Skip to main content

Questions tagged [control-system]

A control system regulates the behavior of other devices or systems, usually using a control loop. Examples are a home heating controller using a thermostat, a regulator keeping a drone stable, and industrial control systems used for controlling processes or machines.

232 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
4 votes
0 answers
1k views

Deriving PI controller transfer function when input is reversed

I'm developing the compensator for the linear DC Bench Power Supply I'm designing. As I've come to deriving the transfer function for the op amp-based compensator, I realize I've been depending on a ...
scanny's user avatar
  • 7,132
3 votes
0 answers
104 views

DC Motor Difference Equation Digital Control System

This shows a DC motor drive with the voltage input. And the discrete-time model is like this The difference equation should be something like this: Where the C_1T is the inverse laplace transform of ...
Kadal's user avatar
  • 31
3 votes
0 answers
164 views

Control system with one setpoint, one process variable, and two outputs?

I asked a version of this question before and got some unhelpful answers, I think because 1) the minutiae of my question distracted from the core concept, and 2) I didn't adequately describe the ...
Ben S.'s user avatar
  • 71
2 votes
0 answers
38 views

How can I explain contradictory damping performance between linear and nonlinear systems?

I have a 3rd order nonlinear dynamical system, representing a power system. After linearizing the system, it turns out that by increasing the parameter L_g, damping is reduced and thus the overshoot ...
Ali Hosseini's user avatar
2 votes
0 answers
124 views

Why do we prefer a cross over slope of -1 (20 dB/decade) for bode plot of power converters?

The video mentions (@12:45), we should ensure the slope at cross over should be around -1 (20 dB/decade). He mentions we can apply phase margin test if this condition is satisfied. As far as I know we ...
Dynamic_equilibrium's user avatar
2 votes
0 answers
47 views

What is the integral variable of a PIDF written as a digital biquad in transposed direct form 2?

I have a PIDF written as a digital biquad in transposed direct form 2. Omitting the construction of the a and b constants the guts of the filter look like: ...
lamont's user avatar
  • 121
2 votes
0 answers
155 views

AC analysis of SMPS shows instability. How to modify the analysis to reflect the transient stability?

Background I have designed a switch-mode power stage with voltage-mode control that uses an LCLC filter in its output to obtain a very low ripple output voltage. I have empirically arrived at a ...
tobalt's user avatar
  • 22k
2 votes
1 answer
37 views

Stability analysis of hybrid discrete-continuous systems

I'm trying to derive the overall state-space system model for a hybrid system, in order to plot its eigenvalues. The system is shown as follows: Which is originally from this paper: Modeling and ...
Derek Topovski's user avatar
2 votes
0 answers
118 views

How do I control the speed of a simple DC motor based on the output of a machine learning algorithm using a Raspberry Pi?

Let's suppose there is a simple machine learning algorithm for detecting speed limit signs using image recognition and it detects a 30 km/hr sign. Is there any way to send instructions to my motor ...
Shaun Jacob's user avatar
2 votes
0 answers
88 views

Underlying reasoning behind lead and lag nomenclature of compensation

If \$0<z, \;p\$, the Laplace transform transfer function \$\frac{s+z}{s+p}\$ constitute two distinct types of compensators. If we look at this schematic, \$0<z<p\$ (lead compensation) implies ...
kbakshi314's user avatar
2 votes
0 answers
92 views

Buck converter with state feedback: does changing the input voltage changes the dynamic of the converter?

Short question: in a buck converter with state feedback, do changes in the input voltage cause changes in the dynamics of the output voltage (and inductor current)? The problem: let's say we have a ...
heavyside's user avatar
2 votes
0 answers
125 views

Standard for electrical schematics in the UK

I'm trying to find out whether there is an accepted standard for electrical schematics in the UK. From my research so far, I've come across IEC 60617 however this appears to have been withdrawn. I ...
Paul H's user avatar
  • 121
2 votes
1 answer
148 views

Singular interval condition for Multi input in Optimal control

The definition of singulr interval is shown in Figure. I've struggled with this problem. I think the solution of this prob is "because if the E_j matrix is not singular, it means the System is ...
Damien's user avatar
  • 21
2 votes
0 answers
276 views

Simulation of field oriented control of three phase induction motor

I have been developing a simulation of the field oriented control algorithm of the three phase squirrel cage induction motor in the Xcos (equivalent of the Simulink). The simulation consists of ...
Steve's user avatar
  • 1,103
2 votes
0 answers
1k views

Controllability and observability from given transfer function

Is it possible to determine whether system is uncontrollable or unobservable or both from given transfer function in which there is pole zero cancellation? for ex.transfer function like this Or it ...
user215805's user avatar
  • 1,184
2 votes
0 answers
165 views

Problem understanding transfer functions of second order filters

The transfer function of any second order filter can be found by analyzing the circuit using the Laplace transform. For example the transfer function of a second order low pass passive RLC filter ...
Jack Danniels's user avatar
2 votes
0 answers
188 views

Mixed sensitivity controller design

I am defining a controller using the mixed sensitivity approach, and I have the following specifications: a low frequency attenuation of 60 dB a maximum resonance peak of 2 and I have chosen to use ...
J.D.'s user avatar
  • 103
2 votes
0 answers
181 views

Stability of Buck Converter when output capacitance is variable

I am designing a buck converter for an application that has several different loads. Depending on what devices are connected, the capacitance seen at the output of the buck converter can vary ...
BB ON's user avatar
  • 2,314
2 votes
0 answers
1k views

Why gain crossover frequency must be lower than phase crossover frequency for stable systems?

