https://it.mathworks.com/matlabcentral/answers/questions?term=pid+controlMATLAB Answers — New Questions matching pid control2019-04-09T13:43:55Ztag:it.mathworks.com,2005:Question/1827942015-03-12T12:09:56Z2015-03-13T14:50:22ZTwo Mass Spring System PID ControlI have a system consisting of two bodies (It and Ic) connected by a rotational spring (constant k). Control is placed on the second body Ic. The state vector consists of the angles and angular rates of the bodies wrt an inertial frame.
It = 1000;
Ic = 10;
k = 1;
A = [0 0 1 0;
0 0 0 1;
-k/It k/It 0 0;
k/Ic -k/Ic 0 0];
B = [0;0;0;1/Ic];
I want to control the angle between the two bodies (it has to be reduced to zero) using PID control. I have full state output available.
Now, the pid-function in Matlab only works on SISO systems. Would it be an idea to modify the output to be just a single output y = [1 -1 0 0]'? And feed this into the PID controller as the error? Or are there other options to make this multiple output system work with the pid controller function in Matlab?
(I want to avoid using Simulink)J. van Delfthttps://it.mathworks.com/matlabcentral/profile/authors/2536559-j-van-delfttag:it.mathworks.com,2005:Question/3601112017-10-07T05:55:32Z2018-12-13T00:50:37ZHow can I reduce the error in this PID controlled stepper motor position control model?I want to verify the accuracy of this model and want to reduce the error it generates.
I have tuned the PID still the error cant be minimized.
Please help.Jerry Paulhttps://it.mathworks.com/matlabcentral/profile/authors/8607517-jerry-paultag:it.mathworks.com,2005:Question/4117512018-07-23T18:24:04Z2018-07-23T22:27:58ZPID to control solenoid valves on simulink?I am using an arduino mega 2560 to control valves. I effectively want to be able to have a PID that controls the flow of air through my valves. For the sake of simplicity lets say the valves can either be on (input flows to output) or off (output flows to exhaust). I want more air to be allowed through to output when the curve of the PID is raising and air to be allowed through from output to exhaust when its decreasing. I am not sure whether I need to look at the transfer function, all I do know is that I need help to get my head around it.
Also to clarify I tried to use a PWM but the valves don't have any other setting then on or off, so sending anything less then the 5V to the MOSFET just turns the valve LED on but doesn't actually turn the valve on. I have 4 valves and 4 pressure sensors, I am using the pressure sensors to find the error of the system.Florence Lansdownhttps://it.mathworks.com/matlabcentral/profile/authors/11437182-florence-lansdowntag:it.mathworks.com,2005:Question/3094752016-10-27T12:19:29Z2016-10-27T12:19:29ZPID control of steering left and rightI am a big fat newbie with Simulink control.
Using a PID controller, I want to steer left and right. At the moment, I am able to proportionally steer to the right (i.e reduced right steering corresponds to left steering). But I like to know how to explicitly steer to the left as well as right.
What is the standard method to determining steering direction?
My guess #1 is that I need to use the sign of the error signal to know which direction to steer. My guess #2 is to compute the directive of the PID output and use that to determine the direction to steer? I observed that the #2 allows change in direction to be predicted earlier although it has high frequency components which could lead to several direction changes.bethel ohttps://it.mathworks.com/matlabcentral/profile/authors/2594329-bethel-otag:it.mathworks.com,2005:Question/1244672014-04-04T09:41:36Z2018-11-15T07:06:40ZIs it possible to tune 2 PID controllers ?I am trying to tune 2 PID controllers but I am not able to get a good results.
Firstly I tuned the first PID then second, If I tune the first one again I got completely different results.
Could anyone give me an idea ?
<</matlabcentral/answers/uploaded_files/10878/Closed_loop.jpg>>Nuh Metehanhttps://it.mathworks.com/matlabcentral/profile/authors/5032430-nuh-metehantag:it.mathworks.com,2005:Question/237042011-12-12T09:42:37Z2018-05-14T22:32:01Zproblem while tuning PID controllerI try to tune a PID-Controller in Matlab2010b
if i use a discrete one i get the error Message "The second input argument of the "d2d" command must be a positive scalar."
if i use a continuous one i get "Input to SVD must not contain NaN or Inf."
what i have to pay attention that this block works fine?
