PID autotuning on CRIO
I'm working on a cRIO, and I want to use the PID AUTOTUNING vi in real-time. I got an error when I tried to start the automatic setting. I know the autotuning to start a wizard with a pop-up window, but I can't get the window pop up on RT. How can I do?
It should be a lot of work so he could work on rt.
Basically, you'll need to rewrite and remove all calls to GUI.
Tags: NI Hardware
I have a project of flow using on LabVIEW PID control.
So I want the controller pid autotuning and if possible then with manual and automatic mode switchable.
Pls see if someone can help me.
Can I use a regulator PID for MCB2300 programming?
I see the problem now. The PID Autotuning VI launches dialog boxes to user as the Automatic Tuning Wizard, which are not taken in charge by the embedded targets. Embedded applications are designed to run without user interfaces. You will need to use the VI PID and adjust your order manually, PID which will give best results in any case, I thought.
I would like to know what is the best and fastest strategy to twist the 3 parameters of the PID knowing that my systems are running in a loop which is executed every 40 years.
I hope this isn't by chance to guess until I have find the right parameters.
There are many ways to make the adjustment PID. The most common approach is the Ziegler-Nichols method (two versions of the open and closed loop). PID help provides an explanation of the PID tuning database (this information is also available in PDF more readable as part of your installation of LabVIEW). For more details, proven methods and best practices for the practice of ControlGuru process control has some good information. You can also try the PID Autotuning feature (I haven't used so I can't comment on its effectiveness).
I found an example of a controller On off on Labview which I enclose. I wanted to see how it would work the same VI replace thermostat a PID block and using the simplified model of a room in the form of the transfer function (R / (RCS + 1)) but I don't know the right way to proceed. the Integrator is to stay? I need to change the VI? I hope that your kind suggestion
Well, if you want just a transfer function and the PID autotuning, why not use this example of the expedition?
C:\Program Files (x 86) \National Instruments\LabVIEW 2013\examples\control\PID\Autotuning PID Online.vi
To change the settings of "Plant", go in the block diagram and double-click the cluster at the bottom of the VI and brand: static gain = 0.5 and lag time = 5?
These values are implementing transfer function 1 /(10s+2) 0.5 /(5s+1).
Control and Simulation is preferable to use, but for the simple simulation, maybe you can use this template. Also note that this function "pid" has also the 'code of autotuning' with different types would this work for you?
I have a control system of gas through a set of rooms. The responses of the system is very slow at first, but then very fast and the PID is therefore not able to prevent a go-around. I tried to adapt my system to use the Autotune PID or PID. I'm not either of these controllers according to my system.
An ideal control system would have put the petal to the first metal but not miss the set goal/point. So, my goal is to reach the set point very quickly with very little or not exceeded.
What are my options, I have other options?
What version of LabVIEW you have? After the 8.2 version, we have added several examples to shipping PID (now called PID and Fuzzy Logic Toolkit) shows how to "Gain Scheduling" or how to use the screws "Advanced PID' that has the non-linear setting. Also note that when you change settings on the PID.vi, he should try to change with a transition smoothly. I recommend you to start with:
Planning \LabVIEW 2009\examples\control\pid\prctrlex.llb\Gain Simulator.VI
Perhaps the main challenge is to identify how the behavior of your plant and how you can set the PID for different areas. If you do not have an initial settings of PI that makes stable plant, do not use the VI of PID Autotuning. This algorithm require you to have at least an initial PI controller and the algorithm will try to improve it.
Let me know if you need more information.
Overview: we build a current servo controlled tube capable of sinusoidal load to 4 Hz control. We have a set of scales to make a contribution to a crio 9014 (9237 module) that runs in scan mode (no FPGA). The value of digital load cell is then sent to a VI PID to allow a calculation of the value of current (I) next to return to the tube of servo, closing the loop on the load control. This calculated value is sent by output module analog crio to the servo amplifier. A copy of the main program (mouseloader.vi) and other relevant files such as project files can be found here.
Problem. The program begins to fail when the load of the sinusoid needs to go above 1htz. Sinusoidal entry to the PID control, called "generator.vi of the basic function", output 1000 points by sinusoid. We can trace sinusoid entering control PID (pid vi) and he appears as a pure. However, the waveform, leaving the PID control suffers from distortions that appear as the effects of staircase, as if there are not enough points to represent the sinusoid. This appears to limit speed, our loading system can operate (max 1htz) but also distorts the wave.
Thoughts. From basic research, the fpga mode (that we do not use) has an independent synchronization module that can multiply on our timer. There is a good answer by dustin w here. http://forums.NI.com/NI/board/message?board.ID=170&message.ID=215968&query.ID=757585#M215968 but I only am not sure this applies as we use the scan mode interface I thought would run on our computer. IM also thinking that the internal PID control timer (dt) is what complicates the calendar. We have disabled then all our other timing devices, but are unable to establish the waveform to fix. Desires: I would like suggestions for us to create a smooth sinusoidal 4 Hz (4 times per second) waveform using the PID command.
