steadycos

Module

• xcos

Description

This function finds the steady state for a given system described by a xcos diagram or sub-diagram. The diagram should have inputs and outputs.The steady state concern only the continuous-time dynamics.

// loading data
exec("SCI/modules/xcos/tests/unit_tests/PENDULUM_ANIM.sci");
exec("SCI/modules/xcos/tests/unit_tests/anim_pen.sci");
importXcosDiagram("SCI/modules/xcos/tests/unit_tests/pendulum_anim45.xcos");

// configure the context
M  = 10;
m  = 3;
l  = 3;
ph = 0.1;

// look for the specific sub-diagram to work on
for i=1:length(scs_m.objs)
    if typeof(scs_m.objs(i))=="Block" & scs_m.objs(i).gui=="SUPER_f" then
        scs_m = scs_m.objs(i).model.rpar;
        break;
    end
end

[X,U,Y,XP] = steadycos(scs_m,[],[],[],[],1,1:$);

Arguments

• scs_m : a xcos data structure

• X : column vector. Continuous state. Can be set to [] if zero.

• U : column vector. Input. Can be set to [] if zero.

• Y : column vector. Output. Can be set to [] if zero.

• Indx : index of entries of X that are not fixed. If all can vary, set to 1:$

• Indu : index of entries of U that are not fixed. If all can vary, set to 1:$

• Indy : index of entries of Y that are not fixed. If all can vary, set to 1:$

• Indxp : index of entries of XP (derivative of x) that need not be zero. If all can vary, set to 1:$. Default [].

• param : list with two elements (default list(1.d-6,0)). param(1): scalar. Perturbation level for linearization; the following variation is used del([x;u])_i = param(1)+param(1)*1d-4*abs([x;u])_i. param(2): scalar. Time t.

• X : steady state X

• U : stationary input U

• Y : output corresponding to steady state found

• XP : derivative of the state corresponding to steady state found

File content

• SCI/modules/scicos/macros/scicos_auto/steadycos.sci

See Also

• lincos - Constructs by linearization a linear state-space model from a general dynamical system described by a xcos diagram (Scilab Function)

• scicos_simulate - Function for running xcos simulation in batch mode (Scilab Function)

• xcos - Block diagram editor and GUI for the hybrid simulator (Scilab Function)

Authors

Ramine Nikoukhah - INRIA

Clément DAVID - DIGITEO