My system can became NaN due to a Sqrt-expression....Martin1986https://it.mathworks.com/matlabcentral/profile/authors/3037089-martin1986tag:it.mathworks.com,2005:Question/98932011-06-20T16:24:12Z2011-06-20T16:24:12Zhow to control motor dc with PIDHi..i have a little problem with my final project. i have to control motor dc with PID controller.. and i don't know the parameters what i have to control. Can you help my to solve my problem... im thanks you very much...wildanhttps://it.mathworks.com/matlabcentral/profile/authors/2796966-wildantag:it.mathworks.com,2005:Question/2241002015-06-16T16:50:29Z2015-06-16T16:50:29ZNeed help converting a control system from PID control to Neural Network based controlHi,
I've tried to simulate an inverted pendulum control problem. I need to change the system to neural network based control.
Now, the current system is working. but i am really struggling trying to adapt it to neural network. any help would be appreciated.
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<</matlabcentral/answers/uploaded_files/32622/Untitled2.jpeg>>
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<</matlabcentral/answers/uploaded_files/32625/Untitled4.jpeg>>Kushagr Goyalhttps://it.mathworks.com/matlabcentral/profile/authors/5988504-kushagr-goyaltag:it.mathworks.com,2005:Question/4552472019-04-09T08:32:42Z2019-04-09T13:43:55ZSimulation of PID without simulinkHello!
I am trying to simulate a plant and I cannot simulate output of PID controller. I got PID object by
pidtude(sys, type)
Method returned me a discrete time PID controller just as I wanted, but the problem is that
y = lsim(sys, u)
function cannot be used to simulate response of improper transfer function systems. Is there any other method which can I use to simulate response of pid object knowing input vector? I prefer not using simulink.
Thank you,
Maksym ZawrotnyMaksym Zawrotnyhttps://it.mathworks.com/matlabcentral/profile/authors/12219646-maksym-zawrotnytag:it.mathworks.com,2005:Question/355932012-04-16T09:47:26Z2017-11-21T21:20:34ZPID setpoint problemHi,
for my bachelor project I'm designing a controller for an inverted pendulum problem. The first simulation I have created in Labview but after purchasing MATLAB R2012a I wanted to try to 'translate' my simulation into simulink. It all works nicely except of one big problem.
When I use a normal continues PID controller, the control works fine and it is controlled to the zero (equilibrium) point. Hence, the automatic set point of the PID(s) block seems to be zero (?).
I have used the following values: P: 500, I:0.01, D:1, N:1. The form is ideal. Now, since I need to be able to set my setpoint myself I replaced the PID(s) block by the PID(s) 2DOF block (is this right?). Here I used: P: 500, I:0.01, D:1, N:1, b:1, c:1. I set the form to ideal and connected a 0 constant to the reference input.
This (to my judgment) should be the same controller as the PID(s) was. However, the system now is highly unstable. What am I doing wrong? Where have I gone wrong? I only want the PID(s) block and set my own setpoint.
I hope this all makes sense!
Thank you so much in advance!
RegardsMoritzhttps://it.mathworks.com/matlabcentral/profile/authors/2634818-moritztag:it.mathworks.com,2005:Question/524262012-10-31T18:36:45Z2012-10-31T18:36:45ZController design - transfer function producing different response from numerical modelI'm producing different results when I use built-in Simulink blocks such as Transfer Function and PID Controller as compared to explicitly describing the system using Derivative, Integrator, Sum blocks etc. I believe it has something to do with the way MATLAB linearises the models in Simulink and other tools like SISOTool.
As an example, I have a simple linear model of the form
x'' = u/1.54
with u as the input and x as the state. Applying a PD controller to this:
u = (2 + 5*s)*e
gives the closed loop TF
x(s)/r(s) = (5*s + 2) / (1.54*s^2 + 5*s + 2)
Comparing the response of this TF to a step input to the explicitly stated model produces different outputs, as seen in the images. Does anyone know the cause of this? They should be identical, but MATLAB seems to be solving one model incorrectly. To reiterate, I get the first response when using PID Control or Transfer Functions blocks or the MATLAB functions "Step" and SISOTool. The second response is obtained from the model with the double integrator.
Cheers,
Murray
<http://userweb.eng.gla.ac.uk/0503796i/SimError.png>
<http://userweb.eng.gla.ac.uk/0503796i/SimError2.png>
Murrayhttps://it.mathworks.com/matlabcentral/profile/authors/3818503-murraytag:it.mathworks.com,2005:Question/286472012-02-10T08:43:25Z2013-10-16T20:12:00Zhow to Design PID controller for second order untable processHow a PID controller can be designed for a second order SISO process, of the form -a/S^2-b, where a,b>0 .Harshit Golehttps://it.mathworks.com/matlabcentral/profile/authors/3318203-harshit-goletag:it.mathworks.com,2005:Question/1690212015-01-06T04:02:00Z2015-01-09T16:39:36Zbumpless transfer for a family of PIDsI have a family of PID controllers (around 100), each designed based on an operating point.
