Questions tagged [control-engineering]
Questions about the models and theories of control engineering and the application of control theory to design systems with desired behaviors.
459
questions
0
votes
1answer
45 views
Is there any other controller than PID Controller?
I have been given a Project to search for a controller having better transient response than PID Controller. I searched but I didn't find any research paper on it. All are talking about improving PID'...
-1
votes
0answers
24 views
Solution to autonomous differential equation with locally lipschitz function
As I was learning about the following theorem and its proof from the book Nonlinear Systems by H. K. Khalil, I encountered a difficulty in grasping some parts of the proof.
Theorem: Consider the ...
-1
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0answers
22 views
Nyquist Plot for the exponential term involved in the equation
I have been trying to solve the part b of this question which was in one of my assignments. I am not able to arrive at the closer values to plot my Nyquist plot. Any help is appreciated.
-1
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0answers
22 views
Calculate propeller's thrust & torque coefficient for a quadcopter brushless motor
I'm building a quadcopter and I need to know how to calculate the thrust and torque coefficient, $F = bw^2$ and $T = cw^2$ I need to get the $b$ and $c$ (but don't know how to). I'm using 1045 ...
0
votes
1answer
57 views
Can someone explain how the output of this control system is derived?
I understand equation (1), but I really don't see the connection between equation (2) and the picture.
For starters, shouldn't the $b_0$ constant be multiplied by
$$net(n)-(a_1 \cdot net(n - 1) + a_2 \...
-1
votes
2answers
42 views
Definition of a 'manipulated variable' in process control - what is a manipulated variable exactly?
I've gathered a lot of different details online - trying to understand exactly what they mean by 'manipulated variable'. So I only decided to finally ask about it here.
In one source - eg. at this ...
-1
votes
1answer
36 views
How to decrease Nitrogen gas consumption in Iron & Steel Plant? [closed]
I need to decrease nitrogen gas consumption in iron & steel plant.
Currently it's not possible to measure every dot from steel mill to determine real usage so they use what air separation unit ...
-1
votes
1answer
65 views
Adapting PID controller parameters using expert rules
I use the following equation to calculate a control signal of a time-discrete PID controller:
$$ u(k) = u(k-1) + K_{R} \cdot \left(1+ \frac{T_{0}}{2 \cdot T_{I} }+ \frac{T_{D}}{T_{0}}\right) \cdot e(k)...
-1
votes
1answer
53 views
Gain and Phase Margins from Bode Plot
What's the interpretation of the margins when the curve of magnitude never crosses 0 dB or the phase curve never crosses the -180Āŗ? For example:
$$G(s) = \frac{s+20}{(s+1)(s+7)(s+50)}$$
I know that ...
-1
votes
1answer
44 views
Nyquist Stability Theorem and Clockwise/Counter Clockwise Encirclements
According to argument principle, if a contour encircles a number of poles and zeros of a transfer function, the number of origin encirclements can be deduced by : ...
-2
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0answers
37 views
boiler superheater transfer function
I am about to doing a project on "control of boiler super-heater temperature with fuzzy logic type-2". My very big problem is that I can not find the Transfer function of the plant (I mean ...
3
votes
2answers
53 views
A clarifying question on Lasalle invariance principle
Given a nonlinear system \begin{equation}
\dot{x}=f(x),~x(0)=x_0 \tag{1}
\end{equation}
where $f\in{\mathcal{C}^{1}}:D\to\mathbb{R}^{n}$. The Lasalle invariance theorem statement goes as follows:
Let $...
1
vote
0answers
8 views
Monitoring Connectivity on ZigBee
I am trying to figure out some ways in which a ZigBee network can be monitored. As is the case in any network, here we have a central coordinator and several slaves joined, however, there seems to be ...
1
vote
2answers
46 views
controllability matrix of a state space system - determinant
For state space systems, there is a test for 'controllability' involving finding the determinant of a 'controllability' matrix. The instructions for the test is typically to see if the determinant is ...
1
vote
0answers
34 views
Why does my motor model match the actual data in transient but not steady state response?
I have created a model of a DC Servo motor using electromechanical system modeling. I simulated the motor in Simulink (MATLAB) and compared the data with data obtained from a real motor having similar ...
0
votes
1answer
43 views
Limitations of LTI systems & control
I'm trying to think of limitations or disadvantages of LTI systems in control theory, however, I can't think of many. The only one I can think of is that not every system is an LTI system.
Linear time-...
