Questions about the models and theories of control engineering and the application of control theory to design systems with desired behaviors.
Questions tagged [control-engineering]
789 questions
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Why are train brakes so complicated?
The concept is simple enough: no pressure in the train line has the brakes locked, full pressure is loose, and partial pressure drags accordingly. So if pressure is lost for any reason, the train stops. (or at least it's supposed to; more on that…
AaronD
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Modern method for teaching controls
Background
When I took my first class in controls (2006-ish as taught by an aerospace professor for a mix of ME and EE students) it was basically all done in Laplace-transform, transfer functions etc.
More recently (2012) I took a graduate level…
Dan
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Can I use a ultrasound sensor to measure water level?
If I use an ultrasonic sensor will it detect the water level?
I was thinking about a product to read water level on water boxes (common in Brazil). I researched about instrumentation for this measure, and I think that an ultrasonic sensor is the…
Henrique Oliveira
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13
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PID controller explanation
I haven't found a text that explains the PID controller in simple words. I know the theory: that it calculates the derivative and the proportional gain and the integral etc, but I need to know in reality what is the output of each function and each…
ergon
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How do I solve an optimal control problem where the dynamics depend on some function of the state?
A typical optimal control problem with state $x(t)$ and control $y(t)$ can be expressed as $$\max_{x(t), y(t)} \int_0^{t_1} f(t,x(t), y(t)) dt$$ subject to $x'(t)= g(t, x(t), y(t))$ and boundary conditions for $x(t)$.
I want to solve a problem that…
Daniel Wills
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11
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1 answer
Observability using the Discrete Extended Kalman Filter (EKF)
I have built (several) discrete Extended Kalman Filters (EKF). The system model I am building has 9 states, and 10 observations. I see that most of the states converge except one. All except 1-2 of the EKF state estimate appears to drift. Since the…
krisdestruction
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What is the significance of a diagonal input in a control diagram?
I have seen several block diagrams with diagonal inputs, drawn with an arrow through the block.
and others like that (via Google image search)
What is difference between this and a typical signal input? What are the dotted lines signifying?
andrewhunter
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11
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What is the difference between direct and indirect learning control?
I found the following comments on direct and indirect control in "Survey on iterative learning control, repetitive control and run-to-run control." by Wang, Gao, and Doyle:
There are two application modes to use the learning-type control. First,…
andrewhunter
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10
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MIMO (multi input - multi output) system decoupling method
A MIMO system with 2 input and 2 output decoupling method to a SISO system is described in many articles and books. How about m*n size transfer functions systems? How can we generalize the method for example to 3*3 or 3*7 MIMO systems?
Here is a 2*2…
lahidj
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What do you call the difference between the on and off temperatures in a simple thermostat?
A simple thermostat will turn on at one temperature and off at a higher temperature. This keeps the thermostat from cycling on and off too quickly. The difference between these values is sometimes called dead band and sometimes called hysteresis.…
ericnutsch
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10
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Differential equations of a (simplified) loading bridge
I am having trouble to calculate the differential equations of a simplified loading bridge.
The system is build as shown in the picture below (just a sketch):
If I use the Newton approach, I am getting the following equations by neglecting…
tlp
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10
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In the context of a known disturbance $d(t)$ in a control loop, what is the $\Delta t$ at which the control loop has to be executed?
As an example, consider a P-T1-system with a PID-controller. First look only at the P-T1 system, set a $y_r$ and wait a long time - then we take a look on its output $x$ and see that it has still a disturbance $d$ which variates with time (see the…
JHK
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10
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Types of state observers/estimators actively used in the industry?
Most introductory books on control theory usually start their state observation part by introducing the Luenberger observer, and after that they might continue by introducing the Kalman filter. When reading papers from academic journals I have also…
Mika Sundland
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How can I approach the application of control theory to real control systems?
I am an engineering student and I took my second dedicated controls class last semester. It was cool math and whatnot, but after all was said and done: I still have no idea how to make an actual working control system.
In other words, there was no…
hakzatchel
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9
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Automatic Shifting without Electronic throttle
I need to design an automatic shifting system, for a FSAE car. Clutch and shifts are electronically engaged and disengaged using a Pi Innovo engine control unit (ECU).
The issue I am worried about is downshifts, I would like to rev-match, for…
Adam
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