During implementation, I am using interpolation.
However, still the transfer is not bumpless.
How do we implement a family of PIDs with bumpless transfer?E Ahttps://it.mathworks.com/matlabcentral/profile/authors/1147286-e-atag:it.mathworks.com,2005:Question/699122013-04-04T20:51:04Z2013-04-04T20:51:04ZI am trying to find if Matlab has a data-based auto tuning of PID function?Hello,
Does Matlab have a function where I can analyze output (plant) data as well as inputs (manipulated variables)?
It should be able to import this and display PID parameters?
I would like to implement a controller on a process without doing a step test on the process - by analyzing data and deriving PID parameters.
Maybe a Zeigler-Nichols function?
Thanks,Syedhttps://it.mathworks.com/matlabcentral/profile/authors/1524906-syedtag:it.mathworks.com,2005:Question/3301022017-03-15T21:57:18Z2018-05-14T06:53:09ZSimulink model to Arduino code?Hello everyone,
I have built a quadcopter and am trying to design a control algorithm to stabilise it in flight. I have done a simulink model of the quadcopter that uses PID control and stabilises fine. I would like to somehow convert this simulink model into arduino code so that i can fly it without it connected to my computer using an arduino board. Is this possible?
The aim is to design my own flight stabilisation algorithm for a quadcopter after simulating it on simulink and then testing it experimentally.
aly abidalihttps://it.mathworks.com/matlabcentral/profile/authors/7584457-aly-abidalitag:it.mathworks.com,2005:Question/3426782017-05-31T09:16:57Z2017-05-31T09:52:31ZPID Signal to physical Voltage.I am making a PID controller for a DC Motor. How do I convert the PID controller signal to a physical voltage source?
<</matlabcentral/answers/uploaded_files/79209/Capture.PNG>>
Meghdeep Janahttps://it.mathworks.com/matlabcentral/profile/authors/10345757-meghdeep-janatag:it.mathworks.com,2005:Question/484692012-09-18T15:06:14Z2012-09-18T15:06:14ZSimulink - PI Control Question - tuned output graph will not overshootI'm using a simple loop involving the following:
-initial setpoint of 12.5 -->
-PID control box -->
-summation of PI control box and random number from -2 to 2 -->
-this random value is subtracted from setpoint, and loop starts again
This is a very basic PI control for the number 12.5 varying up to 14.5 or down 10.5. I set the sample times to .5 for the PID control and random number blocks, however when I tune my PID control, I only get a curve infinitely approaching 1, I don't understand why it is not oscillating and eventually approaching 1 as it should. If anyone could explain this to me I would appreciate it.jeredfighttps://it.mathworks.com/matlabcentral/profile/authors/3696042-jeredfigtag:it.mathworks.com,2005:Question/3267692017-02-23T05:00:00Z2017-02-24T16:25:03ZHow can I constrain my controller output while using "systune" in my Simulink model?How can I constrain my controller output while using "systune" in my Simulink model?
I am using "systune" to tune my controller in a Simulink model. I would like to ensure that the output of my controller does not exceed a certain upper limit. How could I implement this?
MathWorks Support Teamhttps://it.mathworks.com/matlabcentral/profile/authors/4622813-mathworks-support-teamtag:it.mathworks.com,2005:Question/1836132015-03-17T12:37:19Z2015-03-17T18:20:24ZMatching step response from Simulink with MatlabHi I am new to Simulink and am trying to figure out how to get correct results. I modeled a simple control loop in Matlab and Simulink to see if the step response was the same. It's not. I'm guessing this has to do with the solver settings? I used the default for this.
Can anyone help me understand how to get Simulink to give better results? Thanks!
Here is the Matlab code:
sys = tf(1,[1 1 1]);
syscl = pid(4,2,1,0);
sys2 = series(syscl,sys);
sys3 = feedback(sys2,1);
[y,t] = step(sys3);
figure(2)
plot(t,y,ScopeData.time,ScopeData.signals.values)
Here is the simulink model:
<</matlabcentral/answers/uploaded_files/27344/Simulink_model.png>>
And here is a plot of the results:
<</matlabcentral/answers/uploaded_files/27345/defaultsolversettings.png>>wda5https://it.mathworks.com/matlabcentral/profile/authors/4461343-wda5tag:it.mathworks.com,2005:Question/2859522016-05-26T14:19:41Z2016-06-01T23:53:43Znegative P gain for PIDi had used the PID tuner app for matlab and I got the proportional gain to negative (-474) but integral and derivative gains to be positive. Wat all can be done next in order to know whether my PID controller is physically realisable or not?M Gokulhttps://it.mathworks.com/matlabcentral/profile/authors/5747530-m-gokultag:it.mathworks.com,2005:Question/2675302016-02-10T18:37:29Z2016-02-11T13:33:37ZHow do I input a 5(1+0.8s) block into simulink?I am trying to solve a system.
