Modelica Forum > Is OpenModelica implementation compliant to the modelica specifications?

Zied Kelboussi

Aug 7 2007, 08:23 AM

Hi all,
In the modelica specification, the modelica builtin operator reinit() can be equally used inside an algorithm or an equation section. However, the OpenModelica simulator is issuing a simulation error when I try to use the reinit() operator inside an algorithm section.
In fact, I'm trying to model a Hybrid Automaton Behavior in modelica. So, I'm using When-Statements to define the state machine. Each When-Branch of the When-Statement correponds to a transition in the original automaton. here is an example :

CODE

model toto

algorithm
  when (x >= tmax) and (state == on) then
    state := off;
    reinit(x, expression1);   // openModelica does not accept the reinit() operator : generates a simulation error
  elsewhen (x <= tmin) and (state == off) then
    state := on;
    reinit(x, expression2);
  end when;

equation
  some equations...;

end toto;

So is the reinit() operator not supported in algorithm section in OpenModelica? or am I missing some thing?
Thank you.

Carsten

Aug 8 2007, 06:45 AM

Hi,

well I tried the following model in Dymola and it works fine..

QUELLTEXT

model toto
  Real x;
  parameter Real tmax=0.3;
  parameter Real tmin=0.1;
  Boolean state(start = true);
  Real expression1 = 0.05;
  Real expression2 = 0.2;

algorithm
  when (x >= tmax) and (state == true) then
    state := false;
    reinit(x, expression1);   // openModelica does not accept the reinit() operator : generates a simulation error
  elsewhen (x <= tmin) and (state == false) then
    state := true;
    reinit(x, expression2);
  end when;

equation
  der(x) = 1;

end toto;

But you have to make shure, that x is selected as state, otherwise reinit has no influence. E.g. changing in the above model

QUELLTEXT

Real x;

to

QUELLTEXT

Real x = time

and remove

QUELLTEXT

der(x)=1

results in a simulation, where reinit has no influence x, as x is not seleted as state variable. Dymola provides a warning message during translation in that case.

If that is not the reason, then try to contact the people from OpenModelica directly.

regards
Carsten

Jawhar

Sep 26 2007, 06:18 PM

QUOTE(Zied Kelboussi @ Aug 7 2007, 08:23 AM)

Hi all,
In the modelica specification, the modelica builtin operator reinit() can be equally used inside an algorithm or an equation section. However, the OpenModelica simulator is issuing a simulation error when I try to use the reinit() operator inside an algorithm section.
In fact, I'm trying to model a Hybrid Automaton Behavior in modelica. So, I'm using When-Statements to define the state machine. Each When-Branch of the When-Statement correponds to a transition in the original automaton. here is an example :

hello Zied;

I have done an implementation of a hybrid automata with modelica and i have create a modelica library for this. I have published an article about this (in frensh). If you want more details i can help you. Please, ask me here in the forum so the other users can have an idea about this library and the method i had used to model an hybrid automatra with modelica. Thank u.

jfdupuis

Nov 1 2007, 08:28 PM

QUOTE(Jawhar @ Sep 26 2007, 06:18 PM)

hello Zied;

I have done an implementation of a hybrid automata with modelica and i have create a modelica library for this. I have published an article about this (in frensh). If you want more details i can help you. Please, ask me here in the forum so the other users can have an idea about this library and the method i had used to model an hybrid automatra with modelica. Thank u.

Hi Jawhar,

I would be interested to know more about your hybrid automata library. Is it possible for you the give a link where you article is available. French is fine for me.

Thanks