Velocity (incremental) PID
A PID form whose output is a change in output, not the output position itself.
What it means
The positional form of a PID computes an absolute output — the valve position the controller wants right now. The velocity form, also called incremental, computes a change in output, and the actual position is accumulated elsewhere, usually by the actuator or the output tracking logic around it.
The two forms differ at the edges rather than on the trend. A velocity form does not remember an absolute position, so it depends on the output object holding its own last value; when that object resets, a positional controller sits where it is told while a velocity controller has to be re-primed.
Velocity form is common where output is added to a bias, in split-range arrangements, or where several controllers share one output. The distinction is invisible on a trend and fatal at a transfer, which is why it belongs in the same conversation as bumpless transfer.
Related
Where this comes up
Last reviewed 2026-09-18.