PID controller for Speed control for a DC Motor

[MarcoPacora]

Hi,

I'm currentrly working on a project in which i want to design a lettuce harvester. I was focusing right now on the cutting device which will consists basically on a reciprocating blade that moves with a crank shaft powered by a DC Motor. I want to use some kind of control application so i was thinking on using a PID controller to provide an stable speed for the cutting process, so that my motor gives the same rpm despite the loads product of the cutting process, namely when cutting lettuces (there are moments where the blade is cutting and moment when is waiting for the next letucces to come). But i'm a bit doubtful about control theory, ¿a pid control only applies to a transient state or a steady state too? ¿is it a valid applicattion for a pid?

I will apreciate any help!

 

[waross]

Your motor speed will only drop a few RPM when loaded.
Adjust your no-load speed so that your loaded speed is what you want.
In this application, PID control may add more confusion than functionality.

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Ohm's law
Not just a good idea;
It's the LAW!

 

[3DDave]

Usually a flywheel is used to smooth speed variations. This allows the motor to run at the minimum necessary power to return any energy lost to the process.