Questions tagged [control]

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4 votes
1 answer
85 views

Understanding an adaptative single neuron PID controller

I only know the "vanilla" use of a Kalman filter and I am currently trying to understand an article available here (the algorithm is presented in the 6 first pages) : Adaptive Single Neuron ...
1 vote
1 answer
77 views

Digital PID controller implementation

I am not sure whether I have chosen correct forum for my question. The question regards the implementation of a digital PID controller. From my point of view it is a kind of digital filter which is a ...
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0 votes
0 answers
36 views

What is the point of using this derived PID controller?

Previously, I answer for this PID controller that I want to understand completly. This is used for control the opening $U_n$ of a valve let gas pass and reach a certain pressure (SetPoint). There is ...
2 votes
1 answer
121 views

Tuning Active Power Factor Correction converter works in Simulink, but having trouble achieving the same in DPS

I am trying to tune the Active PF Correction converter current and voltage loop to get a sinusoidal input current. I can get to a voltage reference, but the current looks like this. Reading the ...
1 vote
0 answers
16 views

Confused with special cases of Routh-Hurwitz

When the first column only has a zero we replace is with an $\epsilon$ so we don't divide by zero ahead but divide by the $\epsilon$ then take the limit as it goes to zero. meanwhile if an entire row ...
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0 votes
0 answers
24 views

Output signal for space-state

I have a space-state system and I need to find the output signal of it. Can anyone here explain to me how to do it? My soluation: is it a right answer?
0 votes
1 answer
39 views

Why is phase variable called like that?

I just read about phase variable-form here. ...
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1 vote
0 answers
41 views

How can to obtain the hughcut, lowcut and bode constant of a bandpass digital filter?

I need to create a bandpass filter amplifier in python; and determine the transfer function, graph the bode diagram, and print the highcut frequency, lowcut frequency, the bode constant and the ...
2 votes
0 answers
44 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 ...
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1 vote
2 answers
413 views

How to deal with "weird" phase plots in bode diagram when designing a controller

I am trying to design a balance controller for a robot. With MATLAB simulink I arrived at the transfer function between the input and the pitch angle for the robot. I have plotted the bode and Nyquist ...
  • 340
2 votes
1 answer
57 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 ...
2 votes
1 answer
67 views

Why do we use "error quaternions" for control of attitude?

I'm working on an attitude control system in terms of quaternions, and i'm basing my approach on the book Space Vehicle Dynamics and Control (2nd ed.). If we consider a proportionate controller, i.e. ...
0 votes
2 answers
68 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
2 answers
126 views

How to quantify amplitude of oscillations in marginally stable systems?

Transfer function pole on the Imaginary axis indicates that the system is marginally stable which in time domain can be represented as a sinusoidal motion with constant amplitude and frequency of the ...
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2 votes
1 answer
133 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
1 answer
125 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'....
2 votes
1 answer
127 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 $K_i$...
0 votes
1 answer
184 views

Is it a mandatory condition that complex poles and zeros should always exist as conjugate pairs?

Complex poles and zeros always exist in conjugate pairs?If not always, in which context applicable? https://www.informit.com/articles/article.aspx?p=32090&seqNum=9 The above link mentions related ...
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1 vote
1 answer
73 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 ...
0 votes
0 answers
32 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-...
1 vote
0 answers
20 views

Controller design with DQ transform

I'm reading this paper on a 3-phase rectifier control. 3-phase rectifiers are usually connected to 50-Hz or 60-Hz grid. One popular control strategy is to transform the 3-phase currents and voltages ...
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2 votes
2 answers
91 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. ...
4 votes
2 answers
225 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
1 answer
64 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 ...
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0 votes
1 answer
45 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 ...
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3 votes
1 answer
179 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, ...
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2 votes
1 answer
57 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 ...
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1 vote
1 answer
136 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 ...
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3 votes
1 answer
56 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 ...
  • 183
0 votes
1 answer
509 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 ...
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3 votes
2 answers
742 views

Why does the control effort increase if the bandwidth of the system is higher then the bandwidth of the plant?

I am studying control systems and I am focusing on the control effort. I have seen that if I place a pole at higher and higher frequencies, if the bandwidth of the system goes above the bandwidth of ...
  • 183
0 votes
1 answer
20 views

Understand diagram of a process

I've found this diagram in a slide, but i have no backround to properly understand it. Could you explain to me, in simple terms, how this process behaves and what's the purpose of the blocks $z^{-1}$ ?...
0 votes
1 answer
689 views

How do I find transfer functions from a state space representation?

