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.
597
questions
0
votes
2answers
47 views
How to tune a PID controller when plant's step response looks like a ramp?
The system is a boat and I want to specify a yaw angle and the PID controller would operate the rudder of the boat in order to reach the desired yaw angle. So, the step response of the plant (boat) ...
0
votes
0answers
25 views
What is residual oscillation and critically damped oscillation in the context of a controller's performance?
What do these terminology "residual oscillation" and "critically damped oscillation" mean when evaluate a controller's performance? How are they related to the stability of the ...
0
votes
0answers
20 views
How to determine time constant/cutoff frequency of the filters in the controlled loop
I was told to be careful to use filters in the control loops as it will add extra time delays in the system and degrade the system dynamic response, but I also saw there are lots of filters in ...
1
vote
2answers
53 views
How could I verify the stability of a real system with non-linearities?
For a closed loop system, I could do the stability margin analysis using linear method like bode diagram, but in reality there are non-linear elements in the system like saturation/rate limits inside ...
1
vote
2answers
33 views
Control System Response
How does one find the zeta value or the frequency of an over damped response curve. I am used to determining things by using the log-decrement equation. Does that apply here even though there is no ...
0
votes
1answer
49 views
Could someone explain how a compensator shifts the root locus?
I'm reading a root-locus course note from MIT. However, I can't understand this part:
How does adding a compensator with a pole at origin remove the plant pole on the right half-plane into the left ...
0
votes
1answer
46 views
Drawing nyquist diagram by hand for a system with time delay
how can I draw the Nyquist diagram of Kexp(-Ts)/(s*(s^2+s+a) by hand for different a and K values and examine the stability of the system depending on T value? I drew for the case with no time delay ...
1
vote
0answers
28 views
Sliding-mode control is a model-based technique?
The sliding mode control can be considered a model-based control? In my opinion yes since takes the information of the mathematical model of the system to be controlled handling with possible ...
0
votes
1answer
59 views
Controls System experiment
We performed an experiment in which we turned a bicycle on its side and placed a piece of green tap on one of the spokes. We spun the wheel and recorded the wheel spinning until it came to a complete ...
1
vote
1answer
41 views
Can I design/tune the outer loop controller without knowing the details of the inner loop controller?
In cascade PID control loops as below, can I make an assumption that the inner loop will respond much faster than the outer loop, hence I could simplify U1_CMD as U1 and I could design/tune the gains ...
1
vote
0answers
23 views
What is the original paper using Extended Kalman Filter for joint state and parameter estimation [closed]
The title says it all.
I would like to know which was the first paper to apply the Extended Kalman Filter to jointly estimate the state plus some parameter of the system.
(by extending the system ...
0
votes
0answers
35 views
Stability from Gain and Phase Margin
I know that a system with positive gain and phase margin is a stable system. And the one with a negative gain and phase margin is unstable. What will a system with negative phase margin and positive ...
1
vote
1answer
48 views
Is It Possible to Have a Continuous-Time System Controllable but Discrete-Time System Uncontrollable?
I have a continuous-time state-space system $\dot{x} = Ax + Bu$ with
$A = \begin{bmatrix}0 & 0 & 0 & 1.0000 & 0 & 0\\
0 & 0 & 0 & 0 & 1.0000 & 0 \\
0 & 0 &...
0
votes
0answers
20 views
Is it possible to calculate Over Shoot percentage and settling time of an Underdamped 2nd order system with Ramp input?
Most of the books derive Over Shoot percentage, settling time for 2nd order underdamped it for unit step response. Do these parameters exist for 2nd order underdamped system for Ramp response too?
If ...
1
vote
1answer
33 views
Excluding the transient in computing RMSE in control algorithm implementation
I have implemented a control algorithm and I would like to study its performance by looking at the trend of the tracking error and then algebraically transpose what I visualize, I have thought to use ...
1
vote
3answers
90 views
If a control system is unstable does it mean it will oscillate?
When a plant is known to be unstable, does it mean it will have an oscillation response?
0
votes
0answers
33 views
Examples of model-based control techniques
I am trying to find out the differences between the model-based control approach and the data-driven one.
Surely the main difference is the latter's independence from the information of the ...
0
votes
1answer
56 views
Why matlab returns a damp ratio as 1 for a over damped system?
