Close loop control with LIFA/UNO

[lolol]

Hi everyone.

I want to find out if doing a fuzzy-pid control using labview and Arduno is an overkill or may not work? And also doing a PID control using thesame method.

My goal is to creat a variable speed for a single phase AC,read the speed,temperation on labview and also creating a control system for the speed.

Thanks again.

[hrh1818]

Biggest question is what do you mean by a variable speed single phase AC?.  In most applications there are no suitable methods for controlling the speed of sngle phase AC motor over a wide range of speed.  About the only exception is a fan speed controller.  I suggest you do a Google search on "fan speed control" to see if any of the products offered meet your needs.  Otherwise if your application requres high starting torque use a DC motor.

My first reaction is if Labview is just use for a graphical interface and the Arduino is the controller then using an Arduino and Labview is not an overkill and the project is doable.  But this staement depends upon your accuarcy requirementrs and what ou haven't told us. 

With respect to fuzzy logic and PID do a Google search on "fuzzy logic Arduino" and " PID Arduino".  You will find a lot of good help.

hrh1818

[Nathan_B.]

In a project that I worked on, we tried to implement parts of PID.  The major issue here is the timing.  Serial communication is relatively slow so the timestep that you get is probably larger than you might like it to be depending on your system of course.

For the next iteration of the project, we are going to look into implementing the PID on the Arduino then simply reading and setting values.

(I'm not quite sure I know what fuzzy-PID is)

Try it in LabVIEW and see how it turns out.

[lolol]

@hrh1818,you are right,i was talking about a fan controller. The idea is doing the fuzzy-pid or Pid controller within labview and using the arduino board as a DAQ.So will using an Arduino as a DQA be an overkill when implementing a fuzzy-pid or pid withing labview? Thanks for the reply.

@ NathanB,yes,i am actually worry about the timing is achieving an accurate results.Will timing be a big problem if the Arduino board serves as a DAQ only?Thanks for the information.

[Nathan_B.]

lolol wrote:

@ NathanB,yes,i am actually worry about the timing is achieving an accurate results.Will timing be a big problem if the Arduino board serves as a DAQ only?Thanks for the information.

That entirely depends on the timestep you need to achieve the accuracy that you want (and to prevent an unsteady system).

[hrh1818]

Rply fot the following question.

@hrh1818,you are right,i was talking about a fan controller. The idea is doing the fuzzy-pid or Pid controller within labview and using the arduino board as a DAQ.So will using an Arduino as a DQA be an overkill when implementing a fuzzy-pid or pid withing labview? Thanks for the reply.

Using an Arduino board for Data Acquistion will not be overkill.  In fact it is one of the lowest cost methods available for colloecting data with Labview.

Seeing as you are designing a digital control system it looks lkie your biggest challenge will be obtaining a system sample rate that is adequate for your system dynmics. 

hrh1818

[lolol]

@ hrh1818

I just want to send a PWM to run and vary the fan speed,then collect the speed from an encoder,while the fuzzyPID remains within Labview (PC).So what sample rate will be enough?Thanks again for the reply,this is just an idea but i am trying to propose it for my project?

@ Nathan_B

Thanks again.So what do you think,can i proceeed with this idea?

[hrh1818]

Reply for this question.

"I just want to send a PWM to run and vary the fan speed,then collect the speed from an encoder,while the fuzzyPID remains within Labview (PC).So what sample rate will be enough?Thanks again for the reply,this is just an idea but i am trying to propose it for my project?"

One of the methods use to select a digital control systems sample period is to set the sample period to one tenth of the systems domonant time constant. The sample rate is then the reciprocal of the sample period. 

As far as I know you will not be able to use PWM with an AC fan speed controller.  AC fan speed controllers vary speed by varying the phase at wich a Triac fires.   This is proportional control. 

hrh1818