xyhdot.hlp

MATLAB在飞行动力学和控制中应用的工具

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XYHDOT is a masked Simulink subsystem which is contained in the
sub-subsystem '12 ODEs' of the subsystem 'Aircraft Equations of
Motion (Beaver)', within the S-function BEAVER. It computes time-
derivatives of the coordinates xe and ye and the altitude H (last
three state variables of the nonlinear aircraft model).

Inputvector: uxyh (the inputvariables which are not used in
XYHDOT are displayed between accolades).
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  uxyh = [x' Ftot' Mtot' yhlp'], and [u+uw  v+vw  w+ww]'.

  x    = [V alpha beta p q r psi theta phi xe ye H]'     (states)

  Ftot = [Fx Fy Fz]'           (total forces along the body-axes,
                                    computed in the block FMSORT)

  Mtot = [L M N]'             (total moments along the body-axes,
                                    computed in the block FMSORT)

  yhlp = [cos(alpha) sin(alpha) cos(beta) sin(beta) ...
          ... tan(beta) sin(psi) cos(psi) sin(theta) ...
          ... cos(theta) sin(phi) cos(phi)]'
            (frequently used sines & cosines, computed in HLPFCN)

  [u+uw  v+vw  w+ww]' = [u v w]' + [uw vw ww]' = ybvel+uwind(1:3);
  ybvel is computed in the masked subsystem block UVW, uwind is
  an external inputvector with atmospheric disturbances.

furthermore:

 {V    : airspeed [m/s]                                         }
 {alpha: angle of attack [rad]                                  }
 {beta : sideslip angle [rad]                                   }
 {p    : roll rate [rad/s]                                      }
 {q    : pitch rate [rad/s]                                     }
 {r    : yaw rate [rad/s]                                       }
  psi  : yaw angle [rad]
  theta: pitch angle [rad]
  phi  : roll angle [rad]
 {xe   : x-coordinate in Earth-fixed reference frame [m]        }
 {ye   : y-coordinate ''     ''          ''      ''  [m]        }
 {H    : altitude above sea-level [m]                           }

 {Fx, Fy, Fz: total forces along the aircraft's body-axes [N]   }
 {L, M, N   : total moments along the aircraft's body-axes [Nm] }

  u    : component of the airspeed V along the XB-axis [m/s]
  v    : component of the airspeed V along the YB-axis [m/s]
  w    : component of the airspeed V along the ZB-axis [m/s]
  uw   : component of wind + turbulence along XB-axis [m/s]
  vw   : component of wind + turbulence along YB-axis [m/s]
  ww   : component of wind + turbulence along ZB-axis [m/s]

Outputvector: yxyh.
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   yxyh = [xdot ydot Hdot]'

where:

   xdot = d(xe)/dt [m/s]
   ydot = d(ye)/dt [m/s]
   Hdot = dH/dt [m/s]

More info.
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See VABDOT.HLP, PQRDOT.HLP, EULERDOT.HLP, and 12ODES.HLP for more
details about the time-derivatives of the other state variables.
The block XYHDOT uses outputs from UVW, FMSORT, and HLPFCN as in-
put variables; see UVW.HLP, FMSORT.HLP, and HLPFCN.HLP for more
info.

See also EQMOTION.HLP.

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The FDC toolbox, Copyright Marc Rauw 1994-1998.