I have a second order system with the transfer function as: "1/(s^2 + 5.45s + 1)", I thought it should be an over-damped system, but when I use the damp function in MatLab, it returns the ...
0
votes
1answer
37 views
Nominal model and Mathematical model of a real plant [closed]
What is the difference between nominal model and mathematical model of a real plant?
I am interested in understanding the difference since I want to understand why in some cases is not the best idea ...
0
votes
2answers
25 views
Force control of pneumatic piston
I am building a small testing device consisting of a double acting pneumatic cylinder. I am using an existing pneumatic line running at 100 psi and I would like to control the force exerted by the ...
3
votes
0answers
41 views
PI or PID-regulator for control system with hysteresis relay in inner loop
I have such control system (sorry for rough drawing :) )
$G(s)$ - stable object with proper transfer function.
$1/s$ - integrator.
I need to clarify, how synthesized PI or PID controller for such ...
2
votes
1answer
33 views
Full state feedback of a closed loop system
Does Full state feedback gains affect the dynamic or steady state gain of a closed loop system?
0
votes
0answers
26 views
How do I find the gain from the root locus with given perfomance, where I know the real part of the poles?
I have an exercise to draw a root locus plot and determine its gain to make sure that it fulfills the performance requirements.
the given system G(s) is
$$G(s) = \frac{1}{s^2+s}$$
And the given ...
0
votes
1answer
41 views
Quality of the transient response for an arbitrary transfer function
The question is simple and I rather need a reference point.
How the parameters of transients are estimated (as in the picture) from an arbitrary linear transfer function (formula is given).
0
votes
2answers
70 views
Why prefer a discrete-time system because of a practical implementation instead of continuous one
I have previously done this question on math stack, and I think that maybe here is better.
I am studying the theory of discrete-time systems, comparing them with continuous ones in the control theory ...
1
vote
1answer
58 views
LQR control of motor speed for a quadrotor
Im working around with a simulation of a quadrotor.
So i've read articles, did the math to derive the set of equation using lagrangian approach. So far so good.
Then i want to control the system. so i ...
0
votes
2answers
109 views
Aluminum or Copper, which one is better to control and maintain the temperature?
Friends, I am an EE/SW/Controls eng. Please, pardon me of perhaps incorrect terminologies.
I am working on a R&D project: A chemical lab equipment has a 2" long metal pipe enclosed in ...
2
votes
2answers
287 views
How are bode plots drawn for unstable systems with time delay?
All the example of bode plots I see in textbooks are of stable systems without delay. I wanted to know if bode plots can be drawn for unstable systems with time delay.
Using the usual method to draw ...
0
votes
2answers
31 views
How does feedback implementation look like in a real word closed- loop process?
I'm looking for a generic term/process that explains how we can make a closed- loop control system.
The typical elements of a closed loop systems are controller, actuator, plant and sensors.
If you ...
1
vote
0answers
29 views
Equations of motion in matrix form and energy consumption
I am working on Lagrangian derived high-dimensional motion equations for a robot in matrix form. The structure of such an equation is known:
$M(q)\ddot{q}+C(q,\dot{q})\dot{q}+G(q)=0$
In here, $M(q)$, $...
0
votes
0answers
34 views
Phase margin by definition
I'm reading about Gain Margin and Phase Margin in a book and having trouble understanding why they calculate the Phase margin like this:
<G(Wcrossover) - (-180) = PM
Why not: <G(Wcrossover) - (...
0
votes
0answers
24 views
Optimizing error for PID based control of Line Following Robot
I am working to find the optimal PID gains of my line following robot. To do this, I need to optimize any performance index dependent on the error (a typical example is the integral absolute error). ...
0
votes
2answers
50 views
How to simulate open and close and control valve using a simple controller
I have successfully developed a mathematical model for my physical system. My objective is to control the mass of gas in and out of the system.
The mass flowrate is given by:
$V_f = C_d.\sqrt{2.\frac{\...
2
votes
1answer
68 views
How do I study the frequency response of a physical system with Arduino?
I am a control engineering student and I am studying the frequency response of a system, so the Laplace domain, the Bode plot, poles, zeros,etc. ...
I have clear grasp of their meaning, but if I think ...
1
vote
0answers
72 views
How to get the performance index ISE and IAE for a Matlab-Simulink designed Line Follower Robot with PID control?
I am researching a method to determine the optimal PID gains for a line follower robot. The problem is, I don't know how to setup the performance index IAE and ISE in the matlab. Any tips on how to do ...
0
votes
0answers
37 views
If there is a instability issue inside the control loop, and the control system starts oscillating, what will be the oscillation frequency?
I have a closed loop controller to control the vehicle on the centerline with a bandwidth of 2 rad/s, and I saw the vehicle keeps oscillating around the centerline in a sinusoid whose period is around ...
2
votes
1answer
69 views
How can I make a vacuum pump to move rocks from one place to another?
I am trying to build a vacuum pump by myself and move rocks from one place to another. After some online search, I came across this video on Youtube. I am trying to build something like this. Can ...
1
vote
0answers
35 views
What are some obstacles/issues you face while working in industry? [closed]
As part of a project incubator program at my university, I am trying to understand current specific issues, cumbersome processes, and obstacles facing engineering projects in industry. By pinpointing ...
0
votes
1answer
38 views
What is the meaning of this symbol in Control System Diagram
I was reading the paper "Full-Speed Range Self-Balancing Electric Motorcycles Without the Handlebar" released in March 2016 by Professor Yang and Murakami in Keio University.
I couldn't ...
1
vote
1answer
53 views
What is the corresponding transfer function between r and y?
What is the corresponding transfer function between r and y??
I have tried
$$
\frac{( \frac{k_i}{s}+k_p+k_d\ s )\times P(s)}{1-(-1)(\frac{k_i}{s}+k_p+k_d\ s)\times P(s)}
$$
1
vote
0answers
34 views
Jacobians and Manipulator Dynamics
This is a Stanford Manipulator
I started off working on it by initially
setting up the DH table
Transformation Matrix and then Homogeneous Transformation Matrix
I started finding the linear and ...
1
vote
0answers
30 views
Find system equations for the system shown in the figure and F-V analogous circuit
Can't seem to understand how the 2 bodies would interact with each other. For most other problems I use the Nodal method by using the displacements as nodes and then connecting all other elements to ...
3
votes
1answer
162 views
Modeling rigid body dynamics: Trouble with equations, encountering nonsense answers
Hi, I am working on modeling a simple rigid body dynamic system through a certain range of motion. Here is the picture of the system.
I am trying to solve the system for the variables $x_1'', y_1'', ...
1
vote
0answers
43 views
Lyaponuv stability condition of linear systems for homogenous P in V(x) = x^T P x
I am currently learning about using Lyaponuv functions to find Linear Matrix Inequalities (LMIs) as conditions for stability of a linear time invariant system.
i.e.
$$
\dot{x}(t) = Ax(t)
$$
is stable ...
0
votes
0answers
37 views
Issue with LQR Q matrix for a cart-pendulum model
I am currently trying to develop a controller using LQR for a Segway. The model that I am using is an inverted pendulum on a massless cart. I have made animations of the uncontrolled pendulum and of ...
-2
votes
2answers
63 views
Dividing torque of one axle to three in varying proportions [closed]
I want to power a small mechanical monstrosity, which performs three tasks that require three separate axles. For the powering, there's a hand-operated crankshaft connected to the primary axle that ...
0
votes
1answer
65 views
What type of electrical machine component for counting time?
I am looking for the proper piece of hardware to do what I'm looking for on my current prototype machine build.
I want a timer to begin counting upwards in seconds when a switch is activated, and ...
0
votes
0answers
42 views
Demonstration of Controlability and Observability
After I studied my Control Engineering courses some years ago, although I was able to interpret the results obtained after calculating the observability and controllability, I haven't been able to ...
1
vote
0answers
35 views
Robustness to Additive Uncertainty Proof using small gain theorem
I am trying to use the small-gain theorem to prove the robust stability condition for additive uncertainty. I have been stuck on it for a while now.
Question: How can I use the small-gain theorem to ...
0
votes
0answers
41 views
State space representation of a product of transfer functions?
In short, I suppose the question boils down to: If we are asked to find the state space representation of $C(s) \cdot G(s)$, where C(s) and G(s) are both transfer functions, then do we treat them as ...