lincos

Constructs by linearization a linear state-space model from a general dynamical system described by a xcos diagram

Calling Sequence

sys= lincos(scs_m [,x0,u0 [,param] ])

Module

• xcos

Description

Construct a linear state-space system by linearizing a model given as an xcos diagram. The idea is to transform a sub-diagram to a linear state-space model. The sub-diagram should have inputs and outputs.

The output is a Scilab data structure of type continuous-time state- space linear system.

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

`loadXcosLibs`_(); `loadScicos`_();
`importXcosDiagram`_("SCI/modules/xcos/tests/unit_tests/pendulum_anim45.xcos");

// specific context data
M  = 10;
m  = 3;
l  = 3;
ph = 0.1;

// looking for the Superblock to linearize
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

sys = lincos(scs_m);

`bode`_(sys);

Arguments

• scs_m : a xcos data structure
• x0 : column vector. Continuous state around which linearization to be done (default 0)
• u0 : column vector. Input around which linearization to be done (default 0)
• param : 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.
• sys : state-space system

See Also

• steadycos - Finds an equilibrium state of a general dynamical system described by a xcos diagram (Scilab Function)
• scicos_simulate - Function for running xcos simulation in batch mode (Scilab Function)