scilab/modules/xcos/help/en_US/batch_functions/lincos.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
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  24 <refentry xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:svg="http://www.w3.org/2000/svg" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:db="http://docbook.org/ns/docbook" xmlns:scilab="http://www.scilab.org" xml:id="lincos">
  25     <refnamediv>
  26         <refname>lincos</refname>
  27         <refpurpose>Constructs by linearization a linear state-space model from a general dynamical system described by a Xcos diagram</refpurpose>
  28     </refnamediv>
  29     <refsynopsisdiv>
  30         <title>Calling Sequence</title>
  31         <synopsis>sys = lincos(scs_m [,x0,u0 [,param] ])</synopsis>
  32     </refsynopsisdiv>
  33     <refsection id="Module_lincos">
  34         <title>Module</title>
  35         <itemizedlist>
  36             <listitem>
  37                 <para>
  38                     <link linkend="xcos">xcos</link>
  39                 </para>
  40             </listitem>
  41         </itemizedlist>
  42     </refsection>
  43     <refsection id="Description_lincos">
  44         <title>Description</title>
  45         <para>
  46             Construct a linear state-space system by linearizing a model given as a Xcos diagram. The idea is to transform a <link linkend="SUPER_f">sub-diagram</link> to a linear state-space model. The sub-diagram should have <link linkend="IN_f">inputs</link> and <link linkend="OUT_f">outputs</link>.
  47         </para>
  48         <para>
  49             The output is a Scilab data structure of type continuous-time state-space linear system.
  50         </para>
  51     </refsection>
  52     <refsection>
  53         <title>Examples</title>
  54         <programlisting role="example"><![CDATA[
  55 // loading data
  56 exec("SCI/modules/xcos/tests/unit_tests/PENDULUM_ANIM.sci");
  57 exec("SCI/modules/xcos/tests/unit_tests/anim_pen.sci");
  58
  59 loadXcosLibs(); loadScicos();
  60 importXcosDiagram("SCI/modules/xcos/tests/unit_tests/pendulum_anim45.xcos");
  61
  62 // specific context data
  63 M  = 10;
  64 m  = 3;
  65 l  = 3;
  66 ph = 0.1;
  67 z0=-4;
  68 th0=.02;
  69
  70 // looking for the Superblock to linearize
  71 for i=1:length(scs_m.objs)
  72     if typeof(scs_m.objs(i))=="Block" & scs_m.objs(i).gui=="SUPER_f" then
  73         scs_m = scs_m.objs(i).model.rpar;
  74         break;
  75     end
  76 end
  77
  78 sys = lincos(scs_m);
  79
  80 bode(sys);
  81  ]]></programlisting>
  82     </refsection>
  83     <refsection id="Parameters_lincos">
  84         <title>Arguments</title>
  85         <itemizedlist>
  86             <listitem>
  87                 <para>
  88                     <emphasis role="bold">scs_m :</emphasis> a xcos data structure
  89                 </para>
  90             </listitem>
  91             <listitem>
  92                 <para>
  93                     <emphasis role="bold">x0 :</emphasis> column vector. Continuous state around which linearization to be done (default 0)
  94                 </para>
  95             </listitem>
  96             <listitem>
  97                 <para>
  98                     <emphasis role="bold">u0 :</emphasis> column vector. Input around which linearization to be done (default 0)
  99                 </para>
 100             </listitem>
 101             <listitem>
 102                 <para>
 103                     <emphasis role="bold">param :</emphasis> 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.
 104                 </para>
 105             </listitem>
 106             <listitem>
 107                 <para>
 108                     <emphasis role="bold">sys :</emphasis> state-space system
 109                 </para>
 110             </listitem>
 111         </itemizedlist>
 112     </refsection>
 113     <refsection id="SeeAlso_lincos">
 114         <title>See Also</title>
 115         <itemizedlist>
 116             <listitem>
 117                 <para>
 118                     <link linkend="steadycos">steadycos - Finds an equilibrium state of a general dynamical system described by a xcos diagram (Scilab Function)</link>
 119                 </para>
 120             </listitem>
 121             <listitem>
 122                 <para>
 123                     <link linkend="scicos_simulate">scicos_simulate - Function for running xcos simulation in batch mode (Scilab Function)</link>
 124                 </para>
 125             </listitem>
 126         </itemizedlist>
 127     </refsection>
 128 </refentry>