Mauricio Mendes
Guest
Wed Jun 08, 2011 4:29 pm
People,
I am doing my undergraduate thesis about a electronic throttle
control, and i am trying to tunning this using a PID controller and
the second method.
The books always says we must keep increasing the gain until the
system output oscilllate. But if i keep increasing the gain without
change my reference in my system it just doesn't oscillate.
if i change the reference like square wave and than keep incresing the
gain, this will start to oscillate and than i can measure the periode
and the gain critical.
Do you know if that's all right? because the books does't say o have
to change the reference or you can change the reference.
Thank you,
Maurício Mendes
Phil Hobbs
Guest
Fri Jun 10, 2011 4:26 am
Mauricio Mendes wrote:
Quote:
People,
I am doing my undergraduate thesis about a electronic throttle
control, and i am trying to tunning this using a PID controller and
the second method.
The books always says we must keep increasing the gain until the
system output oscilllate. But if i keep increasing the gain without
change my reference in my system it just doesn't oscillate.
if i change the reference like square wave and than keep incresing the
gain, this will start to oscillate and than i can measure the periode
and the gain critical.
Do you know if that's all right? because the books does't say o have
to change the reference or you can change the reference.
Thank you,
Maurício Mendes
This is a simulation rather than a prototype, right?
So if your simulation has exactly two poles, the overshoot will get
arbitrarily bad as you turn up the gain, but it'll never actually oscillate.
Hint: Try measuring a real system and making a more realistic model.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
email: hobbs (atsign) electrooptical (period) net
http://electrooptical.net
