ident/rltool with non-zero initial condition

1 次查看（过去 30 天）

Rodrigo Vernini 2018-10-5

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/422366-ident-rltool-with-non-zero-initial-condition

Hi,

i'm trying to create a PID for a heating system, tried those steps:

-Heated the system from ambient temperature until stabilization; -Inserted on ident the values and estimated "Process Models"; -Validated the model with simulink; -With rltool created a controller; -Simulated again with closed loop on simulink.

The problem is that the final response was 20~30% bellow from what i expected on the last simulation. Actually i had a problem with my model validation, it reached the temperature expected but had zero as initial value, and my real data had 30°C as initial value, this could have caused that dumped output. Than i tried simulating SS models, as it accepts non zero initial condition, but i saw 2 problems: -Couldn't model the delay effect as i was able using Process Models (transfer function); -rltool seems to transform ss into tf anyway (losing initial condition?)

I'm adding some screenshots.