How to simulate a system (time series input) for certain time (~ 10 seconds for each input) and obtain steady-state values

Hello!

I am performing a simulation using the Core CI engine block and am giving inputs from the workspace (defined as times series data). While working with constant input values (instead of workspace data) and a simulation time of ~ 10 seconds, the model response is dynamic in the initial phase (~ 0.5 - 1 second) and then attains a steady state.

However, the system output using a time series input data from the workspace does not correspond to the steady-state value.

Hence, I would like to understand how to perform a simulation in Simulink using a time series input and obtain a steady-state system output point (running each input point for ~ 10 seconds).

[Peter O]

Consider using Simulink's trim function. https://www.mathworks.com/help/simulink/slref/trim.html

Knowing nothing about your system, it's hard to interpret its behavior. Can you give us a litle more information?

Speaking generally about dynamic systems, it's possible that the controls or feedback mechanism interact with your workspace input to push the system to a different equilibirum point. If you have continuously varying inputs and disturbances over time, then it's reasonable to conclude that the dynamics of the model will continue to respond to them, perhaps never reaching a steady state. If those inputs differ at their final value from the constant input and there is no feedback controller loop, then it's reasonable to expect the system to arrive at a different final equilibrium point. Even if there is a controller, the response may take a sizeable amount of time to ring out and it need not remain stable. If your input is continually ramping, then there's a good likelihood that your system output will also continue to increase.

[Pradyumna Saripalli]

Hello Peter!

I think the trim function is not helpful in my case (probably I could not explain my requirement clearly). However, I tried running simulink using a script and a 'For loop' within it. This simulates each of input condition for 10 seconds and gives me a steady state value for that input condition, and this repeats for all the input points.

Anyways, I appreciate your help and thank you for the input on Trim function (its new for me) :)

PS: The system I am trying to simulate has some flow dynamics involved (Engine model in the powertrain blockset), and I wanted the engine output, whn those dynamics are stabilised, for every input condition.