This question is for developer or those who are master in PID control & would like to save cost in certain application. For speed control, it's no longer used PID methodology by programmer. Now PID control is integrated into variable frequency drive control. For example, if you want to stabilize the speed at 1500rpm, no matter load changed, via an advanced VFD, PID is itself tuning to keep it stable at 1500rpm.
I like the auto tuning function on rotating equipment that has high inertia, it is a good starting point when putting together a coordinated VFD system, such as a paper machine drive. The auto tune for the magnetic components is already available and quite adequate, the autotune is helpful when tuning the mechanical response, including the effects of stiction, inertia, noisy mechanical loads such as water crashing around in drying cylinders, sudden application of pure friction loads at the outer diameter of a drying cylinder, and acceleration & deceleration speed regulation.