I know how to input a transfer function, and everything but a 5(1+0.8s) block. Could someone help me with how to input this block in simulink?
Here is a picture of the block diagram
<<http://puu.sh/n2ZX0/8e8b2ce198.jpg>>
Here is what I have, but I know this is wrong...
<<http://puu.sh/n30qT/70a3c05862.png>>
Thanks!!Adamhttps://it.mathworks.com/matlabcentral/profile/authors/4868274-adamtag:it.mathworks.com,2005:Question/1386892014-06-29T19:27:27Z2014-07-09T10:38:02Zconfigure closed-loop control systemIm new to this sooo... help!
My simulink model shows the results of a tank system (2 tanks), the water levels h1 and h2. What do I have to do to make a closed-loop system out if. the bigger the h1 level the bigger the R2 flow, the same goes for the h2 and R3?
<</matlabcentral/answers/uploaded_files/14807/Untitled1.png>>
<</matlabcentral/answers/uploaded_files/14808/Untitled.png>>Amirhttps://it.mathworks.com/matlabcentral/profile/authors/4806762-amirtag:it.mathworks.com,2005:Question/4303152018-11-16T18:42:09Z2018-11-17T22:06:48ZHow can I design a PID Controller to stabllize the plant 1/(s^3+1) ? [beginner]I have a system, it's Transfer function is :
1
------------
s^3 + 1
and I want to design a Discrete PID Controller so discretized the plant at sampling time 0.05s :
0.000019z^2 + 0.00008z + 0.000021
------------------------------------------------- (Sorry, it is not clean..)
z^3 -2.99994z^2 + 3.00006z - 1
This system is unstable and Discrete PID Controller Block's autotuner cannot find Kp, Ki, Kd to stablize the system.
I want to design a PID Controller, not another Controller.
I think it should be added such a filter, derivative filter(Differtiator?) or a Integrator...
How can I design the PID Controller in Matlab and Simulink? It can be designed?
Thanks for read my ask.OHSEONG KWONhttps://it.mathworks.com/matlabcentral/profile/authors/10438734-ohseong-kwontag:it.mathworks.com,2005:Question/248092011-12-27T19:47:22Z2011-12-27T19:47:22ZTransfer function vs. gains, differentiator, integrator = different, but I don't know why?Hi,
I'm really confused why the two systems shown in the picture below give different outputs. I thought they were mathematically equivalent but give different outputs.
<http://www.newelldesign.co.uk/systems.png>
Please could someone show me where I have gone wrong!
Many thanks,
PeterPeterhttps://it.mathworks.com/matlabcentral/profile/authors/3242868-petertag:it.mathworks.com,2005:Question/3208172017-01-17T20:54:52Z2017-01-19T17:28:54ZHow to consider gravity in state-space models?This is not properly a question about MATLAB by I really don't know where to ask such a question.
I have to solve an exercise for the Digital Control System course which stands:
"A ball is suspended inside a vertical tube by airflow 'u' and connected via a spring of stiffness K to the bottom of the tube. The ball is subjected to gravity and a viscous friction with coefficient 'B'. The force 'F' exerted on the ball by the airflow is proportional to the airflow 'u' via the constant G; airflow can only be positive (entering the tube)."
I have also all the data needed to solve the problem numerically, but this is not important for the question. What I need to do is:
"Write the system equations in state space form with airflow as input and the ball vertical position 'z' as output.Then, select a sampling time and design a digital control system that regulates the ball position by acting on the airflow to the following specifications:
- Zero steady-state error (in response to the desired altitude step input).
- Max overshoot: 30%;
- Settling time at 5% less than 8 seconds."
After this we have to compute the transfer function of the plant and put it in unitary feedback with the compensator.
I usually write first the system dynamics equations, then from these I choose a suitable set of state variables and I write the matrices A, B, C and D according to the state variables (I use the 'ss' function). The problem is that I don't know how to consider the gravity in this case because it comes in the system dynamics as a constant term (-g*m). For example by considering the state variables as [z' z] I obtained the following matrices:
A = [-B/m -K/m; 1 0];
B = [G/m; 0];
C = [0 1];
D = 0;
<</matlabcentral/answers/uploaded_files/67749/Screen%20Shot%202017-01-17%20at%2021.53.41.png>>
I tried to design the compensator (a simple PID) without considering the gravity and by adding it later in the Simulink model used to test the system (after designing the compensator we have to build a Simulink model in which the discrete time compensator is tested with the transfer function of the continuous time system) but of course the system output is no more able to meet the requirements.
