PID-filter routine (2nd try).

[Acetronics2]

Hi Alain

The distance values on Excel graph showed a non linear line in comparison to the linear nature of the voltage.
/Daan Joubert

Hi, Daan

I hope you've considered the rotation angle of the arm is linear to the signal ...

But, whatever your transmission system ... only rack and pinion or cable and pulley can give a linear travel !!!

You could use a LOOKUP Table to correct your output ... but, once more, if it is a real PID controller, it will compensate for non-linearities ...

Or try to use ... FUZZY LOGIC !!!

Or find an old LINEAR R/C servo ( Kraft, Robbe, Varioprop, Lextronic ... produced some in the 70-80's )


Alain