-1
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1answer
68 views
designing compensator with certain specification
Īere is an open-loop transfer function and specifications for compensator design.
I defined the required poles and defined the angles according to the normal procedure of the root locus method and ...
0
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0answers
18 views
Is the viscous friction coefficient of a BLDC motor dependent on the system inertia?
I have to model the required torque to move a system composed of several mechanical parts such that this system performs a motion profile. It is a Maxon drive composed of an ECX Speed 16L BLDC micro-...
2
votes
3answers
55 views
Bandwidth vs Capacity
Two questions on wireless transmission, packed into one.
First: I am confused about the meaning of the term 'Bandwidth' in a wireless transmission environment. The two most common definitions I could ...
0
votes
1answer
63 views
Zeroing a ventilator's volume measurement in the face of drifty sensors
I'm a software engineer working with http://respira.works to build an open-source ventilator for COVID-19. Notably, I'm not a controls person or a hardware person, so please forgive me.
Background
...
1
vote
1answer
42 views
Why is there a delta for locally stable in the sense of lyapunov?
Why does this definition (screenshotted above) for locally stable i.s.L. require a $\delta$ term? Why not just say, something is locally stable i.s.L. if "for any ball of size $\epsilon$ around the ...
3
votes
3answers
188 views
What are these rotary to linear movements called?
Iād like to know what the below movement mechanisms are called so I can better research them and incorporate them into my own designs.
They are both quite similar, they are from rotary electrical ...
-1
votes
2answers
57 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
votes
2answers
57 views
What is the easiest way to regulate the speed of a falling object?
I want to design a system that allows a 1kg metal brick to fall under gravity at variable speeds. The brick initial position is 20cm above a flat table. I want to have control on the duration (to ...
2
votes
1answer
71 views
Help understanding a control system represented by coefficients of theta?
I've been working with control systems and transfer functions recently, but I've come across a format that I haven't seen before using coefficients of theta, and I can't find any information about it. ...
1
vote
0answers
12 views
Optimal Control Singular Arcs
This is about linear time-invariant, stationary problems.
According to Donald Kirk's book Optimal Control Theory, for minimum-fuel problems on page 299, I was told that if there exists a singular arc,...
0
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0answers
34 views
Skew-Symmetric Gain Matrix to Encourage Exploration
I am reading a paper on controls and it has the following snippet:
We propose to use the control law
$$u_i = K(CV_i ā p_i)$$
, where K is a (potentially time-varying) uniformly positive definite ...
-1
votes
1answer
38 views
What is Dissipitative Control?
I am reading an article that says:
stabilize the multi-vehicle system to one of its local minima via dissipative control
And other that deals with dissipative system:
(PID) controllers is ...
-1
votes
1answer
59 views
How to find the transfer function of a control system?
I have a linear control system defined by the following equations:
\begin{array}{l}\dot{x}_{1}(t)=-\frac{1}{2}\left(x_{1}(t)-x_{2}(t)\right) \\ \dot{x}_{2}(t)=\frac{1}{10}\left(2 x_{2}(t)-10 x_{1}(t)\...
2
votes
0answers
54 views
Converting nonlinear system into equivalent nonlinear of the Byrnes-Isidori normal form
I have a nonlinear system (Ball & Beam) which is described by the following equations of motion:
$$ \ddot{y} + \frac{mg}{a} \sin(Īø) -\frac{m}{a}y\dot{Īø}^2 = 0 $$
$$ \ddot{Īø} + \frac{2m}{b}y\dot{...
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vote
0answers
41 views
Lyapunon candidate function to derive parameters estimation law
I have a system and a reference model represented in state space in the following form:
\begin{gather}
\dot{x} = Ax+Bu \\\
u = \hat{K}(t)x+\hat{k}_r(t)r \\\
\\
A_m = A+BK \\\
Bk_r = B_m \\\
K,k_r : \...
0
votes
0answers
26 views
What does “Coupling Effect” refer to in MIMO systems?
Here is the block diagram of the system.
G11 relates the input R1 to the output Y1, G12 relates the input R1 to the output Y2 similarly for R2.
What is the effect of coupling-which is as I know is ...
2
votes
1answer
66 views
Input-output representation to state space
How do you create a state space representation of the following input/output equation:
$$ \dot{y} = -ky + u + a\sin(Ļt) $$
where the parameters $k$, $a$, and $Ļ$ are unknown.
The end goal is to ...
