Questions tagged [pid]
28 questions
5
votes
2 answers
How can I experimentally find the bandwidth of my PLL?
I recently designed a phase-locked loop. I would like to quantify its bandwidth so that I can better understand it.
However, I made this bandwidth in an informal manner due to my lack of formal education on the topic. Is there an experimental way…
ExactPlace441
- 111
- 1
4
votes
2 answers
How to set parameters of the PI controller inside the PLL?
I am going to implement in C++ software the synchronous frame phase locked loop (SFPLL) for estimation
of angle and frequency of the three phase grid 220V/50Hz.
For the internal PI controller setting I have decided to use the design by emulation…
Steve
- 231
- 6
4
votes
1 answer
Developing Lead Compensator to Decrease Settle Time
This is a follow up to this question.
I've approximated the transfer function for a system to be H = zpk([0.012 -1.05 18],[-0.22 -0.22 -45 -1000],10000);. My goal is to try to reduce the settle time to under 3 seconds. Thanks to answers on my…
cicey60307
- 63
- 3
4
votes
2 answers
What is the difference between a controller and a compensator?
I recently revisited some texts on control theory. In some textbooks the term compensator is used, seemingly interchangeably with controller (see e.g. The Control Handbook by Levine, chapter 14 on classical control system design methods).
This…
snowflake
- 152
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- 12
4
votes
2 answers
What is the difference between a lag compensation and PI control?
A lag filter or compensator has the Laplace transform transfer function
$$G_c(s) = \frac{s+z}{s+p},$$
with $-z < -p < 0$. In practice, the effect of lag compensation in feedback control, is to increase the DC gain of the open-loop system by the…
Max
- 352
- 2
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4
votes
3 answers
Is $y[k] = y[k-1] + x[k]$ an integrator?
It looks exactly like an integrator to me.
Since $$y[k] = y[k-1]+x[k] = y[k-2] + x[k-1] +x[k] = \sum{x}$$
Applying the Z-transform gives
\begin{align}
Y(z) &= Y(z)\cdot z^{-1} + X(z)\\
\Rightarrow\frac{Y(z)}{X(z)} &=…
richieqianle
- 330
- 4
- 13
3
votes
2 answers
Real time numerical differentiation of signals
I am trying to implement a PID controller in Python and I am having some problems with real time numerical differentiation of my my discrete signal.
I am using the following method:
$$d{\frac{x_n}{t}} = \frac{x_{n-1}-x_n}{d_t}$$
Where $d_t$ is the…
BigZee
- 133
- 5
3
votes
1 answer
General tips for PID tuning of super low-friction actuator?
I realize this question is not directly related to signal processing, however, it's relevant to system analysis which is relevant to most signal processing engineers. There's also no good alternative stack exchange for me to post this question to…
Izzo
- 697
- 4
- 19
3
votes
0 answers
Symbol timing recovery design
I am trying to design the Symbol timing recovery(#STR) block of #DVBS Receiver. These are the specifications
Symbol rate ($f_s$) = $2\textrm{ MHz}$
Acquisition range = $10\%$ of Symbol rate
Acquisition time = better than $50\textrm{ ms}$ …
avi1987
- 181
- 1
- 11
2
votes
1 answer
How to design a Controller that would adjust the steady-state error of a system?
I have a simple model (input-plant-output) with a transfer function :
$$
T(s)=\frac{4}{s^{2}+2s+4}
$$
The goal of this problem is to design a system such that it has the following specification for a step…
CynthiaZ1998
- 133
- 4
2
votes
0 answers
Are there control loops that attempt to maximize a process variable?
I'm working on Remote-Procedure Call (RPC) server that processes incoming streams of data from clients, and looking for a way to set a limit on the number of simultaneous streams allowed.
There is some bottleneck in the system (such as CPU time or…
jacobsa
- 121
- 2
2
votes
1 answer
Tuning a PID Controller
I have the following transfer function
$$10000 \cdot\frac{(s-0.012)(s+1.05)(s-18)}{(s+0.22)^2(s+45)(s+1000)}$$
For which I am trying to tune a PID controller for. I'm using the pidTuner in MATLAB to do so. I wish to have the settle time be less than…
cicey60307
- 63
- 3
1
vote
2 answers
How to deal with "weird" phase plots in bode diagram when designing a controller
I am trying to design a balance controller for a robot. With MATLAB simulink I arrived at the transfer function between the input and the pitch angle for the robot. I have plotted the bode and Nyquist plot below.
As you can see, the Nyquist plot…
Carl
- 298
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1
vote
0 answers
Can an unwrapped phase lag diagram have values beyond $-\pi$ to $\pi$?
I have a PLL that tracks the phase lag of a resonance system. When unwrapped, my system's phase lag has values beyond $-\pi$ to $\pi$.
After unwrapping phase lag, are there any bounds on the phase difference between signals? I assumed that the…
ExactPlace441
- 111
- 1
1
vote
1 answer
PID and convolution
In that formula :
$$
u(t)=K_{\mathrm{P}} e(t)+K_{\mathrm{I}} \int_{0}^{t} e(\tau) \mathrm{d} \tau+K_{\mathrm{D}} \frac{\mathrm{d} e(t)}{\mathrm{d} t}
$$
I know from the formulae collection we refer to that :
$$
\mathcal{L} \left\{ \int_{0}^{t}…
Dovendyr
- 117
- 5