Am I wrong in not considering the gravity when designing the compensator? Or perhaps if correctly implemented the gravity should not affect the system output?Paolo Sassihttps://it.mathworks.com/matlabcentral/profile/authors/7850723-paolo-sassitag:it.mathworks.com,2005:Question/1084502013-12-03T16:25:03Z2014-08-12T18:13:06Zin my master degree project i have to control three set point by using PID ...can i control all these setpoint by single PID?Hello sir,
i master degree student and in my desertation work i have to control more than three setpint can i control all these setpoint by using single PID?RAVINDRAKUMAR PRAJAPATIhttps://it.mathworks.com/matlabcentral/profile/authors/4671919-ravindrakumar-prajapatitag:it.mathworks.com,2005:Question/1596312014-10-22T10:03:20Z2014-10-28T08:21:50ZIs there a way to automatic update the P and I gains of PI controller block in simulinkHi everyone
I have a question regarding to PI controller block in Simulink.
My question is that whether there is a way to update the 'P' Gain and the 'I' Gain automatically of the PI controller block in simulink. I do not there is a way to automatically tune the P and I gains by clicking the 'Tune' button in the PI controller dialog. However, I want to update the PI controller parameters during the simulation.
Is there a way that I can create two input signal path for the parameters (other than the controller input signal) on the PI controller block so that I can run an algorithm which updates or tunes the PI parameters without stopping the simulation.
Please advice me with any possible solution.
Thank you very much
Tommy Tommyhttps://it.mathworks.com/matlabcentral/profile/authors/5069021-tommytag:it.mathworks.com,2005:Question/3115562016-11-10T11:09:57Z2016-12-07T16:45:12ZWhen best to use 1 and 2 DOF PIDI am not sure of the difference between normal single input and the 2 DOF PID controller in simulink.
I noticed that the 2 DOF PID block accepts the reference (r) and the measurement(y) separately but under the hood it computes the error=r-y which is what the normal PID accepts as a single input. They both seem to be doing the same thing.
I have a control problem where the reference point changes as well as the measurement signal. How will the 2 DOF PID controller make a difference to my control problem compared to the normal single input PID block? Or what problem does the 2 DOF PID controller solve compared with the normal single input?bethel ohttps://it.mathworks.com/matlabcentral/profile/authors/2594329-bethel-otag:it.mathworks.com,2005:Question/2627752016-01-05T23:51:05Z2016-12-10T11:09:10ZHow to use Fractional PID(nipid) block?I am using fractional pid block called _nipid_ for finding the step response of a transfer function, but the results are not in expected way. I think i am using it in a wrong way ?
<</matlabcentral/answers/uploaded_files/42880/Fractional%20PID.jpg>>
kintali narendrahttps://it.mathworks.com/matlabcentral/profile/authors/3404364-kintali-narendratag:it.mathworks.com,2005:Question/3159702016-12-08T10:27:44Z2016-12-09T19:15:02ZHow can I convert a Simulink PID block into a Matlab code ?I need to convert a PID block system in Simulink into Matlab code and then into C. Any tips ?Islam Elnadyhttps://it.mathworks.com/matlabcentral/profile/authors/7481436-islam-elnadytag:it.mathworks.com,2005:Question/2760352016-03-29T18:13:52Z2016-04-26T19:42:07ZTrying to stabilise a SISO feedback loop with a Cascade PID controller - but it's not working!Hi there,
I'm in the middle of designing a Cascade Loop PID controller for a quadcopter autopilot simulation, to allow it to move to a designated position by altering its thrust vector by pitching up or down.
However, I'm having some issues producing a viable controller. I've successfully controlled the inner loop (pitch rate) with a PI controller, but the outer loop (position) is proving very difficult to stabilize with a PID: please see the diagram for reference:
<</matlabcentral/answers/uploaded_files/48728/PIDproblem.png>>
I've been using SISOtool and pidTuner to try and get the relevant PID controller and thus PID gain values that I can input into my programmed controller in MatLab - this worked for the inner loop (pitch rate), but it is not working for the outer loop.
My advisor told me that it should work with a PID just fine, so I don't really understand why it isn't.
