Questions tagged [pid-control]
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153
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why Type III systems has at least two gain margins?
I heard the following statement https://engineering.stackexchange.com/a/54322/40848
if we have a type III system, or one that has three or more low-frequency poles that we're closing around, then we ...
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Why are the phase indicators different between the open loop bode plot and the closed loop bode plot?
I have an open-loop transfer function G
num=105*conv([1 1],[1 2 43.25]);
den=conv([2 0 0],conv([1 2 82],[1 2 101]));
G=tf(num,den);
and a closed-loop function of G/(1+G). Here are the open-loop bode ...
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What is the effect of the resonant frequency of the system function Porter diagram on the stability of the system and how to analyze it?
I am a novice in automatic control, the theoretical basis is not very good. We have a large electric clamping jaw, single degree of freedom, the motor is controlled by the torque output, the motor has ...
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Do you need to reset the Integral part of a PID controller?
I'm learning about PID controllers and one thing I don't quite understand from the pseudocode and formulas is the apparent persistence of the "Integral" portion.
For example, imagine the ...
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Discharge through a gate - Feedback needed
I need to make a PI feedback loop for a hydro power plant. The discharge through one gate is given by Q in equation 4.2. I need to keep (regulate) H = 116 m.a.s.l (meters above sea level) where H = Hg ...
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Orientation and horizontal position control of a bar in 2D
I have a scenario where I have a bar of 0.1 m in length, 10N weight is applied in the center. Two forces are applied on the bar at both ends vertically, right one if 5.1 N and the left one is at ...
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What is the original source of the common Ziegler-Nichols PID tuning coefficients?
In many places, including but not limited to the Wikipedia page about PID controllers, I see the following PID coefficients: $K_P = 0.6K_U$, $K_I = 1.2 K_U / T_U$, and $K_D = 0.075 K_UT_U$. When were ...
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What is the gain of a purely integrating process?
Consider a system where: $ \frac{Y(s)}{U(s)}=\frac{k}{s} $. Is the gain k, or infinity? Given that to a step response, steady state is never reached, but it increases linearly with no end. Thanks!
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Python Control library step_info returning nan for all parameters
I am running the following code:
...
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How do you find the gains for a PI controller with a first order plant and 2nd order low pass filter?
How can analytically work out the gains knowing the required bandwidth and damping? The plant to be controlled is first order. The low pass filter is 2nd order in the feedback path.
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What exactly do I do with the output of a PID controller?
Let's say my setup is something simple: I'm trying to heat some liquid to a temperature $T$. I can influence the temperature of the liquid by applying some potential difference $V$ across the liquid. ...
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PC based real time control system
I am newbie, and I want to update an existing control system, which works with a 486 PC with AD/DA card currently. Is it a good idea to find a solution with a windows 10 PC, and a USB AD/DA card? The ...
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Real examples of complex PID regulators
I am currently developing the C library for easy implementation of PID controllers. Can you give some examples of complex PID controllers from real life? I don't mean a simple DC motor with a speed ...
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Boeing 747 Autopilot Vertical Speed Function (PID Controller)
I originally asked this over at the math stack-exchange but was told I might have better luck here. I have simply copy-pasted the question.
I am working on a Boeing 747 autopilot control system for an ...
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Which controller is more suitable in this scenario? P, I or PI controller?
Scenario:
A robot has a ultrasonic sensor which measures the distance to the nearest object in centimetres. The robot has two motors, a motor for the left wheels and a motor for the right wheels. The ...
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How to determine the components of a feedback control loop given following context?
Based on this feedback control loop
where $w$ is the desired setpoint, $x$ the process variable, $e$ the error value, $y$ the correcting value and $z$ the disturbance value.
Did I interpret the ...
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How can I find characteristic equation of complex systems?
I am working on an Overhead crane, where I am supposed to design a controller that controls the position of the crane while minimizing the load's sway angle. I have derived the transfer functions for ...
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Deadbeat gain for system with measurement delay
Say we have SISO system (e.g. the velocity of a permanent-magnet motor) that we're controlling with proportional feedback, with the condition that our measurements of the process variable are delayed ...
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Modelling an S-shaped Second Order Process Response
I am trying to model an S-shaped second order process response as a transfer function in Simulink, as shown in figure 3 in the linked article. Ideally the response should be overdamped. I have tried ...
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Finding optimal PID gain values with no Transfer Function or Plant model
Background:
I have a Matlab simulation model with .m files. The functions simulate a speed control system of a vehicle. I can control the vehicle's speed by adjusting the vehicle’s acceleration and ...
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Control scheme for roll compensation
I'm working on an application that rotates a cylindrical mass in a manner to compensate for roll in a boat. The roll of the boat is rather slow so I was thinking it might be possibly to simply use a ...