Im going to spend it on the forum in real time
I try to use labview FPGA Express VI in my application with cRIO 9022. I write a custom PID and compare the result with the FPGA palette express PID.
It seems that the integral action on the express PID is too large.
I am using PID as a simple Integrator providing zero gain proportional and derivative and Ki = 1. Which provides a signal error of 0.1 and sampling time of 1/5000, after 10 sec, the Integrator must accumulate 1. As usual, we he reach apprx. 10 sec, the express VI increases quickly until saturation.
What is the problem with my VI, I'm sure I'm missing something. The reason why I want to express is that it consumes less space and I have to use 5 parallel PID which I just can't get with a custom because it is written not effectively. I attached the VI and the png for your view.
Thank you all,.
Well, the ZIP file is valid, but I'm on an older version of LabVIEW, so I can not even open your screws, sorry.
I would check your math. Aid for the VI Express FPGA is clear on the functioning of the calculation. It does not count the sample time - which is one of the reasons that gains are standard. Configured the way you need your code, the error integrated - and therefore the output - increase 0.1 for each iteration of the loop, regardless of the rate of loop - so it will take 100 iterations for output reach 10. You can set your full winnings to take account of the actual loop cycle time.
I am the design of a PID controller for each of the three axes (X, Y and Z) of a piezoelectric stage using the FPGA module and a cRIO. I used the example of project "Using Discrete PID - cRIO.lvproj" (labview\examples\control\pid\fpga.llb\CompactRIO) as a starting point and I've basically added two PID loops more on the FPGA VIs to the other two axes. I can get the controller to work for an axis at the same time (in simulation mode), but whenever I try to run all three controllers simultaneously, only one works. In order to synchronize between the host and the FPGA VIs, I used three interruptions for each PID loops, but it seems that a single interruption works when I run the code... No idea how to synchronize the three loops of PID with the host VI?
I think that it is an expected behavior, by the documentation: "VI the interruption is a shared resource, so multiple uses of it induce a further delay and jitter due to arbitration." If you are waiting for the interruption to see, then the other loops cannot continue because interruption VI does not work. On the FPGA if you want all the PIDs to operate at the same speed of loop, put them all in the same loop and use only a single interruption. Or use another synchronization mechanism (set to a boolean of the host, wait it is defined and then erase it on the FPGA). The interruption is only for purposes of simulation, in any case, since the 'central' is running on the host computer. In a real system, the plant works continuously and FPGA directly reads the sensors and outputs, the readers so the only value provided by the host is the set point and is not required for synchronization.
I am developing and application with the following hardware features:
Time real cRIO 9004 target device
HAVE cRIO 9205
and the following programming features:
I run an FPGA VI to establish PID control where the reference signal generated in the FPGA and the real is an acquired signal through the cRIO 9205. I also find target FPGA FIFOs host in order to pass the data from the FPGA to the application of the RT. The time real VI will run in the 9004 cRIO processor. Now, with the data from the FIFO I would write a file (regardless of the extension), in order to do more tests. I did it but I don't want to use the local memory of the RT, instead, there will be a PC (hard drive) where I can place the file in order to write it (with data). I'm not able to do so, as 1) I don't know how to call the PC hard drive and 2) I don't know what communication protocol fits better I want to develop a device to Windows Welcome.
Nobody helps me?
Thank you very much
The cRIO-9004 unfortunately has USB, so you can not write on a USB Flash drive (which would be my first suggestion). If you want to store the data on the host PC, you will need to write a simple TCP/IP client/server to send data to the host through TCP so that the host can receive and save to disk. Façade of the VI may seem as it is running on the PC, but it's actually just show you data be listened to the target (you are not allowed to piggy-back on this same Creek).
There are several examples of TCP/IP client/server integrated into LabVIEW.
I am recently using LabVIEW 2011 and 2011 real time Module. My application requires the PID control.
Now, I have a problem. In the manual for "And Fuzzy Logic Toolkit PID", Chapter 2 "algorithm PID" it indicates non-interactive algorithm (also called the ideal algorithm, Standard or ISA) be used in all the screws of PID in the Toolbox. It seems that Yes from source code. However, in Chapter 3, "Using the PID software" arrays of calculation of PID parameters based on method of Ziegler-Nichols, which was developed for the interactive algorithm (also called the series, the real classic algorithm). D action has been included in the scheme of control, the settings may be different for the two algorithms. In fact, Cohen Coons and adjustment PID Lambda rules can be used for the algorithm used by the box tool with no conversion.
In addition, there is a PID function block comes with the real time Module, and I know not what PID algorithm it uses. Can someone help me?
Thank you in advance.
In the "and Fuzzy Logic PID Toolkit, we use the University structure to implement all algorithms. Tuning techniques we show on the manual to express the original work and we try to keep the same as you would look at the literature. However, in our implementation of autotuning internally converted to the structure used by our algorithms to keep compatibility with our own implementation.
If you use an external source, you can use the Conversion.vi of Structure PID to change University, parallel or series of parameters in one used by our algorithm.
