to grok state space analysis and (discrete time) regular Kalman filters, I am hitting a few questions that ...
0
votes
1answer
105 views
Model necessary for PID control
As I am not from control theory, I do not understand - after reading the Wiki page about PID control (https://en.wikipedia.org/wiki/PID_controller) and watching some videos - whether a model of the ...
4
votes
2answers
90 views
Stabilizing the inverse transform of a system
Currently I am trying to understand an unknown mechatronic system. I used white noise as an input signal and measured the output of the system. Then I estimated a second order SISO transfer function (...
1
vote
1answer
36 views
Why if I place the zero of the lead compensator at lower frequencies, do I obtain a resonance peak?
I am studying control systems, and I am studying the lead and lag compensator. I have seen than if I use a lead compensator for the closed loop transfer function,
$T(s)=\frac{s+2}{(s+1)(s+8)},$
with ...
1
vote
3answers
287 views
Whether $y(t) = x(t/3)$ is a memoryless system?
I am a newbie in signal and system, and feeling confused about the memoryless property, it says at the definition, if a system gives output only depends on present input, then its memoryless. So if at ...
0
votes
1answer
30 views
Measurement delay versus control delay
For a typical conventional control loop (no delay, measurement transfer function is 1) the closed-loop transfer function is
$$H(s) = \frac{G_{comp}G_{process}}{1+G_{comp}G_{process}}$$
With an ...
3
votes
1answer
81 views
What does it mean that a zero is slow?
I am studying control systems, and have encountered the definition of a slow zero. I am searching on internet and in books, but I don't understand the meaning this. I know that if a zero is too slow, ...
2
votes
1answer
36 views
Does a RHP zero imposes some limitation in the time domain?
I am studying control systems and I have seen that a non-minimum phase zero imposes a limitation on the bandwidth, which is that the bandwidth has to be lower than the frequency which is half the ...
1
vote
1answer
69 views
Problem in verifying zero blocking property of a zero of a multiple input multiple output system
I have a multiple input multiple output control system, and in particular a two inputs two outputs system. I want to find the zero state direction and the zero input direction of the system, which has ...
3
votes
1answer
52 views
Is it possible to use a control scheme with a delay as prefilter?
I am studying control systems, and in my studies I have encountered the topic of control scheme of the form
and I have seen thaht this control scheme is really useful since it is possible to add a ...
0
votes
1answer
220 views
Can a pole at the origin be considered a dominant pole?
I am studying control syetems, and I have studied that the dominant poles of a system are the ones closer to the imaginary axis.
Now, consider a system with a pole at the origin. Can this pole at the ...
