Control and Simulation toolkit

Hi everyone,
I added a few screenshots of a simple PID feedback system. I programmed it twice with different blocks but I am not getting the same results. Can anyone spot the cause?
Thanks in advance
Attachments:
labview1.JPG ‏66 KB
labview2.JPG ‏174 KB

Hello KF2,
First:
I had indeed overlooked the link between front panel and block diagram.
I was a bit too fast and that's my fault..
I always find it difficult to troubleshoot code without the code.
For completeness:
I did see the "teller" and the "noemer" you specified (I'm Dutch speaking so that part seems "normal" to me).
But what still stumbles me is that all the PID parameters seem to be 1.
I don't directly see any practical case where this would be like that.
How did you define/calculate Ti,Td,Kd,Ki,Kp ?
If you can share the VI, then I'll do some tests at my side.
It's always easier to test code when you have it available
Also, the utmost right part seems to be missing in the screenshot of the BD.
I'm especially curious to see which discrete TF you have at the output of the Academic PID VI and .
I thought (at first glance) that you had shown that comparison in the block diagram/FP.
My first guess would be that something has gone wrong in the crossing between different "domains" (eg. Laplace TF vs discrete TF),
but I would need to test the code to be sure about this.
Kind Regards,
Thierry C - Applications Engineering Specialist Northern European Region - National Instruments
CLD, CTA
If someone helped you, let them know. Mark as solved and/or give a kudo.

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Where can I find more information on Control and Simulation Software?

Where can I find out more information on Control and Simulation Software for G (GSIM)?
I am currently programming a PID controller using a Siemens PLC. I have installed LabVIEW DataLogging and Supervisory Control Module which allows LabVIEW to interface with my PLC.
Would appreciate if you could offer me some advice on whether it would be possible for the PLC PID controller to control a first order process model created using GSIM? Please email me at [email protected] if you could offer me any advice or assistance.
Merry Christmas and a Happy New Year.
Best regards
Donald

I see that you posted to the DSC forum, but you did not get GSIM information. Below is the link for the user manual for the Control and Simulation Toolkit. It is the single best source for info on the toolkit.
http://digital.ni.com/manuals.nsf/webAdvsearch/63E23F9BA1494FE98625665E00635898?OpenDocument

Design control and simulation palette

After hitting Next bottoms and succesfully installation for Design control and simulation toolkit , when I launchำก Labview programme there is nothing in this function and the palette is blank. Anyone knows what happen. I use Labview 2013 student edition 64 bit(free 6 months version). Thanks in advance+++
Solved!
Go to Solution.

Do you truely have the 64bit version of LabVIEw installed?
If you do, then you will not be able to use this module.
It is only valid for 32bit LabVIEW.
You can see the system requirements here:
http://www.ni.com/labview/requirements/#cds
You can try to install 32bit version of LabVIEW and then install the module.

No icon in the control and simulation palette, toolkit is instaled

only question marks on the palette

Hi Adj;
Do you have more information on the LabVIEW and the control design and simulation toolkit you are using?
Here is a document that solves that issue for LabVIEW 8.2 and Control Design and Simulation Toolkit 2.1.1:
http://digital.ni.com/public.nsf/allkb/57E03AEB671A6D9F8625725A0079E37F?OpenDocument
I hope the information is useful
Good Luck!
Francisco Arellano
National Instruments Mexico
Field Systems Engineer - Energy Segment
www.ni.com/soporte

Control design and simulation toolkit

Hello everyone,
Does anybody know if indexing is possible in a Control and Simulation loop in Labview? I need to save in an array all the simulation data.
Thanks,
Ussr123.
Solved!
Go to Solution.

Solved: the necessary icon is called: Collector.

How to use Fuzzy Logic Controller for transfer function in labview control and simulation loop?