Any advice would be tremendously appreciated, thanks!!Erichttps://it.mathworks.com/matlabcentral/profile/authors/7759313-erictag:it.mathworks.com,2005:Question/3617822017-10-17T15:22:36Z2017-10-20T08:18:05ZDC Motor position control: Downward slope is much less than upward I am trying to make this motor follow a sine wave however the downward slope of position won't match upwards. For example, it will follow the sine wave from 0 to 1 but will not follow closely enough from 1 to 0. I believe it has something to do with the motor block but I'm not sure. Run the program then look at scope 5 for position compared to sine wave. Thanks for any help in advance. Daniel Crockerhttps://it.mathworks.com/matlabcentral/profile/authors/11205284-daniel-crockertag:it.mathworks.com,2005:Question/590052013-01-16T19:21:31Z2013-01-16T19:21:31ZHow do we avoid singularity in PID control system?Working on a simple PID control system for a 2 robot system with 4 degrees of freedom on each robot. We know we have a singularity when both robots are at [0 0 0 0]. No matter what values are going into our Drone Plant it seems to be outputting [0 0 0 0] every time. We tried including initial conditions but after the first iteration, it goes back to the Drone Plant output of [0 0 0 0].
We are looking for any advice, solutions, or troubleshooting techniques...anything. Thank you for your time.
The error:
The error message we are receiving is-
Derivative input 1 of 'TwoDroneMathworks/Drone 1 Plant/transfer Fcn' at time 0.05 is Inf or NaN. Stopping simulation. There may be a singularity in the solution. If not, try reducing the step size (either by reducing the fixed step size or by tightening the error tolerances)
We have tried utilizing resources provided by MathWorks for troubleshooting this specific error without any luck.
Break down of the script:
We have a trajectory signal that is generating our desired trajectory for the cluster which goes into our PID controller. We have an inverse jacobian that converts commanded cluster space velocity into individual robot velocities commands. We plug that into a simple first order plant and integrate to get position. Then our kinematic block converts the individual robot positions into a position of the cluster. We have tested both Matlab scripts (Inverse Jacobian and Forward Kinematics) independently multiple times and believe they are functioning as expected.
Here is a link to the Simulink file (Using Matlab 2012b)
http://dl.dropbox.com/u/16665340/TwoDroneMathworks.mdl
(right click, save link as..)Annehttps://it.mathworks.com/matlabcentral/profile/authors/3969613-annetag:it.mathworks.com,2005:Question/4048642018-06-09T12:33:02Z2018-06-28T08:40:45Zerror of "Too many input arguments." in my program of PSO- PI controller programi m getting "Too many input arguments.
" error while i am running the program for finding the optimum parameter values of fractional PI controller program. Anupam Ghoshhttps://it.mathworks.com/matlabcentral/profile/authors/12378201-anupam-ghoshtag:it.mathworks.com,2005:Question/1130012014-01-20T14:56:23Z2015-04-23T04:11:59Zhow to control the cart position in the inverted pendulum?http://ctms.engin.umich.edu/CTMS/index.php?example=InvertedPendulum§ion=SimulinkModeling
this is a great tutorial for inverted pendulum study. but using the pid controller, the cart moves with the constant velocity in one direction. but practically we would like the cart to stay with in some range. also practically , we could move the cart in both directions(+ve and -ve x axis) with the help of motors.so how could be implement this system to make the cart stay within certain boundary limits given that cart could move in both directions? plz help out. thanks!apps downloadhttps://it.mathworks.com/matlabcentral/profile/authors/4971461-apps-downloadtag:it.mathworks.com,2005:Question/1225762014-03-21T14:20:23Z2015-09-12T16:55:15ZFuzzy Logic adaptive PID control for ph control of waterHello,
i use Matlab r2013a and want to create a fuzzy logic adaptive pid control with simulink. I want to control the ph value for example i got an input of 10 and the control shall regulate it to get a neutral ph value of 7.
I already created a control (but not for 100% sure if the control is right) and used rules for the fuzzy logic which i found in the internet. My problem is how to figure out the right equations to get the control to work.
A picture of the control is in the attachment.
Does anyone can help me?Viktorhttps://it.mathworks.com/matlabcentral/profile/authors/5174575-viktortag:it.mathworks.com,2005:Question/382812012-05-14T08:34:58Z2016-12-01T05:48:38Zhow to write PID function in .m filei need a pid function in my m file. could anyone please write the function.sujanhttps://it.mathworks.com/matlabcentral/profile/authors/3139259-sujantag:it.mathworks.com,2005:Question/1256222014-04-13T16:55:22Z2017-03-11T17:32:00ZSimulink PID autotuning problemHi,
I have tried simple PID auto tuning function, but I'm getting rather strange result. I have attached mdl file, so You can maybe point to me where I'm doing wrong.
