Answer Posted / www.islamqa.com
Actually we can make it simple:
# P:
it's a controller gain which modify the controller o/p
proportional to the error.
# I:
it's a controller gain which modify the controller o/p
proportional to the integral of the error.
# D:
it's a controller gain which modify the controller o/p
proportional to error rate of change.
We have 4 parameters in our control loop to focus on:
1 - the rise time: the period of time during which the pv
get 90% of the desired sp value
2 - max overshoot
3 - settling time: the period of time during which the pv
get the desired sp value and saturate.
4 - error/offset
we can get it clear from this pic:
http://controls.ame.nd.edu/ame437/S2003/hw1/specifications.j
pg
Now we will take a look about the effect of each controller
gain on these parameters:
# P gain:
decrease rise time
increase max.overshoot
increase settling time
decrease error (but not eliminate)
# I gain:
decrease rise time
increase max.overshoot
increase settling time
eliminate error.
# D gain:
no effect on rise time
decrease max.overshoot
decrease settling time
decrease error.
the previous is guidelines to be in background while
dealing with PID,but they are not sharp limits.
Regards,
Ahmed Sabry
Control and Instrumentation Engineer
GPC - General Petroleum Company
ahmedsabry.online@gmail.com
CELL.: 00 2 0121367310
| Is This Answer Correct ? | 7 Yes | 0 No |
Post New Answer View All Answers
There are many type of control cable like pair,core,tried, What are defination each one
Operational amplifiers
what is vibration a part of proceess variable? if vibration is a part variables then how we minimize the actual vibration on machine on load,? vision of instrumentation contrl plz ans me IPGDL interview question
Draw bode plot of any transfer function. Why is plotting bode necessary?
can you send remote seal interface level transmitter calculation steps for oil water saperator.
what is the imbustion control loop
what is different between 2,3&4 wire rtd and how much maximum distance using plc to field.
NPN transistor, SCR, Zener diode, LED, Varactor diode, Vortex meter, RTD, Resistor, Crystal
i have done DAE in Instrumentation and Process Control. i have applied for an apprentice training in chemical company after three day my interview will be conduct but i need more information about industrial process control and controller. my e mail is imran_dilsetu@yahoo.com please tell me interview question relative to instrumentation ?
how 3 out of 2 Logic/interlocks works? give brief explanation with help of diagram.
How to calibration a control valve?
i want to find out iffco get test paper
Why flow/pressure transmitter before control valve?
Explain signal isolator
Tell about your IFFCO plant visit.