As far as I understood from here, phase margin means the amount of phase that needs to be added in order to coincide with 0 db gain and -180 degrees phase. Likewise for the gain margin it means means ...
aadil095's user avatar
  • 233
2 votes
0 answers
103 views

tracking error state space, linear control example

I am trying to understand a detail from an example, from the control textbook Slotine and Li (1991) "Applied Nonlinear Control", Prentice-Hall, Example 6.4, pag. 220. A linear system is given: $$\...
Lello's user avatar
  • 41
2 votes
0 answers
90 views

Designing PID to reject load disturbances of dead-time process

I am using the PID Tuner for the PID Controller Block in Simulink. I am particularly interested in the output disturbance BODE plot. I am trying to achieve an acceptable output disturbance with the ...
gelman_grad's user avatar
1 vote
2 answers
80 views

Proof that two systems are equivalent

I was wondering if someone could help me with the proper answer for this? Below is the question and my solution. I was hoping for partial points but I don't know what can be marked partially correct ...
Caskyll's user avatar
  • 11
1 vote
1 answer
110 views

Zero vs pole of a circuit

Intuitively, what makes a resistor/capacitor combination become a pole or zero in around an amplifier system? My intuition always says that a zero is formed when there is a direct path through a ...
scc28adi's user avatar
1 vote
1 answer
53 views

Finding transfer function in a balance state

I have an ODE that looks like this: $$ \dfrac{d^2y(t)}{dt^2} + 2\sin{y(t)} = u(t) $$ Taking u as input and y as output, considering the balance state with $$ u(t) = \bar{u}, y(t) = \bar{y} $$ ...
Sonamu's user avatar
  • 213
1 vote
0 answers
45 views

Locating variables a and b in a phase lead compensation system

I have a block diagram that looks like this: I am asked to find the maximum angular frequency of the phase lead compensation, thus, in order to locate values a and b, I first find the maximum phase ...
Sonamu's user avatar
  • 213
1 vote
0 answers
55 views

Entire Complex Function for dynamical systems

I am working on my master Thesis and I was going through the 1966 Thesis by K. P. Sriram. Here, the author computes the switching curves for minimum time control of some "famous" systems ...
dodo's user avatar
  • 11
1 vote
0 answers
262 views

What is the Z transform of the discrete PI control model?

I have a discreate PI controller implemented in stm32 MCU, it has the following form: $$ PI=K_p\cdot[r(t_i)-y(t_i)] + (K_I)\cdot\sum_{n=0}^{i}[r(t_n)-y(t_n)]\cdot\Delta t $$ where \$r(t_i)\$ is the ...
zymaster's user avatar
1 vote
1 answer
81 views

Is there any significance of RHP zeroes on a system's open loop behavior?

In a closed loop boost converter, RHP zeroes will cause a phenomenon called ‘non-minimum phase’, which will make the closed loop system go in the opposite direction first when an external excitation ...
Dynamic_equilibrium's user avatar
1 vote
0 answers
377 views

PI controller - output calculation

The propeller of an airship is connected to a DC motor. The motor is being controlled using a PI controller. The PI controller has a proportional gain of Kp = 2, and an integral gain of Ki = 0.5, and ...
puma's user avatar
  • 11
1 vote
0 answers
71 views

Current-mode buck: get current from inductor winding

I was recently reading about current-mode control in switching converters. When discussing the current sense signal, all sources I have read either show the current sense as some kind of additional ...
tobalt's user avatar
  • 22k
1 vote
0 answers
88 views

What is Byrnes-Isidori form and why is it usefu?

I was reading a paper about analysis of "Zero Dynamics" of a system but they initially converted the state-space model of the system into a "Byrnes-Isidori normal" form. What is ...
aakarsh's user avatar
  • 111
1 vote
0 answers
51 views

Loop shaping error

I have a plant transfer function (Gp) as shown, The GCF is at 20 kHz, and my intended switching frequency is 20 kHz, so as a first step in shaping the loop gain I try to shift it to a new desired GCF ...
SM32's user avatar
  • 366
1 vote
0 answers
42 views

Confusion understanding the term "classic control"?