1
vote
0answers
33 views
maintenance of steady flow through pressure or mass flow
let's say I have two points in a line, A and B. Between them there is a valve that can regulate the amount of the stream from A to B. Considering that there is a steady flow of the stream between A ...
0
votes
1answer
80 views
Root Locus and RouthāHurwitz stability criterion
A satellite launcher has a unit feedback system, whose TF global open loop is given by:
$$G_c(s)G(s) = \frac{K(s^2-4s+18)(s+2)}{(s^2-2)(s+12)} $$
a) Draw the root locus for this function
b) ...
2
votes
1answer
50 views
Generating Linear Velocity Movement?
In preparation for a Fluid Mechanics experiment, I am looking for a simple commercial ready made
apparatus to generate a linear velocity trend to prove a new theory:
https://aip.scitation.org/doi/abs/...
1
vote
3answers
95 views
Determine the gain K from a root locus
I'm studying Root Locus method and I still confused. The question below exemplifiques my doubt.
Determine the $K$ gain so that the dominant roots have a damping factor equal to $0.5$, where
$$G(s) =...
0
votes
1answer
64 views
Physical interpretation of a Bode plot
I have a few questions regarding the physical interpretation of the information presented on a Bode plot. I believe it is one of those cases where I "don't know what I don't know", so please bear with ...
0
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0answers
23 views
How to create a Complementary Filter for a linearly accelerating vehicle to obtain estimate of orientation in quaternion?
A complementary filter (CF) uses orientation obtained calculated from gyroscope, accelerometer and magnetometer to find a more accurate measurement of orientation.
However, when my sensor is ...
1
vote
0answers
13 views
Where can i get the aerodynamic data of aircrafts for controller design and testing?
I have some research papers on aircraft controller design that i want to simulate, but no system data is given in the research paper itself. I am also unable to find the aerodynamic data for any ...
3
votes
0answers
34 views
Mathematical transformation of a heading angle to a roll angle
I'm trying to understand a function in a SIMULINK example of a path following UAV simulation. The gist is that, the UAV Waypoint Follower block provides a required heading from a list of waypoints and ...
1
vote
1answer
65 views
Passivity in State Space Systems
Suppose I have the state space system $a\dot{x} = -x + \frac{1}{k}h(x) + u$, and output $y = h(x)$, where $a,k > 0$. The only information I'm given about $h(x)$ is that $h\in[0,k]$. I want to show ...
1
vote
1answer
39 views
Bounds to prove exponential stablity for given Lyapunov function
Problem 3.6 in Khalil's Nonlinear Control: Use given Lypunov candidate function to prove that the origin is exponentially stable. The system is
$$\dot{x}=\begin{bmatrix}x_2\\-h(x_1)-2x_2\end{bmatrix},...
2
votes
0answers
33 views
avoidance with LQR
I'm interested in using linear quadratic regulators (LQR) to model prey avoidance behaviors. I want to adapt the LQR algorithm to incorporate dynamics and state costs that maximize the distance from a ...
2
votes
1answer
44 views
Modeling the torque of a real motor
I am trying to control a real inverted pendulum by means of a DC motor, for this I must model the torque of the motor, the work I've done in this direction is the following (which I believe is right):
...
-1
votes
2answers
86 views
How to obtain transfer function of control diagram with Internal Model Control?
I want to design a robust control system using the internal model design specifications. The block diagram is the one shown below:
I am trying to obtain the transfer function $\ \frac{Y(s)}{R(s)} $ ...
0
votes
1answer
23 views
Evaluate “damping” of higher-order transfer function - something similar to settling time without the discontinuities
I have an 11th order transfer function in the continuous domain (simplified linearized model of a grid-forming converter) and I'm looking for a way to characterize it with a single number for ...
-1
votes
1answer
65 views
Find the transfer function of a basic block diagram
I'm new to Control Systems. I've been given this block diagram and I would like to find the overall transfer function. How can I do it?
I was thinking about simplifying the diagram by placing in ...
1
vote
0answers
73 views
How many kWh this turbine would generate?
My grandfather and I are running some experiments down the river, however we don't have expertise in engineering so I bring up this question to the community and hope someone could help.
How many kWh ...
0
votes
1answer
26 views
Noise sensitivity transfer function
Consider we have a second order system (plant) described by the following transfer function:
$$ P(s) = \frac{b_0}{s^2+a_1*s+a_2} $$
which is controller by a PD-controller:
$$ C(s) = K_p+K_ds $$
...
