PID-filter routine (2nd try).

[RodSTAR]

I have many trys to solve my problem but fail.Actually i want to control GAS engine speed.I am using AGB130 LINEAR ELECTRIC ACTUATOR to drive BUTTERFLY VALVE.I am using MAGNETIC PICKUP UNIT located on flyweel to sense engine speed.After F/V conversion i have 0-5000Hz to 0-5V.
Problem is that ACTUATOR drive only forward direction through given voltage
and reverse direction through SPRING located inside.
ACTUATOR always needed some voltage to remain in a position to maintain speed.But INCPID routine gives 0 output when no error found.
I am giving some examples in atachements which will help to identify problem.
Best regards
IFTIKHAR AHMAD

PID is a loop. If spring moves something, PID will detect it and it will correct it immediatly. Don't confuse error variable with PWM value. In my project it works fine and it responds to dynamic loads and it correct it as it should (read above post of my project). Sorry for answering you, as you only refer to Henrik.