Effect of a low pass filter on the response of a PID controller
Effect of a low pass filter on the response of a PID controller
(OP)
In general terms, could someone please explain the effect that a low pass filter on the input of a PID controller would have on the response of the system? The controller will compare the process variable against a setpoint, but for reasons I'll not get into here, the process variable first goes through a low pass filter. Thank You.





RE: Effect of a low pass filter on the response of a PID controller
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RE: Effect of a low pass filter on the response of a PID controller
I have used in the past a "phase-compensator" to remedy inherent time delays caused in a system. In your case this latency could be caused by the filter, which can cause performance problems or instability.
A phase-lead compensator in s-domain is usually of the form
Comp(s)= (s+1/T)/(s+1/(alpha*T))
Cheers,
"Simplicity is the ultimate sophistication." L. da Vinci
- Gian