I am facing problem with fuzzy PD logic controller for transfer function in control and simulation loop.
Plz Help me in this regard...................
i have attache snapshot of my program
Attachments:
fuzzy in simulation loop.JPG ‏52 KB

Hi Sankhadip,
Sorry for the late response. I was looking at your code and
I noticed that the graph scale does not start from zero. That might be the
reason why you don't see the transient in the simulation. To change the scales
simply double click on the lower limit and set it to zero. If this is not the
expected results, can you please post the expected results, so we can see what are the
differences between the results . Also, you might be using different
solvers, and that gives different results as well.
Thanks and have a great day.
Esmail Hamdan | Applications Engineering | National
Instruments

Can't install Control and Simulation Module in LABVIEW2009

HI all,
I m using LABVIEW2009 x64 and wanted to update control module in it.
when ever I try to install the Control DEsign and Simulation module, the setup won't proceed.
IT shows the following error message :
NI LabVIEW 2009 Control Design and Simulation Module
The Control Design and Simulation Module requires LabVIEW 2009 Full or Professional Development System to be installed.
however, I have already installed and reinstalled once as well. Please help me.

Hi Rishabh,
Unfortunately, we do not have a version of Control Design and Simulation for x64. You can try to install the 32-bit version of LabVIEW instead on a 64-bit OS. This should allow you to install CD&SIM.
Please let me know if can help any further.
Barp - Control and Simulation Group - LabVIEW R&D - National Instruments

Control and simulation

For someone who is skilled in labview and spare some time ,I am new to labview and found an intersting labview application which it can be used as a start for control and simulation. I would like a help to run this vi and see what could be added to it to make it more usefull.
Attachments:
RS.vi ‏84 KB

Bin,
You should post this question to the page where you found the VI, and ask ADEEB or Al S what they used the VI for.
Zvezdana S.

Fpga, Control and Simulation Module

Hello,
I am trying to implement control by Control and Simulation Module through NI CRIO 9024. The error message pops up when trying the run the RT vi.
Other vis which are not coded by the Control and Simulation Module can work properly. However, when it comes to the Control and Simulation Module, the error message pops up. Is there anything wrong with the installation of the Control and Simulation Module? Please let me know if you have an idea about that. I appreciate your help.

Hi Richard629,
As seen in this Knowledgebase article, you most likely do not have the Control Design and Simulation module installed on the controller. You can use NI Measurement & Automation Explorer to install the Control Design and Simulation module on your controller.
Regards,
Allison M.
Applications Engineer
National Instruments
ni.com/support

Synchronize Control and Simulation loops

When simulating control systems with LV Control and Simulation loops, I often have multiple loops running at different rates. For example, I have a PWM loop running at 20 kHz, a data acquisition loop running at 100 kHz, and a control loop running at 10 kHz. How can I synchronize all of these loops so that they stay on the same time base? Obviously the master time base will need to be at least as fast as the fastest simulation loop.
I've tried synchronizing all loops to the 1 kHz clock (I'm running on Windows), but each loop runs one period per clock tick (e.g. my 20 kHz loop counts up 50us per clock tick, my 100 kHz loop counts up 10us per clock tick, etc). I need all of the loops to be synchronized to one master time base so the simulation time is identical in each loop, but each loop will be executed at a different rate.
Any thoughts?
Solved!
Go to Solution.

Hello,
A quick suggestion - why can't you run all three systems in a single simulation loop, but have different sample rates for the blocks for each system ?
Is your system entirely digital, or a mixture of continuous and digital - it may simplify things if you can convert everything to discrete time.
Hope this helps,
Andy Clegg
Consultant Control Engineer
www-isc-ltd.com

Resetting Integrator in Control and Simulation Loop

Hello,
I am trying to run a real-time simulation in Labview 14. I have prepared front panel controls and data flow such that I can reset the simulation to some preset initialization values upon clicking a button. However, I am not able to figure out how to reset the integrator in the control and simulation loop. Even after reinitialization of all the values, the integrators will overwrite the initialization values with whatever they were holding. Please help me find a way out.
Thanks

Please share what code you have so that we can see what you've tried and understand exactly what you're trying to do.

