5
votes
Why can't proportional gain alone, reduce the error to zero?
To understand why proportional gain won't drive the error point to zero, it is best just to look at the math. Consider the PID loop shown in the image below. The loop algebra in the $s$ domain comes ...
- 6,386
5
votes
How to convert a DC motor into a servo motor using a rotary encoder and a microcontroller?
At the very high level you will need
24V Power supply or a method to generate 24V
24V Motor controller
Microcontroller - Arduino is a good place to start
There are also prebuild motor controllers ...
- 7,125
3
votes
Accepted
How to improve a PID control loop by adding feedforward?
The idea of using a feedforward component in a control system is to provide near instant action of the plant output to the input command. So a suitable choice of transfer function which connects the ...
- 228
3
votes
Accepted
mass-friction-spring system with closed loop
Based on the information you've given, I believe your professor is suggesting that a friction term can be represented as shown in the following block diagram.
The transfer function $G(s)$ relates ...
- 1,220
3
votes
Accepted
Can a PID controller have a simple on/off output?
So typically there is proportionality and a continuously varying (analogue) output.
Correct. This could be an analog voltage or a digital value.
In the case of a simple process like a domestic gas ...
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3
votes
Accepted
Is lead filter same as PD combined with a low pass filter?
A lead filter implies that the zero has a lower frequency than the pole. While a PD controller with a low-pass-filter does not necessarily imply that order. Also a lead filter (usually) does not have ...
- 1,653
2
votes
Accepted
Closed loop response of a discrete system
The plant and controller:
$$\text{sys}=\frac{4700 s^2+4393 s+3.245\times 10^8}{s^4+7.574 s^3+120200. s^2}$$
$$pid=0.287\, +0.008 s+\frac{0.5}{s}$$
The closed-loop system obtained as $\frac{pid*sys}{...
- 1,951
2
votes
Accepted
2
votes
Accepted
What type of control system is this? open loop?
This system can be considered "closed loop," since the control input is being determined by some sort of feedback loop (even though the mathematical expression of the feedback loop through the ...
- 1,220
2
votes
How can I get final value of $V_{out}$ at $t=∞$ in RC circuit?
The final value theorem is for a signal, not a transfer function.
Use the transfer function to express the output signal
$$ V_{\mathrm{out}}(s) = \frac{1}{RCs+1} V_{\mathrm{in}}(s),$$
with input $V_{\...
- 884
2
votes
Accepted
Feedback loop and zero - error in steady state
Let's start by obtaining the state space form of the closed-loop system (closed loop means that you plug in the equations the expression of the controller). The controller of this specific system has ...
- 1,019
2
votes
What is a "Unidirectional Input" (?) Closed Loop Control Algorithm Called and How Does it Work?
Perhaps this is an X/Y problem. But here are some suggestions.
1
Design an over damped PID closed loop system. An over damped system will have poorer rise time. Assumptions required for this to work ...
- 949
2
votes
Accepted
How does feedback implementation look like in a real word closed- loop process?
Microprocessors. The measured value from a sensor (either an analog voltage or any other digital processed value) provides the microprocessor with the current output of the system. Internally, this ...
- 1,069
2
votes
Can an electric motor act as a load for the electric generator rotated by that motor?
I think the procedure you want is:
Start the motor. The only load will be the losses in the motor and the unloaded resistance of the generator.
Adjust the generator excitation so that the voltage ...
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1
vote
What is a "Unidirectional Input" (?) Closed Loop Control Algorithm Called and How Does it Work?
SMALL SIGNAL
Let's assume a typical loop. Controller and plant in forward path, unity feedback. Let's add a pre-filter.
Let
C = controller transfer function;
P = plant transfer function;
F = input ...
- 1,387
1
vote
How to convert a DC motor into a servo motor using a rotary encoder and a microcontroller?
Adding to the other answers. I just so happen to have done exactly this. I used a windshield wiper motor and a potentiometer but the principal is the same.
Here's my arduino source code: https://...
- 1,900
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How to convert a DC motor into a servo motor using a rotary encoder and a microcontroller?
You are at the right track. As the DC motor is rather fast for a potential slow microcontroller, using a discrete controller will improve the reliability and stability of the closed-loop system. Even ...
- 1,069
1
vote
What does "analytical design" mean?
I would think that this refers to using mathematical and physical principles and equations to predict the behaviour of a control system.
The opposite would be to empirically design a control system, ...
- 24.3k
1
vote
Accepted
Is it true that points of root locus only satisfiy the angle condition?
Suppose we have a system $G(s) = \frac{1}{s(s+1)}$ and controller $K$ (this is purely a gain) and we close the loop:
$$T(s) = \frac{KG(s)}{1+KG(s)} = \frac{K\frac{1}{s(s+1)}}{1+K\frac{1}{s(s+1)}}$$
$$ ...
- 1,069
1
vote
Feedback Control Question: Finding compensator numerator (B(s)) and denominator (A(s)) polynomials to satisfy a specific requirement
your question is ill-conditioned:
If $A$ must have a higher degree than $B$, 2 things can happen:
$A$ is a constant, meaning $B$ must be 0: which means you cannot solve the equation as there is no $s$ ...
- 1,069
1
vote
Accepted
Tuning Feedforward + PID Controller just with Feedforward Data
The System Identification Toolbox app is indeed the solution, but I can understand the amount of choices and options make it rather confusing at first. Especially if you have no prior knowledge to ...
- 1,069
1
vote
Crossflow HX tube and fin, derive Tout hot side as a function of mdot hot side in
First, find the energy balance - basically mass flow x thermal capacity x delta T is the same on both sides.
Edit to add
There's an error in your energy balance: on the left hand side it's simply $\...
- 4,772
1
vote
mass-friction-spring system with closed loop
You can see how to obtain the transfer function of the mass spring system in many well documented links, e.g.:
Xengineer
10 min youtube video
Youtube Ryan Krauss Series 1, 2 - z, $\omega$, 3 - TFs, 4 ...
- 24.3k
1
vote
Accepted
Physical interpretation of a Bode plot
I apologize in advance for the length of the text but as you can understand these concepts can't be easily defined in few words. I will do some research about the second question and come back to ...
- 1,019
1
vote
What 's the function of COMP pin(Pin 3) in LM5030 - Push Pull IC?
As indicated in LM5030 datasheet COMP is output to an error amplifier.
The circuit for the LM3411 is as follows
The COMP output from the LM5030 is an input to the LM3411 which is an precision ...
- 7,125
1
vote
Can a PID controller have a simple on/off output?
I was looking for a similar question and found this entry. So Transistor answer is right and give me all the hints to implement a version of this in Structural Text.
I am using a cross by zero SSR for ...
- 11
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vote
Finding stability of open loop system connected to closed loop system
Since you're worried about an open-loop system, in theory all you need to do is perform standard stability analysis on the open-loop system alone. The source of the input signal to the open loop ...
- 1,220
1
vote
Calculating a derivative in a loop?
Biswajit Banerjee already indicated that your code has bugs, which is why your results are so far off. I will explain in more detail where these bugs are:
v_phi ...
- 3,044
1
vote
Accepted
What is the name of my feedback procedure in control system that I am using?
I would call this dead reckoning, because you do not have any actual measurement of the position, but are just calculating it based on the estimated speed of the motor.
- 1,943
1
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mass calculation from transfer function or bodeplot
I'm going to derive the transfer function symbolically from the differential equations you provided in the hopes that you might be able to extract the rotational moment of inertia (not the mass ...
- 725
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