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Control Systems: 3rd order system project [duplicate]
I'm in need of help finding a third-order or higher system in which I can derive a transfer function. We have a class project in which we need to find a real-life example of the system that equates to ...
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Best Techniques to design a cascaded precision position controller
I'm looking to design a cascaded controller to transform a BLDC into a servomotor. The system has a motor current controller in the inner loop, which is controlled by a torque controller, which is ...
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Limitations to consider when picking a cut-off frequency low-pass filter for PID control?
Considering a first-order low-pass filter transfer function:
$$ \frac{\omega_c}{s + \omega_c} $$
Where $\omega_c$ is the cut-off frequency. Are there any limitations on where to place this pole?
For ...
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Block-diagram combining two controlled subsystems
I have two subsystems which are shown in the picture below.
One of them is a system of stable and controlled differential equations of a mechanical system.
Second is a block that implements a function ...
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Linearizing nonlinear system for PID control
I have a system where y = 1/x. (y=output, x=input)
If I calculate the PID error not by reading y, but by reading 1/y (so linearizing the system), will my system be nicely linearized, and the PID ...
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(Dominant) Poles very close to zeros in PID control
I have a plant transfer function $G(s)$:
$$ G(s) = \frac{1}{s^2(0.1s + 1) } $$
I want to control this with practical PID control:
$$ C(s) = k_p + k_i \frac{1}{s} + k_d \frac{N}{1 + N \frac{1}{s}} $$
...
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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) ...
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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 ...
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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 ...
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Improving a PID controller from logged historical PID data
Part of our system involves a feedback loop with a PID controller. We log every call to the PID controller, and include in the log information about the Kp, Ki, Kd, the set point, the input, output, ...
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PID or AI or other approaches to this thermal control problem?
I have this boiler controlled manually at the moment, and I am wondering what would be the most proper approach to automate this process.
The boiler in this question basically burns fuel (saw dust, ...
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Servo Motor Input Voltage Equation
I'm working on a Ball & Beam project. As I'm doing it for an engineering project, I'm supposed to model the system mathematically, calculate the PID parameters, etc. to center the ball in the ...
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Is there an equation that can automatically tune a PID controller?
Is there an equation that can automatically tune PID controllers? or do I have to do manually/make an AI to do it for me?
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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 ...
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Discrete-time realization for continuous time domain controller/filter?
Let us say I simply design a low pass filter like (1/s+1) with the cutoff frequency as 1 rad/sec, when I implement it in real software, do I have to do the discrete-time realization? If not, what ...
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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{\...
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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 ...
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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 ...
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Do I need a feedback loop while testing PID controller?
This is a homework for my university course control theory.
The task is simple: Test the P, the I and the D controllers separately to see the effect.
We don't have to connect the controllers to a ...
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Controller to maintain a stable amplitude
I am recording a channel before and after injecting current into that channel. I control the current injection using a switch, when the switch is on current goes to the channel, when the switch is off ...
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What are some techniques for improving stabilization given a mechanical time constant?
Problem: I have a self-stabilizing system that utilizes an intertial measurement unit (IMU) attached to the hull of a vessel. The system self stabilizes by performing matrix rotations based on the ...
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Process disturbance in PI controller help
This is the project i'm working on and i'm struggling to understand one sentence which is stopping me from progressing the project.
I'm struggling to understand what it means when it says to add +/- ...
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object following using pid
in short, I want to implement a PID controller that takes in distance and returns velocity.
Details: I am simulating robots following each other. I wish to maintain a constant distance, ...
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How do I interpret the following Bode, Nyquist and Nichols diagrams?
I am working with an arbitrarily complicated and long-winded transfer function that looks something like this:
$$
H(s) = \frac{as^4+\cdots+b}{cs^6+\cdots+ds^2}
$$
where letters represent constants. ...
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how derivative gain in PD controller influences tracking error
List item
For a proportional and derivative feedback control, the the response and tracking error in frequency domain can be represented as
$Y(s)=\frac{KG+K_dSG}{1+KG+K_dSG}S_p \\
e(s)=\frac{1}{1+KG+...
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Is controlling humidity more precise when calculating with relative or absolute humidity?
I have a tubing system where I need to precisely control relative humidity. All my sensors are giving me temperature [°C] and ...
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Is the PID just an outdated control method and state-space is superior?
So I've been wondering this for a while; is PID just a simple but slightly outdated control method / isn't state-space (SS) a far superior method in pretty much every way?
SS allows for MIMO, PID just ...
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Why does accuracy of temperature PID controller drop over time and how to eliminate it?
What am I trying to control?
I have a container with approximately 3*2*6 meters (width, height, length).
I am controlling through PID the ...
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PID controller - Counterproductive derivative
I'm having trouble understanding the derivative part of a PID controller, because it sometimes seems to react the opposite way that I would like.
Let's use a simple example where :
the controlled ...
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