[Scilab-users] Xcos PID controller problem

[john]

Hello,
I'm new to Scilab and Xcos so may be making a simple mistake, but I have the
following problem.  I created an Xcos model of a simple mass-spring-damper
with PID control using the data from the Matlab example shown  here
<http://ctms.engin.umich.edu/CTMS/index.php?example=Introduction&section=ControlPID> 
.

The Xcos results are the same as the Matlab example except for the case when
all three gains are used as follows Kp=350, Ki=300 and Kd=50 .

My result looks like this (red line) and is clearly giving a different
response to the Matlab example for the same gain values.
  <http://mailinglists.scilab.org/file/n4028669/PID.png> 
I have tried different solvers and time steps, but this doesn't seem to be
the problem.  I have also modelled the problem in Mathcad 7, Mathcad Prime 3
and using csim in Scilab and all those results agree broadly with the Matlab
example.

Any advice would be greatly appreciated and I have attached the Xcos file
for information. spring-damper-PID.zcos
<http://mailinglists.scilab.org/file/n4028669/spring-damper-PID.zcos>  




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