Suppose I have a MIMO system in state space representation, for example: $A=\begin{bmatrix} 1 &2 &3 \\ 4&5 &6 \\ 7&8 &9 \end{bmatrix}$ $B=\begin{bmatrix} 2 &3 \\ ...
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1 vote
0 answers
131 views

Influence of a RHP zero/pole in the frequency response

I am studying loop shaping, and I am looking at loop shaping design with unstable poles and zeros. I have seen that noth unstable poles and zeros introduce limitations in the bandwidth. I have also ...
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0 votes
1 answer
44 views

Doubt on behaviour of frequency responce of a system

I am doing loop shaping using $H_{\infty }$ approch, and I have a plant with an unstable pole: G = 10/((s+10)*(s-1)); K1 = 4*(s+1)/s; where G is the plant, and ...
  • 183
2 votes
1 answer
199 views

Doubt on the relationship between the sensitivity and the complementary sensitivity function

I am doing loop shaping with the following transfer functions: G = 10/((s+10)*(s+1)); K1 = 0.5/s; where G is the process and K1 is the controller, and If I ...
  • 183
0 votes
1 answer
1k views

How can a stable system have a RHP pole?

I am working with a control system which has an unstable pole in the process. So I have the following transfer functions for the controller and for the process: ...
  • 183
2 votes
2 answers
702 views

Understanding Matlab's Automatic Gain Control function

I am trying to understand the automatic gain control block provided by the communications toolbox. The documentation is here: Documentation My questions are in regards to two of the configurable ...
0 votes
1 answer
1k views

Discretizing a Controller with the Backward Difference Method

In the book "Modern Control Engineering" by Paraskevopoulos it's proved how to discretize a generic controller in the form: $G(s)=\frac{Y(s)}{U(s)}=\frac{a}{s+a}$ where $a$ is a constant. Done this, ...
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0 votes
0 answers
35 views

Doubt on inversion of the dynamics

I am studying control system and I have encountered the topic of the inversion of the dynamics. So I have seen that the ideal situation would be $C(s)=P(s)^{-1}$ but there are some problem with ...
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3 votes
1 answer
2k views

Lead compensator vs lag compensator?

I already know that lag compensator acts like PI controller and improves steady state and lead compensator acts like PD controller improves transient state but how they achieve their goal? Despite ...
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0 votes
1 answer
69 views

confusion about poles and zeros of Lead compensator?

I was reading about lead compensator from a website but i am not able to understand how they have extracted zero and pole from transfer function of lead compensator as shown in attached photo? or ...
  • 983
14 votes
6 answers
5k views

Relation between signal processing and control systems engineering?

Control systems engineering and Digital signal processing are both important courses/subjects of electrical engineering But how these two subjects/courses are related to each other?? Also please ...
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1 vote
1 answer
6k views

Effect of origin poles on stability?

What will be stability if we have only one single pole at origin in s domain?? and what will be the case for multiple poles at origin in s domain?
  • 623
1 vote
1 answer
101 views

Is a good practice to use one PID in rise time and another PID for steady time in order to eliminate oscillations during steady time?

I'm trying to control temperature with PID(Kp,Ki, Kd). During the rise time the system use one PID and when target is reached the system switch to another PID with other parameter in order to ...
0 votes
0 answers
43 views

On $H_\infty$ norm for transfer function

For a given scenario in the context of control system, I'm trying to investigate how the $H_\infty$ norm can be calculated for a transfer function as follows: $$G(s)= \frac{w_n^2}{s^2 +2\zeta w_ns +...
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0 votes
1 answer
81 views

Calculating an in-loop signal as part of a hierarchical control loop

I've got a control system with two feedback paths, with each path going to a different actuator that corrects the error in the system. One feedback path provides feedback at low frequencies, and the ...
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1 vote
1 answer
126 views

State space equations

I am stuck on this exercise. I don't know how to deal with this squared y in the denominator. What am I supposed to do to obtain state space equations? ex.1 Simplified dynamic model of the steel ball ...
0 votes
2 answers
69 views

Control optimization problem

I am running into a problem where I have a control system $S[t]$ that takes a control $C[t]$, so that $$S[t+1] = H(C[t,t-1,...], S[t,t-1,...])$$ the response of the system is the history of controls ...
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