This is a very commonly asked question. There are several
things to consider when answering this question. First what are PID and
- PID is a control algorithm based
on position error.
PID is a very common control algorithm in industry. It is used
for systems as varied as precise motion control to fluid level
control to temperature control to ..
- PIV is a control algorithm based on velocity error for its
inner loop and position error for its outer loop.
PIV is similar in concept to a velocity drive that has a position
loop around it. The XMP implements the velocity loop and position
loop inside its DSP.
Here are some things to consider before making the decision
between PID and PIV:
- Are you already comfortable tuning one method? If you are comfortable
with one, you likely will get better performance and reduce your
tuning time significantly.
- Many more people have experience with PID tuning. If you have
experience tuning systems with tachometer feedback, you may find
PIV more familiar.
- Try both. If performance is critical to you, you should explore
all reasonable possibilities. Trying PID and PIV is not an unreasonble
amount of effort if performance is critical.
- How linear is your system? PID has good results if the system
is a simple mass with a force or torque transducer (i.e. simple
permanent magnet motor) powering it. If you have a robot with
linkages that change mass moment of inertia when it moves and
an exotic motor that is not a perfect torque/force transducer,
PIV may work better.
- Systems that care more about velocity regultation than position
error will likely have better velocity regulation with PIV than
- PIV has more parameters to adjust than PID. This is a pro and