Pete
P.S. Sorry if question sounds stupid, I'm a newbie in Matlab/Simulink world Pedjahttps://it.mathworks.com/matlabcentral/profile/authors/4848848-pedjatag:it.mathworks.com,2005:Question/497892012-10-03T21:49:27Z2012-10-03T21:49:27ZHow to customize a Built-in PID Block?I am using a PID controller in a feedback system. I need to change the gain's multiplication type from element-wise to the matrix. I right clicked on the PID block then from link options, I disabled the link. Now after I looked under the mask, I could change the Gain's multiplication type. but after I save the model and run the simulation again everything goes back to its initial settings like I never applied any change!
So my question is How can I customize the PID block in SIMULINK?Mikehttps://it.mathworks.com/matlabcentral/profile/authors/3685780-miketag:it.mathworks.com,2005:Question/18292011-02-23T02:49:30Z2011-02-23T02:49:30ZBuilding PID without transfer functionsIs it possible for me to build a PID without transfer function in Simulink interface?
Let say i have a temperature output (bell shaped) which i want to keep constant. Is it possible to directly use this output for my PID control?Tan Edwinhttps://it.mathworks.com/matlabcentral/profile/authors/2694442-tan-edwintag:it.mathworks.com,2005:Question/1764152015-02-08T13:21:11Z2017-05-10T23:23:11ZSwitching from Constant value to PID controllerHello!
thanks for your time!
i need your help to solve this problem:
i have a system that works with a constant flow rate when the current is zero and, when current is higher than zero, the inlet flow rate must be controlled by a PID controller.
Now i tried to use a Switch block:
- the first input is the pid controller;
- the second one is linked to current (the control variable)
- the last one is the constant block.
the problem encountered are:
- i can't automatically tune the PID block ("Pid Tuner could not find an initial stabilizing controller using plant "Plant")
and so the program does not work..
any other solution/ Approach?
thanks to everyone!
<</matlabcentral/answers/uploaded_files/25069/PId.jpg>>Giuseppehttps://it.mathworks.com/matlabcentral/profile/authors/5770138-giuseppetag:it.mathworks.com,2005:Question/1352282014-06-18T16:49:36Z2014-06-19T19:10:31ZPID Tune: Plant cannot be linearized. Why?Hello everyone,
I'm using simulink for simulating a cooling system.
When I try to use the tune button on the PID it opens the tuning window and say:
Plant cannot be linearized.
Why is this happening?
The PID is doing is job.
I've attached files.
Thank you very much for the help,
NormanNormanhttps://it.mathworks.com/matlabcentral/profile/authors/5412478-normantag:it.mathworks.com,2005:Question/1154322014-02-09T16:32:32Z2014-03-07T16:11:58ZPID linearization failed? Help!I'm currently using SimPowerSystems to model a DC-DC buck converter which regulates the output voltage to 5V. Using the closed-loop configuration, when I try to auto-tune the PID values, I get a message that says linearization failed.
<</matlabcentral/answers/uploaded_files/7944/1.PNG>>
However, when I try to replace the SimPowerSystems block with a control-to-output buck transfer function obtained using state-space analysis, the PID tuning works successfully. What did I do wrong with the SimPowerSystems block? I personally prefer modelling using SimPowerSystems since using these blocks, I can see the voltage and current waveforms in each component. However, I still can't get the PID tuning to work.
I have attached my simulink model with this question.
Thanks!Arfiel Lorenz Herbonhttps://it.mathworks.com/matlabcentral/profile/authors/4407838-arfiel-lorenz-herbontag:it.mathworks.com,2005:Question/2600162015-12-12T15:43:49Z2015-12-16T22:51:16ZImplementing PID Controller into systemHi,
I am currently trying to use Simulink to use a PID to control a closed-loop system, comparing a real out to an approximated one given by a first-order transfer function with delay, as seen in the first attachment.
I know how to design a PID controller in a general case, but trying to integrate it into my system to produce an output for both the real and approximated system is proving difficult and was wondering if anyone could help. The second attachment shows my attempt whilst the third output gives an idea of what I want my output/scope to show.
This is probably too vague but any guidance will help!