The PID included with the real time module is a 'copy' of our algorithm, and they have the same settings and behavior. The only advantage to use this function block, you have access to the parameters through variables.
Hope this helps...
I'm working on a project of PID control with a dreaded heating control. The radiator is small enough ~ 10 watts, so the response time is very fast. My set point increases, my HP decreases. I'm controlling the radiator with a continuous feed, so the nominal value is an environment of tension and I left PID +/-100% 0 voltage swing at full scale.
The Kc is of about 0.4.
With a control P, Kp = 0.2, I get a damped oscillation, which hovers at about 2-4% higher than the set value.
With IP control, Kp = 0.2, Ki = 0.00001, I get a constant oscillation around the setpoint.
An example with PI control is attached. It seems that my sample rate is too slow (the PV and SP are made with GPIB).
The sequence of events is--> order SP-> (wait)--> PV read--> PID use to set the new SP--> (loop)
I tried to improve it by putting the measure of PV in a parallel loop. This seems to help some, but does not eliminate the oscillation. Old time loop was ~ 0.3 seconds, now it is 0.15 seconds. Faster and my loop time< pv="" measurement="">
Any suggestions? I tried the Autotune PID vi, but he could never solve the system.
I've done a few things to improve the response:
1.), I use a PID of two floors. The "inner loop" PID control constantly power from 0 to full scale. The "outer loop" adjusts the power + / to reach the set point. (fine adjustment) Each PID loop has its own set of PID parameters.
(2.) for some reason, control PID never worked well because my point was inversely proportional to the power. I created a formula that has converted my set point to a function which is proportional to the power in watts.
I have a cRIO-9014 with a cRIO-9114 which is used as a stand-alone system controller (we use several types of modules c I / O and DI/O). I want to connect a cable ethernet and view select input/output to facilitate tuning PID control. I am currently using global variables for communication between the host on the PC and the vi rtexe vi. This works that whent the vi rtexe is launched from the PC. If I try to launch the host program, while the rtexe is running on the cRIO, when variables deployment stop the rtexe. If I prevent deployment variables, global variables in the host are not communicating with the cRIO. Anyone know how to get data in real time of the CRIO without interrupting the program running on the cRIO?
If you use variables published shared network and host them on the target (make sure that the library is below the target in the Project Explorer), variables will be deployed when you start the host VI. This way you will not interrupt the program of control over the cRIO.
See the knowledge base article: How can I deploy a compiled executable shared network Variables? for more information.
Hope this helps,
I am trying to learn to use the PID VI in LabVIEW and programmed a simple VI. Here's the problem: the output of the PID VI seems only related to the Kc in the program and the other two values (Ti and Td) do not affect the output, for example ranging from 0.001 to 1000.
Is that all that I missed when programming?
Thank you very much.
Yes, of course, you can use a loop on the cRIO - you must use a loop if you want your code to be executed more than once. Make sure you put everything that should happen several times (for example, the function and control of front that you update while the code is running in the development environment) inside the loop. New LabVIEW users often put out of the loop and wonder then why they are only read once and never update again even if the code is still ongoing.
Hello, I'm trying to set my PID system for different temperature values. I am using 2 power supplies and a monitor of temperature for the temperature control, but in Lakeshore 330 manual, I saw a practical method as follows: now my question is what should be my maximum I appreciate to be able to proceed at the time where I use the PID Labviews function and not using Lakeshore 330?
126.96.36.199 control Gain (proportional)
Register a gain (proportional) value from 000 to 999. To enter a gain value, press the p key. The below command
display window shows the current setting of the P (the default is 50) with flashing of the units place. Use the digital
keypad to enter a new setting. Press ENTER to accept the new setting of proportional or Escape to return to the
normal display and keep the previous setting.
Determine experimentally good gain, follow these steps. Manual Autotune, then cut
Reset (I) and (D) levels. Enter a nominal gain of 50. Check that the radiator turns; If not, increase the
gain setting until the heater turns on, then let the system stabilize. It stabilizes at a certain point below the set value
(usually 2-3 K below). Increase the gain by a factor of two until the temperature of the system starts to oscillate.
Adjust the gain for small sustained oscillations. Measure the period of these oscillations to determine the
a proper setting for resets. Reduce the gain by a factor of two or three, until the temperature stabilizes again. Be
ensure to allow time for each parameter for the system stabilizes (if she will). Some systems and cryogenic detectors
with a low sensitivity require the maximum gain.
188.8.131.52 parameter Reset (integral)
Adjusts the time constant of (full) reset reset in the control function. Reset the time in seconds = (999/value
Entered). For example, if the Reset setting is 20 seconds, the reset time is about 50 (999/20 = 50). Enter a
value between 1 and 999. Reset to zero makes the proportional controller only. To enter a reset value, press the I
key. Lower command window display shows the current I parameter (the default is 20) with units in place
flashing. Use the numeric keypad to enter a new setting. Press ENTER to accept the new setting or escape
return to the normal display and keep the previous setting.
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