Control and simulation - SMP

I am using a LabVIEW Real-Time 2012 and a Desktop RIO for some real-time
simulations. The CPU has four cores. I have a problem when I try to run
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Thanks a lot!
Best regards,
Sinkva

Hi Sinkva,
You can use notifiers or queues to 'trig' synchronous execution of loops, have a look at this white paper:
Application Design Patterns: Producer/Consumer
http://www.ni.com/white-paper/3023/en/
Make sure you are not entering the next iteration in the master loop until all slave loops have finished the current iteration (the slowest loop will set the timing).
Best regards,
Robert P-F
Applications Engineer
National Instruments Sweden

Memory function in Control and Simulation loop - ODE solver problem

Hello,
I am currectly using the control & simulation loop to simulate the behaviour of what is essentially a spring-damper-mass system. In the process the change in time (dt) is being used to integrate an arbitrary value. I am using a built in memory function to store the time, to calculate the time change (dt).
The simulation is rather complex, due to the necessary accuracy needed, not all the ODE solvers can handle it. Currently I am using Adams-Moulton method, this works fine for the simulation. However it cannot detect the change in time, the change is constantly zero. This problem worked it self out by using another ODE solver, but then the simulation was rather messed up (even when I tuned the step sizes and tolerances). So I am quite confident that Adams-Moulton is one of the best suited ODE solver for the problem at hand.
Is there another way to store the previous time and use it calculate the time difference, than using the memory function? Has anyone experienced such problems before?
I have been doing alot of error searching using the probe, but I am quite sure that there is a problem with the ODE solver and the memory function. See picture below, showing in basic how the change in time is being calculated.
I am rather new to LabVIEW, so if there could be something else I have missed I will be glad to hear it.
PS! I have tuned the minimum step size/relative and absolute tolerances for the Adams-Moulton to simulate the behaviour of the system correctly.
Solved!
Go to Solution.

Hi Willy,
I am sorry, I can not upload the VI some of the content is confidential. I have attached a larger picture of the section were the change in volume and time is calculated, dV and dt. Also I have marked the two memory functions used. Hopefully this can help.
My parameters:
- ODE solver Adams-Moulton
- Relative tolerance      1e-8
- Absolute tolerance     1e-7
- Minimum step size 0,0005
- Maximum step size 0,01
- Initial step size         0,01
- Auto discrete time      On
- Decimation                 0
- Synz loop to timing source off
Attachments:
06-05-2014 21-20-00.png ‏52 KB

How to run simulations of MIMO models having direct feedthrough, using the control and simulation loop?

say i have the MIMO model of a system in transfer function as
4s + 4       0
10s+1
                                =   G(s)
0             3s + 3
               10s+1
this model has direct feedthrough. how do i run simulations of to say, a 2 step inputs?
I don't get any output signals. please, see attached VI file.
thank you.
Attachments:
Q1 test.vi ‏56 KB

Hi tomcruize79
Thanks for using the forums! Sorry for the delay in getting back to you - how have you been getting on with this?
One thing to note is that you can use the Signal Generator VI to generate a function as an input. Try this with your model and let me know how you get on.
Regards,
Peter D

Control Design and Simulation and DAQ

I'm learning Control Design and Simulations. I have some questions about it.
1. For System Identification use, we can find the transfer function/model of the system by feeding data measurement from the system. But, how long data do we need to be sufficent for Identification System to estimate the model? Until the get saturated value (steady state)? or any other intervals? What if the system is unstable? How will Identification System Toolkit estimate that case?
2. For connecting to hardware, we just connect the clock in the simulation loop to the hardware? And the simulation loop will simulate the blocks inside once it got the trigger/data from the DAQ? what about the step time and solver? Do they follow the timing from hardware? or they will run on their own supplied values/clock?if we use USB DAQ, we can't have any clock from it (as far as I know it's because USB connection is not that stable for clocking since it might be any jitters or delays.) So, how do we configure the timing parameter for USB DAQ?
3. There is possibility to convert model in transfer function to state space, how do we know the states inside that conversion?
Any helps would be great...
Thanks in advance...