I am trying to study basics of control systems, and I have came across terms like "classic control" and "modern control". These two terms "classic control" and "...
jhn's user avatar
  • 19
1 vote
0 answers
28 views

STF from VCO Signal Flow Graph

I've been looking at this paper that uses a VCO for a resistive sensor readout and I'm rather confused about how to derive this transfer function they have from their signal flow graph. In their work ...
NaP's user avatar
  • 25
1 vote
0 answers
74 views

How to determine difference between LHP poles and zeroes by observing Nyquist plot?

I am solving practice problems on Nyquist Plot and I got stuck at a problem having a solution which I do not get at all. Here it is: Which of the following is the transfer function of a system having ...
aviral upadhyay's user avatar
1 vote
0 answers
193 views

Why are they called delayed integrators

I'm quite confused as to why we call a system with transfer function $$\frac{1}{s+\alpha}$$ a delayed integrator. It does not seem to be an integrator in the first place since it convolves with an ...
Essam's user avatar
  • 327
1 vote
0 answers
92 views

Multiple questions about magnetic levitation including modelling and how to achieve it

I have several questions regarding magnetic levitation. If I have missed something in one of these questions then please do let me know. I am working on a magnetic levitation project using an Arduino ...
Thanos's user avatar
  • 211
1 vote
0 answers
178 views

Tuning controllers in dual-loop control with feed-forward and decoupling signals

What would be the best step-by-step approach to tune PI controllers in a dual-loop control with decoupling and feed-forward signals? I am trying to tune both the voltage and current controller in DSP ...
mikebuba's user avatar
1 vote
0 answers
318 views

How to design PI controller for the field weakening control of the three phase induction motor?

In the book called Electric Motor Control in the Chapter 8 I have found following field weakening strategy for the three phase induction motor The aforementioned field weakening strategy is based on ...
Steve's user avatar
  • 1,103
1 vote
1 answer
149 views

At the feedback voltage divider of a voltage regulator, is it ok to choose a large value for R2?

At the feedback voltage divider of a voltage regulator, is it ok to choose a large value for R2 (the bottom res in divider)? I have read it makes FB pin noise sensitive ( This is from a customer ...
Dynamic_equilibrium's user avatar
1 vote
0 answers
331 views

PID - Root Locus (Sisotool) for Transfer Function (TF) with Zero and Poles in Right Plane

I have a 8th order transfer function, you can see it in the first image: % Transfer function num = [2.091,0,203.3,0,-2151,0,-1.072e05]; den = [1,0,-830.4,0,-1.036e05,0,-5.767e05,0,2.412e07]; tf = tf(...
Brian1776's user avatar
1 vote
0 answers
394 views

How to select minimum bandwidth of a controller?

As a specific example, I'm trying to control the phase currents of a PMSM motor used in an electric vehicle. I'm using a PI controller to do this. I am familiar with control theory and have ensured a ...
pops's user avatar
  • 61
1 vote
1 answer
58 views

Trouble with meeting design specifications of a second order system using Matlab

I am trying to solve the following question. Consider the transfer function $$G(s) = \frac{1.247}{s^2+9.76s+23.8}$$ is in the forward path of a unity feedback control loop. Assume that it is ...
Michio Kaku's user avatar
1 vote
0 answers
242 views

Why are complex valued zero and pole not used in lead or lag compensation design?

Consider the compensation transfer function \$\frac{s+z}{s+p}\$ so that the inequalities \$0<z<p\$ and \$0<p<z\$ correspond to lead and lag compensation respectively. It can be seen that ...
kbakshi314's user avatar
1 vote
0 answers
154 views

S domain transfer functions of full bridge inverter

I need to design an inverter circuit as in the schema. It is driven by the unipolar PWM method. I have a problem with the circuit. It would be great if anyone can help me. I want to get the s domain ...
Gökhan's user avatar
  • 61
1 vote
0 answers
89 views

Multi-cell LiPo charging while still powering system?

I'm working on a control system PCB design that's powered by 2, 3.7V LiPo batteries in series to achieve a higher voltage output. I would like to integrate charging via a mini-B USB connector with ...
ctuer's user avatar
  • 11
1 vote
0 answers
212 views

How to design a PI controller for fourth-order transfer-function?

Fourth-order systems may render very complex characteristic equation that are difficult for tuning. Is there any method to tune controllers for these systems easily?
Domino's user avatar
  • 41
1 vote
0 answers
1k views

PID controller simulation in Scilab/Xcos

I have been attempting to resolve following issue related to the simulation in Scilab/Xcos. I have been developing a control software and at the time being I have been developing a library of the ...
Steve's user avatar
  • 1,103
1 vote
0 answers
199 views

How do I plot the root locus when there are multiple controller gains?

I am trying to design a closed loop system with a PI controller. I have plotted root loci before, but in those, I had assumed that the controller was only Proportional. This gave a characteristic ...
Francis Vellara's user avatar
1 vote
0 answers
69 views

Controller design

I was reading controller design using State space model from book by Norman S. In that topic, the author suggested to design controller by converting given state space represention into phase variable ...
user215805's user avatar
  • 1,184

1
2 3 4 5