A
Anbu Selvarajan
Yes... I too agree with David.
I shall add few more ideas on to this..
Generally Derivative action in PID controller takes rate of change of error, i.e. d(e(t))/dt
The sudden change in the output of the PID controller for a step change in the setpoint due to derivative action, what we usually call "Derivative kick".
This "Derivative kick" can be avoided by computing rate of change of pv, i.e. d(pv(t))/dt instead of conventional method of finding rate of change of error in PID controller.
'Cos the PV, the process output won't respond suddenly to any change in the setpoint due to its inherent lag (time constant).
I shall add few more ideas on to this..
Generally Derivative action in PID controller takes rate of change of error, i.e. d(e(t))/dt
The sudden change in the output of the PID controller for a step change in the setpoint due to derivative action, what we usually call "Derivative kick".
This "Derivative kick" can be avoided by computing rate of change of pv, i.e. d(pv(t))/dt instead of conventional method of finding rate of change of error in PID controller.
'Cos the PV, the process output won't respond suddenly to any change in the setpoint due to its inherent lag (time constant).