Dear Chin ho,
After going through your questions I found some documentation which will be useful for you. But I you still have more questions, you can reply me any time.
1- About the data and amount of it I couldn't find any info but maybe you can use the new functions in LV version 2009 and find your answer.
Estimating States of Nonlinear Stochastic State-Space Models with Extended Kalman Filters
In previous versions of the LabVIEW Control Design and Simulation Module, you can use the Discrete Kalman Filter function and the Continuous Kalman Filter function to estimate the states of a linear discrete or linear continuous stochastic state-space model, respectively. In the LabVIEW 2009 Control Design and Simulation Module, you can use the Continuous Extended Kalman Filter function and the Discrete Extended Kalman Filter function to estimate the states of a nonlinear continuous or a nonlinear discrete stochastic state-space model, respectively.
The Continuous Extended Kalman Filter function and the Discrete Extended Kalman Filter function estimate model states of a partially observable plant based on noisy measurements. First, use the SIM Discrete Nonlinear Plant Model template VI or the SIM Continuous Nonlinear Plant Model template VI, located in the labview\templates\Control and Simulation directory, to define the system model. Then use the the Discrete Nonlinear Noisy Plant function or the Continuous Nonlinear Noisy Plant function to simulate the discrete or continuous nonlinear model, respectively, with the addition of noise. Finally, use the Continuous Extended Kalman Filter function or the Discrete Extended Kalman Filter function to estimate the states of your model.
The Continuous Extended Kalman Filter function and the Discrete Extended Kalman Filter function linearize the nonlinear system either by calculating a Jacobian matrix internally or by using an external Jacobian matrix that you define. Use the SIM Continuous Jacobians template VI or the SIM Discrete Jacobians template VI, located in the labview\templates\Control and Simulation directory, to define an external Jacobian matrix.
Refer to the LabVIEW Control Design User Manual, accessible by navigating to the labview\manuals directory and opening CD_User_Manual.pdf, for more information about estimating the states of nonlinear stochastic state-space models with extended Kalman filters.
2- I think that I found a pdf document about this part of your question which will be helpful. If you would like to give your email address, I can send it to you.
3- About this part you can check the help function in LabVIEW when you open the "CD Convert Transfer function To State-space" function in your front panel.
I pasted some info about the mathematic part below.
The LabVIEW Control Design and Simulation Module provides tools to study the dynamics of systems described by linear time-invariant (LTI) continuous and discrete models. You can create deterministic state-space, transfer function, and zero-pole-gain models. You also can create stochastic state-space models and the second-order statistics noise models. You can use these forms to describe both single-input single-output (SISO) and multiple-input multiple-output (MIMO) systems.
Continuous transfer function and zero-pole-gain models use the s variable to define time, whereas discrete transfer function and zero-pole-gain models use the z variable to define time. Continuous state-space models use the t variable to define time, whereas discrete state-space models use the k variable to define time.
Deterministic State-Space Model
Continuous
x(t) = Ax("t) + Bu(t)
y(t) = Cx(t) + Du(t)
Discrete
x(k + 1) = Ax(k) + Bu(k)
y(k) = Cx(k) + Du(k)
Stochastic State-Space Model
Continuous
x(t) = Ax(t) + Bu(t) + Gw(t)
y(t) = Cx(t) + Du(t) + Hw(t) + v(t)
Discrete
x(k + 1) = Ax(k) + Bu(k) + Gw(k)
y(k) = Cx(k) + Du(k) + Hw(k) + v(k)
Second-Order Statistics Noise Model
Q = E{w . wT} – E{w} . ET{w}
R = E{v . vT} – E{v} . ET{v}
N = E{w . vT} – E{w} . ET{v}
where
t is continuous time.
k is the model sampling time multiplied by the discrete time step, where the discrete time step equals 0, 1, 2, …
x is the model state vector.
u is the model input vector.
y is the model output vector.
w is the process noise vector.
v is the measurement noise vector.
A is an n × n state matrix of the given model.
B is an n × m input matrix of the given model.
C is an r × n output matrix of the given model.
D is an r × m direct transmission matrix of the given model.
n is the number of model states.
m is the number of model inputs.
r is the number of model outputs.
G is a matrix relating w to the model states.
H is a matrix relating w to the model outputs.
Q is the auto-covariance matrix of w.
R is the auto-covariance matrix of v.
N is the cross-covariance matrix between w and v.
E{} denotes the expected value or the mean of the enclosed term(s).

Control and Simulation toolkit

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