Thanks!McNuggethttps://it.mathworks.com/matlabcentral/profile/authors/7399684-mcnuggettag:it.mathworks.com,2005:Question/1401142014-07-03T16:07:10Z2019-04-04T15:31:02Zhow to get PID output?hello
i am currently doin my bachelor thesis ,, the project is ball on beam. i am using PID function for matlab to control a servo motor .
the code is as follows:
s = tf('s');
P_ball = 0.48/s^2;
Kp =2;
Kd =1;
Ki=.75;
C = pid(Kp,Ki,Kd);
sys_cl=feedback(P_ball,1);
t=0:0.01:5;
step(0.25*sys_cl)
disp(sys_cl);
The problem is extracting the output value from the PID function. the output of PID function is supposed to be the angle of the servo motor,, now i dont know how to get this angle in order to give it to the servo motor continuously.
can anyone help? mohamed El Hamzawyhttps://it.mathworks.com/matlabcentral/profile/authors/5358590-mohamed-el-hamzawytag:it.mathworks.com,2005:Question/792592013-06-17T06:04:45Z2016-02-09T11:09:07ZHow can i use the PID controller functionI am trying to use the PID controller in matlab but when i do, i get the message "undefined function or variable". Is there some download that i can install or if someone could give me a solution I'd appreciate it, got some assignments i need to complete.
Thanks in advanceWilliamhttps://it.mathworks.com/matlabcentral/profile/authors/4378188-williamtag:it.mathworks.com,2005:Question/1663542014-12-11T19:38:03Z2014-12-11T23:48:25ZQuadcopter PID Controller Implementation - Derivative FilterHi,
I have been working on UAV project for the past several months. I built the model in Simulink using Cascade PID Control, which works pretty well in simulation. However, upon implementation, I am facing several problems. Primary with the derivative action.
Here's a video of what I got so far after coding everything in an Arduino Due. Instead of using just a normal PID control on the angle, I replace the derivative term with the negative derivative of the process variable. That way, I can just use the Euler Angle Rate instead of calculating the rate and face the exploding noise problem by dividing by a small time step. I was not able to use the gain as used in Simulink because the system get too oscillatory.
<https://www.youtube.com/watch?v=6O_xMvynXNs>
As seen in the video, the system is not really responding well. Therefore, I think I need to do a Cascade Control with one on the Angle Rate and another on the Angle. But to do that I need to calculate the error derivative, which is very noisy. So I need a derivative filter.
<<http://www.mathworks.com/matlabcentral/answers/uploaded_files/8157/3.jpg>>
Here's the Simulink's PID Block. I don't really understand how the derivative term work since the derivative is never really calculated. Instead an integration term is used instead as part of the filter?
Anyway, I tried implementing that part at the Angle level so I have something to compare to. The code is as such:
// Single Pole Derivative Filter
filter_integral += 0.5*((filter_gain * Kd*error) + filter_old)*dt;
// PID Output
return Kp*error + Ki*integral + filter_gain*(Kd*error - filter_integral);
But that don't really work at all. The Derivative term is very unstable and the quadcopter became uncontrollable.
Can someone explain to me what I did wrong?
Thanks!Yu Hin Hauhttps://it.mathworks.com/matlabcentral/profile/authors/4681150-yu-hin-hautag:it.mathworks.com,2005:Question/1401732014-07-04T00:09:43Z2014-07-07T20:45:26ZWhat is the best free tool available to do tuning procedure to the PID controller system belowWhat is the best free tool available to do tuning procedure to the PID controller system below
<</matlabcentral/answers/uploaded_files/15011/Pidddd.jpg>>
Mariahttps://it.mathworks.com/matlabcentral/profile/authors/4776074-mariatag:it.mathworks.com,2005:Question/2030462015-04-14T06:14:30Z2015-05-06T06:33:36Z"The PID tuning tools are not supported for plant models of type "ss"? What is th reason?I am working on a simple plant model but whenever I try to tune by clicking "Tune" button inside the PID controller I am getting this error "The PID tuning tools are not supported for plant models of type "ss"?
So what might be the issue?adi kulhttps://it.mathworks.com/matlabcentral/profile/authors/6315989-adi-kultag:it.mathworks.com,2005:Question/4541142019-04-03T09:06:28Z2019-04-03T09:06:28ZPID controller in Discrete modeHello guys,
I've a simulink model where I am controlling my plant with a PI Controller in Discrete mode. I am planning to bring the model to FPGA. Currently I am simulating the model at same sampling time & it runs perfectly. But in practice, my controller speed is slower by a factor of 10000 sampling time steps. i.e. My plant will update 10000 before my controller gives an output. I tried doing this by changing the sampling time of the PID Block to 10000 & kept the sampling time of the rest of the blocks as 1 (same as before). However, my controller is not able to control the error. Can anyone give me Info regarding this? I'm new in discrete simulations with Simulink. Thank you in advance.Pratik Panchalhttps://it.mathworks.com/matlabcentral/profile/authors/14766339-pratik-panchal