Hello
I know this is not a Matlab forum, but I believe people here has better knowledge to help me with this problem.
I am a E.Eng major student and I have been using Matlab for my Control Systems class. But recently I am having a big confussion in Matlab simulink, that I cannot understand at all.
Here is my problem:
I have this open loop transfer function :
= 173/(s^2 +2.57s)
And I am supposed to find PID gain so that the system's settling time is =0.3sec. Now by solving mathematically I came up with the answer of
Kp = 0.198
Kd = 0.077
Ki = 0
Therefore, the PD controller transfer function will be
= 0.077s + 0.198
WhenI plug that value into the PID controller block, it does not work! But when I combine the open loop transfer function with the PD controller transfer function, i.e.
= 173*(0.077s + 0.198)/(s^2 +2.57s)
it works!
What am I doing wrong? Or is it some kind of glitch in matlab?
Here is the picture that will explain in more detail:
http://img379.imageshack.us/my.php?image=matlabfj7.jpg
i would really appreciate any help here.
I know this is not a Matlab forum, but I believe people here has better knowledge to help me with this problem.
I am a E.Eng major student and I have been using Matlab for my Control Systems class. But recently I am having a big confussion in Matlab simulink, that I cannot understand at all.
Here is my problem:
I have this open loop transfer function :
= 173/(s^2 +2.57s)
And I am supposed to find PID gain so that the system's settling time is =0.3sec. Now by solving mathematically I came up with the answer of
Kp = 0.198
Kd = 0.077
Ki = 0
Therefore, the PD controller transfer function will be
= 0.077s + 0.198
WhenI plug that value into the PID controller block, it does not work! But when I combine the open loop transfer function with the PD controller transfer function, i.e.
= 173*(0.077s + 0.198)/(s^2 +2.57s)
it works!
What am I doing wrong? Or is it some kind of glitch in matlab?
Here is the picture that will explain in more detail:
http://img379.imageshack.us/my.php?image=matlabfj7.jpg
i would really appreciate any help here.
Last edited: