## Copyright (C) 1997 Kai P. Mueller
##
## This file is part of Octave.
##
## Octave is free software; you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by the
## Free Software Foundation; either version 2, or (at your option) any
## later version.
##
## Octave is distributed in the hope that it will be useful, but WITHOUT
## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
## FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
## for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, write to the Free
## Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
## 02110-1301 USA.

## -*- texinfo -*-
## @deftypefn {Function File} {@var{sys} =} jet707 ()
## Creates a linearized state-space model of a Boeing 707-321 aircraft
## at @var{v}=80 m/s 
## @iftex
## @tex
## ($M = 0.26$, $G_{a0} = -3^{\circ}$, ${\alpha}_0 = 4^{\circ}$, ${\kappa}= 50^{\circ}$).
## @end tex
## @end iftex
## @ifinfo
## (@var{M} = 0.26, @var{Ga0} = -3 deg, @var{alpha0} = 4 deg, @var{kappa} = 50 deg).
## @end ifinfo
##
## System inputs: (1) thrust and (2) elevator angle.
##
## System outputs:  (1) airspeed and (2) pitch angle.
##
## @strong{Reference}: R. Brockhaus: @cite{Flugregelung} (Flight Control), Springer, 1994.
## @end deftypefn
##
## @seealso{ord2}

## Author: Kai P. Mueller <mueller@ifr.ing.tu-bs.de>
## Created: September 28, 1997

function outsys = jet707 ()

  if (nargin != 0)
    usage("outsys = jet707()")
  endif
  if (nargin > 1)
    usage("outsys = jet707()")
  endif

  a = [ -0.46E-01,            0.10681415316, 0.0,   -0.17121680433;
        -0.1675901504661613, -0.515,         1.0,    0.6420630320636088E-02;
         0.1543104215347786, -0.547945,     -0.906, -0.1521689385990753E-02;
         0.0,                 0.0,           1.0,    0.0 ];
  b = [ 0.1602300107479095,      0.2111848453E-02;
        0.8196877780963616E-02, -0.3025E-01;
        0.9173594317692437E-01, -0.75283075;
        0.0,                     0.0 ];
  c = [ 1.0,  0.0,  0.0,  0.0;
        0.0,  0.0,  0.0,  1.0 ];
  d=zeros(2,2);
  inam = ["thrust"; "rudder"];
  onam = ["speed"; "pitch"];
  snam = ["x1"; "x2"; "x3"; "x4"];
  outsys = ss(a, b, c, d, 0.0, 4, 0, snam, inam, onam);

endfunction